Abstract: A resonant microstrip radiator wherein the size of the radiator is reduced in the resonant or non-resonant dimensions, or both, without reducing the effective resonant dimension or substantially lowering the efficiency of the radiator. Reduction of the resonant dimension is provided by folding the resonant cavity, while reduction of the non-resonant dimension is facilitated by utilization of a low density, low loss dielectric, such that the loss resistance of the element is appreciable with respect to the radiation resistance of the element. Also disclosed are interdigitated antenna structures and provisions for circularly or elliptically polarized radiation.

Abstract: A resonant circularly or elliptically polarized microstrip radiator wherein the size of the radiator is reduced in the resonant or non-resonant dimensions, or both, without reducing the effective resonant dimension or substantially lowering the efficiency of the radiator. Reduction of the resonant dimension is provided by folding the resonant cavity, while reduction of the non-resonant dimension is facilitated by utilization of a low density, low loss dielectric, such that the loss resistance of the element is appreciable with respect to the radiation resistance of the element. The preferred embodiment comprises interdigitated antenna structures.

Abstract: A conformal microstrip antenna structure formed by a plurality of separated spaced-apart electrically conducting elements on a dielectric substrate overlying a ground plane. The innermost edges of the separated conducting elements define two sets of two intersecting radiators which are fed by microstrip transmission circuits disposed within the space between the separated conducting elements to individually feed the various radiators and/or segments thereof from the common feed point. The dimensions of the conducting elements also determine the resonant frequency of the radiators and their relative phases such that dual frequency operation as well as circular and/or elliptical polarization of the received/transmitted electromagnetic radiation can be conveniently achieved.

Abstract: A dual slot antenna assembly is disclosed herein and generally includes a pair of concentrically positioned and radially spaced cylindrical conductors defining a pair of circumferential slots which are longitudinally spaced one-half wavelength apart at the anticipated operating frequency of the antenna device. An electrical signal feed assembly is connected with the conductors for exciting the slots so as to provide overlapping radiation patterns emanating in the same direction.