Siemens SXG 75 Service Repair Documentation page 11

5.2.1 GSM RX
The GSM Receiver is a zero IF architecture with direct conversion by the IC. Although the IC
provides four input paths, the GSM850 Receiver is not used in the SXG75.
Block diagram RTR6250
5.2.2 UMTS RX
The RFR6250 provides an LNA and an output to allow further input filtering. The balanced signal is
reconnected to the RFR6250 and down converted by the Zero IF Quadrature Downconverter. The
UMTS 1900 RX path (PLNA, PMIX) is not used in the SXG75.
Block diagram RFR6250
5.2.3 GPS
The GPS path is similar to the UMTS path, but uses a LNA with higher amplification to compensate
the DCS self blocking. The RFR6250 allows the GPS RX path to be switched off during GSM
transmit pulses.
Block diagram RFR6250
Technical Documentation
TD_Repair_L3_SXG75_R1.0.pdf
Company Confidential
2006©BenQ
Release 1.0
01/2006
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