Wideband Dual-Polarized 3D Printed Quad-Ridged Horn Antenna

This paper presents the development of a wideband dual-polarized 3D printed quad-ridged horn antenna (QRHA) that can be used for detecting and imaging applications. The QRHA consists of three main parts: the waveguide transducer, the horn, and the ridges. The waveguide transducer is modified into a square shape to obtain dual-polarization. Four variations of ridges were carried out to determine the ridge that best satisfies the required specifications, especially the bandwidth and sidelobe levels. Among the four ridge profiles, the quadratic model was used for the proposed QRHA as it generated the widest bandwidth and enhanced a lower operating frequency, which is beneficial for improving resolution and penetration depth. The double-ridged horn antenna (DRHA) was also investigated in order to make a comparison with QRHA’s performance. The characterization results show that when compared to DRHA, QRHA performs better in terms of bandwidth, beamwidth, gain, and side lobe suppression. Due to the benefits it provides, 3D printing based on polylactic acid (PLA) material was selected as the manufacturing process for the proposed QRHA. The fabricated QRHA had a weight that was three times lighter compared to conventional antennas. The measurement results indicate that the 3D printed QRHA has the wideband characteristics of a −10 dB working bandwidth of 7.9 GHz in frequency ranges of 3.5 GHz to 11.4 GHz. Isolation between the ridges below −20 dB was achieved for most frequency ranges. Co– and cross-polarizations were also performed to evaluate the dual-polarization of the proposed QRHA. The radiation patterns showed that the measurement results agree well with the simulations for low, middle, and high operating frequencies.