Design of Antenna Arrays with Quantized Controlling

Abstract

The rapid advancement of CubeSat technology has increased demand for high-performa{-}nce ground station (GS) antennas capable of fast satellite tracking, high gain, robust interference rejection, and weather resilience in Low Earth Orbit (LEO). This need is exemplified by the VZLUSAT-1 Czech university CubeSat program, which motivates the development of more efficient tracking solutions. Traditional motor-driven tracking systems are slow, costly, and ineffective in isolating signals from complex interference. This work proposes a phased antenna array (PAA) with quantized beamforming control optimized for CubeSat ground station applications to address these limitations. The system employs a geodesic dome structure with a truncated equilateral triangular patch antenna array arranged in a 4×4 grid per planar face to achieve a targeted gain of 20 dBi. The array demonstrates a wide bandwidth of 198.62 MHz, excellent inter-element isolation, and an axial ratio bandwidth of 42.17 MHz. A main innovation lies in the optimization of phase and amplitude quantization for precise beam steering. The Taguchi method is first applied to minimize sidelobe levels (SLL) and suppress the first sidelobe, offering rapid convergence and computational efficiency compared to stochastic methods like particle swarm optimization (PSO) and genetic algorithms (GA). However, for large arrays and 2D scanning tasks, a Multi-Layer Perceptron (MLP) strategy proves superior, balancing accuracy and flexibility. Phase quantization analysis reveals that the proposed Appropriate Mean Phase Error Zero (AMPEZ) method with a 0.45 offset significantly improves beam pointing accuracy and sidelobe stability compared to conventional dithering techniques. When integrated with round-off amplitude quantization, the Quantized-MLP (2-bit) outperforms it and the traditional round-off (3-bit) methods in beam accuracy while maintaining comparable SLL performance. Validation via CST Microwave Studio simulations confirms the theoretical findings, with experimental verification planned for future work. This study advances CubeSat communication by introducing a cost-effective, high-performance PAA solution, combining optimized quantization strategies with scalable control algorithms for real-world GS applications.