Design of a Miniaturized Low-Cost Defective Ground Antenna for K-Band Detectors

This paper proposes a K-band detectors with defected ground structure, employing an antenna array design to enhance gain and reduce beamwidth. By incorporating a defective ground structure (DGS), high isolation between antenna elements is achieved, effectively suppressing mutual coupling and improving array performance, making it suitable for low-cost, miniaturized detectors. The DGS is realized by etching RF circuit patterns on the ground plane, which not only enhances isolation and reduces mutual coupling but also optimizes ground plane utilization and minimizes the footprint of the RF front-end, enabling integrated design. Simulation results demonstrate that the antenna operates within the frequency range of 24.5–25.5 GHz, with a minimum S11 parameter of -30.58 dB and a diameter of 24 mm. This design achieves miniaturization while significantly reducing costs and improving performance, making it applicable to K-band detectors.