Abstract: The slot-mode antenna includes an array of slot antenna units carried by a substrate, and each slot antenna unit having a pair of patch antenna elements arranged in laterally spaced apart relation about at least one central feed position. Adjacent patch antenna elements of adjacent slot-mode antenna units have respective spaced apart edge portions with predetermined shapes and relative positioning to provide increased capacitive coupling therebetween. The spaced apart edge portions may be continuously or periodically interdigitated to provide the increased capacitive coupling therebetween.

Abstract: The slot-mode antenna includes an array of slot antenna units carried by a substrate, and each slot antenna unit has a pair of patch antenna elements arranged in laterally spaced apart relation about at least one central feed position. Adjacent patch antenna elements of adjacent slot-mode antenna units include respective spaced apart edge portions defining gaps therebetween, and a capacitive coupling layer or plates overlap the respective spaced apart edge portions to provide increased capacitive coupling therebetween. The capacitive coupling layer may include continuous or periodic capacitive coupling plates along each gap defined by the respective spaced apart edge portions.

Abstract: A multi-band ring focus antenna system includes a main reflector (408) that is operable at a plurality spectrally offset frequency bands. A first feed (301, 403) includes a first feed horn (301) and a first sub-reflector (403), which are positioned spaced apart from each other at respective locations along a boresight axis of the main reflector. The locations are selected so that the first feed horn and the first sub-reflector share a commonly located first phase center (401). A second feed (302, 404) designed for operation on a second RF frequency band includes a second feed horn (302) and a second sub-reflector (404), each positioned at a location along the boresight axis of the main reflector so that they share a commonly located second phase center.

Abstract: A compact multi-band ring-focus antenna system. The antenna system includes a first and a second main reflector 304, 306, each having a shaped surface of revolution about a common boresight axis (322) of the antenna. A first backfire type RF feed system (302, 312) is provided for feeding the first main reflector (304) on a first frequency band. A second RF feed (301) coaxial with the first RF feed (300) is provided for feeding the second main reflector (306) on a second frequency band spectrally offset from the first frequency band. Further a portion of the second RF feed passes through a first sub-reflectors (302) of the backfire feed. The second RF feed is terminated a distance from the first sub-reflector to illuminate a second sub-reflector (303).