Panasonic EB-X300 Service Manual page 25

Transceiver - - Transmitter
Antenna
TX IN I/Q PA gain
Base-band
section
controller
VAPC
3-wire bus
Band Select
PAVAPC
TXVCO
TX IN
900
1800/1900
PFD
PA
UHF synthesiser
UHF synthesiser
Figure 5.3. Transmitter block diagram
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 Quadrature (I/Q) modulator within a frequency translation loop designed to perform
frequency up-conversion with high output spectral purity.
The clock source is 26 MHz VCTCXO external instead of XTAL function block active.
The VCTCXO provides an external clock source which is more stable over extreme temperature conditions than an internal clock.
It has a power saving function in standby mode.
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