Technical Brief; General Description - LG KF690 Service Manual

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3. TECHNICAL BRIEF

The KF690 supports EGSM-900, DCS-1800, and PCS-1900 based GSM/GPRS/EDGE. All receivers

use the radioOne

Zero-IF architecture to eliminate intermediate frequencies, directly converting signals

between RF and baseband. The quad-band GSM transmitters use a baseband-to-IF upconversion

followed by an offset phase-locked loop that translates the GMSK-modulated or 8 PSKmodulated

signal to RF.

A generic, high-level functional block diagram of KF690 is shown in [Fig. 3.1]. One antenna collects

base station forward link signals and radiates handset reverse link signals. The antenna connects with

receive and transmit paths through a FEM(Front End Module).

The RFIC's Rx analog baseband outputs, for the receive chains, connect to the ESM6270 IC. GSM Rx

baseband outputs share the same inputs to the ESM6270 IC.

For the transmit chains, the RTR6235 IC directly translates the Tx baseband signals (from the

ESM6270 device) to an RF signal using an internal LO generated by integrated on-chip PLL and VCO.

QUALCOMM's branded chipset that implements a Zero-IF radio architecture.

LGE Internal Use Only

[Fig. 3.1] Block diagram of RF part

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Only for training and service purposes

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