Single-/Dual-band Filtering Substrate Integrated Dielectric Resonator Antennas

This paper investigates a new substrate-integrated (SI) filtering dielectric resonator antenna (DRA) using a multilayer microwave substrate, avoiding the need for a dielectric block. It deploys dielectric vias, air vias, and metallic vias, along with a square multi-mode substrate-integrated waveguide cavity to obtain a filtering response. By strategically designing the coupling slots and grounded metallic posts, two cavity TE₁₂₀ and TE₂₁₀ modes are merged with the DR TE^y_1δ1 mode to obtain a wide bandwidth. Measured results show that the single-band design has a 10-dB impedance bandwidth of 9.1%, a peak total antenna efficiency of 75%, and a peak realized gain of 5.7 dBi. Its out-of-band suppression level is greater than 18 dB. As compared with existing SIDRAs, our design has the highest stopband suppression level. This paper also investigates the first-ever dual-band filtering SIDRA. Its lower band is formed by the cavity TE₁₁₀ mode, DR TE^y_1δ1 mode, and a mode associated with a U-slot, while the upper band is created using two DRA-loaded cavity modes. A pair of shorted stubs is also introduced to enhance the roll-off in the lowest stopband. The dual-band design obtains measured impedance bandwidths of 11.3% and 6.1% for the lower and upper bands, respectively. They are suitable for wireless communication systems requiring a planar structure. © 1963-2012 IEEE.