Generalized Chebyshev Bandpass Filter Synthesis Wizard

1. Features

  • Support of arbitrary, user defined topologies,
  • Support of direct source-load coupling and several source(load)-resonator couplings,
  • Support of pure-imaginary and pairs of complex (equalization) zeros,
  • Robust algorithm of coupling matrix synthesis,
  • User-defined signs of the couplings,
  • Low-pass and band-pass input of filter specification,
  • On-the-fly preview of the filter prototype polynomials,
  • Group-delay preview,
  • Built-in optimization module of equalization (complex) zeros placement to flatten group delay,
  • Automated transform between low-pass and band-pass prototypes,
  • User-defined masks on filter response,
  • Easy tuning of the imaginary zeros with slider,
  • Prewiev of the response with finite Q-factor resonators,
  • Export of the coupling matrix to text file.


2. Example of a bandpass coupline matrix synthesis

As an example the synthesis of the coupling matrix of a 12-th order filter is shown. be found. The return loss level is -30dB, the frequency band 10.8GHz-11GHz, two imaginary zeros at 11.02GHz and 11.05GHz and one pair of complex zeros to equalize the group delay response. 

Fig.1 Bandpass coupling matrix synthesis