Q U I E T S O F T™ . F I L T E R . D E S I G N . L I B R A R Y . S C R E E N S H O T S
Note: controls, buttons, menus, ribbon, and scroll bars removed from screenshots for clarity.

B U T T E R W O R T H . L O W P A S S . F I L T E R
This is a plot of a Butterworth lowpass filter with a -3 dB passband edge at 44.1 kHz and a stopband rejection of -25 dB at 88.2 kHz. The design produced a 5th order filter.

The solid red line is the gain response, the dashed blue line is the phase repsonse, and the solid green brackets indicate the passband and rejection band frequencies and gain specifications.

C H E B Y C H E V . H I G H P A S S . F I L T E R
This is a plot of a Chebychev highpass filter with a -3 dB passband edge at 88.2 kHz and a stopband rejection of -25 dB at 44.1 kHz. The design produced a 3rd order filter.

I N V E R S E . C H E B Y C H E V . B A N D P A S S . F I L T E R
This is a plot of an Inverse Chebychev bandpass filter with a -3 dB passband from 19.5 to 20.5 GHz and -33 dB rejection points at 18 and 22 GHz. The design produced a 6th order filter. Note the phase discontinuities at the filter's zeros.

This is a pole-zero plot for the same Inverse Chebychev bandpass filter. As expected for a classical filter, the poles and zeros are in complex conjugate pairs, except for the real zero at the origin, and all the poles are in the left hand plane indicating stability.

E L L I P T I C . N O T C H . F I L T E R
This is a plot of an Elliptic notch filter with a -50 dB stopband from 29 to 30 GHz and -0.5 dB passband points at 27 and 32 GHz. The design produced a 6th order filter. Note the phase discontinuities at the filter's zeros.