Compact UWB Semi-Circular Microstrip Patch Antenna

This paper presents the design, simulation, fabrication, and analysis of a compact Ultra-Wideband (UWB) semi-circular microstrip patch antenna for X-band wireless communication applications. The proposed antenna is designed on an FR4 substrate having dimensions of 40 mm × 30 mm × 1.6 mm and analyzed using ANSYS HFSS software. A semi-circular radiating patch combined with a modified feed structure is utilized to achieve improved impedance matching and stable resonance characteristics. Simulated results show a minimum return loss of approximately −40 dB at 7.8 GHz with a VSWR value close to unity, indicating excellent impedance matching. The fabricated antenna was experimentally tested using a Keysight FieldFox Microwave Analyzer and achieved a measured return loss of −9.714 dB at 8.257 GHz. The radiation pattern exhibits stable broadside directional characteristics with satisfactory gain performance. The obtained results demonstrate that the proposed antenna is suitable for ultra-wideband communication systems, radar applications, wireless sensing, microwave communication, and other high-frequency wireless devices.