Design and Analysis of Multiband Circularly Polarized and Reconfigurable Dielectric Resonator Antennas

Abstract

The development of wireless communication has led to the improvement in antenna technology. The design and development of dielectric resonator antenna have become challenging to meet the demands of modern wireless communication due to a shift in the increased frequency spectrum. These antennas play a significant role in wireless communication devices in terms of performance parameters and radiation characteris- tics. Hence, this thesis presents novel dielectric resonator antenna (DRA) designs that provide different radiating bands and patterns for applications related to satellite com- munication and other wireless devices. In order to meet the required characteristics, canonical shaped dielectric resonators have been used, which involves less fabrication complexity with aperture feeding. The thesis presents aperture coupled dielectric resonator antennas designed to operate at triband, circular polarization and offers reconfigurability between two bands. The different slots are used with a rectangular and cylindrical dielectric resonator that operates with triband, circular polarization and frequency reconfiguration. A trian- gular slot with a cylindrical dielectric resonator antenna is used to obtain triband with hybrid radiating modes with pattern diversity. A hybrid reconfigurable antenna is de- signed using a triangular slot and a PIN diode in the feed line to obtain dual mode frequency reconfiguration. A flag-shaped feed with a triangular slot helps to achieve a triband circular polarized cylindrical dielectric resonator antenna using the concept of degenerative modes. Another design presented in this thesis involves an elliptical slot that offers circular polarization in a rectangular dielectric resonator antenna. The slot overlaps two orthog- onal modes to produce circular polarization. In another design, a pair of metallic strips acting as a load to a rectangular dielectric resonator is used to obtain circular polariza- vtion for a fixed antenna geometric. The sense of polarization is varied by changing the orientation of flag-shaped feed in cylindrical DRA, elliptical slot and metallic strips in rectangular DRA. All the designs are fabricated and different antenna parameters are compared based on simulated and fabricated results. The simple DRAs are designed and the performance measures are compared with earlier works presented in terms of impedance bandwidth, gain, axial ratio bandwidth, axial ratio beam width, DRA volume and radiation efficiency.