Electrospace Systems, Inc.

Richard C Fenwick

A multi-band multi-element directional antenna array having a driven element and at least one parasitic element with a network at the center of each element interconnecting element opposite side radiators. While some of these would be a driven element and either a reflector or director parasitic element array most applications call for at least three elements, a driven element, a reflector element and a director element, and for some applications, additional parasitic director elements are added. While antenna arrays embodying features hereof may be adapted as two band f.sub.1 f.sub.2, f.sub.2 f.sub.3, or f.sub.1 f.sub.3 antenna arrays, primary useage would be in a three radio band f.sub.1, f.sub.2, f.sub.3 version with band nominal center frequencies related, approximately by the progression 1, 1.5, 2 (example 14, 21, and 28 MHz). Reflector and director elements with their center networks as parasitic elements are structured to resonate at frequencies up to ten percent displaced from respective band operating frequencies--reflector elements at lower frequencies and directors at higher frequencies. Some of the arrays employ folded elements for improved unidirectional radiation patterns and structural advantages.

Multi-band directional antenna

A three band monopole antenna with such length as to be of greater electrical length than a quarter wavelength of the two highest frequency bands and shorter than a quarter wavelength of the lowest frequency band. The antenna system includes a matching network at its base matching the antenna on three frequency bands related by, substantially, the progression 1, 2, 4, and with the matching network including a shunt inductor and an inductor and capacitor in series with the signal feedpoint.

Three band monopole antenna

An antenna combiner 2.sup.n antenna element system with switchable variable delay line length broadband beam and null steering through 360.degree. in azimuth.

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Dallas, TX, United States of America

Richard C Fenwick