LG KE990 Service Manual - Page 14

3. TECHNICAL BRIEF 3. TECHNICAL BRIEF 3.1 General Description The KE990/KE990c supports EGSM-900, DCS-1800, and PCS-1900 based GSM/GPRS/EDGE. All receivers and transmitter use the radioOne 1 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 GMSKmodulated or 8-PSK-modulated signal to RF. ESM6270 EGSM / DCS1800/ PCS1900 1. RTR6235 for GSM/EDGE Tx 2. RTR6235 for GSM/EDGE Rx 3. PM6635-3P for Power Management 4. FM radio Module 5. Bluetooth RF Module SW pad pad H-BPF L-BPF GSM/EDGE PA G 900 Tx BPF GSM850 Rx BPF GSM1800 Rx BPF GSM1900 Rx BPF 3 1 BPF BPF BPF BPF Pow er Detector Quadrature Upconverter Quadrature U pc onv ert er LPF DAC_REF LPF LO generation & Distribution Quadrature Downconverter F ref F ref PLL #1 VCO LPF & DC Corr ection LPF RTR6275_TCXO Quadrature Downconverter LPF & DC Correction 2 VDDM Ctls Dugital IO s & controls Quadrature Downconverter LPF LPF & DC Corr ection F ref PLL # 2 VCO Phone VCTCXO PM6635-3P Input Power Management Voltage R egulat ors General H ous ek eeping User Interfaces IC Interfaces RTR6275 _ TCXO 4 MSM_TCXO FM Radio 5 Module Bluetooth M odule [Fig 3.1] Block diagram of RF part A generic, high-level functional block diagram of KE990/KE990c is shown in Figure 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). 1 QUALCOMM's branded chipset that implements a Zero-IF radio architecture. Copyright © 2008 LG Electronics. Inc. All right reserved. Only for training and service purposes - 15 - LGE Internal Use Only