Design of a Wideband Circular Microstrip Patch Antenna for Ka-Band 5G Wireless Communications

The growing demand for high-speed and high-capacity wireless communication has intensified the need for compact, wideband, and efficient antenna solutions suitable for 5G applications, particularly in the Ka-band. To address this, a modified circular microstrip patch antenna is proposed, specifically designed to support 5G communication across multiple Ka-band frequencies. The antenna features a simple yet effective structure comprising a circular patch with a central circular slot, fabricated on a Taconic RF-35TC substrate with a relative permittivity of 3.5 and a low loss tangent of 0.0011. A partial ground plane is utilized on the bottom side to enhance radiation characteristics. The overall dimensions of the optimized antenna are 18 × 17 × 1.5 mm³. The design process involved modeling, simulation, and performance evaluation using CST software. Simulation results reveal that the antenna effectively covers the full Ka-band range from 21.7 GHz to 47.5 GHz, achieving a wide fractional bandwidth of 74.6%. It also demonstrates a peak gain of 8.8 dBi and a maximum radiation efficiency of approximately 94%, making it highly suitable for deployment in key 5G frequency bands such as 24, 26, 28, 38, and 39 GHz.