Patent ID: 6593828
Filing Date: 2003-07-15
Classification: H03H

Abstract:
A method for filter tuning, comprising the steps of:determining a first group of components of a filter that define pole frequencies and pole zeroes of the frequency response of said filter; determining an initial cutoff frequency of adequate accuracy to satisfy requirements of the application of said filter; adjusting said first group of components of said filter by coarse adjustments, such that said filter is set with said initial cutoff frequency of adequate accuracy; determining a second group of components of said filter that define a notch frequency of said filter; determining an initial cutoff frequency of higher accuracy than the adequate accuracy to satisfy requirements of the application of said filter; adjusting said second group of components of said filter by fine adjustments, such that said filter is set with said initial cutoff frequency of higher accuracy than the adequate accuracy to satisfy requirements of the application of said filter; monitoring a temperature of said filter; determining a temperature variation of said filter from the initial temperature of said filter when said filter is set with said initial cutoff frequency of higher accuracy than the adequate accuracy to satisfy requirements of the application of said filter; determining a third group of components of said filter that define said notch frequency of said filter to maintain the accuracy of the initial cutoff frequency in response to cutoff frequency drift dependent on said temperature variation of said filter; and adjusting said third group of components of said filter by fine adjustments, such that said filter is set to maintain the accuracy of the initial cutoff frequency in response to cutoff frequency drift dependent on said temperature variation of said filter.