Sideband suppression in time-modulated arrays using fixed bandwidth elements

A technique for suppressing the sideband levels in time-modulated linear arrays (TMLA) is presented. The technique utilizes the fixed bandwidth of the radiating elements of the array to act as band-pass filters to suppress the out of band harmonics generated by the time-modulation process. The approach is combined with a new element switching sequence which is designed to redistribute the dominant harmonic components of the TMLA to predetermined frequencies which are outside the bandwidth of the array elements. The proposed technique does not require the use of complicated optimisation procedures to generate the TMLA switching sequences and is applicable to a TMLA configured to synthesize arbitrary low-sidelobe patterns. Numerical results are presented to illustrate the proposed approach to by considering a 16 element array of patch antenna elements designed to provide a -30dB Chebyshev sidelobe level radiation pattern.