A Novel Filtering Dielectric Resonator Antenna With Enhanced Gain

In this letter, a novel rectangular filtering dielectric resonator antenna (FDRA) using a fusion design approach with enhanced gain is proposed. An extended microstrip stub and a pair of U-shape metal strips are elaborately designed and loaded to provide two radiation nulls at the edges of the passband. Besides, a mushroom-like electromagnetic band gap (EBG) structure is arranged around the DRA to generate the third radiation null. Consequently, a good filtering response is obtained without extra filtering circuits. In addition, three radiation nulls can be controlled independently by adjusting the length of the extended microstrip stub, the U-shape metal strips and sizes of EBG structure. A prototype FDRA is fabricated and measured for demonstration. The reflection coefficient, the radiation pattern, the antenna gain and total efficiency are studied, and reasonable agreement between the measured and simulated results is observed. The prototype owns a 10-dB impedance bandwidth of 12% (4.63–5.23 GHz), a peak realized gain of 7.32 dBi and a high out-of-band suppression level of 27.4 dB at the lower stopband, respectively. Besides, a cross-polarization discrimination of more than 27 dB in each plane is obtained.