Investigation of Dielectric Resonator Antenna Arrays for Wireless Communications

Description

For all wireless communication systems, the antenna is the front end that directly affects the quality of the signal transmission and reception. For a mobile antenna, a significant amount of the radiated power is dissipated in air without contributing to the information-exchange process. It is because a mobile antenna generally emits power to all directions, giving rise to free-space loss. This power loss can be reduced by increasing the antenna gain or equivalently narrowing the antenna beam. A direct method to provide a high antenna gain is to combine antenna elements to form an array.Over the last three decades, the dielectric resonator antenna (DRA) has been widely studied due to its many advantages such as its small size, low loss, light weight, and ease of excitation. As compared with the 2-D patch antenna, the DRA is a 3-D structure and therefore provides one more degree of freedom for its designs. However, most studies of DRAs have only concentrated on the single element and much less attention has been paid to the array design.In this project, three different kinds of DRA arrays will be investigated for the first time. First, the wide-beam DRA element will be investigated and used to design a square phased antenna array (PAA). The PAA can steer its beam to connect with a moving object. The element spacing and array shape will be studied to maximize the scanning range.Next, a beam-locking DRA array will be investigated for backhauling communications. The phase shifters realized by varactors will be integrated with the feed network of the DRA elements. The DRA array will have a narrow scanning range, about +/- 6 degrees for backhauling communications. The narrow scanning range is for the array to agilely steer and lock the beam. This enables the array to communicate with the other side of the wireless link effectively.Finally, the DR reflectarray and transmitarray will be investigated. Our proposed DR reflectarray can convert a linearly polarized wave to a circular polarized (CP) wave, giving the first CP DR reflectarray. For our proposed DR transmitarray, it has the lowest profile among all transmitarray designs reported in the literature.A design guideline will be devised for each of the antenna element and array to facilitate their designs.