Active aerial for vehicle windscreen - uses signal line between aerial amplifier and receiver to carry supply voltage for aerial amplifier

摘要

The conductor (19) carrying the aerial's received signal between the amplifier and the receiver is also connected to the receiver's voltage supply so that it also acts as a transmission line for the amplifier's supply voltage. A capacitor (15) is connected in series between ground and the coil (14) in the receiver's AM input circuit. The receiver's AM input circuit is at the potential of the supply. An LC circuit (13-15) for AM reception and a choke(12) for FM reception replace the resistor normally present in the drain circuit of the FET in the aerial's amplifier.