Research On Basic Components Of Substrate Integrated Waveguide In Millimeter Wave

Modern microwave and millimeter wave circuits are developing towards miniaturization and highly integrated planar circuits.Although the traditional metal waveguide has the advantages of low loss,high Q value,and large power capacity,it is difficult to integrate with other microwave and millimeter wave circuits due to its large size,and it is difficult to achieve miniaturization.Moreover,the processing of traditional metal waveguides is difficult.The processing cost is high.Substrate Integrated Waveguide(SIW)is a new type of structure that combines traditional rectangular waveguides with planar transmission lines.At present,it has been widely used in microwave and millimeter wave circuits.It has the advantages of low transmission loss,excellent microwave performance,and easy integration in a planar structure.At present,SIW technology has been applied to a large number of microwave components,including attenuators,equalizers,oscillators,power amplifiers,phase shifters,and so on.This article first gives the basis and analysis method of SIW,and then introduces the Empty Substrate Integrated Waveguide(ESIW).ESIW is proposed on the basis of SIW,and its structure is basically the same as that of SIW.But the transmission medium is replaced by air from the medium substrate.The transmission characteristics are basically the same as SIW,but the loss is lower and the quality factor is higher.Then based on the analysis of the traditional phase shifter,this paper designs a new type of equal length phase shifter based on SIW.A design method of phase shift curve linearization is proposed for the first time,which combines the advantages of existing SIW phase shifters and avoids the shortcomings of related circuits.At the same time,it has the following advantages: the physical length is the same,and only one variable needs to be adjusted during phase shift.Broadband,small phase shift fluctuation.Then the theoretical basis of SIW equalizer is given,and then based on this theory,a SIW equalizer using ITO material is analyzed,designed,and demonstrated.The use of ITO film as a resistive material greatly reduces the cost of the SIW equalizer.Finally,the basis and analysis of an attenuator are given,and an improved wideband SIW attenuator is proposed.The simulation and test results are in good agreement.