Multiphase Signal Generator Using Open-Loop Phase Interpolation
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Solution Overview
Problem
Generating multiple phases of local oscillator signals for wireless communication devices using quadrature amplitude modulation results in excessive noise and power consumption, particularly with existing methods like ring oscillators and delay-locked loops.
Innovation Solution
The implementation of multiphase signal generation circuitry that uses delay circuitries and phase interpolators to generate output signals out-of-phase by half of the quadrature delay, avoiding ring oscillators, dividers, and delay-locked loop circuitry, and operating in an open-loop configuration to reduce noise and power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If ring oscillators or delay-locked loops are used to generate multiple phases of local oscillator signals, then the signals can be generated for quadrature amplitude modulation, but excessive noise and power consumption occur
Solution Approach 1:
The patent extracts and removes the delay-locked loop control mechanism from the system, using only open-loop delay circuitries and phase interpolators. This eliminates the high-power feedback control while retaining the essential phase generation function, directly resolving the contradiction between signal generation capability and power consumption
Solution Approach 2:
The patent replaces expensive, high-power components (ring oscillators and delay-locked loops) with simpler, lower-power delay circuitries and phase interpolators. These simpler components achieve the same functional result with significantly reduced power consumption and noise
2Reliability
If ring oscillators or delay-locked loops are used to generate multiple phases of local oscillator signals, then the signals can be generated for quadrature amplitude modulation, but excessive noise is produced
Solution Approach 1:
The patent removes the delay-locked loop feedback mechanism that introduces noise, retaining only the essential delay and interpolation functions. This extraction eliminates the primary noise source while preserving signal generation capability
Solution Approach 2:
The patent substitutes noisy, complex components (ring oscillators and delay-locked loops) with quieter, simpler delay circuitries and phase interpolators, achieving the same phase generation function with significantly reduced noise output
3Measurement precision
If delay-locked loop circuitry is used to generate multiple phases, then phase accuracy can be maintained, but device complexity increases
Solution Approach 1:
The patent extracts and removes the feedback control portion of the delay-locked loop, keeping only the essential delay and interpolation components. This simplification reduces circuit complexity while maintaining adequate phase accuracy for the application
Solution Approach 2:
The patent replaces complex delay-locked loop circuitry with simpler delay circuitries and phase interpolators, reducing overall device complexity while achieving sufficient phase accuracy through the open-loop architecture
Data Source
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AI summary
Multiphase signal generation circuitry receives input signals that are out-of-phase with one another by a quadrature delay (e.g., 90°), and generates output signals that are out-of-phase with one another by half of the quadrature delay. A first input signal may be provided to a first delay circuitry, which is then input to a first phase interpolator. The first delay circuitry is also input to second delay circuitry, which also generates an output that is input to the first phase interpolator. The first phase interpolator outputs a first output signal. The second delay circuitry is input to third delay circuitry, which in turn is input to a second phase interpolator with a second input signal that is out-of-phase with the first input signal by the quadrature delay. The second phase interpolator outputs a second output signal that is out-of-phase with the first output signal by the half of the quadrature delay.