Vctcxo - Nokia 301 Service Manual

RM-839; RM-840; RM-841
System Module
• ADC internal
Figure 65 The functional block diagram of the receive section
The SMARTi UEmicro provides a five band multimode receiver for both GSM and UMTS mode. The receiver is
based on the direct conversion architecture (Zero-IF DCR). By use of frequency dividers (by 2/4) the LO
frequency is derived from the RF frequency synthesizer. The receive path is fully differential to suppress the
on-chip interferences.
The SMARTi UEmicro RX front-end contains in total five integrated fully balanced low noise amplifiers (LNAs)
for UMTS, UMTS/GSM multimode or GSM singlemode. The amplified RF signal is downconverted by a
quadrature demodulator into the orthogonal output signals at baseband frequency. The baseband path
consists of three blocks that is the baseband low pass filter, the baseband buffer providing a programmable
gain control (PGC) and a high resolution analog-to-digital converter (ADC).
The received signal is switched to the right receiving path by FEM, and then filtered to fulfill the channel
selection by SAW, if the working frequency band is occupied by both GSM and UMTS, then we need a duplexer
for filtering. When RF signal reach the transceiver, the subsequent processing will be executed.

VCTCXO

Quark engine need an external reference clock signal which delivered by a VCTCXO module. Quark could
provide several reference frequency outputs for different subsystems like Bluetooth, WLAN, GPS or DVB-H.
Issue 1 NOKIA INTERNAL USE ONLY Page 6 – 33
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