User's Manual

Buffer
When the radio is in transmit mode the diode D201 is forward biases enabling the
modulated RF signal from the VCO to pass to the buffer/pre-amplifier Q204 and
associated components.
The output signal is passed from Q204 to Q205 via a matching network consisting of
Inductor L201 and C208.
PA module
The signal is then amplified for transmission by 207, which is a power amplifier module.
Low pass filter
The amplified RF signal is passed through the stripline coupler and is fed to the
harmonic low pass filter, comprising L213 to L214 and C232-C234 and then to the antenna
connector (ANT).
Antenna Switch
When transmitting, the diodes D205 are forward biased, allowing the RF to pass
to the antenna. D205 is shorted to ground which makes L212 look open circuit (1/4 wave
tuned stub). This prevents the TX signal from passing to the receiver stage.
Power output control .
The RF power tuning by VC2,which make sure the current less than
1300mA@5W output power.
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