Abstract: Antenna elements and systems and other radio and microwave frequency devices are constructed with a high index of refraction medium having high matched values of relative permeability and relative permittivity, and a low loss tangent. By making the permeability of the transmission medium substantially equal to its relative permittivity, the impedance of the material is matched to that of the surrounding free space or air. By immersing a radiating element in such a material, and/or by using such a material between adjacent radiating elements or between a radiating element and a reflective ground plane, the physical size and/or the spacing of the elements may be substantially reduced without appreciable performance loss, thereby resulting in a more compact device that is particularly desirable for mobile applications.

Abstract: A circularly polarized phased array antenna system for both reception and transmission applications includes a plurality of planar radiating (or receiving) elements, a switching matrix for each radiating element, a beamforming network and a transmit/receive module. Each planar element includes 4.times.N radially disposed segments that may be selectively connected with the four modes of a circularly polarized signal such that two opposing segments function as the two respective arms of a dipole radiating element and two orthogonal such dipoles function as a crossed pair of dipoles for receiving or transmitting the circularly polarized signal. The switching matrix and the beamforming network cooperate to determine the polarization phase of the radiating element by commutating the four modes of the circularly polarized signal to any four orthogonal segments of the radiating element.