Impact of Dielectric Insertion on Performance of Quad-Ridged Horn Antenna

In this paper, the impact of dielectric insertion on the performance of quad-ridged horn antenna (QRHA) is investigated. The dielectric material which is inserted into the QRHA is aimed to enhance the performance of QRHA, in particular, the bandwidth response with an extension into the lower operating frequency. To achieve the optimum performance, four kinds of dielectric material with different relative permittivity are utilized. The used dielectric materials are Teflon, Paraffin, Epoxy, and Duroid with the relative permittivity of 2, 2.26, 4, and 6, respectively. The characterization results show that Teflon could exhibit better performance than other dielectric materials yielding the bandwidth response of 11.5 GHz in the frequency range of 2.5 GHz to 14 GHz. Meanwhile, the bandwidth response of QRHA without dielectric insertion is 9.6 GHz in the frequency range of 4 GHz to 13.6 GHz.