Panasonic EB-G50 Service Manual page 33

Transceiver - - Transmitter
Base-band
section
3-wire bus
TX IN
TX path is a translation loop architecture consisting of an IQ modulator, integrated high power VCO, offset mixer,
programmable divider, PFD, charge pump, and power amplifier with its control circuit.
The device consists of an In-phase and Quadrate (I/Q) modulator within a frequency translation loop designed to
perform frequency up-conversion with high output spectral purity.
Clock source is 26MHz VCTCXO external instead of XTAL function block active. VCTCXO is more stable over
extreme condition and current saving in standby mode.
TX IN I/Q
+
–
Figure 5.3. Transmitter block diagram
Power
Detector
PA gain
controller
PAVAPC
PFD
UHF synthesizer
– 5–4 –
Antenna
Coupler
TXVCO
1800/1900
PA
900