A hybrid analytical-optimization framework for sidelobe suppression and beamwidth control in linear antenna arrays

Area of Science:

• Electromagnetics and Antenna Theory
• Signal Processing
• Computational Intelligence

Background:

• Uniform linear antenna arrays (ULAs) are crucial for directed energy transmission and reception.
• Traditional methods for sidelobe suppression and beamwidth control often involve complex iterative optimization, limiting computational efficiency.
• Achieving both significant sidelobe level (SLL) reduction and precise half-power beamwidth (HPBW) control simultaneously remains a challenge.

Purpose of the Study:

• To introduce a novel hybrid analytical-optimization framework for enhanced sidelobe suppression and beamwidth control in ULAs.
• To develop a computationally efficient synthesis strategy for antenna array radiation pattern control.
• To demonstrate the effectiveness of the proposed algorithm in achieving superior SLL and HPBW performance.

Main Methods:

• The Enhanced Window-Based Array Synthesis Algorithm (EWASA), or Raised Cosine Synthesis with Genetic Algorithm (RCS-GA), is proposed.
• A deterministic spatial shaping mechanism using a raised cosine function is adapted for angular domain radiation pattern control.
• A hybrid approach combines analytical synthesis via raised cosine mapping and matrix inversion with genetic algorithm optimization of inter-element spacing.

Main Results:

• The proposed EWASA achieves a sidelobe level (SLL) of -38.05 dB and a half-power beamwidth (HPBW) of 5.526° for a 15-element array.
• This represents a threefold reduction in SLL and over 50% improvement in HPBW compared to conventional uniform arrays.
• Full-wave simulations confirm the practical feasibility and highlight the method's computational efficiency and precise beam control.

Conclusions:

• The hybrid analytical-optimization framework offers a computationally efficient and effective solution for antenna array synthesis.
• The proposed EWASA provides significant improvements in sidelobe suppression and beamwidth control, outperforming conventional techniques.
• The method's precision and efficiency make it highly suitable for high-resolution applications in radar, electronic warfare, and medical imaging.