Spectrum Filters

Butterworth Filter Model

A filter frequency response with flat pass and stop bands.

Parameter	Description
Upper Bandwidth Limit	The filter’s upper limit on the power spectrum. The bandwidth limit is relative to the carrier frequency (the carrier being at zero Hz), and is specified as a positive value. The upper limit is considered to be a sharp cutoff point and the spectrum is zero beyond the limit.
Lower Bandwidth Limit	The filter’s lower limit on the power spectrum. The bandwidth limit is relative to the carrier frequency and is specified as a negative value. The lower limit is considered to be a sharp cutoff point and the spectrum is zero beyond the limit.
Bandwidth	A read-only field equal to the difference between Upper Bandwidth Limit and Lower Bandwidth Limit. It is the total spectral bandwidth over which the filter has a defined response. The filter will only compute over frequencies that are in its defined response; outside its defined response, complete attenuation occurs.
Insertion Loss	A fixed signal attenuation with the spectrum loss computed by the filter’s response characteristics.
Order	Specifies the order of the filter. In general, higher order filters have sharper roll-offs at the cutoff frequencies.
Cut-off Frequency	Specifies the -3dB (50 percent) filter attenuation response point.