Functional Description - LG GM200 Service Manual

The transmitter features a translation-loop architecture for directly modulating baseband signals onto
the integrated TX VCO. The translation-loop modulator and TX VCO are extremely low noise removing
the need for external SAW filters prior to the PA.
The AD6548 uses a single integrated LO VCO for both the receive and the transmit circuits. The
synthesizer lock times are optimized for GPRS applications up to and including class 12.

3.14.1 FUNCTIONAL DESCRIPTION

3.14.1.1 RECEIVER CHAIN
The AD6548/9 receiver section fully integrates all the RF and baseband signal processing. Each major
block is described in the following sections.
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Figure. 3-4-2 Receiver Chain Block Diagram
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3. TECHNICAL BRIEF
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