I - Q Vector Modulator Research Ka-band Balance

Vector modulator has been applied in the microwave and millimeter wave systems more and more widely. High-performance vector modulator is generally used in microwave and millimeter wave systems for direct modulation of microwave RF signal as an electronic control device. Vector modulator has been researched for a long time abroad, and the processing technology is very mature, and the coupler in vector modulator commonly uses the form of Lange couplers by monolithic MMIC technology. The vector modulator generally uses a hybrid integrated circuit structure due to the restrictions of the process in domestic. In this paper, the design uses high characteristic impedance of the branch line coupler to combine with PHEMT switching tube, and produces Ka-band balanced I-Q vector modulator on the substrate Rogers5880with hybrid integrated production process.This thesis designs Ka-band balanced I-Q vector modulator, and the operating frequency is34-36GHz. It is produced on the dielectric substrate Rogers5880by using the form of hybrid integrated circuit structure. It is used in millimeter-wave FMCW radar RF cancellation system for the leakage signal cancellation. This paper first describes the application, development and prospects of the vector modulator in detail, analysis the different types of vector modulator, points out their advantages and disadvantages, and focuses on balanced I-Q vector modulator. Subsequently, this paper uses the simulation software HFSS to design and simulate Ka-band balanced I-Q vector modulator, including the branch line coupler, microstrip to waveguide transition of the dorsal fin line and microstrip magic T as well as their form of cascade, and uses the mapping software Auto CAD and Solidworks to design the cavity circuit and PCB board. Finally, this paper assembles and debugs the designed vector modulator, analysis results, and proposes improvement program.