Tunable filter employing feedforward cancellation
First Claim
1. A tunable transmissive filter, comprising:
- a splitter for splitting an input signal into a first signal and a second signal;
a first modifier circuit for modifying a characteristic of the first signal to produce a modified first signal;
a second modifier circuit for using feedforward cancellation to modify a characteristic of the second signal to produce a modified second signal, the second modifier circuit including an N-path filter, N being an integer greater than 0, the N-path filter having a desired frequency response, wherein the N-path filter includes a first N-phase passive mixer, a baseband filter for implementing a desired filter response, and a second N-phase passive mixer, and wherein the baseband filter comprises a plurality of active baseband networks between the first and second passive mixers to realize the desired filter response; and
a combiner for combining the modified first signal and the modified second signal to produce a filtered output signal having a desired inverted frequency response.
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Accused Products
Abstract
Methods, systems, and computer readable media for a tunable filter employing feedforward cancellation are disclosed. According to one aspect, the subject matter described herein includes a tunable transmissive filter that includes a splitter for splitting an input signal into a first signal and a second signal, a first modifier circuit for modifying a characteristic of the first signal to produce a modified first signal, a second modifier circuit for using feedforward cancellation to modify a characteristic of the second signal to produce a modified second signal, the second modifier circuit including an N-path filter, N being an integer greater than 0; and a combiner for combining the modified first signal and the modified second signal to produce a filtered output signal having a bandpass response.
53 Citations
33 Claims
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1. A tunable transmissive filter, comprising:
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a splitter for splitting an input signal into a first signal and a second signal; a first modifier circuit for modifying a characteristic of the first signal to produce a modified first signal; a second modifier circuit for using feedforward cancellation to modify a characteristic of the second signal to produce a modified second signal, the second modifier circuit including an N-path filter, N being an integer greater than 0, the N-path filter having a desired frequency response, wherein the N-path filter includes a first N-phase passive mixer, a baseband filter for implementing a desired filter response, and a second N-phase passive mixer, and wherein the baseband filter comprises a plurality of active baseband networks between the first and second passive mixers to realize the desired filter response; and a combiner for combining the modified first signal and the modified second signal to produce a filtered output signal having a desired inverted frequency response. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A tunable reflective filter, comprising:
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a first reflecting load comprising an N path terminated filter having a plurality of switching devices for selectively connecting an input to ground through at least one of a plurality of active termination devices, N being an integer greater than 0; a second reflecting load; and a coupler for coupling a filter input signal to the input of the first reflecting load and to the input of the second reflecting load and for coupling the input of the first reflecting load and the input of the second reflecting load to a filter output signal, wherein the coupler uses feedforward cancellation to combine a signal reflection from a delay line with a signal reflection from the terminated filter to produce a filtered output signal having a bandpass response. - View Dependent Claims (13, 14, 15, 16)
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17. A method for tunable transmissive filtering, comprising:
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splitting an input signal into a first signal and a second signal; modifying a characteristic of the first signal to produce a modified first signal; using feedforward cancellation to modify a characteristic of the second signal to produce a modified second signal, including using an N-path filter, N being an integer greater than 0, wherein using the N-path filter includes using a first N-phase passive mixer, a baseband filter, and a second N-phase passive mixer, and wherein using the baseband filter comprises using a plurality of active baseband networks between the first and second passive mixers; and combining the modified first signal and the modified second signal to produce a filtered output signal having a desired frequency response. - View Dependent Claims (18, 19, 20, 21, 22, 23, 24, 25, 26)
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27. A method for tunable reflective filtering, comprising:
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providing, via a coupler, a filter input signal to an input of a first reflecting load and to an input of a second reflecting load and coupling the input of the first reflecting load and the input of the second reflecting load to a filter output signal, the first reflecting load comprising an N path terminated filter having a plurality of switching devices for selectively connecting an input to ground through at least one of a plurality of active termination devices, N being an integer greater than 0; using feedforward cancellation to combine a signal reflection from a delay line with a signal reflection from the terminated filter to produce a filtered output signal having a bandpass response. - View Dependent Claims (28, 29, 30, 31)
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32. A non-transitory computer readable medium having stored thereon executable instructions that when executed by the processor of a computer control the computer to perform steps comprising:
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splitting an input signal into a first signal and a second signal; modifying a characteristic of the first signal to produce a modified first signal; using feedforward cancellation to modify a characteristic of the second signal to produce a modified second signal, including using an N-path filter, N being an integer greater than 0, wherein using the N-path filter includes using a first N-phase passive mixer, a baseband filter, and a second N-phase passive mixer, and wherein using the baseband filter comprises using a plurality of active baseband networks between the first and second passive mixers; and combining the modified first signal and the modified second signal to produce a filtered output signal having a desired frequency response.
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33. A non-transitory computer readable medium having stored thereon executable instructions that when executed by the processor of a computer control the computer to perform steps comprising:
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providing, via a coupler, a filter input signal to an input of a first reflecting load and to an input of a second reflecting load and coupling the input of the first reflecting load and the input of the second reflecting load to a filter output signal, the first reflecting load comprising an N path terminated filter having a plurality of switching devices for selectively connecting an input to ground through at least one of a plurality of active termination devices, N being an integer greater than 0; using feedforward cancellation to combine a signal reflection from a delay line with a signal reflection from the terminated filter to produce a filtered output signal having a bandpass response.
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Specification