Theory of Controlled Aperture Field for Advanced Superstrate Design of a Resonance Cavity Antenna With Improved Radiations Properties

An insight based on a new theoretical approach has been developed to facilitate the design of a superstrate which plays a key role in realizing a high gain resonance cavity antenna (RCA). The work is aimed to address a profound theoretical basis of controlling the aperture fields by proper shaping of superstrate and to apply it to alleviate the earlier shortcomings along with further improvement in radiation characteristics. This demonstrates an interesting transformation of a metal superstrate from rectangle to an ellipse or an ellipse-circle combination to achieve significant improvements in the aperture fields and hence the sidelobe level (SLL). The antenna characteristics have been verified using simulated data followed by experiments using different sets of prototypes. About 50% reduction in size along with an improvement in the SLL by 5-17 dB compared to its immediate predecessor has been experimentally demonstrated. Proposed theory should find the potential applications in conceiving efficient RCA designs in the future.