Nokia 3105 Servicehandbuch

RH-48

System Module

CCS Technical Documentation

Page 22

 ©

2003 Nokia Corporation         Confidential

Issue 1 11/2003

The receiver is a dual conversion I/Q receiver with a first IF of 183.6 MHz. The front-end 
RFIC (Alfred) contains a low noise amplifier (LNA), a radio frequency amplifier (RFA), a 
down-converter, an intermediate frequency amplifier (IFA), and a local oscillator ampli-
fier (LOA). Between the LNA and the RFA is a bandpass filter which will reject out-of-
band spurious and act as image rejection. The IF filter is between the Alfred IC and the 
Yoda IC. The purpose of this filter is to guarantee rejection in adjacent and alternate 
channels.

The RX IF ASIC Yoda is used to convert the IF down to baseband I and Q. The ASIC con-
tains a VGA section, IQ demodulator, and baseband filters (BBFIL) for CDMA. Fix gain 
baseband amplifier (BBAMP), and RX VHF PLL. The I/Q BB signals are output to UEM chip 
for analog-to-digital conversion and further signal processing. 

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