Car receiving aerial with negative feedback amplifier - has passive network connected to output aerial cable forming minimum impedance with transistor

摘要

Active car receiving aerial consists of a passive aerial section (A) and active three-pole (D) and a high frequency feedback impedance. The active three-pole has a control connection, an output connection (3) and one or several current supply terminals (2) linked for h.f. with the earthing point (4) of the active aerial. There is a passive network connected to the output of the output cable connected to the aerial. This together with the input impedance of the input transistor (TE) forms the minimum impedance at the operating frequency. The impedance increases as the frequency increases from the operating frequency. The input impedance of the cable has the characteristics of a series resonance circuit with a resonance frequency approximating that of the operating frequency.