Technical Brief; General Description; Receiver Part - LG T5100 Service Manual

2. TECHNICAL BRIEF

2. TECHNICAL BRIEF

2.1 General Description

The RF part consists of a transmitter, a receiver, a synthesizer, a voltage supply and a VCTCXO
part. And the main RF Chipset TRF6151 [U702] is a single-chip triple-band transceiver for the
extended global system for mobile communication [GSM900MHz] /Digital communication
system [DCS1800MHz] voice and data transfer applications.
This device integrated direct conversion receive architecture, a transmitter based on a modulation loop
architecture and fractional-N synthesizer part with built in TXVCO and Local-VCO.

2.2 Receiver Part

The Receiver part in TRF6151 [U702] 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 base-band output. The receive path is supported by internal channel filtering.
FL700
FEM
SW404
Mobile
Switch
U702
TRF6151
DCS/PCS Tx
EGSM Tx
Fig 1. Receiver Part Block Digram
LNA
PCS
:2/:4
DCS
N divider
GSM900
- 12 -
I
Q
26MHz
R div.
X700
VC-TCXO