Rear window antenna component description - GF82.62-P-3123TM

MODEL 211.0/2 as of 1.6.06 except CODE (494) USA version except CODE (498) Japan version with CODE (413) Panoramic glass roof with top sliding roof 

MODEL 211.0/2 as of 1.7.06 with CODE (498) Japan version with CODE (413) Panoramic glass roof with top sliding roof 

MODEL 211.2 as of 1.7.06 with CODE (494) USA version with CODE (413) Panoramic glass roof with top sliding roof 

Location 

The antennas (AM, FM, RCL and TV) are part of the heating wires of the rear window defroster. The telephone antenna and GPS antenna are attached above the heating field of the rear window.

The visible wires at the top of the rear window are antennas and are not heated.

Task 

The antennas must convert the high frequency (HF) oscillation of the electrical field in the air to a high frequency AC voltage in an electrical conductor.

Design 

The antennas are an integral part of the wires in the rear window defroster. A block circuit consisting of a number of inductive coils is integrated into the heating wires.

Function 

The high frequency oscillation of the electrical field in the air is converted into a high frequency AC voltage in an electrical conductor.

A standing electrical wave is formed in the antenna as a result of the correct matching of the length of the antenna to the wavelength of the frequency to be received. In this case, the amplitude of the RF signal has a constant value at a random point of the antenna. However, at the connecting point the HF signal level is at the maximum. Any deviation in antenna length from the optimum length will result in a reduction of the HF signal level at the antenna output.

If the deviation is too large, no further HF signal is received (e.g. if the antennae are connected to the antenna amplifier incorrectly). The telephone antenna and the GPS antenna at the top section of the rear window are active antennas.