Research On Empty Substrate Integrated Waveguide

Substrate Integrated Waveguide(Substrate Integrated Waveguide,SIW)is a new type of transmission line structure,which has been widely used in microwave and millimeter wave circuits because of its excellent microwave performance,such as low insertion loss and convenient integration.The loss of Substrate Integrated Waveguide mainly comes from the dielectric loss and the loss caused by skin effect of metal wall,in which the loss caused by skin effect of metal wall is inevitable,and the dielectric loss varies with the m dielectric we choose.Therefore,when the loss of selected dielectric is low,such as air,we get the Substrate Integrated Waveguide with lower loss.In particular,we call the Substrate Integrated Waveguide filled with air as Empty Substrate Integrated Waveguide(Empty Substrate Integrated Waveguide,ESIW).Compared with the traditional Substrate Integrated Waveguide,the most obvious difference between the Empty Substrate Integrated Waveguide and the traditional Substrate Integrated Waveguide is that the insertion loss of the Empty Substrate Integrated Waveguide is lower,and it has the advantages of high power capacity of the traditional Waveguide and convenient integration of the microstrip line,so it can be integrated into the circuits together with other circuit modules.Application of ESIW/SIW in microwave device design is studied in this article.First,starting with the Substrate Integrated Waveguide,this article firstly introduces the electric field distribution of the Substrate Integrated Waveguide,and then discusses conductor loss,dielectric loss,radiation loss of SIW.Secondly,considering the scenario of Empty Substrate Integrated Waveguides in practical applications,ESIWs are generally used with microstrip lines in practical applications,and the characteristic impedance and propagation modes of microstrip lines and esiw need to be transitioned and converted.Therefore,we focus on the transition structure between esiw and microstrip lines in chapter 3.Then,we also investigate the loading surface resistance on the Substrate Integrated Waveguide surface and conduct theoretical analysis.Furthermore,according to the loss characteristics of Substrate Integrated Waveguide after surface resistance,a new equalizer and attenuator are designed and tested in this article,which can achieve amplitude equalization and attenuation in millimeter wave band.As far as we know,this is the first time to propose a Substrate Integrated Waveguide equalizer and attenuator based on surface resistance,which has strong theoretical value and engineering significance.Finally,combining the dispersion characteristics of delay line shifter and equal length and unequal width shifter,this paper presents an equal length broadBand 3D-ESIW phase shifter,which can theoretically achieve arbitrary phase shift,and the horizontal length of the phase shifter remains the same,which is convenient to integrate in the phased array.