A Compact Circular Patch Antenna with Adaptive Beam Steering and Band Notch Filtering for UWB Applications

This paper presents a compact circular patch antenna specifically designed for ultra-wideband (UWB) applications, operating efficiently across the 2–6 GHz frequency range. A dedicated notch at 2.4 GHz is incorporated to effectively suppress interference from WLAN signals. The antenna is fabricated on an FR4 substrate with compact dimensions of 35 × 32 × 1 mm³, offering a low-profile solution ideal for integration into modern wireless systems. To enhance functionality, three precisely engineered rectangular slots are introduced—two on the ground plane to influence the radiation pattern and one on the patch to achieve the desired notch behavior. Beam steering capability is enabled via diodes D3 and D4, allowing directional reconfiguration up to ±60°, with observed gain variations between 3.8 dB and 4.5 dB. Simulated and measured results exhibit strong agreement, with only minor deviations—0.1 GHz in notch frequency and 0.1 dB in gain—validating the design's precision. Compared to traditional UWB monopole and patch antennas, the proposed antenna offers a smaller footprint, efficient interference rejection, and enhanced beam steering, making it a promising candidate for next-generation adaptive wireless communication systems.