Compact dual-band microstrip patch antennas optimized by genetic algorithms: a low-cost solution for 5G and V2X connectivity

Next-generation 5 G and intelligent transportation systems require compact, low-cost antennas that can provide dual-band operation in the sub-6 GHz range without sacrificing bandwidth or radiation performance. This paper presents two ultra-compact dual-band microstrip antennas optimized by a binary genetic algorithm applied to the ground-plane topology. The problem addressed is how to achieve dual-band coverage and sufficient impedance bandwidth on a single-layer FR-4 substrate while keeping the footprint close to 0.175λ₀ × 0.175λ₀. In the proposed method, the ground plane is discretized into binary cells, and a genetic algorithm coupled to an HFSS solver searches over slot patterns using a VSWR-based fitness function. Two15 × 15 mm 2 (0.175λ₀ × 0. 175λ₀ at 3.50 GHz). prototypes are fabricated and measured. Antenna I covers 3.14–4.01 GHz and 5.55–6.08 GHz, suitable for LTE band 42/43, WiMAX, 5 G n78, and DSRC, while Antenna II operates from 4.46 to 4.98 GHz and 5.71–6.14 GHz, covering 5 G n79 and DSRC. Simulated and measured S₁₁ and VSWR show good agreement, with −10 dB bandwidths of several hundred megahertz and stable radiation patterns with realized gain on the order of 2–3 dBi. These results demonstrate that GA-driven ground-plane topology optimization provides a practical and fabrication-friendly route to miniaturized dual-band antennas for low-cost 5 G and V2X terminals.