Electrically small unbalanced four-arm wire antenna

An electrically small antenna element is presented. It is an unbalanced antenna, consisting of four wire arms arching over a groundplane. One of the wire ends is the feed, and the other three are connected to the groundplane, via a capacitance, short, and load, respectively. The resonance frequency is tuned by varying the capacitance, which can be set fixed or used to accomplish electronic tunability with a tuning range of several octaves. The momentary bandwidth of the antenna is approximately 3%. Applications are typically antennas for very small terminals in narrowband systems, or alternatively broadband systems where electronical tuning can be implemented in the antenna. The exact shape of the wires is not critical and can be chosen to conform to mechanical design requirements.

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