A Low-Cost Miniaturized Filtering Dielectric Resonator Antenna Based on SISL for 5G Applications

To realize a low-cost, miniaturized, and high selective design, the filtering dielectric resonator antenna (FDRA) for 5G applications is first proposed based on the substrate-integrated suspended line (SISL). The FDRA consists of two same rectangular DRs embedded in air cavities, which are fixed by the hollowed substrate rings. A T-shape feeder, rectangular feeder, and metalized holes are introduced to excite the fundamental ${\mathrm {TE}}_{\delta 11}^{x}$ mode of DRA. The substrate rings and DR are regarded as a composite dielectric to miniaturize the antenna and have effects on the radiation nulls. Because of the different loading effects from the different feeders, the resonance frequency of the ${\mathrm {TE}}_{\delta 11}^{x}$ mode excited by the different feeders is slightly different. Therefore, a wide bandwidth can be achieved. In the hybrid feed scheme, three radiation nulls are introduced near the edge of the frequency band without an extra filtering circuit. To improve the suppression level, the effective size of the radiator is increased by increasing the width of the substrate rings without changing the size of the whole structure. Therefore, two prototype antennas with different widths of substrate rings are designed, manufactured, and measured. Good agreement can be observed between simulated and measured results.