Performance Characterization of Aluminium-based Dual-Polarized Wideband Quad-Ridged Horn Antenna

Abstract

A dual-polarized wideband antenna is required for the applications that need high accuracy in object detection. One of antenna types frequently used to satisfy the requirement is a quad-ridged horn antenna (QRHA). In this paper, performance characterization of aluminium-based dual-polarized wideband QRHA is presented. The proposed QRHA utilizes a square waveguide transducer which is modified from a WR90 type waveguide appropriates to operate at the frequency range of 8.5-12.5GHz. Four quadratic ridge profiles are inserted into the horn section to improve the bandwidth characteristic toward lower working frequency. Aluminium is chosen as a material to construct the proposed QRHA with manufacturing process using a computer numerical control (CNC) milling technique. The measurement shows that the performance of realized QRHA is agreed well with the simulation. The bandwidth response of about 8.2GHz in the frequency range of 4.4GHz to 12.6GHz could be achieved for the reflection coefficient of less than -10dB. Whilst the isolation between ports below -20dB is obtained at the frequency range of 6GHz to 9.7GHz. In addition, the characterization result indicates that aluminium-based QRHA has a wider bandwidth of about 4% compared to Polylactic Acid (PLA) based 3D printed QRHA.