This paper presents the effect on resonant frequency, co and cross polarization of multilayered microstrip annular ring antenna for linear and circular polarization. Effect of resonant frequencies of different size of antenna due to cover dielectric space dielectric and two superstrates have been studied. In order to provide a suitable input impedance match, a strip stub into the annular ring is employed axially and radially to feed the antenna for proper matching. It has been observed resonant frequency decreases as the cover height increases. The increment change in the resonant frequency is becoming small as cover thickness increases. For the space dielectric, the resonant frequency tends towards the resonant frequency of simple annular ring microstrip antenna. Two superstrate over annular ring antenna will further reduce the resonant frequency of covered dielectric. The co and cross polarization of the antenna has also been studied for these configurations. A great dependence on resonant frequencies, gain, axial ratio, co and cross polarization has been observed. Such type of study is useful for portable wireless system.

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Resonant frequency Cover dielectric Superstrate Circular microsrip antenna and annular ring microstrip antenna