GaAs IC Control FET Series DC–2.5 GHz
AF002C1-39, AF002C4-39
T/R and Antenna Changeover Switch for Mobile Cellular Systems
Mobile
Antenna
Phone
Antenna
Diplexer
LNA
PA
Changeover
Switch
T/R Switch
From Transmitter
To Receiver
Disconnect
T/R Switch
System Block Diagram
T/R Switch Schematic
Changeover Switch Schematic
Antenna
Antenna
LT (nH)
D
S
λ/4
CT
D
S
TX
RX
10 kΩ
GaAs FET
AF002C
Series
G
C (pF)
G
VCTL
D
S
G
GaAs FET
AF002C
Series
VCTL
To T/R Switch
Truth Table for T/R Switch
Truth Table for Changeover Switch
VCTL (V)
TX to Antenna
RX to Antenna
High Isolation
Low Loss
VCTL (V)
Antenna
Connected
Isolated
0
Low Loss
-5
-5
High Isolation
0
See next page for positive voltage operation.
See next page for positive voltage operation.
Component Values for T/R Switch Circuit
Part Number
AF002C1-39
AF002C4-39
AF002C1-39
AF002C4-39
LT (nH)
165
85
CT (pF) Freq. (GHz)
18.8
18.8
4.7
0.45
0.45
0.90
0.90
44
22
4.7
Alpha Industries, Inc. [781] 935-5150 • Fax [617] 824-4579 • Email sales@alphaind.com • www.alphaind.com
3
Specifications subject to change without notice. 3/99A
ALPHA [ ALPHA INDUSTRIES ]
