Substrate Integrated Current Sensor for High Bandwidth Sensing
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Solution Overview
Problem
Current sensing methods, such as resistive sensors and Rogowski coils, face challenges in high bandwidth AC applications due to high parasitic capacitance and inductance, which reduce sensitivity and are not suitable for high-frequency current sensing.
Innovation Solution
A current sensor design utilizing a sensing trace within a substrate to detect electromagnetic forces generated by magnetic flux inductively coupled from a current carrying trace, allowing for reduced parasitic capacitance and inductance, thereby enabling higher bandwidth and sensitivity without direct coupling to the current carrying wire.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple turns are used in Rogowski coil to increase sensitivity, then measurement precision is improved, but parasitic capacitance and inductance increase reducing bandwidth
Solution Approach 1:
The patent replaces the traditional mechanical winding structure of Rogowski coils with an integrated circuit implementation using planar traces and magnetic coupling structures. This substitution eliminates the need for multiple physical turns while achieving equivalent or superior sensitivity through optimized magnetic flux coupling and integrated amplifier circuits, thereby resolving the bandwidth limitation imposed by parasitic elements in conventional multi-turn coils
Solution Approach 2:
The patent changes the fundamental operating parameters by using magnetic coupling between separate traces instead of direct multi-turn winding. By optimizing the magnetic coupling coefficient, trace geometry, and using differential sensing with integrated amplification, the system achieves high sensitivity without the parasitic capacitance and inductance that limit bandwidth in traditional Rogowski coil designs
2Measurement precision
If resistive current sensor is used to measure current, then current detection is achieved, but energy loss increases due to resistance in current path
Solution Approach 1:
The patent introduces magnetic flux as an intermediary between the current-carrying trace and the sensing circuit. The magnetic coupling structure detects current through magnetic field interaction rather than direct electrical contact, eliminating the need for resistive elements in the current path and thereby eliminating I²R energy losses while maintaining accurate current detection capability
Solution Approach 2:
The patent replaces the resistive measurement mechanism with a magnetic coupling-based sensing mechanism implemented in integrated circuit form. This substitution uses electromagnetic induction and magnetic flux detection instead of ohmic voltage measurement, achieving current detection without the energy dissipation inherent in resistive sensors
3Measurement precision
If Rogowski coil is placed in close proximity to current carrying wire to increase sensitivity, then measurement precision is improved, but disturbance to current flow increases
Solution Approach 1:
The patent uses magnetic flux as an intermediary that allows the sensing trace to be positioned close to the current-carrying trace for high sensitivity while maintaining electrical isolation. The magnetic coupling mechanism transfers current information through the magnetic field without requiring direct physical or electrical contact, thereby achieving high measurement precision without introducing disturbance to the current flow
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 solution allows for effective detection of high-frequency AC currents with increased sensitivity and reduced parasitic effects, enabling efficient current sensing in integrated circuit devices without disturbing the current flow.
Implementation Method 1
a sensing trace located within the substrate proximate to the current carrying trace; wherein the sensing trace detects an electromagnetic force (emf) generated by magnetic flux inductively coupled from the current carrying trace
Data Source
AI summary
A current sensor comprises a current carrying trace located within a substrate; and a sensing trace located within the substrate proximate to the current carrying trace; wherein the sensing trace detects an electromagnetic force (emf) generated by magnetic flux inductively coupled from the current carrying trace for transmitting to a current sensing device.