Analysis of circularly and linearly polarized U-slot-excited hemispherical dielectric resonator antennas with a backing cavity

Abstract

The linearly polarized ( LP ) antenna has been widely used in wireless communications because of its ease of design as compared to the circularly polarized ( CP ) antenna. On the other hand, the CP antenna is still playing an important role because it is less sensitive to the orientations between the transmitting and receiving antennas. It is also less sensitive to propagation effects and, thus, is commonly used in satellite communications. In this research, the LP hemispherical dielectric resonator antenna ( DRA ) is excited by a symmetric U-slot to enhance the impedance bandwidth. In addition, the CP excitation using an asymmetric U-slot hemispherical DRA is also analyzed. In this thesis, the Green’s functions are used to formulate the integral equations of the slot current, which is then solved by using the method of moments ( MoM ). Experiments are done to verify the theory. The symmetric U-slot can excite LP fields to give an impedance bandwidth of about 15%, whereas the asymmetric U-slot can excite CP fields with the 3-dB axial ratio bandwidth of about 4 %.

Date of Award	3 Oct 2005
Original language	English
Awarding Institution	City University of Hong Kong
Supervisor	Kwok Wa LEUNG (Supervisor)