Surface H-field mapping of a microwave limiter chip based on quantum diamond probe

With the increasing integration and complexity of chips, the problem of wafer-level electromagnetic compatibility (EMC) is becoming more and more prominent, and the spatial resolution and operating frequency of existing EMC test techniques can no longer meet the demand for wafer-level EMC testing. In this work, a surface H-field imaging system based on a micron-sized diamond crystal containing nitrogen-vacancy centers is proposed, which is micrometer resolved, quantum calibrated, frequency tunable, and nonintrusive to the H-field of the device to be tested. The surface H-field of a limiter chip at different input power is scanned for imaging, revealing how the energy is dissipated across the chip when exceeding limiting power. The result is essential for understanding the workings of the limiter chip and for optimizing the chip design.