COMPACT DUAL-POLARIZED QUAD-RIDGED UWB HORN ANTENNA DESIGN FOR BREAST IMAGING

A compact dual-polarization, ultra-wideband quad-ridged horn antenna has been proposed for breast imaging. CST Microwave Studio Simulation has been used to design the horn antenna. The antenna size was reduced, and impedance matching was achieved by a modest change in the dielectric constant of the matching liquid and by the introduction of four semi-elliptical structure at the flared ridges. To test the polarization isolation, many field probes were distributed at different positions in front of the antenna. The probes have been set to measure both vertical and horizontal electric field components at each location. Results show that adding elliptical parts can provide impedance matching over the whole frequency band of the antenna. Measurements show high isolation between the transmitted vertical and horizontal electric fields. Almost 40 dB polarization isolation exists at boresight of the antenna over the entire frequency band. This characteristic is central to polarimetric radar work. Effective gain and ports isolation were obtained.