Shortened mast antenna with compensating circuits
AssigneeHarada Kogyo Kabushiki Kaisha
InventorsKazuhiko Nakase, Tetsuyoshi Abiko
Life of this patent
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Abstract
A shortened mast antenna with a compensating circuit between the antenna and a receiver and used in a state shorter than the resonant state of the antenna. The compensating circuit includes an FM compensating circuit made up with passive elements and compensating FM broadcast signals and an AM compensating circuit equipped with active elements which convert a high impedance into a low impedance so that the AM compensating circuit compensates AM broadcast signals. The attachment part of the antenna, to which the compensating circuit is directly connected, has a stray capacitance of 10 PF or less.
Claims4
A shortened mast antenna equipped with compensating circuits, said antenna having a length shorter than a resonant length at AM and FM broadcast bands and comprising:
- an attachment part of said antenna which has a stray capacitance of not greater than 10 PF;
- an FM compensating circuit coupled to said attachment part which consists of passive elements only and having an output connected directly to a feeder line to be coupled to an input of a receiver, said FM compensating circuit for reducing distortion of and increasing the sensitivity to FM broadcast signals;
- and
- an AM compensating circuit coupled to said attachment part equipped with active elements that convert a high impedance into a low impedance and having an output connected directly to said feeder line to be coupled to said input of said receiver, said AM compensating circuit for reducing distortion of and increasing sensitivity to AM broadcast signals.
Dependencies are inferred from the claim text.