Patent ID: 9287851
Filing Date: 2016-03-15
CPC Classification: G06F,H03H,H03K

Claim Text:
1. A method of designing a finite impulse response filter having a delay line containing a plurality of delay elements, comprising: receiving at a processor a selected frequency response for the filter; calculating by the processor an impedance value for each of a first plurality of impedance elements of a single type by approximating a first set of Fourier transform coefficients of a Dirac function corresponding to the selected frequency response with a first phase factor and selecting a set of impedance values that are an inverse of the first set of Fourier transform coefficients, each impedance element from the first plurality of impedance elements to be coupled to the delay line after a different delay element than each other impedance element in the first plurality of impedance elements so as to receive a delayed input signal and provide an output weighted by the impedance value of the impedance element, the impedance values of the first plurality of impedance elements calculated such that a sum of the outputs of the first plurality of impedance elements is a first output signal of the selected frequency response; calculating by the processor an impedance value for each of a second plurality of impedance elements of a single type by approximating a second set of Fourier transform coefficients of a Dirac function corresponding to the selected frequency response with a second phase factor and selecting a set of impedance values that are an inverse of the second set of Fourier transform coefficients, each impedance element from the second plurality of impedance elements to be coupled to the delay line after a different delay element than each other impedance element in the second plurality of impedance elements so as to receive a delayed input signal and provide an output weighted by the impedance value of the impedance element, the impedance values of the second set of impedance elements calculated such that a sum of the outputs of the second plurality of impedance elements is a second output signal of the selected frequency response, but having a different phase from the first output signal; and connecting the outputs of the first plurality of impedance elements to provide the first output signal, and connecting the outputs of the second plurality of impedance elements to provide the second output signal.