28 GHz Substrate-Integrated Filtering Dielectric Resonator Antenna Array

Abstract

A 28 GHz substrate-integrated filtering dielectric resonator antenna (DRA) and its 2 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times $ </tex-math></inline-formula> 2 arrays are investigated. The cylindrical DRA, enclosed by two rings of air vias and metallic vias, is fabricated out of a high-permittivity substrate. It is excited by a microstrip feedline on a second substrate through four slots on the common ground plane of the antenna and feed substrates. The metallic vias and ground plane form a substrate-integrated cavity, which enhances the antenna gain in the passband by <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\sim 1$ </tex-math></inline-formula> dB. A cavity mode, the DRA HEM <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$^{\text {y}}_{11\delta } $ </tex-math></inline-formula> mode, and a perturbed HEM <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$^{\text {y}}_{11\delta } $ </tex-math></inline-formula> mode are simultaneously excited, giving a wideband substrate-integrated DRA. A dual-loop structure is introduced to the DRA to provide two radiation nulls that give a filtering response. To demonstrate the idea, a 28 GHz filtering DRA and its 2 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times $ </tex-math></inline-formula> 2 arrays were designed, fabricated, and measured. Reasonable agreement between the measured and simulated results is observed.