2-D Wide-Angle Scanning Phased Array With Hybrid Patch Mode Technique

Abstract

In this letter, a microstrip patch hybrid mode technique is introduced to design a 2-D wide-angle scanning planar phased array. The proposed element consists of a circular patch and four rectangular parasitic patches distributed around the circular patch. In order to obtain wider radiation beamwidth (BW) in two orthogonal azimuth planes, the TM <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">11</sub> mode of the circular patch and the zeroth-order resonant mode of the parasitic rectangular patches are separately excited. Experimental results show that the proposed element can obtain 3 dB BW more than 156° in the two orthogonal azimuth planes. Moreover, an 8 × 8 planar phased array formed by this element can realize wide-angle scanning in a range of about ±65° in the two orthogonal azimuth planes. In the above scanning range, the sidelobe levels of the phased array are always less than -7.8 dB, the scanning gain fluctuation is less than ±1.73 dB, and the main polarizations on the two orthogonal planes are both θ-polarized. In addition, the phased array has a simple structure, a low profile, and convenient fabrication.