Research And Design Of High Performance Filtering Dielectric Resonator Antenna

With the advancement of technology,devices in wireless communication systems are developing towards smaller size,higher integration and more diversified functions.Antenna and filter are two key devices,which are directly related to the transmission and reception quality of wireless signals.In the early design,the antenna and filter are usually regarded as two separate devices,which are designed independently and then connected,which is not conducive to miniaturization and will also generate additional connection loss.Therefore,it is proposed to realize the radiation and filtering functions on one device at the same time,and integrate the antenna and filter to form a filtering antenna,which can meet the trend of miniaturization design and avoid connection loss.Dielectric resonator antennas have the characteristics of high design flexibility,low loss,high radiation efficiency,and rich operating modes.If the filtering antenna is designed based on dielectric resonators,these advantages can be fully utilized to achieve excellent performance.In this thesis,three filtering dielectric resonator antennas with excellent performance are designed.The main research contents are summarized as follows:1.An antenna is designed based on microstrip-slot coupling feeding.By adding a pair of transverse stubs on the microstrip feeder and etching two slits on the floor,a radiation null is realized on the left and right sides of the passband respectively to realize the filtering function.Since the high-order modeTE_1δ3^y of the dielectric resonator is excited,the peak gain in the passband can reach 9.4d Bi,and the average gain is about9d Bi,which is improved compared with the gain of a typical rectangular dielectric resonator antenna.The impedance bandwidth is 16%（6.04-7.06GHz）,and the designed antenna was manufactured and tested,and the test results were consistent with the simulation results.2.An antenna is designed based on microstrip coupling feeding.The microstrip line and the dielectric resonator have the same length in the x-axis direction,and realize a radiation zero point on the left side of the passband.Deform the microstrip line directly below the dielectric resonator into a circular patch as large as the bottom of the dielectric resonator,and etch two annular gaps with different radii on the circular patch,then two radiation nulls are realized on the right side of the passband.Out-of-band rejection exceeds 17d B.By stacking two dielectric resonators with different dielectric constants to excite higher-order modes,the peak gain in the passband can reach 9.2d Bi,and the impedance bandwidth is 20.3%（2.88-3.53GHz）.3.An antenna is designed based on coaxial probe feeding.Two open annular gaps are etched on the floor,the current direction is opposite on both sides of the gap,and the far-field radiation is offset,so that a radiation null is generated on both sides of the passband to realize the filtering function.Three resonant modes are excited in the passband.The-10d B impedance bandwidth of the antenna is 52.2%（2.83-4.82GHz）,and the 1d B gain bandwidth is 50.9%（2.87GHz-4.83GHz）.The bandwidth performance is excellent,and the average gain in the passband is 5.5d Bi.The physical model of the antenna is made and tested,and the results show that the simulation and test results are in good agreement.