A Varactor-Based Frequency Reconfigurable Rectangular Dielectric Resonator Antenna

A novel reconfigurable technique for dielectric resonator antenna by implementing frequency continuous adjustable bandpass filters is proposed in this paper. It is achieved by changing the total capacitance of the modified O-shaped filter with uniform impedance resonator via an integrated varactor within its structure. Moreover, the reconfigurable bandpass filter is incorporated within the offset microstrip feedline for the rectangular dielectric resonator antenna with wideband characteristic to form one resonant structure. The combination contributes to the operation frequency tuning for the antenna without multiple feeding paths or different excitation positions. The method makes the antenna has the filtering ability while preserve the good radiation performance. The simulated results have shown a frequency reconfigurable behavior, which is necessary for cognitive radio system and smart wireless communication applications.