Integrated microwave filter and method of constructing same

摘要

Cascaded dual-mode resonance cavities are separated by plates having each a cruciform iris therein, the arms of which have lengths determined by a direct and precise procedure starting from a conventional Butterworth prototype filter. The transfer function parameters are altered to change the filter response and the group delay performance is determined and compared to an ideal flat response for producing a penalty function signal from the difference in order to modify the parameters again in such direction that the penalty function signal is likely to be reduced. The process is repeated until the penalty function signal is minimum, whereby a compact structure is realized which provides an attenuation response having sharp cut-off slopes at the edges of the signal bandwidth together with a close to flat in-band group delay response.