Siemens C25 Service Manual page 18

• Mixer to mix down the IF signal to the baseband, generating and
inphase (I) and a quadrature (Q) signal.
• Offset compensation for the I/Q signals.
5) Transmitter Circuit PMB 2255
This circuit provides the IF synthesizer, the I/Q modulator, prescalers to regulate the
RF synthesizer and a buffer stage to feed the PA.
The antenna switch is mechanical, located in the connector for the external antenna.
Service Manual C25 / C2588
Sm_C25_lvl2_v10_w97
Private Communication Systems
V 1.0
Page 18 of 32
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