Transmitter Block; Receiver Block - Panasonic KX-TGC450G Service Manual

4.3.6 Transmitter/Receiver
● Audio Circuits and DTMF tone signal circuits.
Base Unit and Handset mainly consist of RF Module and DECT BBIC.
Base Unit and Handset transmit/receive voice signal and data signal through the antenna on carrier frequency.
Signal Path:
*Refer to [4.6 Signal Route].
4.3.6.1 Transmitter Block
The voice signal input from the TEL LINE interface goes to DECT BBIC (IC501) as shown in
Unit_Main)].
The voice signal passes through the analog part of IC501 where it is amplified and converted to a digital audio stream signal.
The burst switch controller processes this stream performing encryption and scrambling, adding the various other fields to produce
the GAP (Generic Access Profile) standard DECT frame, assigning to a time slot and channel etc.
In IC501, the carrier frequency is changing, and frequency modulated RF signal is generated.In IC501,RF signal is amplified, and
radiated from antenna. Handset detects the voice signal or data signal in the circuit same as the following explanation of Receiver
Block.
4.3.6.2 Receiver Block
The signal of 1900 MHz band which is input from antenna is input to IC501 as shown in
In IC501, the signal of 1900 MHz band is downconverted to 864 kHz signal and demodulated, as GAP (Generic Access Profile)
standard DECT frames. It passes through the decoding section burst switch controller where it separates out the frame
information and performs de-encryption and de-scrambling as required. It then goes to the DSP section where it is turned back
into analog audio. This is amplified by the analog front end, and goes to the TEL LINE Interface.
[4.1 Block Diagram (Base
- 17 -
[4.1 Block Diagram (Base
Unit_Main)].