Non-Foster Active Impedance Circuit for Electrically Small Antennas
AssigneeThe Government of the United States, AS Represented By the Secretary of the Navy
InventorsJia-Chi Samuel Chieh, Lu Xu, Albert Ryu, John D. Rockway, Diana Arceo, Justin A. Church
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Abstract
An antenna comprising: a driven element; an input feed coupled to the driven element wherein the input feed is configured to be connected to a receiver; a non-Foster circuit having a negative impedance, wherein the non-Foster circuit is configured to actively load the antenna at a location on the antenna other than at the input feed; and wherein the antenna may be contained within an imaginary sphere having a radius a, and wherein the product ka is less than 0.5, where k is a wave number.
Claims20
An antenna comprising:
- a driven element;
- an input feed coupled to the driven element wherein the input feed is configured to be connected to a receiver;
- a non-Foster circuit having a negative impedance, wherein the non-Foster circuit is configured to actively load the antenna at a location on the antenna other than at the input feed;
- and
- wherein the antenna may be contained within an imaginary sphere having a radius a, and wherein the product ka is less than 0.5, where k is a wave number.
A method for providing an electrically small antenna where ka<0.5 with a bandwidth beyond a Bode-Fano limit, where the antenna may be contained within an imaginary sphere having a radius a, and where k is a wave number, comprising the following steps:
- providing a driven element having an input feed;
- and
- actively loading the antenna with a Non-Foster circuit at a location on the antenna that is not at the input feed.
Dependencies are inferred from the claim text.