Bandwidth enhancement of L-probe proximity-fed annular ring microstrip slot antenna

A parametric study and simulation of wide-band orthogonally slit cut annular ring microstrip antenna (SC-ARMSA) fed by an L-shaped probe is investigated using Modal expansion cavity model and circuit theory concept. The radiating patch is located about 8 mm (~0.1 λ) above the ground plane. The broadband characteristic of antenna is achieved by employing a thick substrate (~0.1 λ) of 1.07 relative permittivity (Rohacell Foam). The annular ring patch is cut ortogonally with slot of 1 mm width. The E- and H-plane radiation pattern are presented and VSWR is compared with the simulated result. Good agreement is obtained between computed and simulated results. The effects of the geometric parameters of the L-strip like length of the horizontal portion of the strip are investigated. An impedance bandwidth of about 36.76% and 33.23% (VSWR <; 2) at 13.5 mm and 15 mm length of horizontal L-probe respectively.