Only For Training And Service Purposes - LG TU550 Service Manual

The UMTS LNA output is routed to the RFR6202 through a band selection filter that transforms a
single-ended 50Ω source to a differential impedance that is matched to the RFR6202 IC. The RFR input
uses a differential configuration to improve second-order inter-modulation and common mode rejection
performance. The RFR6202 input stages include MSM-controlled gain adjustments that further extend
receiver dynamic range.
The RFR6202 IC (Figure 3.3.1-1) provides the UMTS Zero-IF receiver signal path, from RF to analog
baseband. The input gain stage implements MSM controlled gain adjustments to extend receiver
dynamic range. The amplifier output drives the RF port of the quadrature RF-to-baseband
downconverter then the downconverted baseband outputs are routed to lowpass filters (one I and one
Q) whose passband and stopband characteristics are suitable for DS-WCDMA signals. The filter
outputs are buffered and routed to the MSM device for further processing. This baseband interface is
shared with the RTR6250 GSM850/GSM900/DCS/PCS receiver outputs.
Copyright © 2007 LG Electronics. Inc. All right reserved.

Only for training and service purposes

Figure 3.3.1-1 RFL6202 IC functional block diagram
3. TECHNICAL BRIEF
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LGE Internal Use Only