Spectrum Filters

IIR Filter Model

A filter frequency response modeled by using a ratio of nth order polynomials each with a given set of complex coefficients.

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.
Sampling Frequency	The rate at which the discrete filter is sampling the input signal.
Numerator Polynomial	The complex coefficients of the nth order polynomial representing the numerator of the filter function used to model filter frequency response characteristics. The numerator polynomial must be used in conjunction with a denominator polynomial.
Denominator Polynomial	The complex coefficients of the nth order polynomial representing the denominator of the filter function used to model filter frequency response characteristics. The denominator polynomial must be used in conjunction with a numerator polynomial.