Design of Linear and Planar Arrays with Low Sidelobe Levels and High Directivity Using Two-way Array Factor

Sidelobes in the two-way radiation pattern are of serious concern in a radar array. Several techniques have evolved to mitigate the problem, which include amplitude tapering, Genetic Algorithm (GA) optimization, thinning transceiver aperture, and two-weight amplitude distribution. With such optimization schemes, the sidelobes can be considerably suppressed but at the cost of a reduction in directivity or taper efficiency. Further, such amplitude tapers require a complex feeding network design. This work alleviates such design restrictions and proposes a systematic approach to lower the sidelobes in radar two-way shared aperture arrays. The proposed methodology can achieve a sidelobe level (SLL) of below -52 dB in both linear and planar arrays, which is about 18 dB enhancement in SLL compared with uniform transmit and thinned receive arrays. In addition, as a result of the equal transceiver array size in the proposed design, an improvement of approximately 0.44 dB and 0.68 dB in directivity is achieved in linear and planar arrays, respectively. A novel feeding architecture is also illustrated to reduce the cost and complexity of the overall feeding network. A set of full-wave simulations have also been performed to validate the theoretical results.