Dual-polarized Wideband Horn Antenna with Lower Frequency Extension for Microwave Imaging Application

Abstract

Horn antenna is frequently used for microwave imaging since its characteristics satisfied the required specification. However, its dimension is too large for low frequency usage and commonly produces single polarization. In this paper, a dual-polarized wideband horn antenna with lower frequency extension is investigated for microwave imaging application. This design is supposed to accommodate the requirements of high resolution. The usage of ridges and dielectric inserted into the horn is proposed to produce dual polarization of the antenna and extend the bandwidth in low frequency. The characterization results show that the proposed antenna yields reflection coefficient less than -10 dB, isolation between ports below -25 dB and sidelobe level better than -20dB at the frequency range of 2.5-14GHz for each polarization suitable for the desired application.