Radiation pattern optimization by Apicalis Ant algorithm for smart Array antennas

In modern mobile communications systems, both desired and interfering signals change their directions continuously. Therefore, a fast tracking system is needed to constantly track the users and then adapt the radiation pattern of the antenna to direct multiple narrow beams to desired users and nulls interfering sources. This paper proposes a smart array antenna system, which can improve performance by spatial filtering. Smart array antennas backed by strong signal processing algorithms are able to automatically change the beam pattern in accordance with the changing signal environment. The adaptation is achieved by multiplying the incoming signals with complex weights and then summing them together to obtain the desired radiation pattern. Adaptive array optimization is an NP-hard problem. In this paper, a technique based on the API (Pachycondyla Apicalis algorithm) is presented to solve this problem. Several illustrative examples of patterns with imposed single and multiple null directions are given to show the versatility of the present method.