Efficient Full-Wave Analysis of Resonant Modes of Circular Microstrip Antenna Printed on Isotropic or Uniaxially Anisotropic Substrate

In this work, the influence of uniaxial anisotropy in the substrate on the radiation pattern of circular microstrip antenna is investigated theoretically. The analytical approach is based on the spectral-domain method of moments in conjunction with the stationary phase method. A new concise expression is derived for computing the radiation electric field. The validity of the solution is tested by comparing the computed results with the experimental data. Finally, numerical results of the variations of resonant frequency and radiation patterns of the structure of higher order mode, with respect to the anisotropy ratio of the substrate, for several values of substrate thickness and patch radius are also presented.