LG G5200, Service Manual

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3. TECHNICAL BRIEF
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3. TECHNICAL BRIEF
3.1 General Descreption
The RF parts consists of a transmitter part,a receiver part,a synthesizer part,a voltage supply part,a
VCTCXO part. And the main RF Chipset CX74017[U411]is a single-chip dual-band transceiver for
the extended global system for mobile communication[E- GSM900MHz]/Digital communication
system[DCS1800MHz] voice and data transfer applications.
This device integrated a direct conversion receiver architecture, which eliminates the need of
Intermediate Frequency, a transmitter based on a modulation loop architecture and fractional-N
synthesizer part with built in TXVCO and Local-VCO.
3.2 Receiver
The Receiver part in CX74017 contains all active circuits completely, full receiver chain with the
exception of discrete front-end RF SAW filters. The filtered and amplified signal is down converted
in the RF-mixer to the baseband output. The receiver path is supported by internal channel filtering.
The RF front-end circuit is shown Figure 3-1.
Figure 3-1. RF front-end circuit.