A K u band frequency‐reconfigurable dielectric resonator antenna using metallic pillars

A K u band frequency‐reconfigurable dielectric resonator antenna (DRA) using metallic pillars is presented in this letter. A novel frequency tuning method of the DRA is proposed by selectively loading metallic pillars at two narrow sides of the DRA. Resonating at its fundamental TE 111 y mode, the operating frequency of the DRA can be continuously controlled by changing the heights of the pillars in a large frequency tuning range. In the range, the DRA remains good impedance match, stable radiation patterns, and low cross‐polarization level. To verify the proposed method, a prototype operated at K u band is designed, fabricated and measured. A measured frequency tuning range of 33% with gain higher than 5.3 dBi and cross‐polarization level less than −20 dB are achieved within the range, showcasing reasonable agreement with the simulated results.