Auto-Zeroing Sustaining Amplifier for Low Allan-Deviation Oscillators
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Solution Overview
Problem
Resonator-based oscillators suffer from high 1/f noise corner frequencies, leading to significant near-phase noise, which conventional technologies have not effectively mitigated.
Innovation Solution
The implementation of auto-zeroing sustaining amplifiers with active offset cancellation techniques, such as zero-crossing detection and feedback capacitors, reduces the 1/f noise corner frequency from approximately 5 KHz to less than 10 Hz or 1 Hz, achieving low Allan Deviation performance by synchronizing the amplifier operation with resonator oscillations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional sustaining amplifiers are used in resonator-based oscillators, then the oscillator can maintain oscillation, but the 1/f noise corner frequency remains high (approximately 5 KHz), resulting in significant near-phase noise
Solution Approach 1:
The patent extracts and removes the offset component from the sustaining amplifier's signal path using offset cancellation circuitry. By separating the offset error from the main signal path and actively canceling it, the system eliminates the primary source of 1/f noise without affecting the oscillation maintenance function.
Solution Approach 2:
The patent implements feedback mechanisms where the offset cancellation circuitry continuously monitors and adjusts to counteract offset errors in the sustaining amplifier. This closed-loop feedback approach dynamically reduces the 1/f noise corner frequency by compensating for amplifier imperfections in real-time.
2Object-generated harmful factors
If auto-zeroing sustaining amplifiers with active offset cancellation are implemented, then the 1/f noise corner frequency is reduced to less than 10 Hz, but the device complexity increases due to additional circuitry
Solution Approach 1:
The patent merges the offset cancellation functionality with the sustaining amplifier by integrating the cancellation circuitry directly into the amplifier structure. This consolidation allows the system to reduce 1/f noise while minimizing the increase in overall device complexity through shared components and integrated design.
Solution Approach 2:
The auto-zeroing sustaining amplifier is designed to automatically compensate for its own offset errors without requiring external intervention. The amplifier self-corrects by using internal circuitry that continuously monitors and cancels offset components, reducing the need for additional complex external control systems.
3Manufacturing precision
If offset cancellation circuitry is added to reduce near-phase noise by 20 to 30 dB, then timing signal generation accuracy is enhanced, but the manufacturing complexity increases
Solution Approach 1:
The patent segments the oscillator design into modular components, with the offset cancellation circuitry implemented as a distinct functional block that can be independently designed, tested, and manufactured. This segmentation allows for specialized fabrication processes for the cancellation circuitry while maintaining standard manufacturing for other oscillator components.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach significantly reduces near-phase noise by 20 to 30 dB, enhancing the timing signal generation accuracy and stability of resonator-based oscillators.
Implementation Method 1
a resonator and a sustaining amplifier synchronized to the resonator oscillations
Implementation Method 2
feedback capacitors, achieves low Allan Deviation performance
Data Source
AI summary
An oscillator includes a resonator, sustaining circuit and detector circuit. The sustaining circuit receives a sense signal indicative of mechanically resonant motion of the resonator generates an amplified output signal in response. The detector circuit asserts, at a predetermined phase of the amplified output signal, one or more control signals that enable an offset-reducing operation with respect to the sustaining amplifier circuit.