Philips CT6558 Tuning Up Procedure & Operational Manual page 10

PHILIPS
Tuning Up procedure & Operational Manual
LNA
The receiver consists of two distinct parts, the RF receiver front-end and IF section. The RF
front-end amplifies the EGSM/DCS/PCS aerial signal, converts the chosen channel down to a low IF of
–100kHz,and provides in addition more than 35dB image suppression. Fout LNAs are available on chip
and can be configured to allow 3 bands(low, high and switched).The switched LNA will be used for
roaming in different countries. some selectivity is provided at this stage by an on-chip low-pass filter,chan
channel selectivity is provided by means of a high performance integrated band-pass filter. The IF section
further amplifies the wanted channel, performs gain control to tune the output level to the desired value
and rejects DC.
5.Four IQ signals input to CPU , go through A/D ,DSP, and D/A section in CPU , then output to receiver.
IQ Down mixer Channel Filter
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Revision :
Date :2004-9-7
Page No. : Page 10 of 10
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