Millimeter-Wave Monopulse Filtenna Array with Directive Dielectric Resonators

Abstract

This paper presents a new millimeter-wave monopulse dielectric resonator (DR) filtering antenna (filtenna) array based on substrate-integrated waveguide (SIW) technology. The monopulse comparator realized by a square dual-mode (<i>TE</i>₁₀₂ and <i>TE</i>₂₀₁) SIW feed cavity uses diagonal irises, of which couplings between the feed and next-stage cavities lead to almost identical filter responses for the sum and difference channels with compact size and a planar single-substrate structure. Both dielectric resonator antennas (DRAs) adopting <i>HEM</i>₁₃₃ mode for enhanced directivity are implemented with two filters based on SIW. The DR acts as the last resonator and the radiator in the filtenna. The prototype is designed at the Ka-band with a center frequency of 27.65 GHz and an operation bandwidth of 700 MHz. The measurement shows a 15-dB fractional bandwidth of 2.36%, a gain of 10.84 dBi for the sum channel, and a null depth of -15.6 dB for the difference channel.