Antenna Pattern Synthesis Using Phase Mode for Circular Array with Reduced Side-lobe Level

This work investigates the pattern synthesis of discrete antenna elements placed equidistantly on a circular ring. In order to synthesize the antenna pattern, the phase mode analysis is investigated to compute the excitation amplitude and phase of discrete elements. A very low side-lobe level compared with earlier phase mode based approaches is achieved using the modified $|J_{1}(x)/x|$ pattern. The desired side-lobe level (SLL) and beam direction in the pattern characteristics are also effectively achieved. It is observed that a variation in the phase distribution with the amplitude distribution constant results in beam steering, while, for reducing the SLL, both the amplitude and phase distributions need to be suitably changed. A slight increase in beamwidth is observed with the reduction in the SLL.