Microwaves101.com
Electronic Symbols.doc
Revision 20
Last modified July 6, 2011
You wouldn’t believe how many engineers download this free Word file each month!
This Word document contains some schematic symbols for use in Microsoft Word, PowerPoint
and Excel files for reports and presentations. If you happen to have Agilent ADS or AutoCAD,
you may find these tools more convenient for creating schematics. If you are a microwave
cheapskate, you may have created these symbols yourself a hundred times. Using this
downloadable file, now you won’t have to!
Did you find some useful schematic symbol(s) missing? Drop a line to
techwriter@microwaves101.com and we’ll see if we can add it!
The Microsoft Word Drawings are pasted into tables to keep them “anchored” within the text.
Just double-click on a figure to edit it. When you are editing a figure, remember that everything
started out on a 0.05 inch grid. You may have to turn off the grid snap to get things to align
properly.
Around the pictures (inside the Microsoft Word Drawings) are invisible boxes with clear filling.
These are used to define the outside edges of the pictures.
Microsoft software does some peculiar things if you try to scale the pictures. We recommend
that if your picture is too big, you should work on decreasing the size of the elements inside the
picture rather than squeezing the entire picture down to size. Once you shrink any of the
schematic elements, all bets are off as to whether they will look aligned when you connect them
up.
It is very simple to copy from one picture to another. You need to double-click the picture you
are copying from, then click and control C the element you want to copy, then exit the picture,
click into the second picture and hit control V.
Good luck!
Microwaves101.com
Jumpers and
dots
Capacitors
Ground
symbols
Resistors
Inductors
Resistors, capacitors and inductors
FB
Coax, ferrite bead
MOSFETs
MESFET
NMOS
BJT NPN
PMOS
BJT NPN
FETS and transistors
Microwaves101.com
Port 2
Port 1
Port 1
Pi attenuator
Port 3
Port 1
Port 2
Port 3
Port 2
Port 1
Port 2
Tee attenuator
Circulators and isolators
Attenuators, circulators and isolators
RF
IF
LO
Microwaves101.com
RF
IF
LO
Double-balanced mixers
Microwaves101.com
Inside only
Outside only
Inside/outside
DC Blocks
RF only
RF & DC
RF
IF
LO
Bias tee
DC only
Mixer
Diodes
Variable
attenuator
Zener
Phase
shifter
Diodes, DC blocks, mixer, phase shifter/attenuator
Microwaves101.com
HPF
F
BPF
LPF
BSF
Lumped element filters
Flow
Flow
Fmed
Fhigh
Fhigh
Diplexer
Triplexer
Filters and multiplexers
Microwaves101.com
Lumped element filters
LP Pi
HP Pi
LP Tee
HP Tee
Lumped Filters
SPDT
SPST
SP3T
Switches
Microwaves101.com
Single box hybrid
0.707 Z0
Vin
(port 1)
0.707 Vin<-90
(port 2)
Z0
isolated port
(port 4)
Z0
0.707 Vin<180
(port 3)
0.707 Z0
all arms are
in length
Double box hybrid
Z0
Z0
0.707 Vin<180
(port 2)
Vin
(port 1)
2.414 Z0
1.414 Z0
Z0
isolated port
(port 4)
2.414 Z0
0.707 Vin<-90
(port 3)
Z0
all arms are
in length
Unequal-split hybrid power divider
Z0A
VIN
(port 1)
PA
(port 2)
Z0B
isolated port
(port 4)
Z0B
Z0A
PB
(port 3)
all arms are
in length
Branchline hybrid couplers
Microwaves101.com

PIN
PB


PA

isolated port
Unequal split rat race coupler

0.707 Vin<90
(port 2)
Vin
(port 1)




0.707 Vin<-90
(port 4)


isolated port
(port 3)
Equal-split rat race coupler
Rat race coupler
Microwaves101.com
2 Z0, /4
Port 2
Port 1
2Z0
2 Z0, /4
Port 3
Basic 3 dB Wilkinson splitter
Port 2
(50 )
/4
Port 1
(50 )
59.4 
100
59.4
/4
42
Port 3
(50 )
/4
Wilkinson with input transformer (Z0=50
/4
/4
Port 1
(50 )
56.3 
66.0 
/4
39.8
Port 2
(50 )
66.6 
/4
93.7 
155.5 
56.3 
Port 3
(50 )
/4
Two stage Wilkinson with input transformer
/4
/4
PIN
(port 1)
Z0C
PA
(port 2)
Z0

/4
RW
Z0D
/4
PB
(port 3)
Unequal split Wilkinson power divider
Wilkinson power splitters
Microwaves101.com
N-section Wilkinson
ZN-1
Z1
Z2
Port 2
ZN
Port 1
ZN
RN
RN-1
ZN-1
R2
Z2
R1
Z1
Port 3
N-section Wilkinson - odd mode
ZN
ZN-1
Z2
Z1
Port 2
Zin,odd
odd
0 ohms
0.5xRN
0.5xRN-1
0.5xR2
0.5xR1
N-section Wilkinson - even mode
ZN
ZN-1
Z2
Z1
Port 2
Zin,even
odd
2xZ0
N-section Wilkinson, Even/odd modes
Microwaves101.com
High-pass/low-pass
Switched filter - High-pass
SW1
SW1
Bypass state
C1
L1
Hi-pass state
C1
L1
L1
L1
SW2
SW2
Q1
Q1
Q1
L1
L1
Q2
L2
L1
L1
C1
Q2
L2
C1
L1
L1
Q2
L2
Microwaves101.com
Phase shifters
Port 2
/4
Port 2
Port 1
Port 1
/4
Port 3
Port 3
Series SPDT switch
Shunt SPDT switch
/4
Port 2
Port 2
Port 1
Port 1
/4
Port 3
Port 3
Series-shunt SPDT switch
Series-shunt-shunt SPDT switch
/4
Port 2
/4
Port 1
/4
/4
Port 3
Shunt-shunt SPDT
switch
Switch configurations
Microwaves101.com
3 Z0, /4
Port 2
Z0
Port 1
3 Z0, /4
3 Z0, /4
Port 3
Z0
Z0
Port 4
Three-way Wilkinson splitter, star resistors
3 Z0, /4
Port 1
3 Z0, /4
Port 2
Port 3
3Z0
3Z0
3 Z0, /4
3Z0
Port 4
Three-way Wilkinson splitter, delta resistors
Three-way Wilkinsons
Z0/3
Port 2
Z0/3
Port 3
Z0/3
Port 1
Y-type 6 dB resistive splitter
Z0
Port 2
Z0
Port 1
Z0
Port 3
Delta-type 6 dB resistive splitter
Resistive splitters
Microwaves101.com
R1
Z1
Z2
R2
L-pad matching network (Z1>Z2)
L-Pad
R1
Port 2
R2
Z0
Port 1
Z0
R3
Port 3
R4
Owen resistive splitter
Z0
Microwaves101.com
0.707 Vin<-90
(port 2)
all arms are
in length
isolated port
(port 4)
Z3
R=Z0
Z2
Z4
Z2
Z4
Z1
Vin
(port 1)
R=Z0
Z3
Equal-split Gysel
isolated port
(port 5)
0.707 Vin<-90
(port 3)
Gysel power splitter
Detector
diode
RF
In
Input
matching
network
Video
out
RF
choke
Bypass
cap
Basic
detector
Detector circuits
Microwaves101.com
+
-
+
Cell
-
+
+
+
-
+
-
+
-
Multiple cells (as
in a flashlight)
Battery
Multiple
batteries (ganged
for more current)
-
-
+
-
+
-
Multiple batteries (ganged for more voltage)
Meters, power supplies and batteries
Series
resonance
L
Parallel
resonance
C
C
R
Resonant circuits
L
R
Microwaves101.com
D
TSC427
G
S
S
N-channel
D
G
G
D
S
P-channel
P-channel
MOSFETs and Drivers
AND
OR
Logic
NAND
NOR
NOT
XOR
XNOR
Microwaves101.com
Mixer
IF
RF
RF
Input
pad
IF
output
LO
LNA
IF amp
LO
Input
Receivers
Microwave Capacitor model
C
LS
CP
Capacitor model
ESR
Microwaves101.com
Current
source
Lossless transmission
line model
General transmission line model
DC
Voltage
source
AC
Voltage
source
L'
L'
R'
C'
G'
C'
+
-
Voltage and current sources, transmission line model
Capacitive switch
Three-terminal Ohmic switch
Four-terminal Ohmic
switch
VA
VA
VA1
MEMS switches
VA2
Microwaves101.com
Coupled
port
Input
port
Input
port
Direct
port
Isolated
port
Output
port
Balanced amp
Lange couplers. balanced amp
Carrier amplifier
0.707 Z0
Z0
Z0
Input
port
Z0
Z0
0.707 Z0
0.707 Z0
Peaking amplifier
Doherty amp
Doherty amp
Output
port
Microwaves101.com
Driver
amp
Power
amp
SW2
Circulator
To
antenna
Attenuator
Phase
shifter
SW1
To
manifold
Commonleg amp
LNA
Limiter Isolator
Driver
amp
Power
amp
SW3
Phase
shifter
To
manifold
Attenuator
SW1
Pre-amp
TR modules
LNA
Limiter
SW2
To
antenna
Microwaves101.com
The FET images below came from James. Thanks!!
Depletion mode MOSFET
Enhancement Mode MOSFET
Microwaves101.com
p Channel JFET
n-channel JFET