RADIO FREQUENCY FILTERING TECHNIQUE WITH AUTO CALIBRATED STOP-BAND REJECTION
First Claim
1. A method for filtering a radio frequency (RF) signal, comprising:
- amplifying a first RF communication signal in a first signal path;
filtering the first RF communication signal in a second signal path, said filtering the first RF communication signal in the second signal path includingdown-converting the first RF communication signal to a down-converted signal,high pass filtering the down-converted signal, andup-converting the high pass filtered down-converted signal to a second RF communication signal;
adjusting a signal phase in the second signal path; and
subtracting the second RF communication signal from the amplified first RF communication signal to generate a third RF communication signal.
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Accused Products
Abstract
Methods, systems, and apparatuses for filtering received radio frequency signals are provided. A first RF communication signal is received that includes a desired information signal portion and an undesired blocker signal portion that is offset in frequency from the desired portion. The first RF communication signal is amplified in a first signal path and is filtered in a second signal path. The filtering of the first RF communication signal in the second signal path includes: down-converting the first RF communication signal to a down-converted signal, high pass filtering the down-converted signal, and up-converting the high pass filtered down-converted signal to a second RF communication signal. The filtering of the first RF communication signal filters out the desired information signal portion from the second signal path. A signal phase is adjusted in the second signal path to match phase shifts between the first and second signal paths. The second RF communication signal is subtracted from the amplified first RF communication signal to generate a third RF communication signal. Third RF communication signal includes the desired information signal portion but does not include the blocker signal, which is canceled during the subtraction.
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Citations
22 Claims
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1. A method for filtering a radio frequency (RF) signal, comprising:
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amplifying a first RF communication signal in a first signal path; filtering the first RF communication signal in a second signal path, said filtering the first RF communication signal in the second signal path including down-converting the first RF communication signal to a down-converted signal, high pass filtering the down-converted signal, and up-converting the high pass filtered down-converted signal to a second RF communication signal; adjusting a signal phase in the second signal path; and subtracting the second RF communication signal from the amplified first RF communication signal to generate a third RF communication signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A system for filtering a radio frequency (RF) signal, comprising:
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an amplifier in a first signal path, wherein the amplifier is configured to amplify a first RF communication signal; a receiver translational circuit in a second signal path, wherein the receiver translational signal is configured to filter the first RF communication signal to a second RF communication signal; and a subtractor configured to subtract the second RF communication signal from the amplified first RF communication signal to generate a third RF communication signal; wherein the receiver translational circuit includes a phase adjustor configured to adjust a signal phase in the second signal path. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
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Specification