A K-band circularly polarized cavity backed dielectric resonator

A high efficiency linear polarized antenna consisting of a patch fed cavity has already been developed for use in personal communication terminals. It possesses several desirable features for active array applications, particularly the ease of RF component integration and heat removal. As part of the continued development of this antenna, it is very desirable to extend the capabilities to include future circularly polarized (CP) applications. The logical step for achieving the CP performance is to replace the linearly polarized feed patch with a single point feed CP patch. A single point feed is preferred in order to maintain the simplicity of the feed network. This approach, however, has a major drawback of possessing a narrow axial ratio bandwidth. To improve the axial ratio bandwidth, an alternative CP feed antenna is required. Research in circularly polarized dielectric resonator antennas (DRAs) has shown that a wide axial ratio bandwidth can be achieved from a single point fed DRA. The performance of the dielectric cross within a cavity structure is investigated. The optimization of the geometry and the effects on overall operation are discussed.