The proliferation of mobile communication systems and protocols mean frequency spectrum
There are several simulation techniques that can be used in the tuning process of coupled-resonator filters. One traditional approach is to sequentially build up the filter by adding only one resonator at a time, while the group delay of the reflected signal is used as the figure of merit for the optimization. Another approach is to apply the inverse chirp Z-transformation to the reflected signal and from the transient response identify the individual detuned resonators and couplings. It is also possible to add additional ports to the full-wave simulation model and connect lumped components in a coupled schematic for space mapping[. All of these techniques typically involve using an equivalent circuit as a surrogate model where intermediate results can quickly be obtained as a reference during the process.