Intrinsic Path Characteristic Definitions – 2/8/11
1.1 Fixed Path Component
1.1.1 Cabling – One or more electric conductors or combinations of conductors
bundled together and encased by a protective sheath
1.1.1.1
1.1.1.2
1.1.1.3
1.1.1.4
Name – A unique name given to the fixed path component
Id number – A unique Id number given to the fixed path component
Length – Length of cable in meters (m)
Type – One of the conductor types listed below
1.1.1.4.1 Single wire – A single metallic strand, thread, or rod which is flexible and
usually has a circular cross section which serves as an electric conductor.
1.1.1.4.2 Shield - A material or enclosure which blocks the effects of an electric field,
while allowing free passage to magnetic fields
1.1.1.4.3 Coaxial – A concentric two-conductor transmission line in which the center
conductor is surrounded by a dielectric, which is surrounded by the second
conductor, which in turn is surrounded by the protective jacket.
1.1.1.4.4 Triaxial – A cable similar to a coaxial cable, except that the second conductor
is surrounded by a dielectric material, followed by a third conductor, with a
protective jacket enveloping the third conductor.
1.1.1.4.5 Twinaxial – A coaxial cable with two inner conductors, as opposed to one.
1.1.1.4.6 Ribbon – A cable in which the conductors are arranged along the same plane,
and laminated or molded into a flat flexible ribbon.
1.1.1.4.7 Trace – PCB trace that is printed on a circuit board or flex board
1.1.1.4.8 Fiber optical multimode –An optical fiber with multiple modes of
transmission
1.1.1.4.9 Fiber optical single mode – An optical fiber with one mode of transmission
1.1.1.5 Conductor count – Number of conductors in a cable
1.1.1.6 Shield count – Number of shields in a cable
1.1.1.7 Shield – The shield or shields associated with this wire.
1.1.1.7.1 Name – A unique name given to this shield
1.1.1.7.2 Id number – A unique Id number given to this shield
1.1.1.8 Shield type – Type of shield, either braid, mesh, or foil
1.1.1.8.1 Braid – Metal wires weaved together
1.1.1.8.2 Mesh – Arrangement of interlocking metal links or wires with evenly spaced
uniform small opening in between
1.1.1.8.3 Foil – Thin sheet of metal
1.1.1.9 Impedance – Characteristic impedance of the cable ratio of the
electric field strength to the magnetic field strength for waves
propagating in the cable (Volts/m / Amps/m = Ohms) (AC) in Ohms
(Ω)
1.1.1.10
Conductor diameter – Width of conductor in a cable in meters
(m)
1.1.1.11
Trace width – The width of the trace in meters (m)
1.1.1.12
Trace weight – The weight of the conductor on one square
foot of board in ounces (oz)
1.1.1.13
Trace Roughness
1.1.1.13.1
Trace Type – (Electro-deposited or Rolled)
1.1.1.13.2
Trace Roughness Thickness – (in mils)
1.1.1.14
Cross-sectional area – The cross-sectional area of the
conductor
1.1.1.15
Conductor composition – Material composition of conductor
1.1.1.16
Shield composition – Material composition of shield
1.1.1.17
Insulation – A material that has a sufficiently high resistance
to the passage of electric current, so that current flow through it is
minimal or negligible.
1.1.1.18
Inner material – Type of insulation between conductor and
shield of coax
1.1.1.19
Outer material – Type of insulation on the outside of a wire
1.1.1.20
Cutoff frequency – The upper and lower frequencies at which
fixed path component drops 3 decibels or another reference
amount.
1.1.1.20.1 Power Loss – A reduction in the power level of a signal which has traveled
through the fixed path component. Expressed in decibels.
1.1.1.20.2 Frequency – frequency at the power loss level described in power loss.
1.1.1.21
Power rating – A rated or named value stating the power that
a fixed path component can safely handle.
1.1.1.21.1 Value – numeric value of the rating.
1.1.1.21.2 Type – Power, Voltage or Current
1.1.1.22
EMI – Electromagnetic interference – An electromagnetic
disturbance which brings about a degradation in performance
measured in decibels (dB).
1.1.1.23
Insertion loss – The reduction in power, amplitude, current,
resulting from the insertion of the fixed path component. Expressed
in decibels.
1.1.1.24
Propagation delay – The time interval required for a signal to
move through the fixed path component.
1.1.1.25
Fiber attenuation – A reduction over time or distance in
amplitude or energy.
1.1.1.26
Wavelength – Wavelength of optical signal measured in
meters (m). The distance an electromagnetic wave travels in the
time it takes to oscillate through a complete cycle.
1.1.1.27
Core Refractive Index – The refractive index of the fiber core,
measures how the material refracts light.
1.1.1.28
Cladding Refractive Index – The refractive index of the fiber
cladding, measures how the material refracts light.
1.1.1.29
Acceptance angle – The angle over which the core of an optical
fiber accepts incoming light.
1.1.2 Terminations – The point at which a transmission line ends.
1.1.2.1 Name – A unique name given to the termination.
1.1.2.2 Id Number – A unique identification number given to the
termination.
1.1.2.3 Contact Type – Type of connector.
1.1.2.4 Conductor count – Number of conductors in the connector.
1.1.2.5 Shield propagation – Whether or not shield is maintained through a
connector
1.1.2.5.1 Maintained – Shield exists on both sides of connector
1.1.2.5.2 Not maintained – Shield does not exist on both sides of connector
1.1.2.6 Bond type – Type of connection between cable and termination
1.1.2.6.1 Solder – A metal or alloy that is utilized to join two metals, such as the leads
of circuit components to conductive portions of printed circuits.
1.1.2.6.2 Crimp – A connection in which the joined conductors are pressed, pinched, or
twisted together.
1.1.2.6.3 Clamp – A mechanical device which serves to bind, press, or otherwise firmly
hold the termination.
1.1.2.6.4 Screw Terminals – A terminal, used for making electrical connections, that
incorporates a screw which is usually adjusted by hand.
1.1.2.7 Contact Impedance – Any impedance from the termination.
1.1.2.8 Insertion life – The usable life span of terminations
1.1.2.9 Insertion count – Number of times the termination was inserted into
another connector
1.1.3 Switch Component
1.1.3.1 Name – A unique name given to the switch
1.1.3.2 Identifier – A unique identification number given to the switch
1.1.3.3 Format – Switch format as in number of poles and throws
1.1.3.3.1 Poles – Number of terminals within a given switch
1.1.3.3.2 Throws – Number of positions in which the switch may be placed to create a
signal path or connection
1.1.3.4 Type – Type of switch
1.1.3.4.1 Matrix – Connects multiple inputs to multiple outputs
1.1.3.4.2 Scanner – Connects multiple inputs to single outputs in sequential order
1.1.3.4.3 Multiplex – Connects single instruments to multiple devices or multiple
instruments to single devices. Allows multiple simultaneous connections and
sequential or non-sequential switch closures
1.1.3.4.4 Isolated – A type of card where each channel is electrically isolated from all
other channels
1.1.3.4.5 Individual relay – Relay not grouped with other relays
1.1.3.4.6 Group assembly – Isolated relays grouped together
1.1.3.4.7 Combinations – Multiple switch types
1.1.3.5 Signal Intent – The intent of the signal to be used, options below
1.1.3.5.1 Power
1.1.3.5.2 Signal
1.1.3.5.3 RF
1.1.3.5.4 Optical
1.1.3.6 Default state – Normally open, normally closed or not connected.
1.1.3.7 Current rating – The highest level of current that can be switched
without damage to the switch card. Measured in Amperes (A)
1.1.3.8 Contact material type – Material composition of the relay contacts.
1.1.3.9 Contact life – The maximum number of expected closures before
failure
1.1.3.10
Switching events – A list of switching occurrences describing
current level, event type and if hot switching was used.
1.1.3.10.1 Current level – Current level of the signal applied to the switch.
1.1.3.10.2 Voltage level – Voltage level of the signal applied to the switch.
1.1.3.10.3 Event type – Switch opened or closed.
1.1.3.10.4 Hot switching – If the signal was active prior to switch closure.
1.1.3.11
Offset Voltage – Voltage that is produced between contact
terminals due to the temperature gradient across the relay contacts,
and the reed-to-terminal junctions of dissimilar metals. Measured
in Volts (V)
1.1.3.12
Isolation resistance – The measure of leakage resistance
between paths on the switch card. Measured in Ohms (Ω)
1.1.3.13
Insertion loss – The reduction in power, amplitude, current or
the like, resulting from the insertion of a component or network
between portions of a system. Measured in decibels (dB)
1.1.3.14
Crosstalk (sometimes called path isolation) – Unwanted
coupling occurring between two switch channels. Measured in
decibels (dB)
1.1.3.15
Voltage Standing Wave Ratio (VSWR) – The ratio of the
maximum voltage to the minimum voltage. It is the measure of the
impedance matching of the line.
1.1.3.16
Bandwidth – The interval of frequencies between which a
switch can produce a given proportion of its maximum output.
1.1.3.17
Output & Input Return Loss – The difference between the
power incident upon a discontinuity in a transmission system and
the power reflected from the discontinuity. Measured in decibels
(dB)
1.1.3.18
Propagation delay - The total time for a signal to propagate
through the switch.
1.1.3.19
Actuation Time – The time between application of the
nominal relay coil voltage and the final closure of the relay contacts
after the contract bounce interval. Seconds (s)
1.1.3.20
Release Time – The time between the removal of the coil
voltage and the stabilized opening of the contacts.
1.1.3.21
Settle Time – The time required for a signal through a switch
to remain at a given value once the contact is closed.
1.1.3.22
Common Mode Rejection Ratio – The ability of a switch to
reject interference from a common mode voltage at its input
terminals with respect to ground. Usually expressed in decibels at a
frequency (dB)
1.1.3.23
Differential Input Isolation – The isolation from signal HI to
LO. Specified as resistance and capacitance.
1.1.3.24
Leakage Current – Error current that flows through insulation
resistance when a voltage is applied
1.1.3.25
Offset Current – A current that comes from a switching card
even though no signals are applied.
1.1.3.26
Switched Current – The maximum current level that can be
reliably handled while opening and closing contacts
1.1.3.27
Maximum Switching Voltage – The maximum voltage level
that can reliably handled while opening and closing contacts
1.1.3.27.1 AC Voltage Level – Maximum switching voltage for an AC signal.
1.1.3.27.2 DC Voltage Level – Maximum switching voltage for a DC signal.
1.1.3.28
Maximum Switching Power – The maximum power that can
be reliably handled while opening and closing contacts
1.1.3.29
Termination Requirement – Contains each relay contact and if
it requires a termination for an open.
1.1.3.30
Path Resistance – The opposition the switch path offers to the
flow of current. Measured in Ohms (Ω)
Type
Relevant Characteristics
Single wire – A single metallic strand, thread, or rod
which is flexible and usually has a circular cross
section which serves as an electric conductor.
Length, impedance, diameter, Cross sectional area,
composition, insulation, cutoff frequency, power
rating, EMI, insertion loss, propagation delay
Shield - A material or enclosure which blocks the
effects of an electric field, while allowing free
passage to magnetic fields
Length, impedance, Cross sectional area, shield
composition, cutoff frequency, power rating, EMI,
shield type
Coaxial – A concentric two-conductor transmission
line in which the center conductor is surrounded by
a dielectric, which is surrounded by the second
conductor, which in turn is surrounded by the
protective jacket.
Length, impedance, diameter, Cross sectional area,
conductor composition, shield composition, insulation,
cutoff frequency, power rating, EMI, insertion loss,
propagation delay
Triaxial – A cable similar to a coaxial cable, except
that the second conductor is surrounded by a
dielectric material, followed by a third conductor,
with a protective jacket enveloping the third
conductor.
Length, impedance, diameter, Cross sectional area,
conductor composition, shield composition, insulation,
cutoff frequency, power rating, EMI, insertion loss,
propagation delay.
Twinaxial – A coaxial cable with two inner
conductors, as opposed to one.
Length, impedance, diameter, Cross sectional area,
conductor composition, shield composition, insulation,
cutoff frequency, power rating, EMI, insertion loss,
propagation delay
Ribbon – A cable in which the conductors are
arranged along the same plane, and laminated or
molded into a flat flexible ribbon.
Length, impedance, diameter, Cross sectional area,
conductor composition, conductor count, shield count,
shield composition, insulation, cutoff frequency,
power rating, EMI, insertion loss, propagation delay
Trace – PCB trace that is printed on a circuit board
or flex board
Cross sectional area, surface roughness, length, width
height, conductor composition, insulation, inner
material, outer material, power rating, EMI,
propagation delay, impedance
Fiber optical multimode –An optical fiber with
multiple modes of transmission
Core refractive index, cladding refractive index, cross
sectional area, fiber attenuation, wavelength, length,
composition, acceptance angle, power rating.
Fiber optical single mode – An optical fiber with
one mode of transmission
Core refractive index, cladding refractive index, cross
sectional area, fiber attenuation, wavelength, length,
composition, acceptance angle, power rating.