Research And Implementation Of Dielectric Resonator Antenna Bandwidth Extension Technique

In recent years,the dielectric resonator antenna(DRA)has been investigated by many scholars because of the little influence of conductor loss and surface wave loss,and its characteristic of stable performance,high radiation efficiency and simple feeding.However,the dielectric resonator antenna usually adopt higher dielectric constant dielectric materials,so the 10 db bandwidth is usually less than 10% when it works in a single mode resonance unable to meet the requirements of modern communication system for antenna bandwidth,the application is limited.In order to overcome this shortcoming,this paper mainly carries on the research of the dielectric resonator antenna bandwidth extension technology,the main contents include:1.A slotted broadband dielectric resonator antenna is designed.On the one hand,the bandwidth of the antenna is expanded by digging the slotted columns on the traditional rectangular dielectric resonator,reducing its overall Q value,on the other hand,feeding technology uses elliptical patch and coaxial probe combined probe diameter coupling feed mechanism,in order to enhance the coupling between the resonator and the probe,and adjust the impedance matching of the antenna.The results show that the antenna has been expanded with a relative bandwidth of 63%,the impedance bandwidth is 3.15GHz-6.95 GHz,which can cover the TDD-LTE(3.4GHz-3.8GHz)band and WLAN(5.15GHz-5.825GHz)in the wireless communication system at the same time.2.A broadband dielectric resonator antenna is designed.On the one hand,using the inherent resonant frequency each layer of dielectric materials by stacking the two kinds of different dielectric materials to generating multi-resonance mode to expand the antenna impedance bandwidth,on the other hand,digging a rectangular groove to the upper dielectric layer,which can reduce the overall Q value of the DRA and further increase the antenna impedance bandwidth.Using the above methods to obtained bandwidth of the antenna is 3.2GHz-8.8GHZ(S11<-10dB),the relative bandwidth is 79% and the maximum gain is 9.15 dBi over the entire frequency band,which can cover the TDD-LTE band and WLAN band in the wireless communication system at the same time.Using the above method,the S11 <-10 dB impedance bandwidth of the antenna is 3.2GHz-8.8GHz,the relative bandwidth is up to 93%,the maximum gain in the band is 9.15 dBi,and the TDD-LTE communication band and the WLAN communication band can be covered at the same time.In general,the antenna has good gain and wideband characteristics,and the pattern remains basically stable in the operating frequency band.3.Two more practical broadband dielectric resonator antennas have been designed to introduce multi-resonant modes by using a hybrid radiation structure combined with a resonator and a planar monopole antenna,reducing the overall profile height and processing complexity of the antenna.Expanding the antenna bandwidth by adjusting the size of the planar monopole antenna and the dielectric resonator,the resonant frequency of the antenna can be changed and the resonant frequency points can be adjusted to the same frequency range.The first wideband rectangular dielectric resonator antenna adds microstrip lines to the floor plane,which can further tune the antenna's impedance bandwidth.The results show that the impedance of the antenna reaches 91%,which has good broadband characteristics and the profile height is reduced to 4 mm.The second section of the wideband ring dielectric resonator antenna by using less radiation leakage and flexible design of the coplanar waveguide structure,making the overall height of the antenna is only 2mm,and the antenna is produced.The results show that the measurement results are consistent with the simulation results.The obtained bandwidth of the antenna is 2.9GHz-7.2GHZ(S11<-10 d B),the relative bandwidth is 86% which can cover the TDD-LTE band and WLAN band in the wireless communication system at the same time.Designs of the four antennas have very good broadband features,which can fully meet the requirements of the wireless communication system on the antenna performances,and all of them have important engineering significances.