Rf Sub-Systems - LG KG195 Service Manual

4. Circuit Description

4.2.19 RF Sub-systems

MT6129 is a highly integrated RF transceiver IC for multi-band Global Systems for Mobile
communication (GSM) and General Packet Radio Service (GPRS) cellular system applications. The
MT6129 includes four LNAs, two RF quadrature mixers, an integrated channel filter, programmable
gain amplifiers (PGA), an IQ demodulator for the receiver, a precision IQ modulator with offset PLL for
the transmitter, two internal TX VCOs, a VCXO, on-chip regulators, and a fully programmable sigma-
delta fractional-N synthesizer with an on-chip RF VCO. The MT6129 also includes control circuits to
enable different operating modes. The device is housed in a 56-pin QFN SMD package with a downset
paddle for additional grounding.
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