20.4. Transmitter/Receiver
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 Pass:
*Refer to
SIGNAL ROUTE
().
20.4.1. Transmitter Block
The voice signal input from the TEL LINE interface goes to RF Module (IC3) through DECT BBIC
(IC2) as shown in
BLOCK DIAGRAM (BASE UNIT)
()
The voice signal passes through the analog part of IC2 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 DECT frame, assigning to
a time slot and channel etc.
In IC3, the carrier frequency is changing, and frequency modulated RF signal is generated and
amplified, and radiated from antenna. Handset detects the voice signal or data signal in the
circuit same as the following explanation of Receiver Block.
20.4.2. Receiver Block
The signal of 19.2 MHz band (18.81792 MHz ~ 18.97344 MHz) which is input from antenna is
input to IC3 as shown in
BLOCK DIAGRAM (BASE UNIT)
().
In IC3, the signal of 19.2 MHz band is downconverted to 864 kHz signal and demoduleted, and
goes to IC2 as 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.
21. BLOCK DIAGRAM (HANDSET)
22. CIRCUIT OPERATION (HANDSET)
22.1. Outline
Handset consists of the following ICs as shown in
BLOCK DIAGRAM (HANDSET)
().
- DECT BBIC (Base Band IC): IC1
- All data signals (forming/analyzing ACK or CMD signal)
- All interfaces (ex: Key, Detector Circuit, Charge, DC/DC Converter,
EEPROM, LCD)
50
Summary of Contents for KX-TCD400GC
Page 46: ...18 FREQUENCY TABLE MHz 46 ...
Page 52: ...24 CPU DATA BASE UNIT 24 1 IC2 BBIC 52 ...
Page 56: ...45 MICP A I 56 ...
Page 60: ...60 ...
Page 61: ...28 CABINET AND ELECTRICAL PARTS LOCATION HANDSET 29 ACCESSORIES AND PACKING MATERIALS 61 ...
Page 62: ...30 TERMINAL GUIDE OF THE ICs TRANSISTORS AND DIODES 30 1 Base Unit 30 2 Handset 62 ...
Page 91: ...4 1 5 8 PbF 1 28 18 IC3 IC2 IC1 11 64 1 16 17 32 49 48 33 Marked ...
Page 93: ...Marked PbF IC1 IC2 100 80 5 8 4 1 50 51 30 31 1 11 18 1 28 IC3 ...