A Switched Beam Antenna With Shaped Radiation Pattern and Interleaving Array Architecture

A six-beam switched beam antenna (SBA), whose beam patterns are shaped in the azimuth plane, is designed and fabricated. A synthesis method, which is based on a four-elements array and can generate a flat-top beam pattern with 46 degrees flat gain region (gain fluctuation within +/- 0.5 dB), 60 degrees 3-dB beam width, and less than -20.1 dB side lobe level (SSL), is proposed. By combining six of those beams together, the proposed SBA can provide near consistent gain and good interference rejection in the azimuth plane. Meanwhile, an interleaving array architecture, which minimizes the size of the proposed array, is also implemented. To extend the beam coverage, a series-fed in-phase array with tapered amplitude distribution is introduced in the elevation plane. The peak gain of the beam reaches 16.6 dB, and the SLL is controlled under -23.2 dB in this plane.