Research On Beam Manipulation And Quasi-Optical Technology In Millimeter Wave Power Combining

Millimeter-wave have the physical characteristics of higher bandwidth,shorter wavelength,thinner beam,and anti-jamming,and so on,which have widely used in applications in cutting-edge fields such as ship detection,tracking and guidance,satellite relay,and radio astronomy.Nowadays,with the rapid advancement of s with the rapid development of millimeter-wave systems,the power generation and transmission of millimeter-wave systems have also become the focus of design.For the whole system,the millimeter-wave signal source is the core device when the power generated by a single signal source cannot support the use of the entire system,the research on high-efficiency power combining methods become very important and inevitable.Scholars at have developed and designed a variety of new power combining structures,such as intrawaveguide power combining and quasi-optical power combining.The biggest advantage of these methods is that the loss of the system is very low.Quasi-optical power synthesis is the object of design and research in this thesis.It mainly applies the theory and characteristics of quasi-optical technology,and realizes the effective synthesis of power within the specified space by constraining the transmission path of the beam.The main research contents of this thesis include:1.Investigate the coupled wave equations and a new type of profiled Gaussian radiator is designed by using the solved numerical values.The simulation results show that its radiation characteristics have advantages of high symmetry,low side-lobes,and long-distance transmission which is comparable to corrugated horns.It can be used an efficient radiation source to replace complicated and expensive corrugated horns.2.Investigate the interference coupling of Gaussian beams with the same amplitude and the same polarization in space,and a single-channel transmission path with extremely high transmission efficiency is designed by using ellipsoidal mirrors and parabolic mirrors.The simulation results show that the effective beam combining efficiency is about 75%,and the loss is mainly due to the generation of high-order modes during coupling and the high requirement for the consistency of spatial distribution.It can be used as a reference when there are many combining paths.3.Investigate the design of combining structures based on quasi-optical devices.Two structures were designed by taking advantage of the unique properties of Gaussian beams when delivered to quasi-optical devices.One is a composite structure based on wire grids which uses an ellipsoid mirror to transform the beam,so that two beams with the same polarization and orthogonal parameters are transmitted to the same position of the collimator grating at the same time,one beam is fully transmitted and the other beam is fully reflected,so as to achieve the purpose of power combining.The simulation results show that the synthesis efficiency is as high as 98.9%.This structure is simple and efficient,with low loss and good combining performance when there are few combining paths.The other is a synthetic structure designed based on a 3d B dielectric substrate.Using the unique beam splitting properties of the dielectric substrate,the two beams are combined into one.The simulation results show that the synthesis efficiency is as high as95.2%,which is suitable for projects with complex beam polarization methods.4.Investigate power detection device,and a porous equidistant coupler is designed.The simulation results show that it has good coupling,directivity,higher bandwidth and can strictly maintain the linear detection relationship between the power of the main waveguide and the power of the secondary waveguide which are consistent with theoretical analysis results.