Reseach On Marching-on In-time Scheme And The Fast Algorithm Of Time Domain Integral Equation

Directional coupler possesses good directionality and is widely applied in microwave integrated circuits of microwave passive components, whose performance directly affect the whole integrated microwave circuit system. Directional coupler are often used in the measurement system, power monitoring system, power matching and distribution system as well as the synthesis of microwave devices etc. due to it’s advantage of small volume, high performance and easy processing. In the active circuit, directional coupler is mainly used in the phase shifter, attenuator, mixer, balanced amplifier, modulator and separator. While in passive circuit, the directional coupler can be applied in filter, tuner, delay line and matching network. Substrate integrated waveguide is a new generation of three-dimensional periodic waveguide structure, which integrated the dielectric substrate. It can effectively conduct coplanar integration with active and passive components and has the merits of low radiation, low loss, high power capacity, and high Q value, which traditional rectangular waveguide possesses as well. Meanwhile, it enjoys the advantages of the micro strip line, small size and easy to integrate. Thus Substrate integrated waveguide greatly reduced the volume of original mm waveguide device, also greatly narrowed the size, the volume the quality and the cost of other waveguide microwave passive components. In the meanwhile, it increased the repeatability and reliability of the device in the manufacturing process, and improved the efficiency. Therefore, microwave devices designed by use of substrate-integrated waveguide have great application value.This paper designs a kind of microwave passive components based on substrate integrated waveguide directional coupler through studying the structure parameters of substrate-integrated waveguide and the principle of directional coupler. The selection of the size of substrate integrated waveguide and the design process of directional coupler contains the establishment of the basic model and the data analysis of the impact that the various parameters of devices brought to its performance, thus obtains the target device with the optimal model parameters. It also proved that directional coupler, designed by using the substrate integrated waveguide, had a good directional and coupling, and effectively reduce the volume of the device, so as to benefit for the integration of the microwave circuit.This paper conduct external impedance matching design for the further optimized substrate integrated waveguide directional coupler, and get its optimal matching form through analyzing the date obtained from two types of matching. This design satisfied the target bandwidth of substrate integrated waveguide and micro strip line impedance matching. In the design process, since SIW and the frequency changes contrary to the characteristic impedance of micro strip line, reducing the standing wave was used to extend the bandwidth. The end of this paper detailed summary to the whole subject research, and put forward the problems and necessary improvement in the process of the experiment.