Differential Micromachined Ultrasonic Transducer Noise Cancellation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Capacitive micromachined ultrasonic transducers (CMUTs) are susceptible to noise from supply voltage lines, bias voltage lines, and ground lines, leading to signal degradation and reduced image quality in ultrasound devices due to their single-ended signaling techniques.
Innovation Solution
Implementing differential micromachined ultrasonic transducer (MUT) technology with differential signaling techniques, where multiple MUTs are biased with different voltages, allowing noise cancellation and reduced signal processing distortion, thereby enhancing image fidelity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If single-ended signaling techniques are used in CMUTs, then device complexity is reduced, but noise from supply voltage lines, bias voltage lines, and ground lines increases leading to signal degradation
Solution Approach 1:
The patent applies differential signaling which inverts the conventional single-ended approach by using two complementary signal paths with opposite polarities. This inversion allows noise cancellation through subtraction of the two signals, effectively eliminating common-mode noise from supply voltage lines, bias voltage lines, and ground lines while maintaining robust operation
2Reliability
If differential MUT configuration is implemented, then noise cancellation and signal quality improve, but device complexity increases due to multiple MUTs and differential circuitry
Solution Approach 1:
The patent merges multiple MUT elements into a single integrated differential MUT element structure where first and second MUTs are combined with shared biasing circuitry and integrated readout electronics. This merging approach achieves noise cancellation and improved signal quality while reducing overall device complexity through consolidation of functions
Solution Approach 2:
The differential MUT element structure serves multiple functions simultaneously: it acts as both a transmit and receive element, provides noise cancellation, enables differential signaling for improved immunity to interference, and integrates multiple sensing functions within a single element, thereby improving reliability without proportionally increasing 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
The differential MUT configuration reduces noise interference and improves the quality of ultrasound data and images by canceling out common noise sources and minimizing ground bounce, resulting in more robust and high-fidelity imaging.
Implementation Method 1
Capacitive micromachined ultrasonic transducers (CMUTs) are known devices that include a membrane above a micromachined cavity. The membrane may be used to transduce an acoustic signal into an electric signal, or vice versa.
Data Source
Figure 1A
Figure 1B
Figure 2A~2B
AI summary
Aspects of the technology described herein relate to ultrasound circuits that employ a differential ultrasonic transducer element, such as a differential micromachined ultrasonic transducer (MUT) element. The differential ultrasonic transducer element may be coupled to an integrated circuit that is configured to operate the differential ultrasonic transducer element in one or more modes of operation, such as a differential receive mode, a differential transmit mode, a single-ended receive mode, and a single-ended transmit mode.