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 semicircular DDPs are etched, and two semicircular 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.