Mutual-Coupling Compensation in Time-Modulated Antenna Arrays for Flat-Top Pattern Synthesis

A method that can be used to compensate for the mutual-coupling effect in time-modulated antenna arrays for synthesizing flat-top patterns is proposed in this article. Based on the measured complex embedded element patterns, the differential evolution algorithm is employed to optimize time sequences and phase excitation of each element in the array and to suppress the sideband level, leaving the amplitude excitations to be uniform. A -20-dB sidelobe level flat-top pattern is successfully synthesized in which the ripple level of the mainlobe is lower than 0.5 dB and the sideband level is lower than -10 dB. An S-band eight-element printed dipole with a double-layered structure linear array is used in the experiment to verify the proposed method, and the measured results are in good agreement with the simulated results.