Service manual

Information and Communication Products
Mobile Phones
• 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 S25 / S2588 V 1.0 ICP CD ST
R. Fleuren
Sm_S25_lvl2_v11.doc Page 20 of 35 06/99