BST Capacitor Configuration via Iterative Feedback Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
BST capacitors face inaccuracies in capacitance control due to manufacturing tolerances, temperature variations, and hysteresis-related issues, which existing methods fail to accurately address.
Innovation Solution
A method involving the injection of a constant current into the BST capacitor for a set time interval, measuring the bias voltage, calculating the capacitance, and adjusting until the desired value is reached, using formulas ΔC=Ic*ΔT/ΔV and C=Ic*ΣΔT/Vbias to account for hysteresis and other variations, with a microcontroller circuit to implement this process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a dedicated control circuit performing high-voltage digital-to-analog conversion is used to set the bias voltage of a BST capacitor, then the capacitance can be adjusted to adapt to external environment, but inaccuracies occur due to manufacturing tolerances, temperature variations, and hysteresis effects
Solution Approach 1:
The patent implements a feedback mechanism where the actual capacitance value is measured and compared with the target value, and the bias voltage is adjusted iteratively until the desired capacitance is achieved. This closed-loop control compensates for manufacturing tolerances, temperature variations, and hysteresis effects, achieving capacitance setting accuracy within 1% of the target value.
Solution Approach 2:
The patent applies a preliminary constant current to the BST capacitor before measurement to ensure the dielectric material reaches a stable state and hysteresis effects are minimized. This preliminary action allows for more accurate capacitance measurement and setting by establishing a consistent initial condition.
2Measurement precision
If a constant current is applied to the BST capacitor for measurement, then the capacitance can be calculated using the formula C=Ic*ΣΔT/Vbias, but the measurement process requires multiple iterations to achieve the desired precision
Solution Approach 1:
The patent applies a constant current that is sufficient to charge the capacitor completely during the measurement interval, ensuring that the voltage reaches a stable plateau. This excessive action (applying more current than minimally needed) ensures complete charging and eliminates measurement uncertainties, achieving high precision within a fixed time interval.
Solution Approach 2:
The patent uses periodic measurement cycles where a constant current is applied for a fixed time interval, followed by measurement and comparison with the target capacitance. This periodic action repeats with adjusted bias voltage until convergence is achieved, systematically reducing the number of iterations needed while maintaining high precision.
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 method improves the accuracy of setting BST capacitor capacitance values, making it independent of manufacturing tolerances, temperature variations, and dielectric hysteresis, achieving precision in the order of one percent.
Implementation Method 1
C=Ic*ΣΔT/Vbias where C represents the calculated capacitance and Vbias represents the measured voltage
Implementation Method 2
A solution capable of taking into account variations due to the hysteresis of the dielectric material of the capacitor
Data Source
AI summary
A capacitor has a variable capacitance settable by a bias voltage. A method for setting the bias voltage including the steps of: (a) injecting a constant current to bias the capacitor; (b) measuring the capacitor voltage at the end of a time interval; (c) calculating the capacitance value obtained at the end of the time interval; (d) comparing this value with a desired value; and (e) repeating steps (a) to (d) so as long as the calculated value is different from the set point value. When calculated value matches the set point value; the measured capacitor voltage is stored as a bias voltage to be applied to the capacitor for setting the variable capacitance.