A high gain reduced side‐lobe miniaturized frequency and pattern reconfigurable planar array operating in higher‐order mode

Abstract

In this work a low profile (˂0.01λ0), single layered, high gain reduced side-lobe miniaturized microstrip planar array operating at higher-order broadside mode (HOM) with frequency tuning and 2-D beam scanning ability is proposed. The gain is enhanced significantly by array configuration using elements operating at TM03 mode. A rectangular slot is etched in the middle of the patch to reduce the side-lobe level (SLL) below −15 dB in both principal planes. λ/2 parabolic shaped current linkages are connected between the outer λ/2 patch strips supporting TM03 mode to reduce the non-resonant length from 1.5λ to 1.167λ; hence minimizes the patch area by 22%. A 2 × 2 miniaturized planar array is designed at 2.45GHz using these elements; hence reducing the array footprint. Frequency tuning mechanism is incorporated by placing varactor diodes on the radiating edges of the array elements. Also 360° beam switching at azimuth plane and ± 40° (including 3 dB beam width) at elevation plane is achieved by suitably detuning the varactor capacitances. The simulated and measured results are found to be consistent throughout the 10% frequency tuning range. Maximum 17.1 dBi realized gain is measured which remains consistent within 2 dBi variation for entire frequency tuning and beam scanning range.