Phase detecting circuit for interchain local oscillator (LO) divider phase alignment
First Claim
1. A circuit for phase detection, comprising:
- a mixer configured to mix a first input signal having a first frequency with a second input signal having a second frequency to produce an output signal having frequency components at the sum of and the difference between the first frequency and the second frequency, wherein the first frequency is the same as the second frequency;
a filter connected with the mixer and configured to remove one of the frequency components at the sum of the first frequency and the second frequency, thereby leaving a direct current (DC) component; and
an analog-to-digital converter (ADC) connected with the filter and configured to determine whether the first input signal is in-phase or out-of-phase with the second input signal based on a comparison between the DC component and a reference signal.
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Accused Products
Abstract
Certain aspects of the present invention provide methods and apparatus for detecting phase shift between signals, such as local oscillating signals in adjacent transceiver paths. One example circuit for phase detection generally includes a mixer configured to mix a first input signal having a first frequency with a second input signal having a second frequency to produce an output signal having frequency components at the sum of and the difference between the first and second frequencies; a filter connected with the mixer and configured to remove one of the frequency components at the sum of the first and second frequencies, thereby leaving a DC component; and an analog-to-digital converter (ADC) (e.g., a comparator) connected with the filter and configured to determine whether the first input signal is in-phase or out-of-phase with the second input signal based on a comparison between the DC component and a reference signal.
22 Citations
30 Claims
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1. A circuit for phase detection, comprising:
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a mixer configured to mix a first input signal having a first frequency with a second input signal having a second frequency to produce an output signal having frequency components at the sum of and the difference between the first frequency and the second frequency, wherein the first frequency is the same as the second frequency; a filter connected with the mixer and configured to remove one of the frequency components at the sum of the first frequency and the second frequency, thereby leaving a direct current (DC) component; and an analog-to-digital converter (ADC) connected with the filter and configured to determine whether the first input signal is in-phase or out-of-phase with the second input signal based on a comparison between the DC component and a reference signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A circuit for wireless communications, comprising:
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a first transceiver path having a first local oscillating signal with a first frequency; a second transceiver path having a second local oscillating signal with a second frequency, wherein the first frequency is the same as the second frequency; and a first phase detector connected with the first transceiver path and the second transceiver path, wherein the first phase detector comprises; a first mixer configured to mix the first local oscillating signal with the second local oscillating signal to produce a first output signal having frequency components at the sum of and the difference between the first frequency and the second frequency; a first filter connected with the first mixer and configured to remove one of the frequency components at the sum of the first frequency and the second frequency, thereby leaving a first direct current (DC) component; and a first analog-to-digital converter (ADC) connected with the first filter and configured to determine whether the first local oscillating signal is in-phase or out-of-phase with the second local oscillating signal based on a comparison between the first DC component and a first reference signal. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21)
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22. A method for detecting phase shift between signals, comprising:
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mixing a first input signal having a first frequency with a second input signal having a second frequency to produce an output signal having frequency components at the sum of and the difference between the first frequency and the second frequency, wherein the first frequency is the same as the second frequency; filtering the output signal to remove one of the frequency components at the sum of the first frequency and the second frequency, thereby leaving a direct current (DC) component; comparing the DC component to a reference signal; and determining whether the first input signal is in-phase or out-of-phase with the second input signal based on the comparison. - View Dependent Claims (23, 24, 25, 26, 27, 28, 29, 30)
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Specification