Design of Frequency Selective Surface-Based Patch Antenna Array for Ultra-Wideband Radar Systems

In this study, a frequency-selective surface (FSS)-based patch antenna array design was developed to create a high-gain antenna structure for ultra-wideband (UWB) radar systems operating within the 3.1 – 4.8 GHz range. Initially, two-element and four-element patch antenna arrays were constructed. Subsequently, FSS reflectors were employed to suppress the back lobes and enhance the gain. To ensure the FSS exhibited effective reflective characteristics within the specified frequency band, the S11 and S21 parameters of the unit cell structure were optimized. The unit cells were periodically arranged and positioned behind the antenna arrays at a specific air gap distance. The designed FSS structure resulted in a gain increase of 3.55 dBi for the two-element array and 3.41 dBi for the four-element array. Additionally, S11 measurements of the designed antenna arrays were conducted, revealing alignment with the simulation results. These findings indicate that FSS-based patch antenna arrays offer high-performance antenna solutions for UWB radar applications.