Microstripline- and stripline-fed aperture-coupled cylindrical rectangular microstrip antennas

Stripline-fed and microstripline-fed aperture-coupled cylindrical rectangular microstrip antennas are investigated. The equivalence principle is invoked to separate the feedline and the antenna patch with equivalent magnetic currents distribution on the aperture region. The Lorentz reciprocity theorem is applied to find the interactions between the aperture and the feedline. The unknown patch current and aperture field are determined by solving coupled integral equations, which involve spectral-domain Green´s functions, using the Galerkin procedure. Numerical results of input impedance and far-field patterns are compared with those for antennas on a planar surface