Design And Verification Of Millimeter Wave Antenna And Passive Device Based On Quartz Substrate Material

With the development of wireless communication technology,the use of microwave bands is becoming saturated,to meet the large-scale application of wireless technology such as 5G in production and life,the millimeter wave band has attracted wide attention.However,with the increase of the operating frequency,the loss of the device dielectric material also increases rapidly,which seriously affects the performance index.The relative permittivity of dielectric materials fluctuates with increasing frequency,which also makes the actual performance of the device very different from that expected in the design.In the industry,the rapid development of Internet of Things technologies such as autonomous vehicle radar has put forward the requirements of low loss,low cost,small size,and high efficiency for millimeter wave devices.Therefore,the performance of high-purity quartz glass substrate and its application in the design of millimeter wave antenna is studied in this thesis.Firstly,the transmission and dielectric properties of 99.9997% high-purity quartz glass are studied utilizing the microring resonance method.The insertion loss of coplanar waveguide structures based on the medium is tested in the frequency range of40～110 GHz.The test results show that the average insertion loss of the structure is between 0.096～0.176 dB/mm.The insertion loss of the coplanar waveguide on the high-purity quartz glass substrate is 0.096 dB/mm,0.125 dB/mm,and 0.176 dB/mm at40 GHz,77 GHz,and 110 GHz,respectively.The relative permittivity of high-purity quartz is 3.7-3.85(V band)and 3.85-4(W band),respectively.The loss angle tangent value obtained in the V band test is about 0.004,and the loss angle tangent value obtained in the W band test is between 0.004 and 0.006.Compared with other high-frequency materials,the results show that high-purity quartz glass has great transmission and electrical properties.Secondly,a 24 GHz microstrip comb array antenna was designed based on the comb antenna theory.The sidelobe level of the antenna is reduced by fillet cutting off the connection area between the radiation element and the feeder and adding a notch on the transverse current path of the radiation element.The designed 1×10 microstrip comb array has a gain of 13.6 dBi at 24 GHz,a half-power beamwidth of 17.7° and a sidelobe level of-19.1 dB in plane E pattern,and a half-power beamwidth of 68.9° and a sidelobe level of-22 dB in a plane H pattern.Then,the design of the 8×10 microstrip comb array is completed through the feed network.The gain of the antenna is 20.4 dBi at 24 GHz,and the sidelobe level of the E plane and H plane is-16.1 dB and-26.3 dB,respectively.It has the characteristics of high gain and low sidelobe.Finally,77 GHz microstrip comb array antennas are designed on two verified substrates of high-purity quartz glass and Rogers 3003 respectively.The advantages of high-purity quartz glass substrate in millimeter wave circuit/device design are verified by comparing the performance indexes of the two substrates.