Microsemi
Page 1
Copyright 2005
Rev. 0, 2005-09-15
WWW.Microsemi .COM
UM9401 / UM9402 / UM9415
COMMERCIAL TWO-WAY RADIO
ANTENNA SWITCH DIODES
DESCRIPTION
Microsemi offers a series of PIN diodes
specifically designed and characterized for
solid state antenna switches in commercial
two-way radios. Antenna switches using the
UM9401 and UM9415 series PIN diodes
provide high isolation, low loss and low
distortion characteristics formerly possible
only with electromechanical relay type
switches.
The UM9401 and the UM9402 diodes can
handle 100 W of transmitter power, while
The UM9415 will handle over 1000 W. The
extensive characterization of these PIN diodes in
antenna switch applications has resulted in
guaranteed low distortion specifications under
transmit and receive conditions. These diodes
also feature low forward bias resistance and high
zero bias impedance which are required for low
loss, high isolation and wide bandwidth antenna
switch performance.
IMPORTANT: For the most current data, consult MICROSEMI’s website: http://www.microsemi.com
ABSOLUTE MAXIMUM RATINGS AT 25º C
(UNLESS OTHERWISE SPECIFIED)
Package
Condition
UM9401 UM9402 UM9415
Reverse
Voltage @ Ir = 10 uA 50 V 50 V 50 V
Average
Power
Dissipation
(PA)
½ in. total length to 25 OC
Contact
25 oC (Package Flange
Temperature
Free Air
5.5 W 10 W
10 W
1.5 W 2.5 W
KEY FEATURES
High transmitter power
UM9401/UM9402 => 100 W
UM9415 => 1000 W
Low harmonic distortion
Low third order distortion
High carrier lifetime
Non cavity design
Thermally matched configuration
Low capacitance at 0 V bias
Low conductance at 0 V bias
Compatible with automatic insertion
equipment
APPLICATIONS/BENEFITS
Isolated stud package available
Surface mount package available
U
UM
M9
94
40
01
1
/
/
U
UM
M9
94
40
02
2
/
/
U
UM
M9
94
41
15
5
Microsemi
Page 2
Copyright 2005
Rev. 0, 2005-09-15
WWW.Microsemi .COM
UM9401 / UM9402 / UM9415
COMMERCIAL TWO-WAY RADIO
ANTENNA SWITCH DIODES
-5
10 -4
10 -3
10 -2
10 -1
10 0
10
If (A)
-1
10
0
10
1
10
2
10
3
10
Rs (Ohms)
Rs versus If
TYPICAL
UM9401/UM9402
UM9415
f = 100 MHz
UM9401/UM9402 UM9415 Units
Parameter Symbol Conditions
Min Typ Max Min Typ Max
Reverse Current IR Vr = 50 V 10 10 uA
Series Resistance RS If = 50 mA, F= 100 MHz 1.0 1.0
Ohm
Capacitance CT VR = 0 V, F = 100 MHZ 1.5 4 pF
Parallel Resistance RP VR = 0 V, F = 100 MHz 5k 1k
Ohms
Carrier Lifetime τ IF = 10 mA 2.0 5.0 us
Forward Voltage Vf If = 50 mA 1.0 1.0 V
Transmit Harmonic Distortion R2A/A
R3A/A
Pin = 50 W
f = 50 MHz, If = 50 mA
80 80
-dB
Receive Third Order
Distortion
R2AB/A Pin = 10 W, 0 V Bias
fA = 50 MHz, fB = 51
MHz
60
60
-dB
E
EL
LE
EC
CT
TR
RI
IC
CA
AL
LS
S
Microsemi
Page 3
Copyright 2005
Rev. 0, 2005-09-15
WWW.Microsemi .COM
UM9401 / UM9402 / UM9415
COMMERCIAL TWO-WAY RADIO
ANTENNA SWITCH DIODES
10 100 1000
f (MHz)
1
10
2
3
4
5
6
7
8
Ct (pF)
Ct versus f
TYPICAL
UM9401/UM9402
UM9415
Vr = 0 V
Vr = 0 V
Vr = 50 V
Vr = 50 V
0.0 0.2 0.4 0.6 0.8 1.0 1.2
Vf (V)
-5
10
-4
10
-3
10
-2
10
-1
10
0
10
If (A)
Vf versus If
TYPICAL
UM9401/UM9402
UM9415
E
EL
LE
EC
CT
TR
RI
IC
CA
AL
LS
S
Microsemi
Page 4
Copyright 2005
Rev. 0, 2005-09-15
WWW.Microsemi .COM
UM9401 / UM9402 / UM9415
COMMERCIAL TWO-WAY RADIO
ANTENNA SWITCH DIODES
1
10 2
10 3
10 4
10
f (MHz)
0
10
1
10
2
10
3
10
Rp (kOhms)
Rp versus f
TYPICAL
UM9401/UM9402 Vr = 0 V
UM9401/UM9402 Vr = 50 V
UM9415 Vr = 0 V
UM9415 Vr = 50 V
E
EL
LE
EC
CT
TR
RI
IC
CA
AL
LS
S
Microsemi
Page 5
Copyright 2005
Rev. 0, 2005-09-15
WWW.Microsemi .COM
UM9401 / UM9402 / UM9415
COMMERCIAL TWO-WAY RADIO
ANTENNA SWITCH DIODES
25 50 75 100 125 150 175 200
Lead Temperature ( C)
3000
10
100
1000
Maximum Transmitter Power (W)
MAXIMUM TRANSMITTER POWER
UM9415
If = 50 mA
If = 100 mA
If = 200 mA
If = 500 mA
If = 1 A
Zo = 50 Ohms, L = 1/2", SWR = INFINITE
o
E
EL
LE
EC
CT
TR
RI
IC
CA
AL
LS
S
Microsemi
Page 6
Copyright 2005
Rev. 0, 2005-09-15
WWW.Microsemi .COM
UM9401 / UM9402 / UM9415
COMMERCIAL TWO-WAY RADIO
ANTENNA SWITCH DIODES
25 50 75 100 125 150 175 200
Lead Temperature ( C)
1
10
100
1000
Maximum Transmitter Power (W)
MAXIMUM TRANSMITTER POWER
UM9401/UM9402
If = 10 mA
If = 20 mA
If = 50 mA
If = 100 mA
If = 200 mA
Zo = 50 Ohms, L = 1/2", SWR = INFINITE
o
Maximum Transmitter Power
E
EL
LE
EC
CT
TR
RI
IC
CA
AL
LS
S
E
EL
LE
EC
CT
TR
RI
IC
CA
AL
LS
S
Microsemi
Page 7
Copyright 2005
Rev. 0, 2005-09-15
WWW.Microsemi .COM
UM9401 / UM9402 / UM9415
COMMERCIAL TWO-WAY RADIO
ANTENNA SWITCH DIODES
The maximum CW transmitter power, PT(max), a PIN
diode antenna switch can handle depends on the
diode resistance, RS, power dissipation, PD, antennae
SWR, σ, and the nominal impedance, ZO. The
expression is as follows:
Characteristic curves are shown in the data section
which gives both the maximum and typical diode
resistance, RS as a function of forward current. The
maximum power dissipation rating of the PIN diode
depends both on the length of the diode leads and the
temperature of the contacts to which the leads are
connected. A graph defining the maximum power
dissipation at various combinations of overall lead
length (L) and lead temperature (TL) is given in the
data section. From these curves and the above
equation, the power handling capability of the PIN
diode may be computed for a specific application.
Curves are also presented which show the
maximum transmitter power that an antenna
switch using UM9401s and UM9415s can safely
handle for various forward currents and lead
temperatures. These curves are based on a typical
design condition of a ½ in. total overall lead length,
50 Ω line impedance, and a totally mismatched
antenna (σ = ∞). For the case of a perfectly matched
antenna, the maximum transmitter power can be
increased by a factor of 4.
Design Information
A circuit configuration for a two-way radio antenna
switch using PIN diodes consists of a diode placed in
series with the transmitter and a shunt diode placed a
quarter wavelength from the antenna in the direction
of the receiver as shown. For low frequency
operation, the quarter wave line may be simulated by
lumped elements. Typical performance of antenna
switches using PIN diodes forward biased at 100 mA
is less than 0.2 dB insertion loss and 30 dB isolation
during transmit; at zero bias the receive insertion loss
is less than 0.3 dB. This performance is achievable
across a ±20 % bandwidth at center frequencies
ranging from 10 to 500 MHz.
ANTENNA
ANTENNA
DC SUPPLY
D1
D2
LD1
D2
DC SUPPLY
/4
TRANSMITTER
TRANSMITTER
RECEIVER
RECEIVER
L = ZO / 2 πfO (H)
C = 1/2 πfO ZO (F)
L
CC
Microsemi
Page 8
Copyright 2005
Rev. 0, 2005-09-15
WWW.Microsemi .COM
UM9401 / UM9402 / UM9415
COMMERCIAL TWO-WAY RADIO
ANTENNA SWITCH DIODES
STYLE “UM9401B” STYLE “UM9415B”
STYLE “UM9401SM” STYLE “UM9415SM”
M
ME
EC
CH
HA
AN
NI
IC
CA
AL
L
Microsemi
Page 9
Copyright 2005
Rev. 0, 2005-09-15
WWW.Microsemi .COM
UM9401 / UM9402 / UM9415
COMMERCIAL TWO-WAY RADIO
ANTENNA SWITCH DIODES
UM9401 STYLE “SM” FOOTPRINT
NOTES:
1. These dimensions will match the terminals and provide for additional solder fillets at the outboard ends
at least as wide as the terminals themselves, assuming accuracy of placement within 0.005”
2. If the mounting method chosen requires use of an adhesive separate from the solder compound, a round
(or square) spot of cement as shown should be centrally located.
UM9415 STYLE “SM” FOOTPRINT
M
ME
EC
CH
HA
AN
NI
IC
CA
AL
L
Microsemi
Page 10
Copyright 2005
Rev. 0, 2005-09-15
WWW.Microsemi .COM
UM9401 / UM9402 / UM9415
COMMERCIAL TWO-WAY RADIO
ANTENNA SWITCH DIODES
Microsemi
Page 11
Copyright 2005
Rev. 0, 2005-09-15
WWW.Microsemi .COM
UM9401 / UM9402 / UM9415
COMMERCIAL TWO-WAY RADIO
ANTENNA SWITCH DIODES
NOTES:
N
NO
OT
TE
ES
S
