US 9,438,196 B2 · Integrated tunable filter architecture

Abstract

An apparatus and method for a frequency based integrated circuit that selectively filters out unwanted bands or regions of interfering frequencies utilizing one or more tunable notch or bandpass filters or tunable low or high pass filters capable of operating across multiple frequencies and multiple bands in noisy RF environments. The tunable filters are fabricated within the same integrated circuit package as the associated frequency based circuitry, thus minimizing R, L, and C parasitic values, and also allowing residual and other parasitic impedance in the associated circuitry and IC package to be absorbed and compensated.

Claims20

Dependent claims

An integrated circuit package for selectively filtering unwanted frequencies from a signal path of a frequency based circuit, including:

(a) a frequency based circuit having a signal path;
(b) one or more digitally tunable filters coupled to the signal path of the frequency based circuit, wherein at least one digitally tunable filter includes corresponding direct control lines and is configured to be selectively activated to filter unwanted frequencies from the signal path of the frequency based integrated circuit, wherein the frequency based circuit and such at least one digitally tunable filter are co-designed so as to absorb and compensate for residual and other parasitic impedances present in the integrated circuit, and wherein the direct control lines corresponding to each such digitally tunable filter are configured to receive a digital control word that sets the digitally tunable filter to a selected one of a plurality of states;
and
(c) a lookup table, coupled to at least one digitally tunable filter, for arbitrarily mapping an initial digital control word to the digital control word.

1 more element

A method of calibrating a frequency based circuit that includes digitally tunable circuit elements, including:

(a) providing an integrated circuit package for selectively filtering unwanted frequencies from a signal path of a frequency based circuit, including:
(1) a frequency based circuit having a signal path;
and
(2) one or more digitally tunable filters coupled to the signal path of the frequency based circuit, wherein at least one digitally tunable filter includes corresponding direct control lines and is configured to be selectively activated to filter unwanted frequencies from the signal path of the frequency based integrated circuit, wherein the frequency based circuit and such at least one digitally tunable filter are co-designed so as to absorb and compensate for residual and other parasitic impedances present in the integrated circuit, and wherein the direct control lines corresponding to each such digitally tunable filter are configured to receive a corresponding digital control word that sets the digitally tunable filter to a selected one of a plurality of states;
(b) measuring the frequency response of at least one digitally tunable filter of one or more samples of the frequency based circuits at selected test points while sequencing the received corresponding digital control word over a selected range of available values for the digital control word;
(c) determining a corresponding nominal value for the received corresponding digital control word for the at least one digitally tunable filter based on the measured frequency response;
(d) measuring, for units of the frequency based circuit to be tested, a corresponding frequency response of at least one digitally tunable filter at selected test points while varying the digital control word over a subrange of available values for the digital control word that includes the corresponding nominal value;
and
(e) storing a selected best value for the digital control word from the subrange of available values if such best selected value achieves at least a selected frequency response criteria.

6 more elements

A method of calibrating a frequency based circuit that includes digitally tunable circuit elements, including:

(a) providing an integrated circuit package for selectively filtering unwanted frequencies from a signal path of a frequency based circuit, including:
(1) a frequency based circuit having a signal path;
and
(2) one or more digitally tunable filters coupled to the signal path of the frequency based circuit, wherein at least one digitally tunable filter includes corresponding direct control lines and is configured to be selectively activated to filter unwanted frequencies from the signal path of the frequency based integrated circuit, wherein the frequency based circuit and such at least one digitally tunable filter are co-designed so as to absorb and compensate for residual and other parasitic impedances present in the integrated circuit, and wherein the direct control lines corresponding to each such digitally tunable filter are configured to receive a corresponding digital control word that sets the digitally tunable filter to a selected one of a plurality of states;
(b) measuring the frequency response of at least one digitally tunable filter of one or more samples of the frequency based circuits at selected test points while sequencing the received corresponding digital control word over a first selected range of available values for the digital control word;
(c) determining a corresponding nominal value for the received corresponding digital control word for the at least one digitally tunable filter based on the measured frequency response;
(d) measuring, for units of the frequency based circuit to be tested, a corresponding frequency response of at least one representative digitally tunable filter at selected test points while varying the digital control word over a second selected range of available values for the digital control word that includes the nominal value;
(e) determining, for each such measured unit, a difference between the nominal value and the digital control word corresponding to a selected frequency response criteria of such at least one representative digitally tunable filter;
and
(f) storing, for each such measured unit, the determined difference as a global offset for each digitally tunable filter on such measured unit that is similar to the measured at least one representative digitally tunable filter.

7 more elements

Dependencies are inferred from the claim text.

Integrated tunable filter architecture

Life of this patent

Integrated tunable filter architecture

Life of this patent

Abstract

Claims20