Design And Optimization On Traveling Wave Slot Array Of Inverted Trapezoidal Single Ridge Waveguide

Waveguide slot array antenna is easy to control aperture distribution and be conformal,has high power capacity, so it has been used widely in radar and communication fields. With increasingly high requirement of modern communication system for antennas, especially in the field of electronic warfare, antennas are required to be small and light. However, the traditional rectangular waveguide slot array has large size and narrow bandwidth, and its attenuation coefficient is large. The drawback is reflected more serious in modern wireless communication. For above problems, the improvement and optimization of slot array model with new design methods can effectively improve the communication quality and meet the high requirement of modern wireless communication.With the better transmission characteristics, inverted trapezoidal single ridge waveguide was used as feed waveguide instead of traditional rectangular waveguide. Traveling wave was transported by matching load in termination. Initial design on traveling wave array of inverted trapezoidal single ridge waveguide was finished by transmission line theory combined with three-dimensional finite element. In the basis, the pattern of slot array was optimized by using genetic algorithms.Domestic and foreign research status and development direction of waveguide slot array was summarized. On the basis, waveguide slot radiation theory was researched, active admittance was calculated under array environment, and the effect of mutual coupling on active admittance was analyzed. On the basis, a method of extracting active admittance was proposed by using transmission line theory combined with three-dimensional finite element.General structure of slot array was determined according to design index. Array aperture distribution was calculated by Taylor synthesis method, and then the conductance distribution curve of slots was determined by constructing load impedance. The curve of relationship between slots conductance and physical parameters was calculated by the method of extracting active admittance. On the basis of above analysis and calculation, complete model of traveling wave slot array of inverted trapezoidal single ridge waveguide was established,accordingly, its pattern and voltage standing wave ratio was simulated. The result showed that the performance of traveling wave array is favorable. Compared with existing literature,antenna performance has been improved and volume decreases greatly, and it achieve low side-lobe in the case of small volume.The deviation during design process was analyzed. Approaching aperture distribution was set as object function, and performance of inverted trapezoidal single-ridge waveguide slot array was optimized by using genetic algorithms. Main program run in Matlab software,and HFSS software module was used to calculate fitness. Data was delivered between the twosoftware by scrip interface. On the basis, the optimization on traveling wave slot array of inverted trapezoidal single ridge waveguide was finished. And then the optimized slot array was modeled and simulated in HFSS software. Compared to the initial design, the pattern characteristic and gain of the optimized slot array are improved.