Research And Design Of Artificial Magnetic Conductor In Millimeter Wave Passive Devices

With the gradual commercial and deployment of the new generation of 5G communication system,microwave and millimeter-wave communication has been developed rapidly.However,the implementation of 5G communication system with high rate and low delay is limited by a variety of RF devices with superior electrical performance,especially in the millimeter-wave frequency band.Artificial Magnetic Conductor as a new material,it has excellent electromagnetic characteristics that traditional physical materials do not have in nature,that is,it has the characteristics of in-phase reflection of plane waves by ideal magnetic conductors and the characteristics of electromagnetic stopband that limits the propagation of electromagnetic waves,and it can break through the RF antenna and RF devices structure design limit,improve the overall performance of the RF antenna and RF device.This paper focuses on the design and application of the electromagnetic stopband characteristics of AMC in millimeter-wave passive devices.In this paper,an AMC structure working in millimeter-wave frequency band is proposed on the basis of analyzing and studying the working principle of the electromagnetic stopband characteristics of the AMC structure,the effects of the structure parameters of AMC on the central frequency and relative bandwidth of the electromagnetic stopband characteristics are also discussed,then introduced a kind of Perfect Magnetic Conductor packaging structure which based on the AMC structure,thus designed a millimeter-wave power divider based on AMC structure with PMC package.The millimeter-wave power divider loaded with the ideal PMC packaging structure realizes the equal-amplitude in-phase output of each output port between 27GHz and 31.5GHz frequency band.Compared with the traditional microstrip power distributor,the transmission performance is improved by about 20%,and the resonance characteristics are improved.Then,in view of the problems mentioned above,such as few adjustable parameters of mushroom type AMC structure and difficulty in adjusting the range of electromagnetic stopband,a new kind of cross-shaped AMC structure is improved and designed.Compared with the mushroom type AMC unit mentioned above,this novel structure is simple in design.It not only reduces the profile height by about 46.7%and the volume,but also has a more easily adjusted parameterized characteristic,which can obtain a more accurate electromagnetic stopband,and applied to the millimeter-wave 3-d B directional coupler,benefited from the three-layer structure design in the previous paper,the directional coupler realized that in the relative bandwidth of about 20%,the insertion loss from the input end to the pass-through end and the coupling end was basically less than 3.5d B,the return loss was less than-30d B,the isolation degree was more than 15d B,and the pass-through port and the coupling port had phase difference of 90~o±2.5~o.Finally,the model structure,working principle and dispersion characteristics of Printed Ridge Gap Waveguide which based on AMC structure are introduced and analyzed,and its feasibility as millimeter wave transmission waveguide is verified.Late for processing the measured accuracy,this paper proposes a simple and effective clearance from the microstrip to the Printing Ridge Gap Waveguide transition structure,and the the half-wavelength microstrip resonator is analyzed based on the Printing Ridge Gap Waveguide.Finally,a fourth-order coupling resonator bandpass filter using millimeter wave Printing Ridge Gap Waveguide technology with two transmission zeros is designed.The insertion loss in the passband of the bandpass filter is less than 0.8d B,the return loss is more than 15d B,and there is a transmission zero at each end of the passband,which has the characteristics of good frequency selectivity and strong suppression ability outside the passband.The previous three-layer design was improved to a two-layer design,further reducing the profile height and volume,and making it easier to integrate with other microwave and millimeter-wave circuits and systems.