Aperture-coupled microstrip antennas loaded with very high permittivity ceramics

Abstract

The use of very high permittivity ceramic materials (εr = 38, 80) to miniaturize an aperture-coupled microstrip patch antenna is reported in this article. A loss of the antenna gain in such a technique is observed, and then a novel substrate-superstrate structure is developed to enhance the gain. The whole process of gain enhancement is analyzed by using the finite-difference time-domain (FDTD) method. The simulations are excellently correlated with the experiments. They validate that the loss of the antenna gain can be recovered up to that of conventional microstrip antennas loaded with low permittivity materials (εr < 3). In addition, the performance comparison of the aperture-coupled microstrip antenna of very high permittivity with the probe-fed microstrip antenna of very high permittivity is presented. It is shown that the aperture-coupled antenna has wider impedance and radiation bandwidths than the probe-fed one while keeping the antenna gain at about the same level. © 2003 Wiley Periodicals, Inc. Int J RF and Microwave CAE 13: 154–160, 2003.