...under perpetual construction.

Here is a brief comparison between the *minimum loss*, *equiripple* and *maximally flat* filter types. As in the previous example a bandpass filter for the LF band with 3 resonators, having a Q of 350, centered at 137.7 kHz and with a 26.3 kHz bandwidth at an attenuation of 60 dB was designed, this time with three bandpass response types.

The `bpfilt` input screen is:

Enter Center Frequency [Hz] : 137.7e03 Enter Bandwidth [Hz] : 26300 Enter Stopband Attenuation [dB]: 60 Enter Number of Resonators : 3 Enter Resonators Unloaded Q : 350 Enter Inductance L [H] : 1.031e-03 Enter Source Impedance [ohm] : 50 Enter Load Impedance [ohm] : 50

Here is a graph with the frequency response of these three filters:

- Cohn
- Tchebyscheff
- Butterworth

where it can be seen that they have the same bandwidth at -60 dB.

Here is a graph with the close-in frequency response. As expected the *Cohn* type has the lowest losses, even though the *Tchebyscheff* is quite close and the *Butterworth* not much worse.

Actually the latter two filter types should be called here * pseudo equi-ripple* and