Research Of Microwave And Millimeter-wave Waveguide Power Dividing/Combining Circuit

With the continuous development of microwave and millimeter-wave communication systems and devices, the research of multi-way, low loss and high isolation waveguide power dividing/combining circuit has become a major trend. Based on substrate integrated waveguide and rectangular waveguide, several multi-way and high isolation power dividing/combining circuit were studied in this paper. The main work is as follows:1. Based on slotted-SIW(substrate integrated waveguide) and slotted-HMSIW(half mode substrate integrated waveguide), by integrating the theory of slotted-waveguide, two four-way power dividing/combining circuits were proposed, which reduced the size and saved the cost compared with the traditional slotted-rectangular waveguide power dividers. By integrating the isolation technology of SIW, a four-way power dividing/combining circuit with high isolation was proposed by improving the traditional Y-junction. Transmission line equivalent-circuit model was used to analyze these circuits, and the validity of the research was verified by simulations and final tests.2. Based on traditional waveguide T-junction and double microstrip-slot coupling structure, a multilayer four-way power dividing/combining circuits with isolation characteristics was proposed. On this basis, a four-way power dividing/combining circuits with high isolation was studied by changing arrangement of the output ports and slotting in the branch of T-junction to assemble isolation resistance, which improved the isolation and increased the practicability of the circuit. Besides, by introducing the coupling of slotted-SIW and input microstrip line, a four-way power dividing/combining circuits with high isolation was proposed, which reduced the transition loss between microstrip line and SIW. At the same time, an eight-way radial power dividing/combining circuit was developed based on the cross-shaped SIW ring cavity, and the high isolation characteristic of it under multi-output was realized by employing radial slots and loading isolation resistors.3. Based on rectangular waveguide and the operating principle of Gysel power dividers, a waveguide Gysel power divider with high isolation in Ka band was proposed, which implemented the application of Gysel power divider in millimeter-wave and provided a new design idea for the research of millimeter-wave high isolation waveguide power dividers. Based on the transition between rectangular waveguide and slotted-SIW, two millimeter-wave slotted-waveguide power dividing/combining circuits were developed, which expand the applications of the theory of slotted-waveguide in millimeter-wave circuits.