Pantech PG-1810, Service Manual

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PG-1810 Service Manual
PANTECH R&D CONFIDENTIAL
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4.2.4.2 Transmitter Part
A. 6dB attenuators : U304, U305
These passive components are adopted for PAM to operate in a stable output power.
B. Antenna Switch Module With SAW Filter : U301
These filters pass through the signals of which frequency band of 824~849MHz,
1710MHz~1785MHz, 1850MHz~1910MHz which is the transmit frequency of GSM850, DCS,
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 53% typically in GSM
band and amplification of 27dB and efficiency of about 53% typically DCS/PCS band.
D. RF Switch connector : J301
RF Switch connector used to test Mainboard’s RF characteristics and to calibrate.
E. Antenna: Antenna Contact Plate : INT301
This device enables signals to be transmitted and received from BTS by Um interface.
External Antenna can be contacted with Mainboard through Antenna Contact Plate.
Fig.4-9. Transmit part PCB Layout