In this letter, a wideband substrate integrated dielectric resonator antenna (SIDRA) with filtering response for millimeter-wave (mm-wave) applications is proposed. The antenna contains a dual-mode substrate integrated dielectric resonator (SIDR), which is fed by a slot-coupled double-T-shaped microstrip feeding structure. The stacked substrates with the peripheral air vias and a metallic via cavity are the main body of the SIDR, which ensure dual-mode operation with the TE111 mode and the TE131 mode. The pair of strips, the small patches with shorting pins and the two center air vias are the accessory parts of the SIDR, which play roles of converting the TE131 mode into the perturbed-TE131 mode, providing radiation nulls, and improving the out-of-band suppression level. The double-T-shaped feeding structure has two pairs of stubs with different lengths, providing a radiation null and a reflection zero, improving the impedance matching of the slot resonant mode and enhancing the suppression level at the upper stopband. For demonstration, a prototype of 1×4 array is designed and measured. The prototype operating at 24 GHz has a 10-dB impedance matching bandwidth of 34% (19.8-27.9 GHz), a peak gain of 13.1 dBi, and an out-of-band suppression level of about 21 dB.

A millimeter-wave (mm-wave) end-fire substrate integrated dielectric resonator antenna (EFSIDRA) is proposed to provide dual-beam radiation. The dual-beam radiation is caused by the multilayer rectangular dielectric resonator (DR) with metallic walls on both sides and air vias at the center, which are used to generate modified TE13δ mode and adjust the distribution of E-fields, respectively. The metallic walls, air vias, DR and feeding line can all be implemented with printed circuit board (PCB) process, which enhances the integration level of the end-fire dielectric resonator antenna. The theoretical analysis of the dual-beam radiation is provided to guide the practical design. Compared with the state-of-the-art designs, the proposed antenna not only achieves dual-beam radiation in end-fire dielectric resonator antenna, but also exhibits the capability of substrate integration and high radiation efficiency. For demonstration, a dual-beam prototype is fabricated and measured. The proposed antenna shows a dual-beam radiation with ±61° beam direction and more than 13 dB suppression at the end-fire direction.

A wideband dual-beam dielectric resonator antenna (DRA) with substrate integration capability was proposed for millimeter-wave (mm-wave) applications. The four rows of air vias along the x-direction and two extended rectangular patches could shift the undesirable radiation mode upward and move the conical-beam radiation mode downward, respectively. Thus, the TE₂₁₁ mode and the TE₄₁₁ mode of the patch-loaded perforated rectangular substrate integrated dielectric resonator (SIDR) supporting the dual-beam radiation can be retained in the operating band, and their radiation can be improved by the air vias along the y-direction. The T-shaped line coupled dual-slot structure could excite the above two modes, and a dual-slot mode supporting dual-beam radiation could also work. Then, a wideband DRA with a stable dual-beam radiation angle can be achieved, and its impedance matching can be improved by two air slots on two sides. Compared with the state-of-the-art dual-beam antennas, the proposed antenna shows a wider bandwidth, a higher radiation efficiency, and the substrate integration capability of DRA, making it more suitable for mm-wave applications. For demonstration, a 1 × 4 array was designed with the 10 dB impedance matching bandwidth of 41.2% and the directions of the dual beams between ±30° and ±35°.