GB310 Service Manual
1
PANTECH
4.2.4.2 Transmitter Part
A. 6 dB attenuator : Z301, Z302
These passive components are adopted for PAM to operate in a stable output power.
B. ASM(Antenna Switch Module / built in LPF): U320
These filters pass through the signals of which frequency band of 824~849MHz,
1850MHz~1910MHz which is the transmit frequency of GSM850, PCS system terminal, and it
suppresses other images and spurious frequencies when the terminal transmits GMSK modulated
frequencies.
C. Power AMP Module(PAM): U303
This device amplifies signals ahead of transmiting them through the antenna to provide a
sufficient RF power. It has amplification factor of 28dB and efficiency of about 50% typically in
GSM850 band and amplification of 27dB and efficiency of about 50% typically PCS band.
D. RF Switch connector: J301
RF Swithch connector used to test Mainboard’s RF characteristics.
E. Intenna: Intenna Contact Plate
This device enables signals to be transmitted and received from BTS by Um interface.
The antenna is contacted through Antenna Contact Plate.
Fig.4-9. Transmit part PCB Layout
Intenna
ASM
6dB
Attenuator
PAM
RF Switch
Connector
