| In recent years,as the wireless communication system is in the process of upgrading,the antenna as a radio frequency front end has higher requirements.Filtering antennas have gradually become one of the research hot in the field of antenna systems,because their design greatly reduces the size of wireless communication systems,enhances the compactness of antenna units,and improves antenna performance.Compared with the traditional patch antenna,the dielectric resonator antenna（DRA）has the advantages of light weight,small size,low loss,high radiation efficiency,easy fabrication and easy integration with other devices.Therefore,the use of dielectric resonators to design filtering antennas has also attracted more and more attention of scholars.Combining filtering antennas and DRAs can have the advantages of both and realize multi-functional filtering DRAs.Therefore,this paper analyzes and designs three filtering DRAs based on the research of DRA related theories.The main contents are as follows:（1）A filtering dielectric resonator antenna based on Stepped Impedance Resonator（SIR）is proposed.Based on the SIR design method and theory,the half-wavelength SIR is used as a unit,and the folded structure and the electrical coupling cascade method are used to realize the design of a compact,bandwidth-adjustable band-pass filter.A transmission null is introduced on both sides,it is finally embedded in the microstrip feeder of the DRA,and the filtering DRA design is completed.The simulation and test are basically consistent,which verifies the correctness and effectiveness of the design method.（2）A design method of a filtering dielectric resonator antenna based on Coplanar Waveguide（CPW）feeding is proposed.Using the fusion design method,the open-circuit stub is connected in series on the signal band of the CPW feed structure,thereby generating a radiation null and increasing the out-of-band selectivity of the high-frequency side of the passband of the antenna.In addition,a metal column is loaded inside the rectangular DRA to generate a radiation null increases the selectivity of the low-frequency side of the passband.At the same time,the additional radiation pattern generated by the open-circuit stub and the TE111mode of the DR are combined to complete a filtering DRA with a gain response similar to an ellipse filtering.（3）A broadband filtering DRA design method based on CPW feed is proposed.Using the band-stop filter method,by introducing two band-stop resonators on the signal band and the ground of the CPW feed structure,the design of a compact band-pass filter with two transmission nulls individually controllable is realized.The feeding method excites the fundamental modes of the rectangular DRA at three different frequencies,broadening the antenna bandwidth,and the relative bandwidth of the antenna reaches 13.6%,thus completing the broadband filtering DRA design. |
