Study Of Microwave Filter Synthesis Designing And Tuning

With the rapid development of radio communication, the microwave filter as a frequency selecting component is in a great progress to mitigate the crowded frequency spectrums. By utilizing the EDA electromagnetic simulators and integrating new technology and new materials, various designs of microwave filters have been proposed and they tend to be refined. However, the engineers usually need spend much time on the full-wave electromagnetic simulations or manual debugging. So, computer-aided diagnosis or debugging has become a hot topic in recent years. The proposed methods on computer-aided diagnosis mainly extract parameters of filters using nonlinear optimization methods with complicated optimization algorithms or sensitive initial values. The Cauchy algorithm makes less effect on the evaluating the influence of phase and extracting parameters of filters with loss.This thesis has listed the common methods in filter design and debugging with simple illustrations. After that, the method of extracting filter parameters using vector fitting has been proposed. The accurate analysis of curve fitting on the parameters of important admittance has been investigated and the coupling–matrix of filter and quality factor has also been extracted. These extracted data can be used in the process of simulation and debugging. Then, the fast filter design process can be achieved. Moreover, hybrid debugging approach with absorbent cross-coupling concept has been proposed in the debugging process of cross-coupling filter.