Low-loss dielectric radome with RFID for intelligent scanning in sub-THz, future autonomous defense systems

Abstract

The proposed antenna design incorporates a 0.3 mm thick Roger substrate, a 0.00125 mm thick patch, and a cylindrical hollow radome made of Preperm HF H1500 material. The radome encloses a 1 × 11 linear array with a radius of 5.40 mm without affecting its radiation characteristics. The antenna operates at two distinct resonance frequencies: 129.5 GHz and 238.9 GHz. At 129.5 GHz, the antenna shows a minimum 3 dB beamwidth of 50°, indicating a broader directional focus. In comparison, at 238.9 GHz, the performance significantly improves, with a peak gain of 7.8 dBi, a wider minimum 3 dB beamwidth of 130°, and a sensitivity of -2 dB. The front-to-back ratio improves to 12 dB, demonstrating enhanced directional capability. Return loss characteristics for both resonances show excellent impedance matching, with values of 20.7 dB at 129.5 GHz and 18.43 dB at 238.9 GHz. The bandwidth percentages at both frequencies (0.93% at 129.5 GHz and 6.35% at 238.9 GHz) are within acceptable limits. The design effectively addresses critical challenges in sub-THz scanning, such as environmental interference and limited range, making it a versatile solution for logistics, healthcare, IoT, and industrial automation applications. Furthermore, the design supports automated beam steering and integration with AI-enhanced radar logic, making it a viable candidate for future autonomous defense systems and cyber-physical infrastructure with sub-THz communication and scanning.