Akg Acoustics Gmbh

Heinrich Kofler

The invention concerns an antenna system of a radio microphone that includes an antenna path starting at an in port and ending at an out port along with an amplifier and a radio frequency (RF) cable. In order to compensate for various cable attenuations, an attenuator is provided in series with a variable slope compensator between the amplifier and the RF cable. In order to avoid a negative effect on a large signal behavior of variable slope compensators, field effect transistors (FETs) or pin diodes are used for switching of the resistances so that a large signal behavior is achieved.

Antenna system of a radio microphone

A diversity receiving device includes two signal paths. Each path interfaces an antenna that receives a radio frequency signal and an amplifier that amplifies the received radio frequency signal. A variable signal level attenuator in each path attenuates the amplified signal and receives current from current sources. The current sources are coupled to the amplifiers through variable signal level attenuators. The variable signal level attenuators are in parallel with controllable bypass lines which comprise variable resistance elements. The two signal paths are combined into a common path.

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Vienna, Austria

Heinrich Kofler