A compact dielectric rod-loaded conical horn antenna for millimeter-wave apllications

A new design concept for compact conical horn antenna exhibiting high directive gain and low cross-polarization is proposed. In this work, a dielectric rod-loaded conical horn antenna with rectangular waveguide structure feed was built and tested. By inserting a E-plane tapered dielectric rod material of relative permittivity ε_r = 2.08, the guided mode excited at the feed end is smoothly converted into that at the free end in a tapered dielectric rod. The diameter of the fabricated circular horn aperture is 20 mm and axial length is 28 mm. A peak gain of 16 dB with cross-polarization of 32 dB was measured at 37.3 GHz.