Technical Brief; General Description - LG U250 Service Manual

3. TECHNICAL BRIEF

3.1 General Description

The U250/KU250 supports UMTS-2100, GSM-900, DCS-1800, and PCS-1900 based
GSM/GPRS/UMTS. All receivers and the UMTS transmitter use the radio One
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 signal to RF.
UMTS (2100)
GSM (900, 1800, 1900)
Bluetooth
1. RTR6275 for GSM Tx
and WCDMA Tx
2. RTR6275 for GSM Rx
and WCDMA Rx
3. Bluetooth RF module
4. PM6650 for power
management
1 QUALCOMM's branded chipset that implements a Zero-IF radio architecture.
[Fig 1.1] Block diagram of RF part
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3. TECHNICAL BRIEF
1 Zero-IF architecture to