FULL-WAVE ANALYSIS OF THE ANNULAR-RING LOADED SPHERICAL-CIRCULAR MICROSTRIP ANTENNA

In this paper, an annular-ring loaded (ARL) spherical-circular microst rip antenna is studied theoretically, The antenna is excited by a coax ial probe, The theoretical formulation is based on full-wave analysis in the spectral domain by using vector Legendre transform and Galerkin 's moment method is used for numerical calculation, Numerical results of the resonance frequencies, input impedance, voltage standing wave r atio (VSWR), and radiation characteristics are presented, It is shown that the impedance bandwidth of the spherical-circular microstrip ante nna can be broadened by adding an annular-ring parasitic patch, By com paring ten the single circular-patch case, the spherical-circular micr ostrip antenna with an annular-ring parasitic patch has larger minor l obes and larger cross-polarization radiation.