Analytical Investigation of a Low-Profile Multiband Circular Microstrip Antenna With Monopolelike Radiation Patterns

摘要

A circular patch antenna loading symmetrically with some conductive shorting vias can radiate monopolelike pattern in its fundamental mode as well as the higher order modes. As a result, this antenna can be considered as a candidate to replace the conventional large profile monopole antenna in many communication systems. However, no comprehensive analytical study has been presented for it. In this paper, an analytical method based on cavity model and the generalized multipole technique is intended to investigate the antenna. A sample of the antenna is designed and analyzed using the proposed theory. The electromagnetic fields, radiation pattern, input impedance, and return loss of the antenna are analytically expressed. The designed antenna is implemented and measured. The measurement results are compared with the analytical results to justify the analysis.