Using Non-Uniform Distribution of Elements with Different Excitation Amplitutes as an Effective Method to Reduce the Maximum Sidelobe of Circular Array Antennas

Zanganeh, Amirhosein; Dalili Oskouei, Hamidreza; Mohammadi Shirkolaei, ‪Morteza

doi:10.22034/joeds.2022.164609

Using Non-Uniform Distribution of Elements with Different Excitation Amplitutes as an Effective Method to Reduce the Maximum Sidelobe of Circular Array Antennas

Document Type : Original Article

Authors

Amirhosein zanganeh ¹

Hamidreza Dalili Oskouei ²

‪Morteza Mohammadi Shirkolaei ³

¹ Instructor, Faculty of Computer, Shahid Sattari Aeronautical University, Tehran, Iran.

² Associate Professor of Electrical Engineering, Shahid Sattari Aeronautical University, Tehran, Iran

³ Assistant Professor of Electrical Engineering, Shahid Sattari Aeronautical University, Tehran, Iran.

10.22034/joeds.2022.164609

Abstract

The Concentric Circular Array Antennas (CCAAs) are made up of elements that are distributed on different concentric circular areas with different radiuses. In this paper we determine the non-uniform distribution of elements excitation amplitude and their positions, in order to achieve more reduction in sidelobe level and beam width. The difference of side lobe levels becomes more important when the beam width of the antenna needs to be kept fixed. The sidelobe level reduction is proposed as an optimization problem and a Genetic Algorithm (GA) is used to handle the large mass of parameters that associate with each other.
In this article, experiments have been performed for 3 different cases. In the first case, it is assumed that 18 elements have been distributed on 3 centered rings, and in second case we assumed that 24 elements have been distributed on 7 non-uniform distribution centered rings and in third case 30 elements are distributed on 6 non-uniform distribution centered rings. Based on the results obtained, for first case the proposed method represents -1.89 dB reductions, for second case the proposed method represents -8.16 dB reduction, and For third case also the first sidelobe level -0.44 dB Reduced.
The results showed that the design of the non-uniform distribution of elements with non-uniform excitation amplitude for CCAAs, decreased significantly the sidelobe level and beam width.

Keywords

Concentric Circular Array Antenna

Non-uniform Distribution

Sidelobe level

Genetic Algorithm

Beam width