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TABLE OF CONTENTS
1
INTRODUCTION................................................................................................................................ 3
1.1
1.2
1.2.1
1.2.2
1.2.3
1.3
1.4
2
NCLT MECHANICAL INTERFACE ............................................................................................... 6
2.1
2.2
2.3
3
DIMENSIONS AND MOUNTING FOOTPRINTS................................................................................... 6
INTERFACE CONNECTORS AND CONNECTOR PIN-OUTS................................................................. 6
NCLT COMPONENT WEIGHT SUMMARY ..................................................................................... 6
NCLT ENVIRONMENTAL REQUIREMENTS ............................................................................. 7
3.1
3.2
3.3
4
OVERVIEW ..................................................................................................................................... 3
DOCUMENT SCOPE ........................................................................................................................ 3
Interface Definition ............................................................................................................. 3
NCLT-to-Spacecraft Command and Data Product Definition............................................ 3
Cross-Link TDMA DataTransmission................................................................................. 3
NCLT COMPONENT INTERCONNECT BLOCK DIAGRAM ................................................................ 4
REFERENCE DOCUMENTS .............................................................................................................. 5
NCLT COMPONENT THERMAL INTERFACE ................................................................................... 7
NCLT COMPONENT POWER SUMMARY ........................................................................................ 7
NCLT COMPONENT LAUNCH VIBRATION REQUIREMENTS ........................................................... 8
NCLT MODULE STACK ELECTRICAL INTERFACE ............................................................. 10
4.1
NCLT COMPONENTS ELECTRICAL BOND TO STRUCTURE .......................................................... 10
4.2
GPS RECEIVER MODULE INTERFACE .......................................................................................... 10
4.2.1
NCLT Stack GPS RF Input................................................................................................ 10
4.2.2
TX 10 MHz Output ............................................................................................................ 10
4.2.3
RX 10 MHz Output ............................................................................................................ 10
4.2.4
EXT 10 MHz...................................................................................................................... 11
4.2.5
GPS Test Points................................................................................................................. 11
4.3
S-BAND RECEIVER MODULE INTERFACE .................................................................................... 11
4.3.1
S-Band RF Input................................................................................................................ 11
4.3.2
Spacecraft Power and T/R Interface ................................................................................ 11
4.3.2.1
4.3.2.2
4.3.3
4.3.3.1
4.3.3.2
Power ...................................................................................................................................... 11
T/R Control Interface.............................................................................................................. 13
Spacecraft Analog Telemetry Interface............................................................................ 14
Analog Telemetry Test Points ................................................................................................ 14
1PPS........................................................................................................................................ 14
4.3.4
RX Test Points Connector ................................................................................................. 15
4.3.5
RX 10 MHz ........................................................................................................................ 15
4.4
TRANSMITTER MODULE INTERFACE ............................................................................................ 15
4.4.1
S-Band Transmitter RF Output ......................................................................................... 15
4.4.1.1
TX Spectral Envelop .............................................................................................................. 17
4.4.2
TX 10 MHz ........................................................................................................................ 17
4.4.3
TX Test Point Connector................................................................................................... 17
4.5
PROCESSOR MODULE INTERFACE ................................................................................................ 18
4.5.1
Spacecraft Serial Communications Interface.................................................................... 18
4.5.1.1
4.5.1.2
4.5.1.3
4.5.2
Serial Port #1 .......................................................................................................................... 18
Serial Port #2 .......................................................................................................................... 18
Processor Reset....................................................................................................................... 19
CPU Test Port ................................................................................................................... 19
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GPS PREAMPLIFIER ELECTRICAL INTERFACE .................................................................. 19
5.1
GPS PREAMPLIFIER RF INPUT .................................................................................................... 19
5.2
GPS PREAMPLIFIER RF OUTPUT ................................................................................................. 20
5.3
EMI REQUIREMENTS APPLICABLE AT GPS PREAMPLIFIER INPUT .............................................. 21
5.3.1
Susceptibility of GPS Performance to EMI....................................................................... 21
5.3.2
GPS EMI Survival Levels.................................................................................................. 21
6
S-BAND PREAMPLIFIER MODULE ELECTRICAL INTERFACE ........................................ 23
6.1
S-BAND PREAMPLIFIER ELECTRICAL INTERFACE ........................................................................ 23
6.1.1
S-Band Preamplifier RF Input .......................................................................................... 23
6.1.2
S-Band Preamplifier RF Output........................................................................................ 23
6.2
EMI REQUIREMENTS APPLICABLE AT S-BAND PREAMPLIFIER INPUT ........................................ 24
6.2.1
NCLT TX/RX Isolation ...................................................................................................... 24
6.2.2
Susceptibility of S-Band Performance to EMI .................................................................. 24
6.2.3
EMI S-Band Survival Levels ............................................................................................. 24
7
T/R SWITCH ELECTRICAL INTERFACE.................................................................................. 26
7.1
T/R SWITCH INTERFACE .............................................................................................................. 26
7.1.1
Actuating Voltage and Current ......................................................................................... 26
7.1.2
T/R Switch State Control................................................................................................... 26
7.1.3
T/R Switch Telltale ............................................................................................................ 26
7.1.4
RF Ports ............................................................................................................................ 26
7.1.4.1
7.1.4.2
7.1.4.3
7.1.4.4
RF Antenna Port (Labeled IN on figure 1)............................................................................. 26
S-Band Input Port (Labeled #2 on figure 1) .......................................................................... 27
S-Band Output Port (Labeled #1 on figure 1) ........................................................................ 27
RF Port Specifications ............................................................................................................ 27
7.2
CIRCULATOR INTERFACE ............................................................................................................. 27
7.2.1
RF In Port ......................................................................................................................... 27
7.2.2
RF Out Port....................................................................................................................... 27
8
SYSTEM INTERFACE REQUIREMENTS ................................................................................... 27
8.1
8.2
8.3
8.4
8.5
SPACECRAFT ATTITUDE STABILITY............................................................................................. 27
GPS ANTENNA ELECTRICAL REQUIREMENTS ............................................................................ 28
S-BAND ANTENNA REQUIREMENTS ........................................................................................... 29
ANTENNA ISOLATION REQUIREMENTS ........................................................................................ 30
LINK BUDGET FOR MAXIMUM RANGE ........................................................................................ 30
Annex A – NCLT Mechanical Interface
Annex B -- NCLT Interface Connectors and Connector Pin-Outs
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1
Introduction
1.1 Overview
The NCLT is a low power GPS navigation and data communication system designed for
spacecraft formation flying applications. Its function is to provide (a) absolute spacecraft
position and velocity and UTC time, based on GPS navigation, and (b) data
communications between spacecraft in the formation. Spacecraft-to-spacecraft
communication links are located at S-Band and operate using time division multiple
access (TDMA) techniques.
1.2
Document Scope
1.2.1 Interface Definition
This Interface Control Document (ICD) specifies and controls the detailed electrical,
mechanical, and thermal interface between NanoSat Cross-Link Transmission (NCLT)
System components and the host Nanosat spacecraft. The current plan is to build three
NCLT flight systems and install on three Nanosat spacecraft built by Utah State
University, Virginia Technical University, and Washington State University respectively.
The intent of this ICD is to provide sufficient information to install and integrate the
NCLT on each respective NanoSat spacecraft. The three NCLTs are identical and the
specifications given here in apply to all.
Each set of NCLT hardware delivered by JHU/APL shall include (a) a NCLT module
stack, (b) a GPS preamplifier module, (c) an S-Band preamplifier module, and (d) a
transmit/receive (T/R) switch and associated circulator. This document provides interface
specifications for all of the aforementioned NCLT hardware components.
A complete NCLT system must include a GPS antenna and an S-Band antenna. These
items are provided and installed by the NanoSat program. To meet NCLT operating
requirements, these items must satisfy interface and performance guidelines as set forth
in this document.
1.2.2 NCLT-to-Spacecraft Command and Data Product Definition
The NCLT will communicate with the NanoSat spacecraft over a serial communications
interface defined in this document. Specific data products exchanged and communication
protocols will be given in a future annex to this ICD.
1.2.3 Cross-Link TDMA DataTransmission
The standard operating mode for the 3 spacecraft NCLT configuration, to send and
receive data over the cross-link, is time division multiple access (TDMA). The data
sequence transmitted during each NCLT TDMA time slot will include data provided by
the respective spacecraft. The final version of this ICD will provide an overview of
NCLT TDMA operation and transmission message structure.
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1.3 NCLT Component Interconnect Block Diagram
The following figure depicts (a) the interface between NCLT components and (b) the
interface of NCLT components to the spacecraft. Although each set of NCLT
components delivered by JHU/APL are identical, component location and cable routing
on each spacecraft varies. NCLT component placement and cabling (consistent with
interface definition and requirements given in this document) are the responsibility of the
respective spacecraft integration teams. As shown in the following figure, interconnects
between NCLT components generally consist of RF cable connections.
NCLT
Module
Stack
* --
GPS RF
EXT 10
MHz
J4
GPS
Test
Points
J2
GPS
Antenna
1575.42
MHz
Indicates respective RF cable carries +5 v DC power
to preamplifier on center conductor
*
Out
J3
GPS
Preamplifier
Module
In
GPS
RCVR
Module
J5 TX 10 MHz
J6
RX 10 MHz
J5
J4
All interface cables
are built and installed by nanosat program
Power & T/R Cntrl
+5 v, ±12 v, RTN
NanoSat
Power System
T/R Control & Status
RX
Test
Points
NCLT
S-Band
RCVR
Module
J7
J3
TX
Test
Points
CPU
Test
Port
1575.42
MHz
+28 v
Switch
Power
J3
Analog Telemetry
Receive
S-Band *
Out
J2
J4
Transmit S-Band
S-Band
Preamplifier
Module
In
In
T/R
Switch
Out
In
Circulator
NCLT
S-Band
Transmitter
Module
2060 MHz
S-Band CrossLink
1
2
MonoPole
Omnidirectional
S-Band Antenna
Termination
50 Ohm
J2
NCLT
Processor
Module
4
J2
4
NCLT Serial Communications --- Port 1
NCLT Serial Communications --- Port 2
Processor Reset
J3
From J4
S-Band Rcvr
Module
1PPS
NanoSat
Command
and
Telemetry
System
Analog Telemetry Points
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NCLT Component Interconnect and Spacecraft Interface
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1.4
Reference Documents
Doc Number
Source
Description
JHU/APL
Document
7397-9100
JHU/APL
NCLT Product Assurance Implementation
Plan
JHU/APL
Document
TBD
JHU/APL
NCLT Software ICD
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NCLT Mechanical Interface
2.1 Dimensions and Mounting Footprints
Drawings of each NCLT component, indicating dimensions and mounting footprint, are
given in Annex A of this document.
2.2 Interface Connectors and Connector Pin-Outs
A listing of all NCLT component connectors and connector pin-outs are given in Annex
B of this document.
2.3
NCLT Component Weight Summary
The following table lists the maximum weight budgeted for each NCLT component. The
weight of NCLT interface cables, provided by the Nanosat program, and installed during
spacecraft integration, are not included.
NCLT Weight Summary
NCLT Component
Weight Budget [kg]
NCLT Module Stack
0.75 kg
GPS Preamplifier
0.15 kg
S-Band Preamplifier
Pending
T/R Switch
Pending
RF Circulator
0.05 kg
Total NCLT Weight
(Exclusive of Cables)
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NCLT Environmental Requirements
3.1
NCLT Component Thermal Interface
Operating Temperature
The temperature at the mounting surface of all NCLT components shall be maintained by
the spacecraft to the range of 0°C to +50°C. This temperature range shall be maintained
with the NCLT powered either on or off; power dissipated by each NCLT when powered
on is given below. The NCLT shall meet all operational interface and performance
requirements over this range of temperatures.
Survival Temperature
All NCLT components shall survive without damage temperatures ranging from –10°C
to +60°C at the respective NCLT mounting interface.
3.2 NCLT Component Power Summary
The table below lists the maximum power dissipated by each NCLT component. Power
drawn on each input power line is given in the electrical interface section of this
document.
NCLT Component Power Dissipation
NCLT Component
Maximum Power [mw]
Transmitting 250 mw
Transmitter Off
NCLT Module Stack
5400
4400
GPS
300
300
S-Band Preamplifier
300
300
T/R Switch
12
0
Circulator
12[1]
0
Radiated from
Antenna
250 mw
0
6275
5000
Preamplifier
Total NCLT Power
Note [1] – power consumed goes to 0.25 watts if T/R switch is in the receive state and
the transmitter is on
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3.3
NCLT Component Launch Vibration Requirements
All NCLT components shall survive without degradation in performance random
vibration and sine vibration given as follows.
Random Vibration
The NCLT shall survive random vibration levels to 12.9 grms. This specification is
applicable to all three axis.
The spectral density of random vibration is given below.
Spectral Density of Random Vibration
Spectral Density
1.000
20
50
600
2000
PSD (g2/Hz)
12.9 grms
0.100
0.010
Frequency (Hz)
Spectral Density Vibration Parameters
Frequency (Hz)
20
20-50
50
600
600-2000
2000
Power Spectral Density (g2/Hz)
0.025
+6 dB/oct
0.15
0.15
-4.5 dB/oct
0.025
Axes
Overall Level
Duration
X, Y, Z
12.9 grms
1 minute per axis
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Sine Sweep
The NCLT shall survive a sine sweep from 20 Hz to 500 Hz at a level of 0.5 g’s. This
specification is applicable to all three axis.
Sine Burst
The NCLT shall survive spacecraft sine burst testing levels of 23.8 g in each of the
primary axis of the spacecraft. The test frequency will not exceed 20 Hz. The figure
below is an example of what the sine burst test will look like.
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NCLT Module Stack Electrical Interface
4.1 NCLT Components Electrical Bond to Structure
It is anticipated the mounting interface of NCLT components will be in electrical contact
with the spacecraft structure. It is recommended efforts be made to keep the DC electrical
impedance -- between the NCLT component cases and spacecraft structure -- less than
2.5 millohms.
4.2
GPS Receiver Module Interface
4.2.1 NCLT Stack GPS RF Input
Connector:
SSMA female
GPS RF Power Level
-105 dBm to –85 dBm typical GPS signal (30 dB preamp
gain)
GPS RF Frequency
1575.42 MHz center frequency
Input RF Impedance
50 ohms nominal, VSWR < 1.5:1
Input Noise Figure
< 10 dB
Input Signal BW
2 MHz nominal
Input Signal Doppler
< ± 50 kHz in 350 km circular LEO
Grounding
Connector case electrically bonded to NCLT structure
DC Voltage
+5 volts DC on center conductor to provide power to GPS
preamplifier
DC Load Current
< 60 ma
4.2.2 TX 10 MHz Output
This is a 10 MHz reference signal output from the GPS receiver module to the S-Band
transmitter module. Cabling is installed by JHUAPL and this is considered an interface
internal to the NCLT.
4.2.3 RX 10 MHz Output
This is a 10 MHz reference signal output from the GPS receiver module to the S-Band
receiver module. Cabling is installed by JHUAPL and this is considered an interface
internal to the NCLT.
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4.2.4 EXT 10 MHz
This is a test point input to the GPS receiver module and is considered an interface
internal to the NCLT.
4.2.5 GPS Test Points
This interface provides test signal outputs for monitor of GPS receiver operation. This
interface does not connect to the spacecraft and is considered an interface internal to the
NCLT.
4.3
S-Band Receiver Module Interface
4.3.1 S-Band RF Input
Connector:
SSMA female
S-band RF Power Level
-100 dBm to –40 dBm typical signal (30 dB preamp gain)
S-band Center Frequency
2060 MHz
Input RF Impedance
50 ohms nominal, VSWR < 1.5:1
Input Noise Figure
< 10 dB
Input Signal BW
2 MHz nominal
Input Signal Doppler
< ± 1 kHz
Grounding
Connector case electrically bonded to NCLT structure
DC Voltage
+5 volts DC on center conductor to provide power to Sband preamplifier
DC Load Current
< 60 ma
4.3.2 Spacecraft Power and T/R Interface
4.3.2.1 Power
4.3.2.1.1
NCLT Power Input Voltage Requirement
The NanoSat spacecraft shall provide all power input to the NCLT. Power shall be
provided via a+5.0 volt line and ±12.0 volt lines. Approximately 6.275 watts is required
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for a 100% functional NCLT operation. Detailed NCLT power requirements are given
below.
4.3.2.1.2
Voltage Regulation
Static regulation of each voltage input to the GNS shall be regulated to within ±3% of its
nominal value listed above. This requirement is applicable over the complete range of
temperatures experienced by the NCLT (0°C to +50°C at NCLT mounting surface), for
all load variations (NCLT loads or otherwise), and input line variations to the DC-DC
converter.
4.3.2.1.3
Power Draw
Power loads (mw) on each voltage input line are listed below. These figures apply for a
fully functional NCLT that is transmitting at full power. Operating loads may be less if
the NCLT is placed in any lower transmit power levels.
NCLT Power Draw Requirement
NCLT Component
NCLT Module Stack
Maximum Power [mw]
Transmitter Radiating 250 mw
With 10 % Margin Added
+5 v
tbd
tbd
+12 v
tbd
tbd
-12 v
tbd
tbd
Total NCLT Power
6275 mw
T/R Switch
+12 v
At switch transition, draws 500 ma pulse for 15 ms ; otherwise 0 ma drawn
Note -- NCLT module stack power draw includes power provided via module stack to
GPS preamplifier and S-Band preamplifier
4.3.2.1.4
Voltage Spikes
Voltage spikes on any power input to the NCLT shall not exceed 150 mv peak-to-peak
(pp). Spectral components shall be limited to a band from 10 kHz to 10 MHz.
4.3.2.1.5
Voltage Ripple
Voltage ripple on any input power line to the NCLT shall not exceed 100 mv pp.
4.3.2.1.6
Inrush Current
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The NCLT shall not be required to provide current limiting on power input lines during
power turn-on.
4.3.2.1.7
Reverse Voltage Protection
Not Required
4.3.2.1.8
DC Low Voltage Survival
The NCLT shall survive without permanent damage a low voltage condition -- defined as
greater than 0 volts and less than 3% below nominal-- on any power input for an
indefinite period.
4.3.2.1.9
Overvoltage Survival
The NCLT shall survive without permanent damage an overvoltage condition of 20%
above nominal on any power input. These requirements apply to an overvoltage time
duration of 15 ms or less.
4.3.2.2 T/R Control Interface
4.3.2.2.1
T/R Position Control
TX_ON_P(N) Definition
This balanced set of digital signals -- output from the NCLT through the power
connector -- shall control the state (transmit or receive) of the T/R switch.
TX_ON_P(N) Signal Level
Compatible with EIA standard RS-422A electrical interface.
TX_ON_P(N) Polarity
A high signal, i.e., TX_ON_P > TX_ON_N, selects the transmit position of the T/R
switch, the reverse selects the receive position
4.3.2.2.2
T/R State Telltales
A set of telltale signals is received back from the T/R switch to indicate actual position of
the switch. The telltales are comprised of 3 lines, namely Telltale POS 1, Telltale POS 2,
and a common return. Telltale POS 1 shorted to the telltale common indicates the
transmit state, Telltale POS 2 shorted to the telltale common indicates the receive state.
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4.3.3 Spacecraft Analog Telemetry Interface
4.3.3.1 Analog Telemetry Test Points
A number of analog level test point signals shall be output from the NCLT to the
spacecraft. These signals, consisting of NCLT temperature test points, receiver AGC test
points , and voltage input test points, are intended for downlinking in spacecraft
housekeep telemetry. These signals will not exceed 4 volts full scale and the output
impedance is 10 k ohms. A specific listing and description of each telemetry test point is
given in the connector pinout table given in Annex B.
4.3.3.2 1PPS
In addition to the analog telemetry test points, this interface shall also carry a one pulse
per second (1PPS) signal specified as follows.
1PPS Definition
This signal is a 1 Hz square wave synchronized to UTC (USNO) 1PPS epoch times. This
signal is actively steered by the GPS – when the GPS system is tracking GPS SVs and is
navigating – to maintain alignment to within ±1 µs of UTC (USNO) 1PPS epoch times.
GPS derived position, velocity, and UTC time tag data -- output over the serial
communications bus in synchronism with the 1PPS – are valid on the respective 1PPS
epoch.
In the event the GPS drops out of the navigation state (due for example to GPS signal
blockage), the 1PPS signals shall continue to be output. However, since time is no longer
available from a navigation solution, the 1PPS will drift wrt to the UTC (USNO) epoch
by no more than 1 µs per second.
1PPS Voltage Level
CMOS +5 volt level
1PPS Polarity
The 1PPS epoch is defined to occur on the positive going transition of the signal.
1PPS Epoch Time Step
On entry to the GPS navigation state, the 1PPS epoch is delayed on a one-shot basis in
order to synchronize to UTC (USNO) epochs. This process is referred to as a time step.
The one-time delay between the two associated 1PPS epochs shall range from 1 to 2
seconds. (The spacing between 1PPS epochs is exactly one second at all other times). To
alert the spacecraft that a time step is to occur, a time jump message shall be sent over the
port #1 interface one second prior to the actual 1PPS time jump.
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4.3.4 RX Test Points Connector
This interface is a test port and is considered internal to the NCLT. It does not connect to
the spacecraft. Test signals and pin-outs are given in Annex B.
4.3.5 RX 10 MHz
This is a reference 10 MHz input signal provided from the GPS receiver module. Cabling
is installed by JHUAPL and this is considered an interface internal to the NCLT.
4.4
Transmitter Module Interface
4.4.1 S-Band Transmitter RF Output
Connector:
SSMA female
TX Power Level
Range of 27 dBm to ≈ -33 dBm in 2 MHz bandpass
about center frequency
TX Center Frequency
2060 MHz nominal
Center Frequency Stability
< ± 1 PPM (±2.060 kHz)
Carrier Phase Noise
1 Hz
< -65 dBc
100 Hz
< -125 dBc
10 kHz
< -145 dBc
TX RF Impedance
50 ohms nominal, VSWR < 1.5:1
Grounding
RF connector case electrically bonded to NCLT
structure
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Signal Structure
Modulation Type
BI-Phase Shift Key (BPSK)
Modulation
PRN sequence modulated modulo-2 by message
data
PRN Chip Rate
1.023 MHz
PRN Code Length
1023 chips
PRN Code Epoch Rate
1 kHz
Message Data Rate
500 bps (exactly 1/2 code rate)
Message Data Format
NRZL
PRN Code Assignments
GPS SV 33 through 37, selectable by command
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4.4.1.1 TX Spectral Envelop
TX power spectral component outputs shall not exceed the RF spectral envelope levels
indicated in the figure below.
24 dBm In ±1.023 Mhz Channel Bandwidth About fo
fo - 3 MHz
fo + 3 MHz
+7 dBm
+7 dBm
-15 dBm
Note: Power level figures given refer to
power in 1 Mhz Bandwidth
-15 dBm
-36 dBm
-36 dBm
-50 dBm
-50 dBm
1950
MHz
2025
MHz
fo
fo -4 MHz
fo +4 MHz
2110
MHz
2210
MHz
fo = 2060 MHz
NCLT Transmitter RF Power Spectral Envelope
4.4.2 TX 10 MHz
This is a reference 10 MHz input signal provided from the GPS receiver module. Cabling
is installed by JHUAPL and this is considered an interface internal to the NCLT.
4.4.3 TX Test Point Connector
This interface is a test port and is considered internal to the NCLT. It does not connect to
the spacecraft. Test signals and pin-outs are given in Annex B.
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4.5
Processor Module Interface
4.5.1 Spacecraft Serial Communications Interface
The NCLT serial ports connect to the spacecraft command and data handling (C&DH)
system. Port #1 is used to send commands to the NCLT and transfer data from the NCLT.
For the Utah State nanosat spacecraft only, Port #2 is used to transfer additional NCLT
data to the spacecraft.
A definition of all commands and telemetry data will be given in a future annex to the
ICD. The electrical interface for serial ports #1 and #2 are specified below.
4.5.1.1 Serial Port #1
Protocol
RS-232C protocol compliant, Asynchronous
Transmit and Receive
Electrical Level
Balanced EIA standard RS-422A voltage levels
Data Transfer
Full Duplex
Baud rate
38.4 kbaud
Interface Signals
Defined on pinout list, Annex B
Data Size
8 bit
Number of Start bits
one
Number of Stop bits
one
Parity
none
Flow Control
None
4.5.1.2 Serial Port #2
Protocol
RS-232C protocol compliant, Asynchronous
Transmit and Receive
Electrical Level
Balanced EIA standard RS-422A voltage levels
Data Transfer
Transmit from NCLT to spacecraft only
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Baud rate
9.6 kbaud
Interface Signals
Defined on pinout list, Annex B
Data Size
8 bit
Number of Start bits
one
Number of Stop bits
one
Parity
none
Flow Control
none
4.5.1.3 Processor Reset
Processor Reset Definition
This signal is a pulse output from the spacecraft command and data handling (C&DH)
system to the NCLT. A 1 ms time duration pulse will reset the NCLT processors and
force the GPS and NCLT software to reboot.
Processor Reset Level
CMOS +5 volt level. A ‘low’ voltage level forces the processor to reset.
Automatic Reset at Processor Power-Up
At power-up of the NCLT, no external reset pulse is required to initiate processor boot-up
and software load – at power-up this operation is performed automatically by the
processor.
4.5.2 CPU Test Port
This interface is a test port and is considered internal to the NCLT. It does not connect to
the spacecraft. Test signals and pin-outs are given in Annex B
5
GPS Preamplifier Electrical Interface
5.1 GPS Preamplifier RF Input
This interface connects to the GPS antenna
Connector:
SMA Female
GPS RF Power Level
-135 dBm to –115 dBm typical GPS signal
GPS RF Frequency
1575.42 MHz center frequency
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GPS Signal Bandwidth
2 MHz
Preamplifier BW
(3 dB)
(90 dB)
36 MHz ± 3 MHz
250 MHz ± 25 MHz
RF Impedance
50 ohms nominal, VSWR < 1.5:1, over signal bandwidth
Preamplifier Noise Figure
< 2.5 dB
Preamp 1 dB Compression
> 0 dBm
DC Input Impedance
< 1 ohm
Preamplifier Gain
30 dB nominal over signal bandwidth
Input Signal Doppler
< ± 50 kHz in 350 km circular LEO
Grounding
Preamplifier case electrically bonded to spacecraft frame
5.2 GPS Preamplifier RF Output
This is the GPS preamplifier output and connects to the GPS RF input connector on the
GPS receiver module installed in the NCLT stack. The GPS RF input electrical interface
is described in prior sections of this document.
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5.3
EMI Requirements Applicable at GPS Preamplifier Input
5.3.1 Susceptibility of GPS Performance to EMI
The maximum EMI Levels for GPS receiver operation without degradation in
performance are given below. These EMI levels are applicable at the GPS preamplifier
module input.
In-Band CW
-120 dBm maximum in passband of 2.8 MHz about center
frequency
In-Band Wide-Band (WB)
-120 dBm maximum measured in 1 MHz bandwidth,
applicable in 2.8 MHz band about center frequency
Out-of-Band EMI
+10 dBm maximum total in stopband – see figure which
follows
5.3.2 GPS EMI Survival Levels
The maximum EMI levels the GPS preamplifier will survive without damage are given
below
In-Band CW
0 dBm maximum in 275 MHz band about center
frequency
In-Band WB
0 dBm maximum total in 275 MHz band about
center frequency
Out-of-Band EMI
+20 dBm maximum total in stopband – see figure
which follows
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+10 dBm
+10 dBm
<-- 275 MHz -->
<- 2.8 MHz ->
0
10 GHz
-120 dBm
1575.42 MHz
GPS Susceptibility to EMI -- Maximum EMI Power Levels
+10 dBm
+10 dBm
<-- 275 MHz -->
0
10 GHz
39 MHz
0 dBm
1575.42 MHz
GPS Survivable EMI Power Levels
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6
6.1
S-Band Preamplifier Module Electrical Interface
S-Band Preamplifier Electrical Interface
6.1.1 S-Band Preamplifier RF Input
This interface connects to the output (RF port #1) on the T/R switch. An S-Band RF input
signal is received from the S-band antenna when the T/R switch is in the receive state.
Connector:
SMA Female
Preamplifier Passband (1 dB)
2025 MHz to 2110 MHz
Preamplifier Gain
30 dB ±3 dB over passband
S-Band Receive Center Frequency
2060 MHz
S-Band Receive RF Power Level
-130 dBm to –70 dBm typical
Preamplifier Input Impedance
50 ohms nominal, VSWR < 1.5:1, over
passband
Preamplifier Noise Figure
< 2.5 dB over passband
Preamp 1 dB Compression
> 10 dBm over passband
DC Input Impedance
< 1 ohm
Input Signal Doppler
< ± 1 kHz
Grounding
Preamplifier case is electrically bonded to
spacecraft frame
6.1.2 S-Band Preamplifier RF Output
This is the S-Band preamplifier output and connects to the S-Band RF input connector on
the GPS receiver module installed in the NCLT stack. The S-Band RF input electrical
interface is described in prior sections of this document.
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6.2
EMI Requirements Applicable At S-Band Preamplifier Input
6.2.1 NCLT TX/RX Isolation
A minimum of 80 dB of isolation is required between the NCLT TX signal input to the
T/R switch and the T/R switch input to the S-Band preamplifier when the T/R switch is in
the transmit mode. This requirement is applicable in the band from 2025 to 2110 MHz.
6.2.2 Susceptibility of S-Band Performance to EMI
The maximum EMI Levels for S-Band receiver operation without degradation in
performance are given below. These EMI levels are applicable at the S-Band preamplifier
module input.
In-Band CW
-120 dBm maximum in band from 2025 MHz to 2110 MHz
In-Band Wide-Band (WB)
-120 dBm maximum measured in 1 MHz bandwidth,
applicable in band from 2025 MHz to 2110 MHz. Total
WB power in band from 2025 MHz to 2110 MHz shall not
exceed –100 dBm
Out-of-Band EMI
+10 dBm maximum in stopband – see figure which follows
6.2.3 EMI S-Band Survival Levels
The maximum EMI levels the S-Band preamplifier will survive without damage are
given below
In-Band CW
0 dBm maximum in band from 2025 MHz to 2110 MHz
In-Band WB
0 dBm maximum in band from 1925 MHz to 2210 MHz
Out-of-Band EMI
+20 dBm maximum in stopband – see figure which follows
for transition band
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1925 MHz
2210 MHz
+10 dBm
+10 dBm
0
-120 dBm
fo MHz
2025 MHz
2110 MHz
NCLT S-Band Receiver Susceptibility to EMI -- Maximum EMI Power Levels
1925 MHz
2210 MHz
+10 dBm
+10 dBm
0
0 dBm
fo MHz
2025 MHz
2110 MHz
NCLT S-Band Receiver Survivable EMI Power Levels
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7
T/R Switch Electrical Interface
7.1 T/R Switch Interface
The function of this switch is to connect the S-Band antenna either to the transmitter RF
output or to the input of the S-Band preamplifier.
7.1.1 Actuating Voltage and Current
A +12 volt actuation voltage shall be provided by the spacecraft power system. During
each switch transition, from the transmit mode to the receive mode or vice-versa, the
switch will draw 500 ma or less for a period of 15 ms or less. Otherwise, no power is
drawn from the +12 volt line. Connector pinout is given in Annex B.
7.1.2 T/R Switch State Control
The state of the T/R switch is controlled by TTL+5 volt level signals output from the
NCLT module stack. Connector pinout is given in Annex B. These control signals are
labeled POS1 and POS2 and control the T/R mode (state) as follows. Switching time,
from one state to the other, takes 15 ms or less.
POS1 POS2 T/R State
0v
+5 v
Transmit
+5v
0v
Receive
7.1.3 T/R Switch Telltale
Telltales are returned from the T/R switch to the NCLT to confirm the state of the T/R
switch. The telltales are in the form of contact closures indicating the actual T/R state as
follows. Connector pinout is given in Annex B.
Telltale POS 1 shorted wrt to common: Indicates Transmit State
Telltale POS 2 shorted wrt to common: Indicates Receive State
7.1.4 RF Ports
7.1.4.1 RF Antenna Port (Labeled IN on figure 1)
This RF port connects to the S-band antenna. When the T/R switch is in the transmit
mode, the transmitter RF S-Band received at the S-Band input port connects to the
antenna. When the T/R switch is in the receive mode, the RF S-Band received at the
antenna connects to the S-Band output port.
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7.1.4.2 S-Band Input Port (Labeled #2 on figure 1)
This RF port is cabled to the S-Band circulator output. The S-Band transmitter RF output
interface is given in prior sections of this document.
7.1.4.3 S-Band Output Port (Labeled #1 on figure 1)
This RF port is cabled to the S-Band preamplifier input. The S-Band preamplifier input
interface is given in prior sections of this document.
7.1.4.4 RF Port Specifications
RF Insertion Loss
< 0.2 dB from DC to 3 GHz
VSWR
< 1.2:1 from DC to 3 GHz
Impedance
50 ohms nominal
RF Isolation
> 80 dB
7.2 Circulator Interface
The function of the circulator is to absorb S-Band transmitter output power in the event
the S-Band transmitter is powered while the T/R switch is in the receive state. (As shown
in figure 1, this device is inserted between the TX S-band output from the NCLT module
stack and the T/R switch S-Band input). The insertion loss - from RF In to RF Out -is0.2 dB typical, 0.3 dB maximum at 2060 MHz
7.2.1 RF In Port
This port connects to the S-Band RF output connector on the S-Band transmitter module
located in the NCLT stack. This interface is specified in prior sections of this document.
Connector type is given in Annex B.
7.2.2 RF Out Port
This port connects to the S-Band input port on the T/R switch. The output is identical to
the RF input, reduced by the insertion loss of 0.2 dB typical. Connector type is given in
Annex B.
8
System Interface Requirements
8.1 Spacecraft Attitude Stability
The NCLT will meet operational and performance requirements when the spacecraft is
operating and configured as follows.
( a ) the spacecraft attitude is stable to within ±2°
( b) the spacecraft is nadir pointing
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( c ) the GPS antenna is mounted on the spacecraft top (zenith pointing) deck and meets
field of view requirements given in following sections of this document
(d) the S-Band antenna meets field of view requirements given in following sections of
this document
8.2 GPS Antenna Electrical Requirements
All requirements that follow apply to the GPS antenna following installation on the
spacecraft.
Center RX Operating Frequency
1575.42 MHz
Bandwidth
≥ ± 2.5 MHz about center frequency
Polarization
RHC Circular
Field of View (FOV)
surface that extends from an
elevation of 0° to 90°. (The angle of
elevation is defined as the angle
between the local azimuth plane and
the zenith direction)
Input Impedance
50 ohms nominal, VSWR < 1.5:1
RHC Gain
> –3 dBic over at least 90 % of
surface extending from 10° to 90°
elevation
LHC Suppression
> 7dB with respect to RHC in FOV
Sidelobe Gain
< –10 dBic over the surface
extending from –10° to –90°
elevation.
Antenna Axial Ratio
< 2:1, over the surface extending
from +10° to +90° elevation and 2.5
MHz bandwidth
S-band Antenna to GPS Antenna Isolation
> 50 dB, applicable from 1573 MHz
to 2110 MHz
Nanosat D.L. Antenna to GPS Antenna Isolation
> 50 dB, applicable from 1573 MHz
to 2290 MHz
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Operating Temperature Range
Based on input from the NanoSat system engineer, it is anticipated the GPS antenna must
operate and meet all aforementioned performance requirements over a temperature range
of –40°C to +85°C.
Survival Temperature Range
Based on input from the NanoSat system engineer, it is anticipated the GPS antenna must
survive -- without degradation in performance requirements -- a temperature range of
–60°C to +100°C.
8.3 S-Band Antenna Requirements
All requirements that follow apply to the S-band antenna following installation on the
spacecraft.
Operating Bandwidth
2025 to 2110 MHz
All specifications that follow are applicable over this frequency band.
FOV (Field of View)
360° azimuth, ±10° elevation
Polarization
Vertical Polarization (VP)
(at 0° elevation, the radiated E-field is
parallel to the spacecraft nadir-zenith axis)
Gain
> -6 dBic within FOV
Input Impedance
50 ohms nominal, VSWR < 1.5:1
Transmit Power
30 dBm maximum
Cross-Polarization
< -15 dB relative to the VP signal,
applicable over the FOV
Operating Temperature Range
Based on input from the NanoSat system engineer, it is anticipated the NCLT S-Band
antenna(s) must operate and meet all aforementioned performance requirements over a
temperature range of –40°C to +85°C.
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Survival Temperature Range
Based on input from the NanoSat system engineer, it is anticipated the NCLT S-band
antenna(s) must survive – without degradation in performance -- a temperature range of
–60°C to +100°C.
8.4 Antenna Isolation Requirements
To meet GPS and NCLT S-Band performance requirements, RF isolation is required
between the S-Band antenna and the GPS antenna. In addition, isolation is required with
respect to the NanoSat downlink antenna. Minimum isolation requirements, including the
frequency bands over which these isolation requirements apply, are given in the table that
follows.
NCLT Antenna Isolation Requirements
GPS Antenna
NCLT S-Band Antenna
Radiating
Antenna
Radiating
Frequency/
Power
Minimum
Isolation
Requirement
Applicable
Frequency band
Minimum
Isolation
Requirement
Applicable
Frequency band
NCLT S-Band
2025-2110
MHz/0.25 watts
50 dB
1573 to 2110 MHz
not applicable
not applicable
Nanosat Downlink
Antenna
2200-2290
MHz/tbd watts
50 dB
1573 to 2290 MHz
50 dB
2025 to 2290 MHz
8.5
Link Budget For Maximum Range
The NCLT will meet all S-Band signal tracking and data recovery requirements at a
minimum input carrier-to-noise spectral power density (C/No) of 42 dB-Hz (referenced
to the S-Band preamplifier input). Maximum NCLT range occurs when the received SBand signal level results in this value of C/No.
The table that follows is a link budget for a NCLT range of 50 km. Four items in this
budget, namely minimum C/No, transmit power level, preamplifier noise figure, and T/R
switch insertion loss, are NCLT system parameters that are the responsibility of
JHU/APL. The remaining items are a function of NanoSat spacecraft design and –to meet
a 50-km range requirement -- it is the responsibility of the NanoSat program to assure
that portion of the budget is satisfied.
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Item
Budget
Units
Requirement
Responsibility
Required C/No
42
dB-Hz
JHU/APL
Minimum power spectral density ratio for 2 meter code
jitter, 500 bps at BER =10E-7
Preamp NF
3
dB
JHU/APL
S-Band preamplifier noise figure (Maximum)
TX Power
24
dBm
JHU/APL
Max transmitter power output from CLT
RX Antenna Gain
-6
dBi
Nanosat
Minimum receive antenna gain in FOV
TX Antenna Gain
-6
dBi
Nanosat
Minimum transmit antenna gain in FOV
TX/RX switch
insertion loss
-2
dB
JHU/APL
two way loss in T/R switch (Maximum)
Polarization Loss
-0.1
dB
Nanosat
Antenna polarization loss due to antenna misalignment
and spacecraft pointing offset
RX Cable/connector
losses
-0.5
dB
Nanosat
Losses in cables and connectors (4) from antenna toSBand preamp (Maximum)
TX Cable/connector
losses
-0.5
dB
Nanosat
Losses in cables and connectors (4) from antenna to CLT
transmitter output (Maximum)
dB
Nanosat
Propagation loss assuming 2100 MHz S-Band signal
frequency
° kelvin
Nanosat
Maximum anticipated antenna temperature
Propagation Loss at -132.9
50 km
Antenna
Temperature
340.0
Computed Received -123.97
Power level @ 50
km
dBm
Computed System -171.1
Spectral Noise
Power
dBmHz
Remarks
Received signal power as seen at the s-band preamp
input
Computed C/No @
50 km
47.18
dB-Hz
Signal-to-noise spectral density at preamplifier input
Margin C/No @ 50
km
5.18
dB-Hz
Margin -- may be interpreted as amount TX power level
may be reduced (via command)
Max Range @ 90.740
C/No=42 dB-Hz
km
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JHU/APL NCLT Mechanical Interface
Annex A – TABLE OF CONTENTS
1.
NCLT MODULE STACK DIMENSIONS AND MOUNTING FOOTPRINT ......................... A-2
1.1
1.2
1.3
NCLT TOP VIEW DIMENSIONS (INCLUDES MOUNTING FEET).................................................. A-2
NCLT SIDE VIEW (INCLUDES CONNECTOR LOCATIONS) ......................................................... A-3
NCLT SURFACE........................................................................................................................ A-3
2.
GPS PREAMPLIFIER MODULE DIMENSIONS AND MOUNTING FOOTPRINT............ A-4
3.
S-BAND PREAMPLIFIER MODULE DIMENSIONS AND MOUNTING FOOTPRINT..... A-5
4.
T/R SWITCH MOUNTING FOOTPRINT AND DIMENSIONS .............................................. A-6
5.
RF CIRCULATOR MOUNTING FOOTPRINT AND DIMENSIONS..................................... A-6
A-1
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Annex A to JHU/APL NCLT Interface Control Document – Draft #2
JHU/APL NCLT Mechanical Interface
1. NCLT Module Stack Dimensions and Mounting Footprint
1.1
NCLT Top View Dimensions (Includes Mounting Feet)
A-2
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Annex A to JHU/APL NCLT Interface Control Document – Draft #2
JHU/APL NCLT Mechanical Interface
1.2
NCLT Side View (Includes Connector Locations)
1.3 NCLT Surface
The NCLT mounting surface is flat aluminum. The exposed surface is black alodyned.
A-3
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Annex A to JHU/APL NCLT Interface Control Document – Draft #2
JHU/APL NCLT Mechanical Interface
2. GPS Preamplifier Module Dimensions and Mounting Footprint
4.50
4.25
0.125
4.00
0.25
0.25
0.50
IN
1.00
Mounting Surface
1.250
1.50
OUT
0.250
0.125
0.50
0.125
Units are in inches
A-4
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Annex A to JHU/APL NCLT Interface Control Document – Draft #2
JHU/APL NCLT Mechanical Interface
3. S-Band Preamplifier Module Dimensions and Mounting Footprint
Initial vendor estimates of dimensions are 1 x 3 x 8 inches exclusive of mounting feet
S-Band preamplifier module mounting footprint and hole Pattern will be available after
vendor receipt of purchase order.
A-5
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Annex A to JHU/APL NCLT Interface Control Document – Draft #2
JHU/APL NCLT Mechanical Interface
4. T/R Switch Mounting Footprint and Dimensions
The dimesions of the T/R switch are approximately 2.42 inches by 2 inches by 0.56
inches exclusive of connectors. Switch dimensions, mounting footprint, and hole pattern
drawings will be available after vendor receipt of purchase order.
5. RF Circulator Mounting Footprint and Dimensions
To be provided.
A-6
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Annex B -- JHU/APL NCLT Interface Control Document -- Draft #2
JHU/APL NCLT Interface Connectors and Connector Pin-Outs
ANNEX B TABLE OF CONTENTS
1.
INTERFACE CONNECTORS........................................................................................................B-2
2.
NCLT MODULE STACK CONNECTOR PIN-OUTS ................................................................B-4
3.
2.1.
SPACECRAFT POWER INPUT & T/R INTERFACE ........................................................................B-4
2.2.
SPACECRAFT ANALOG TELEMETRY ...........................................................................................B-5
2.3.
SPACECRAFT SERIAL COMMUNICATIONS INTERFACE ................................................................B-6
2.4.
GPS TEST POINTS ......................................................................................................................B-7
2.5.
S-BAND RX TEST POINTS ..........................................................................................................B-8
2.6.
TX TEST CONNECTOR ...............................................................................................................B-9
2.7.
CPU TEST CONNECTOR ...........................................................................................................B-10
T/R SWITCH CONNECTOR PIN-OUT ....................................................................................B-11
B-1
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Annex B -- JHU/APL NCLT Interface Control Document -- Draft #2
JHU/APL NCLT Interface Connectors and Connector Pin-Outs
1. Interface Connectors
All NCLT component interface connectors including part numbers are listed in the tables
below and on the next page
NCLT Module Stack Interface Connectors
Interface
Description
Connector
Designatio
n
Connector Type or Part
Number
Mating
Connector
Pin-Out
Connector
URL
GPS RF Input
J3
SSMA male
not applicable
GPS Test Points
J2
SSMA Female - M/A-COM
P/N 1052-1300-00
15 Position Female Nanonics
P/N STM015L2HN
15 Position Male Nanonics
P/N STM015PC2DCxxx
RX 10 MHz
J6
SSMA Female - M/A-COM
P/N 1052-1300-00
Cabled by JHU/APL to J6 on
S-Band Receive Module
not applicable
TX 10 MHz
J5
SSMA Female - M/A-COM
P/N 1052-1300-00
Cabled by JHU/APL to J2 on
S-Band Transmitter Module
not applicable
EXT 10 MHz
J4
SSMA Female - M/A-COM
P/N 1052-1300-00
Test Point
Not Connected
not applicable
S-Band RF Input
J2
Spacecraft Analog
Telemetry
J3
SSMA Female - M/A-COM
SSMA male
not applicable
P/N 1052-1300-00
15 Position Female - Airborn 15 Position Male - Airborn NCLT ICD Annex 2 http://www.airborn.com/pdf
P/N MM-222-015-275-32OS P/N MM-212-015-165-41Wx
/mseries/m45-4853.pdf
S-Band RX Test
Points
J7
15 Position Female Nanonics
P/N STM015L2HN
Spacecraft Power
Input & T/R Interface
J4
21 Position Male - Airborn 21 Position Female - Airborn NCLT ICD Annex 2 http://www.airborn.com/pdf
P/N MM-212-021-175-32OS P/N MM-222-021-265-41Wx
/mseries/m45-4853.pdf
RX 10 MHz (Input)
J5
SSMA Female - M/A-COM
P/N 1052-1300-00
Cabled by JHU/APL to J6 on
GPS Module
not applicable
SSMA Female - M/A-COM
P/N 1052-1300-00
15 Position Female Nanonics
P/N STM015L2HN
SSMA male
not applicable
15 Position Male Nanonics
P/N STM015PC2DCxxx
SSMA Female - M/A-COM
P/N 1052-1300-00
Cabled by JHU/APL to J5 on
GPS Module
GPS Receiver Module
NCLT ICD Annex 2 http://www.nanonics.com/d
wgs/n138-230.pdf
S-Band Receiver Module
15 Position Male Nanonics
P/N STM015PC2DCxxx
NCLT ICD Annex 2 http://www.nanonics.com/d
wgs/n138-230.pdf
S-Band Transmitter Module
S-Band TX RF
Output
TX Test Connector
J4
TX 10 MHz
J3
J2
NCLT ICD Annex 2 http://www.nanonics.com/d
wgs/n138-230.pdf
not applicable
Processor Module
Spacecraft Serial
Communications
Interface
CPU Test Connector
J2
J3
25 Position Male - Airborn 25 Position Female - Airborn NCLT ICD Annex 2 http://www.airborn.com/pdf
P/N MM-212-025-175P/N MM-222-025-265-41Wx
/mseries/m45-4853.pdf
32OS
9 Position Female - Airborn
9 Position Male - Airborn
NCLT ICD Annex 2 http://www.airborn.com/pdf
P/N MM-222-0009-275-32OS P/N MM-212-009-165-41Wx
/mseries/m45-4853.pdf
NCLT Interface Connectors -- Continued
B-2
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JHU/APL NCLT Interface Connectors and Connector Pin-Outs
GPS Preamplifier Module Interface Connectors
Interface
Description
GPS RF Input
GPS RF Output
Connect Connector Type or Part
or
Number
Designa
tion
Mating Connector
Input
SMA Female
SMA male
Output
SMA Female
SMA male
S-Band Preamplifier Module Interface Connectors
Interface
Description
S-Band RF Input
S-Band RF
Output
Connect Connector Type or Part
or
Number
Designa
tion
Mating Connector
Input
SMA Female
SMA male
Output
SMA Female
SMA male
T/R Switch Components Connectors
Interface
Description
Connect Connector Type or Part
or
Number
Designa
tion
Mating Connector
T/R Switch
S-Band RF
to/from Antenna
S-Band to
Preamplifier
S-Band from
Transmitter Via
Circulator
Power and T/R
Control Interface
RF Circulator
Input (from
Transmitter)
Output (to T/R
Switch J2)
Input
SMA Female
SMA male
J1
SMA Female
SMA male
J2
SMA Female
SMA male
In
SMA Female
SMA male
Out
SMA Female
SMA male
---
B-3
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Annex B -- JHU/APL NCLT Interface Control Document -- Draft #2
JHU/APL NCLT Interface Connectors and Connector Pin-Outs
2. NCLT Module Stack Connector Pin-Outs
2.1. Spacecraft Power Input & T/R Interface
NCLT Power and T/R Switch Connector Designation: J4 on S-Band Rcvr Module
Conector Type: 21 Position Male Airborn P/N MM-212-021-175-32OS
Pin #
Signal ID
Voltage
Max Load (ma)
Power Signals
1
+5V
+5.0 ±0.15 volts
2
Return
Return
12
+5V
+5.0 ±0.15 volts
13
Return
Return
3
+12V
+12.0 ±0.36 volts
4
Return
Return
14
+12V
+12.0 ±0.36 volts
15
Return
Return
5
-12V
6
Return
16
-12V
17
Return
T/R Switch Signals
-12.0 ±0.36 volts
Return
-12.0 ±0.36 volts
Return
Type
Description
7
TX_ON_P
Digital level output
High level turns S-Band T/R
switch to the transmit state
18
TX_ON_N
Digital level output
Complement of the
TX_ON_P signal
9
T/R_State1
Digital level Input
Low level indicates T/R
switch in the RX state
8
10
RTN
T/R_State2
Return
Digital level Input
11
19
20
21
RTN
RTN
RTN
RTN
Return
Return
Return
Return
B-4
Low level indicates T/R
switch in the TX state
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Annex B -- JHU/APL NCLT Interface Control Document -- Draft #2
JHU/APL NCLT Interface Connectors and Connector Pin-Outs
2.2. Spacecraft Analog Telemetry
Spacecraft Analog Telemetry Connector Designation: J3 on S-Band Rcvr Module
Conector Type
15 Position Female - Airborn P/N MM-222-015-275-32OS
Pin #
Signal ID
Type
1
Analog output
Analog output
0 to 4 volts
10 k
3
GPS_AG
C
RX_TEM
P
1_PPS
Output
Impedance
(Ohms)
0 to 4 volts
10 k
CMOS 5
volt
1k
4
TX_PWR
Digital 1Hz
square-wave
output
Analog output
0 to 4 volts
10 k
5
RTN
Return
Ground
6
+5V_MO
N
Analog output
0 to 4 volts
7
RTN
Return
Ground
2
Range
10 k
Scale
Factor
tbd
GPS receiver AGC voltage
tbd
S-Band receiver card
temperature
UTC one pulse per second
epochs coincident on
positive going edge
Indicator of transmitted
power level
tbd
+0.5 V/V +5 voltage input to S-Band
receiver card (+5 V = +2.5
V Nominal)
8
+12V_M
ON
Analog output
0 to 4 volts
10 k
+0.207
V/V
9
GPS_TE
MP
TR_STAT
E1
TX_TEM
P
SBAND_A
GC2
SBAND_A
GC1
TR_STAT
E2
12V_MO
N
Analog output
0 to 4 volts
10 k
tbd
Digital Output
0 to 5 volts
10 k
Analog output
0 to 4 volts
10 k
tbd
Analog output
0 to 4 volts
10 k
tbd
Analog output
0 to 4 volts
10 k
tbd
Digital Output
0 to 5 volts
10 k
Analog output
0 to 4 volts
10 k
10
11
12
13
14
15
B-5
Description
-0.207
V/V
+12 voltage input to S-Band
receiver card (+12 V = +2.5
V Nominal)
GPS receiver card
temperature
Low level indicates T/R
switch in the RX state
S-Band transmitter card
temperature
S-Band receiver AGC
voltage of RX #2
S-Band receiver AGC
voltage of TX #1
Low level indicates T/R
switch in the RX state
-12 voltage input to S-Band
receiver card (-12 V = +2.5
V Nominal)
Draft
Annex B -- JHU/APL NCLT Interface Control Document -- Draft #2
JHU/APL NCLT Interface Connectors and Connector Pin-Outs
2.3. Spacecraft Serial Communications Interface
NCLT Spacecraft Serial Communications Connector Designation: J2 on Processor
Module
Conector Type 25 Position Male - Airborn P/N MM-212-025-175-32OS
Pin #
1
14
7
20
4
17
10
23
Signal
ID
Type
Level or Range
Description
RS-422
RS-422
Data bits transmitted from the CLT to
spacecraft
Complement of 'P' data
RS-422
Data bits received from the spacecraft
RX1
Digital data input
Data -N
TX2 Digital data output
Data -P
RS-422
Complement of 'P' data
RS-422
Data bits transmitted from the CLT to
spacecraft
TX2 Digital data output
Data -N
RX2
Digital data input
Data -P
RX2
Digital data input
Data -N
RS-422
Complement of 'P' data
RS-422
Data bits received from the spacecraft
RS-422
Complement of 'P' data
TX1 Digital data output
Data -P
TX1 Digital data output
Data -N
RX1
Digital data input
Data -P
2
RTN
return
ground
8
RTN
return
ground
5
RTN
return
ground
11
RTN
return
ground
25
RTN
return
24
12
13
3
CLT Digital reset pulse
Reset-P
input
CLT Digital reset pulse
Reset-N
input
CHASSI
Chassis
S
NC
No Connection
15
NC
16
6
ground
RS-422
RS-422
Positive going pulse > tbd µs resets
CLT & GPS software/hardware
Complement of 'P' data
Chassis
Connection to chassis ground
-
No Connection
-
RTN
return
ground
NC
No Connection
-
18
NC
No Connection
-
19
RTN
return
ground
9
NC
No Connection
-
21
NC
No Connection
-
22
RTN
return
ground
B-6
Draft
Annex B -- JHU/APL NCLT Interface Control Document -- Draft #2
JHU/APL NCLT Interface Connectors and Connector Pin-Outs
2.4. GPS Test Points
GPS Test Points Connector Designation: J2 GPS Module
Conector Type: 15 Position Female Nanonics P/N STM015L2HN
Pin #
Signal ID
Type
Level or
Output
Range* Impedanc
e (ohms)
Scale
Factor
Description
Analog Signals
7
+5 V MonGPS
Analog
output
0 to 4
volts
10 k
1.2 v/v
+5 voltage input to GPS receiver card
14
+12 V MonGPS
-12 V MonGPS
GPS_IF_OU
T
Analog
output
Analog
output
Analog
output
0 to 4
volts
0 to 4
volts
-7 dBm
10 k
3 v/v
+12 voltage input to GPS receiver card
10 k
-3 v/v
-12 voltage input to GPS receiver card
1k
--
RTN
Ground
15
8
5
GPS downconverter IF Prior to A-D Converter
Digital Test Point Signals
1
3
GPS_TEST_ Digital level open/short
EN*
Input
10 k
Short to ground enables the GPS digital test point
interface
Digital
CMOS 5
pulse output
volt
1k
Digital 1 µs pulse, 1 kHz rate, aligned with chan
1 C/A code epoch
Digital
CMOS 5
pulse stream
volt
output
GPS_C_CLO
Digital
CMOS 5
CK
clock output
volt
1k
Digital C/A code bits, 1.023 MHz chip rate, GPS
chan 1
1k
Digital C/A code clock, 1.023 MHz, GPS chan 1
Digital baseband magnitude signal, 30 % duty
cycle (average), high when analog BB exceeds 1
sigma average
Digital baseband sign signal, 50 % duty cycle
(average), high when analog BB exceeds 0 volts
RTN
9
GPS_EPOC
H
4
GPS_CODE
10
Ground
12
GPS_MAG
Digital BB
Data
CMOS 5
volt
1k
6
GPS_SIGN
Digital BB
Data
CMOS 5
volt
1k
2
GPS_SA_CL Digital level CMOS 5
K
output
volt
1k
GPS Receiver Sample Clock, digital 5.714MHz
13
1_PPS_MON Digital level CMOS 5
output
volt
1k
One pulse per second output
11
RTN
Ground
* -- Output voltage into open load
B-7
Draft
Annex B -- JHU/APL NCLT Interface Control Document -- Draft #2
JHU/APL NCLT Interface Connectors and Connector Pin-Outs
2.5. S-Band RX Test Points
S-Band Rcvr Test Points Connector Designation: J7 on S-Band Receiver Module
Conector Type: 15 Position Female Nanonics P/N STM015L2HN
Pin #
Signal ID
Type
Level or
Output
Range* Impedance
(ohms)
Description
Analog Signals
8
RX_IF1_OUT
9
RX_IF2_OUT
5
RTN
Analog
output
Analog
output
Ground
0 to 4
volts
0 to 4
volts
1k
open/
short
10 k
Short to ground enables the S-Band receiver digital test
point interface
1k
S-Band Receiver 1 downconverter IF Prior to A-D
Converter
S-Band Receiver 2 downconverter IF Prior to A-D
Converter
Digital Test Point Signals
1
3
RX_TEST_E
N*
RTN
Digital
level Input
Ground
4
SIGN1_MON Digital BB CMOS 5
Data
volt
1k
Digital baseband sign signal, 50 % duty cycle (average),
high when analog BB exceeds 0 volts
6
SIGN2_MON Digital BB CMOS 5
Data
volt
1k
Digital baseband sign signal, 50 % duty cycle (average),
high when analog BB exceeds 0 volts
7
DATA_POL
10 k
Short to ground invertes RX_DATA
10
SA_CLK_MO
N
1k
Digital 5.714MHz Sample Clock, S-Band Receiver
1k
Digital baseband magnitude signal, 30 % duty cycle
(average), high when analog BB exceeds 1 sigma
average
12
Digital open/short
level Input
CMOS 5
Digital
volt
clock
output
MAG1_MON Digital BB CMOS 5
Data
volt
13
MAG2_MON Digital BB CMOS 5
Data
volt
1k
Digital baseband magnitude signal, 30 % duty cycle
(average), high when analog BB exceeds 1 sigma
average
2
RX_STATUS
CMOS 5
volt
1k
S-Band Receiver On/Off Status
14
RX_DATA
CMOS 5
volt
1k
Demodulated data for BER testing
15
RX_CLK
CMOS 5
volt
1k
Data clock for BER testing
11
RTN
Digital
level
output
Digital
level
output
Digital
level
output
Ground
* -- Output voltage into open load
B-8
Draft
Annex B -- JHU/APL NCLT Interface Control Document -- Draft #2
JHU/APL NCLT Interface Connectors and Connector Pin-Outs
2.6. TX Test Connector
NCLT S-Band TX Test Points Connector Designation: J2 on Transmitter Module
Conector Type: 15 Position Female Nanonics P/N STM015L2HN
Pin #
Signal ID
Type
Level or
Output
Range* Impedanc
e (ohms)
Description
Analog Signals
7
+5 V MonTX
+12 V MonTX
-12 V MonTX
Analog
output
Analog
output
Analog
output
0 to 4 volts
10 k
+5 voltage input to S-Band Transmitter card
0 to 4 volts
10 k
+12 voltage input to S-Band Transmitter card
0 to 4 volts
10 k
-12 voltage input to S-Band Transmitter card
5
EXT_DATA
Digital
level Input
CMOS 5
volt
1k
External data for Bit Error Rate (BER) testing
13
RTN
Ground
14
15
Digital Test Point Signals
1
TX_TEST_E
Digital
open/short
N*
level Input
10 k
Short to ground enables the TX digital test point
interface
3
BER_TEST_
Digital
open/short
EN*
level Input
10 k
Short to ground enables the Bit Error Rate (BER)
test interface
9
TX_EPOCH
Digital
pulse
output
CMOS 5
volt
1k
TX 1 kHz code epoch, one chip duration
4
TX_CODE
CMOS 5
volt
1k
TX digital code bits
10
TX_C_CLO
CK
Digital
pulse
stream
output
Digital
clock
output
CMOS 5
volt
1k
TX digital code clock, 1.023 MHz
12
TX_DATA
Digital BB
Data
CMOS 5
volt
1k
TX data modulated onto CLT S-band output
signal
6
TX_D_CLK Digital BB
Data
CMOS 5
volt
1k
TX data clock, 500 hz square wave
2
TX_STATU
Digital
CMOS 5
S
level output
volt
1k
S-Band Transmitter On/Off Status
8
TEST_DAT
A
1k
TX data monitor point
11
RTN
Digital
Level
Output
Ground
CMOS 5
volt
* -- Output voltage into open load
B-9
Draft
Annex B -- JHU/APL NCLT Interface Control Document -- Draft #2
JHU/APL NCLT Interface Connectors and Connector Pin-Outs
2.7. CPU Test Connector
CPU Test Connector Designation: J3 on Processor Module
Conector Type: 9 Position Male - Airborn P/N MM-222-009-275-32OS
Pin #
Signal ID
Type
Level or Range
1
TX Data 0
Digital data output
HCMOS
Data bits transmitted from the CLT
3
TX Data 1
Digital data output
HCMOS
Data bits transmitted from the CLT
2
RX Data 0
Digital data input
HCMOS
Data bits received by CLT
4
RX Data 1
Digital data input
HCMOS
Data bits received by CLT
6
RTN
return
ground
7
RTN
return
ground
8
RTN
return
ground
9
RTN
return
ground
5
Reset
Open Collector
B-10
Description
Short to ground to reset
Draft
Annex B -- JHU/APL NCLT Interface Control Document -- Draft #2
JHU/APL NCLT Interface Connectors and Connector Pin-Outs
3. T/R Switch Connector Pin-Out
T/R Connector Located on T/R Switch
Conector Type: 7 Position Male?? Switch
Connector
Pin #
Vendor ID
Type
Description
1
+12 VDC
Power Input
Switch Actuating Voltage
Spacecraft Power System
2
DC Return
Return
Actuating Voltage Return
Spacecraft Power System
3
POS 1
TTL +5 v
Level
T/R State Contorl Input
POS 1 = 0 v, POS 2 = +5 v à Transmit ??
mode
NCLT S-Band Receiver
Module Connector J2
Pin # tbd
4
POS 2
5
Teltale POS 1
Contact
open/close
6
Teltale
Common
Return
7
Teltale POS 2
Contact
open/close
TTL + 5 v level T/R State Control Input
POS 1 = +5 v,POS 2 = 0 v à Receive ??
mode
Destination
NCLT S-Band Receiver
Module Connector J2
Pin # tbd
Teltale – closure wrt common indicates
transmit state
NCLT S-Band Receiver
Module Connector J2
Pin # tbd
Teltale common return
NCLT S-Band Receiver
Module Connector J2
Pin # tbd
NCLT S-Band Receiver
Module Connector J2
Pin # tbd
Teltale – closure wrt common indicates
receive state
B-11
Destination Signal ID
Draft