Shaped-beam Of Slotted Waveguide Arrays

Waveguide-fed slot arrays are applied widely in radar and communication fields, because they have peculiarities such as aperture field controlled easily, easy and compact configuration and excellent electric capability. Especially for the slot antenna in a rectangular waveguide broadwall, it not only has excellent electric capability, but also has traits of small thickness, power capacity and so on. Thus it has special advantages in aspects of airborne fire control radar and missile guidance and the research on its synthesis and design has been paid more and more attention to. Shaped-beam of the slot antenna in a rectangular waveguide broadwall is researched in this paper. From the point of view of the content, it can be divided into three parts.An improved genetic algorithm applying to shaped-beam of antenna array is researched. Firstly, an improved genetic algorithm is presented by changing its genetic parameters. The element's voltage amplitude of linear array and rectangular plane array is optimized to reduce the maximum side level using this improved method. Secondly, the element's voltage amplitude and phase of linear array antenna are optimized synchronously by the method, and shaped-beam is realized primely. Finally, the improved algorithm and Schelkunoff's method have been combined to optimize roots which are not on the unit circle of linear array, then shaped-beam and zeros control are realized.Synthesis and design of slotted waveguide array are studied. At the first, longitudinal slot on the broad face is selected as an element of slotted waveguide array. It has been analyzed and solved. Then the design equations of traveling-wave fed slotted array are educed and the design flow is also given in the condition of not considering coupling and considering coupling separately.Combining two parts mentioned above, shaped-beam of slotted waveguide array is researched. Above all, adopting Chebyshev antenna distribution, slotted waveguide array is designed in the condition of not considering coupling and considering coupling separately. The design results are emulated by Ansoft HFSS. By comparing the results, the design progress proves to be correct and considering coupling is essential. And then Taylor synthesis method is employed to shape pattern of slotted waveguide array and the antenna pattern and VSWR are obtained. In the end, by trying to divide slotted waveguide array into several segments, voltage amplitude and space between units of every segment and space between segments are optimized using the improved genetic algorithm and the synthesis of shaped-beam is realized. The design results are acquired and emulated by Ansoft HFSS. The outcome shows good.