Lo Generation And Distribution Circuit - LG -P970 Service Manual

3. TECHNICAL BRIEF

3.5 LO GENERATION and DISTRIBUTION CIRCUIT

The PMB 5703 contains two synthesizer blocks (see Figure3-6). Depending on UMTS or GMSK/8-PSK mode
different VCOs, LF and CPs settings are used. In GMSK/8-PSK mode only the TRX PLL loop with the 2G TRX VCO is
working, which is available in the TX synthesizer block (left). In UMTS TX/RX mode, two separate synthesizer
blocks are available. The TX synthesizer is in the UMTS TX block (left), where the loop is working with the 3G TX
VCO. The RX synthesizer is in UMTS RX block working with the 3G RX VCO.
[Figure 3-6] RF Synthesizer (GMSK/8-PSK and UMTS)
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