A Wideband Substrate Integrated Filtering Dielectric Resonator Antenna for Millimeter-Wave Applications

In this letter, a wideband substrate integrated dielectric resonator (SIDR) antenna with filtering response for millimeter-wave (mm wave) applications is proposed. The antenna contains a dual-mode 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 TE
₁₁₁
mode and the TE
₁₃₁
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 TE
₁₃₁
mode into the perturbed-TE
₁₃₁
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.