Wideband subterahertz antenna based on the symmetrical path‐length lens for sidelobe level reduction

Abstract

AbstractThis letter presents a high‐gain fully metallic antenna designed with a symmetrical path‐length lens for subterahertz applications over a wide frequency range. The symmetrical path‐length lens divides the E‐plane horn into two symmetrical halves, which can compensate for the phase difference generated by the E‐plane horn individually. Compared to the conventional asymmetrical path‐length lens, the numerical results show the sidelobe level (SLL) can be reduced from −11 to −15.7 dB with the symmetrical path‐length lens. Measured results show the proposed antenna exhibits a reflection coefficient of less than −10 dB from 110 to 170 GHz. In addition, the measured SLL is about −15 dB at 140 GHz. The measured results indicate that the symmetrical path‐length metallic lens is an effective way to improve the poor lobe suppression resulting from an asymmetrical path‐length lens.