Key Technologies Of Millimeter-wave Antennas Based On Substrate Integrated Waveguide

As an emerging technology,substrate integrated waveguide(SIW)features low radiation loss,high power capacity,high Q factor,easy fabrication,and high integration,compared with conventional transmission lines such as microstrip line or CPW.These virtues make the substrate integrated waveguide widely used in the microwave field.In recent years,with the rapid development of millimeter-wave technology,millimeter-wave antennas based on the substrate integrated waveguide have drawn many interests in 5G,wireless local area network(WLAN),radar system,security imaging,etc.due to the advantages of small size,low profile,low cost,and high integration.However,millimeter-wave antennas have a series of problems and cause many challenges in processes of design,packaging,and measurement.These problems hinder the further application of millimeter-wave antennas in practical application.This thesis focuses on above problems of the millimeter-wave antenna,including the following aspects:1.Research on the measurement of relative dielectric constantBased on the substrate integrated waveguide technology,a method to accurately extract the unloaded resonant frequency of the SIW cavity is proposed in Section V.To validate this method,three sets of substrate integrated waveguide resonators operating at different frequencies are designed and manufactured based on the TSMC 0.18 um CMOS process.This method innovatively takes into account the effects of the feed structure impedance and the feed structure itself on the calculation of the unloaded resonant frequency of the cavity.Meanwhile,this method can even remove the influence of external connectors such as the probe and transmission line of the vector network analyzer.Consequently,the more accurate measurement result can be achieved.Additionally,the measurement of this method is simple,and all the required information can be obtained by simply measuring the S parameter of the samples.In contrast,the traditional extraction methods need to plot the Smith chart and extract key parameters by using fitting algorithms.2.Evaluation of probe-fed millimeter-wave antenna measurement setupThe back-to-back horn antenna and the slotted back-to-back horn antenna are proposed and theoretically analyzed in this paper.These antennas are then experimentally validated by the measurement setup described in Section IV.The proposed antennas simultaneously radiate at the end-fire and broadside direction and therefore can be used to replace two standalone samples such as patch and Yagi antennas.Moreover,this horn array features rippled pattern with a precisely-controllable series of nulls for sensitivity measurement and straightforward comparison for evaluation.By employing the substrate integrated waveguide structure,these antennas are fabricated in a single-layer printed circuit board(PCB)to feature easy fabrication and low cost.Good agreement between simulation and measurement shows that the proposed antennas significantly facilitate a fast and low-cost evaluation of the probe-fed antenna measurement setup.3.Research on millimeter-wave antenna packagingBased on the substrate integrated waveguide technology,a broadband cavity-backed patch antenna that can be directly bonded to the chip without extra packaging structure is designed and manufactured based on the PCB technology.This antenna integrates the principle of filter design into the antenna design so that the antenna and the bonding wire exhibit the characteristics of a filter,which eliminates the parasitic inductance effect of the bonding wire.The proposed antenna does not require the extra package interconnection structure,which not only simplifies the design process but also utilizes the inductance of the bonding wires to broaden the bandwidth of the antenna.The simulation shows that the designed antenna bandwidth is 23.3% with the highest gain of 7.4dBi.Based on the substrate integrated waveguide technology,this thesis tries to solve the problems arose in the millimeter-wave antenna design,packaging,and measurement.This paper promoted the development of the substrate integrated waveguide millimeter-wave antenna,which laid the foundation for subsequent research and design.