Antenna system (ATS), function - GF82.62-P-0001SXJ
MODEL 221 with CODE (498) Japan version up to Model Year 08
Preliminary remarks
The following description deals with the antenna systems for
- HIGH Class Japan (code 529),
- Sound system (code 810) and
- Radio remote control with reduced range without panic button (code 761)
are described in the following.
General information
The various antennas are designed according to their special reception and transmission ranges. There are active and passive antennas. The antennas can be designed as transmission, reception or as transmission/reception antennas.
The antennas transmit or receive voice information by converting electromagnetic radio waves into an electric voltage and vice versa.
Passive antennas
Passive antennas do not require a power supply.
Active antennas
Active antennas are supplied with power and have an integrated amplifier. The voltage supply can be provided on separate lines or via a coaxial cable (phantom feed). The actual signal is transmitted via this coaxial cable.
Transmit/receive antennas
The transmission/reception antennas are
- the telephone antenna (A2/49a1) in the telephone and GPS roof antenna (A2/49)
- the electronic toll collection antenna, and
- the Bluetooth antenna (A2/91).
Reception antennas
Receive antennas are
- the AM antenna in the rear window,
- the FM1 to FM4 antennas in the rear window,
- the TV1 to TV4 antennas in the rear window,
- the radio remote central locking antenna in the rear window and
- the GPS antenna (A2/49a2) in the telephone and GPS roof antenna.
Location of components
Block diagram of antenna systems
Description, block diagram of antenna system
The rear window FM1 to FM4 and AM antenna signals are picked up, filtered and amplified by the rear window antenna amplifier module. A diversity processor in the rear window antenna amplifier module selects the strongest signal from the FM antenna signals and relays it to the audio tuner control unit. The AM signal is also relayed to the audio tuner control unit.
A phantom voltage (DC offset) is used to switch between AM and FM. If a direct voltage of 0 volts is present at the intermediate frequency input of the rear window antenna amplifier module, it operates in AM mode.
If a direct voltage of 12 volts is present at the intermediate frequency input of the rear window antenna amplifier module, it operates in FM diversity mode.
Antenna signals TV1 to TV4 are picked up, amplified and relayed to the TV antenna selector by the rear window antenna amplifier module. The best TV signal is relayed to the COMAND control unit from here. The TV antenna selector is switched via two inputs by switching voltages from the COMAND control unit.
The signals of the radio remote central locking antenna in the rear window are picked up, demodulated and amplified by the rear window antenna amplifier module. Then the signals are relayed to the rear SAM control unit with fuse and relay module for further processing.
External equipment can communicate with the COMAND control unit via the Bluetooth antenna. Signals can be transmitted to or received from the external equipment.
The signals received by the GPS antenna are directly relayed to the COMAND control unit.
The telephone signals are transmitted and received by the telephone antenna. The portable CTEL is connected to the COMAND control unit via the portable CTEL separation point.
The electronic toll collection control unit communicates with the toll station via the electronic toll collection (ETC) antenna and automatically processes the payment.
The electronic toll collection (ETC) control unit is connected to the COMAND control unit via an interface.
| TV antenna selector component description | GF82.62-P-3006SXJ | ||
| Rear window antenna component description | GF82.62-P-3123SX | ||
| Rear window antenna module component description | GF82.62-P-3131SXJ | ||
| Telephone and GPS roof antenna component description | GF82.62-P-4119SX | ||
| Bluetooth antenna component description | GF82.62-P-4201SX | ||
| Electronic Toll Collection (ETC) antenna component description | GF82.88-P-5001SXJ |