Radio Transceiver Section - Pantech GB310 Service Manual

GB310 Service Manual

4.2 Radio Transceiver Section

The GB310's RF Transceiver(U304), which is AERO I, consists of the GSM transmitter,the GSM
Receiver, and the RF synthesizer. The highly integrated solution eliminates the IF SAW filter,
external low noise amplifiers (LNAs) for three bands, transmit and RF voltage controlled oscillator
(VCO) modules, and more than 60 other discrete components found in conventional designs.
The receive section uses a digital low-IF architecture that avoids the difficulties associated with
direct conversion while delivering lower solution cost and reduced complexity.
The transmit section is a complete up-conversion path from the baseband subsystem to the power
amplifer (U303) and uses an offset phase locked loop (PLL) with a fully integrated transmit VCO.
The RF synthesizer includes integrated RF and IF VCO's, Varactors, and Loop filters. The unique
integer-N PLL architecture used in the RF synthesizer produces a transient response that is
superior in speed to fractional architectures without suffering the high phase noise or spurious
modulation effects often associated with those designs.
The following Figure shows GB310's top view of PCB artworks.
Fig.4-1. RF Transceiver block diagram
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