Square-Wave Frequency Characterization of Electronic Systems
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Solution Overview
Problem
Current methods for frequency characterization of electronic systems, such as those using chirp signals, face limitations including long recording times, hardware complexity, and cost due to the need for additional power electronic components and specific coupling adaptations, which restrict bandwidth and signal-to-noise ratio, especially in DC-based applications.
Innovation Solution
A device and method utilizing two ports to couple a test signal into an electronic system, with a control circuit generating a square-wave signal and a coupling circuit featuring adjustable impedance, allowing non-invasive coupling and synchronous measurement of current and voltage signals, enabling cross-correlation and Fourier transformation to derive frequency curves without distorting the system's operating point or requiring extensive hardware adjustments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If chirp signals are used for frequency characterization, then the frequency response can be measured, but the recording time becomes very long especially for low frequency ranges
Solution Approach 1:
The patent uses periodic square-wave signals instead of chirp signals to excite the system under test. The square-wave signal has rich harmonic content that allows broadband frequency characterization to be achieved in a fixed, short time period regardless of the frequency range being measured.
2Measurement precision
If capacitive or inductive coupling is used to introduce chirp signals, then the system can be characterized, but additional hardware components and complexity are required
Solution Approach 1:
The patent extracts the coupling circuitry from the measurement system by using the device under test's own power electronics (switches, MOSFETs) to generate the excitation signal directly at the power stage, eliminating the need for external capacitive or inductive coupling components.
Solution Approach 2:
The device under test uses its own power electronic components to generate the square-wave excitation signal, making the system self-exciting and eliminating the need for external signal injection hardware.
3Reliability
If inductive coupling elements are introduced into the measurement arrangement, then galvanic isolation can be achieved, but the hardware outlay increases
Solution Approach 1:
The patent removes the need for separate isolation hardware by utilizing the existing switching elements in the power electronic converter, which naturally provide the necessary isolation and signal injection functionality.
4Measurement precision
If network analyzers are used with higher performance levels, then measurement accuracy improves, but the signal levels available are no longer sufficient to ensure adequate signal-to-noise ratio
Solution Approach 1:
The square-wave excitation signal provides high amplitude periodic switching that generates strong fundamental and harmonic components, ensuring adequate signal-to-noise ratio across the frequency spectrum without requiring external power amplifiers.
5Measurement precision
If additional power electronic components are introduced into the measuring circuit, then frequency characterization can be performed, but the operating point and frequency behavior of the entire measuring circuit can be distorted
Solution Approach 1:
The device under test uses its own existing power electronic components to generate the excitation signal, avoiding the introduction of additional components that could distort the operating point or frequency behavior.
Data Source
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AI summary
A device for frequency characterization of an electronic system is proposed. The device includes two terminals configured to couple with the electronic system. Furthermore, the device includes a control circuit configured to generate a test signal. The device also includes a coupling circuit with adjustable impedance and a switch, coupled in series. The end nodes of the coupling circuit are coupled to the two terminals. The switch is configured to electrically couple the two terminals based on the test signal.