Resonant circular patch microstrip antenna with air gap
The resonant frequency and bandwidth characteristics of superstrate loaded air gap tuned circular patch microstrip antenna are investigated for different structural parameters. The problem is formulated in spectral domain and Galerkin's method is used for the solution. It is shown that adjustable air gap between the ground plane and substrate compensates superstrate loading effect on the resonant frequency, increases bandwidth and provides tunable operational characteristics.
Hankel transform domain analysis of dual-frequency stacked circular-disk and annular-ring microstrip antennas
A theoretical and numerical analysis of the dual-frequency stacked circular-disk and annular-ring microstrip antennas is discussed. The problem is formulated in the Hankel transform domain. First, the Green's function is derived, relating the transformed electric surface currents on the patches and the transformed tangential electric field components on the substrates. Galerkin's method is used with Parseval's relation for Hankel transformation to solve for the resonant frequencies and the unknown currents. The far-zone radiation patterns are expressed in terms of the transforms of the currents. Numerical results obtained for the resonant frequencies and radiation patterns are found to be in excellent agreement with the experimental data available in the literature. >
Study of multilayer microstrip antennas with radiating elements of various geometry
A study of multilayer microstrip antennas fed by coaxial probe or microstrip line is presented. The method developed is applicable to structures with stacked or offset radiating elements of various shapes including rectangles, discs and triangles. Theoretical and experimental results of input impedance are given for the different structures. Radiation information is presented and the relative merits of different structures are discussed.