The Design And Research Of Millimeter-Wave Power Combining System

This thesis presents the work of the author involved in the project "The verification of the quasi-optical technical solution applied in millimeter-wave power combining system".Located between the microwave and infrared bands, the millimeter-wave techniques with the key advantages such as short wavelength, enough bandwidth and full-weather characteristics is widely used in radar-guided, air detection and other fields. As the research of millimeter-wave system puts forward higher requirements for the power of the source, it brings out the study of the millimeter-wave power combining devices.Quasi-optical is an advanced technology using the quasi-optical devices to adjust the electromagnetic signals, which can replace the circuit power combining and spatial power combining techniques with the advantages such as low loss, strong multi-polar processing capability and the capability in high power radiation. Corresponding to the existing techniques, the author applied the frequency selective surface to design the power combining system with44.5GHz as the central frequency and2GHz as the bandwidth to meet the time-domain power combining design target. The design consists of two parts, which are the millimeter power combining system and the circular polarization selective surface, and both of them can work properly in the high-power radiation situation.The3dB power divider, the polarization selector and the polarization reversal and phase delay device are the three key equipments in the millimeter-wave power combining system design. Also in the design of the circular polarization selective surface scheme, the author finishes the work in both vertical incidence and oblique incidence. The simulation procedure was taken out with CST. After analyzing from the simulation results, the author finds as for the former design, it is easy to fabricate the system but there will be some phase problem. However, there will be no phase limitation for the later one, while the fabricating procedure becomes difficult. Meanwhile this paper also gives out the verification work of the feasibility for several new design structures.