Resonant Impedance Sensing With Controlled Negative Impedance
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Solution Overview
Problem
Resonant sensors face challenges in maintaining steady-state oscillation when detecting changes in resonant impedance due to targets, leading to inaccuracies in sensing responses.
Innovation Solution
Implementing a negative impedance control loop that includes a resonator as a loop filter, generating controlled negative impedance to cancel out resonant impedance, thereby maintaining steady-state oscillation and providing accurate sensor response data.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If resonant sensing is used to detect changes in resonant impedance, then sensing capability is improved, but maintaining steady-state oscillation becomes difficult
Solution Approach 1:
The patent implements a feedback control system where the resonator's oscillation state is continuously monitored and used to adjust the negative impedance generation. The feedback loop detects changes in resonant impedance and dynamically adjusts the negative impedance to maintain steady-state oscillation, resolving the contradiction between sensing capability and oscillation stability.
Solution Approach 2:
The patent changes the electrical parameter of the resonator by introducing a controllable negative impedance that dynamically compensates for variations in resonant impedance. This parameter adjustment allows the system to maintain steady-state oscillation while detecting impedance changes, thus resolving the technical contradiction.
2Stability of the object's composition
If negative impedance control loop is implemented to maintain steady-state oscillation, then oscillation stability is improved, but device complexity increases
Solution Approach 1:
The patent merges the resonator and the negative impedance control circuit into an integrated system where the resonator serves dual purposes: as the sensing element and as part of the control loop. This integration reduces the overall device complexity while maintaining oscillation stability through the unified design.
3Measurement precision
If controlled negative impedance is used to cancel resonant impedance, then sensing accuracy is improved, but circuit complexity increases
Solution Approach 1:
The patent introduces a negative impedance generator as an intermediary element that mediates between the resonator and the measurement system. This intermediary dynamically cancels the resonant impedance to improve sensing accuracy while maintaining a relatively simple circuit architecture through its targeted function.
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 ensures consistent resonator oscillation amplitude and frequency, enhancing the accuracy of sensor responses to targets by maintaining steady-state oscillation, even in the presence of changes in resonant impedance.
Implementation Method 1
generating a controlled negative impedance which is presented to the sensor; controlling the negative impedance based on a detected resonance state to substantially cancel the sensor resonant impedance
Implementation Method 2
a resonator configured for steady-state (non-sensing) operation at a resonant frequency and amplitude. Resonant sensing is based on changes in sensor resonance state as manifested by, for example, changes in resonator oscillation amplitude and frequency
Data Source
AI summary
Resonant impedance sensing with a resonant sensor (such as LC) is based on generating a controlled negative impedance to maintain steady-state oscillation in response to changes in resonance state caused by interaction with a target. Resonant impedance sensing can include: (a) generating a controlled negative impedance at the sensor; (b) controlling the negative impedance based on a detected resonance state to substantially cancel the sensor resonant impedance, such that the sensor resonance state corresponds to steady-state oscillation, where the negative impedance is controlled by a negative impedance control loop that includes the sensor resonator as a loop filter; and (c) providing sensor response data based on the controlled negative impedance, such that the sensor response data represents a response of the sensor to the target. Thus, the response of the sensor to the target corresponds to the negative impedance required for steady-state oscillation.