三阶微带滤波器快速设计方法OA

The distributed parameter effect makes the design of microstrip filters time-consuming.Solely relying on designers'experience may not necessarily meet the technical specifications in the end.Therefore,it is highly necessary to conduct in-depth research on their physical mechanisms,develop analytical methods,and accelerate their design process.This paper carried out an in-depth study on a third-order microstrip filter,which is composed of a parallel coupled-line section,an open-end stub,and another parallel coupled-line section connected in sequence.By establishing a lumped-parameter equivalent circuit for it,the physical mechanisms were clearly revealed,including the generation mechanism of transmission poles and the formation mechanism of the passband.Furthermore,explicit calculation formulas were established,and a fast design method was developed based on these formulas,which can be used to guide the design under different technical specifications.Finally,an example with a center frequency of 4.0 GHz and a relative bandwidth of 30%was used to verify the effectiveness of the proposed fast design method.A set of good initial values of structural parameters was obtained through this method.After full-wave simulation optimization,only simple fine-tuning is required to achieve the design target,which reflects the superiority of the fast design method.