A Quantized Water Cycle Optimization Algorithm for Antenna Array Synthesis by Using Digital Phase Shifters

摘要

In this article, a quantized water cycle algorithm (QWCA) is used for thernantenna array pattern synthesis with low side-lobe levels (SLLs) and nulls at desired directionsrnby using four-bit digital phase shifters. In addition to the standard features as a metaheuristicrnalgorithm, QWCA has an internal quantization mechanism and a precalculatedrnarray factor method. The latter provides an accelerated procedure to QWCA under favourrnof the digitized values that can be stored in a three-dimensional array. This acceleration isrnbased on the reality that the accessing data in the memory need less time than the usage ofrnthe mathematical functions throughout the optimization process. The internal quantizationrnmechanism of QWCA is utilized to achieve digital values matching to the discrete values ofrnthe phase shifter instead of the simple rounding up/down routines after optimization. Thernnumerical results showed that QWCA can obtain very good SLLs and null depth levelsrn(NDLs) on the synthesized pattern. Moreover, the results are achieved in remarkably shortrnoptimization times. SLL and NDL values obtained by QWCA are also compared with thernavailable literature values. The comparisons reveal that QWCA is able to produce betterrnresults than the other compared alternatives.