CST2013: Filter Analysis / Group Delay Computation

Home: MacrosMacrosFilter AnalysisGroup Delay Computation

The Group delay time is defined as the negative derivative of the S-Parameter phase versus omega (2*pi*f). The macro performs this mathematical operation for any S-Parameter data and any mode pertinent to the port. If the phase signal is low in resolution with respect to frequency, unphysical discontinuities might appear and can be blend away by a userdefined threshold angle. An extra window pops up in this case containing a list of frequencies where this has happened.

The group delay is available under 1D Results/Group Delay Time. Additional output for narrowband bandpass filters is also accessible: the loaded Q-factor and coupling distance Ke for the first resonator stage.

There exists also a 1D Result Template to calculate Group delay time during parameter sweeping and optimization: 1D / Group Delay Time

Here some typical result curves are shown:

Group delay output

Loaded Quality factor Qe

Coupling Bandwidth versus Frequency