Sidelobe Suppression and Bandwidth Enhancement of Series-Fed Patch Antenna Arrays Using Coplanar Ground Conductor

Sidelobe suppression and bandwidth enhancement technique for a series-fed 4 × 1 microstrip patch antenna array is proposed. The array designed with the proposed technique is a modification of a series-fed antenna array comprising four microstrip patch elements connected together via a single straight transmission line fed by a grounded coplanar waveguide port. Sidelobe suppression was achieved with amplitude tapering and by surrounding the radiating elements with a coplanar ground conductor. The proposed antenna offers a wide impedance bandwidth from 9.25 GHz to 9.81GHz, a gain of 13.79 dBi, a sidelobe level of 21.80 dB and a half power beam width of 20.39° at the center frequency of 9.55 GHz. The proposed technique provides a good solution for applications requiring a wideband series-fed antenna array with a low sidelobe level.