A Wide Stopband Filtering DDPA with Metal Vias and Metal Strips

In this communication, a wide stopband filtering dense dielectric patch (DDP) antenna (DDPA) with metal vias and metal strips is proposed. The feeding structure consists of a short-circuited microstrip line and a separated slot. Based on this feeding structure, the TE ₁₁ and TE ₁₂ modes of DDP are successfully excited. The electric field region of the TE ₁₁ mode is much smaller than the physical region of DDP. The electric field region of the TE ₁₂ mode is basically the same as the physical region of DDP. The resonant frequency of TE ₁₁ mode is close to the resonant frequency of the TE ₁₂ mode and the passband is formed. Two semi-circular DDPs are etched, and two semi-circular metal strips are introduced to generate the low-frequency radiation null. Then ten metal vias are loaded inside the DDP to further change the resonant frequencies of TE ₁₁ and TE ₁₂ modes. The ten metal vias also adjust the H-plane radiation pattern of TE ₁₂ mode and improve the impedance matching of the proposed filtering DDPA. The measured results are basically consistent with the simulated ones. The relative impedance bandwidth is 4.2% (3.08-3.21 GHz). The low-frequency stopband range is 0.1-3.05 GHz, and the high-frequency stopband range is 3.38-7.0 GHz. The filtering DDPA has good sideband selectivity and wide stopband.