  Peak sidelobe level reduction (PSLR) is crucial in the application of
large-scale array antenna, which directly determines the radiation performance
of array antenna. We study the PSLR of subarray level aperiodic arrays and
propose three array structures: dislocated subarrays with uniform elements
(DSUE), uniform subarrays with random elements (USRE), dislocated subarrays
with random elements (DSRE). To optimize the dislocation position of subarrays
and random position of elements, the improved Bat algorithm (IBA) is applied.
To draw the comparison of PSLR effect among these three array structures, we
take three size of array antennas from small to large as examples to simulate
and calculate the redundancy and peak sidelobe level (PSLL) of them. The
results show that DSRE is the optimal array structure by analyzing the
dislocation distance of subarray, scanning angle and applicable frequency. The
proposed design method is a universal and scalable method, which is of great
application value to the design of large-scale aperiodic array antenna.
