Acoustic Resonator Circuit Using Negative Capacitance Cancellation
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Solution Overview
Problem
Acoustic resonators in wireless devices often create electrical capacitance that causes them to resonate outside their intended frequency, compromising their performance, particularly in high-frequency communication applications.
Innovation Solution
Incorporating an active circuit in parallel to the acoustic resonator that generates negative capacitance to cancel out the electrical capacitance created by the resonator, thereby improving its performance by ensuring resonance only at the intended frequency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an acoustic resonator is used to pass RF signals at a resonance frequency, then signal transmission is improved, but electrical capacitance is generated that causes resonance outside the intended frequency
Solution Approach 1:
The patent converts the harmful electrical capacitance effect into a beneficial one by generating negative capacitance through an active circuit. The negative capacitance cancels out the positive electrical capacitance of the acoustic resonator, eliminating the harmful off-frequency resonance while preserving the desired signal transmission at the resonance frequency.
Solution Approach 2:
The patent introduces an active circuit as an intermediary element between the input and output nodes. This active circuit generates negative capacitance that mediates the interaction between the RF signal and the acoustic resonator's electrical capacitance, canceling out the harmful capacitive effect and enabling precise frequency control.
2Measurement precision
If an active circuit is added in parallel to cancel electrical capacitance, then resonance frequency precision is improved, but device complexity increases
Solution Approach 1:
The active circuit is designed to perform multiple functions: it generates negative capacitance to cancel the electrical capacitance effect, maintains the desired resonance frequency, and ensures proper signal transmission. By consolidating these functions into a single circuit block coupled in parallel, the patent achieves frequency precision without excessive complexity.
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 solution effectively cancels the electrical capacitance, enhancing the resonator's ability to pass radio frequency signals within the desired frequency range while rejecting signals outside that range, thus improving the overall performance of the acoustic resonator.
Implementation Method 1
an acoustic resonator coupled between the input node and the output node. The acoustic resonator is configured to resonate in a resonance frequency to pass an RF signal from the input node to the output node
Implementation Method 2
The active circuit is configured to cause a negative capacitance being generated between the input node and the output node
Data Source
AI summary
An acoustic resonator structure is provided. The acoustic resonator structure includes an acoustic resonator configured to resonate in a resonance frequency to pass a radio frequency (RF) signal from an input node to an output node. However, the acoustic resonator may create an electrical capacitance in parallel to the acoustic resonator. The electrical capacitance may cause the acoustic resonator to resonate outside the resonance frequency, thus compromising performance of the acoustic resonator. In this regard, an active circuit is provided in parallel to the acoustic resonator in the acoustic resonator structure. The active circuit can be configured to cause a negative capacitance between the input node and the output node. As such, it may be possible to cancel the electrical capacitance created by the acoustic resonator, thus helping to improve performance of the acoustic resonator.