A magnetic field measurement technology of high altitude electromagnetic pulse

For the high altitude electromagnetic pulse testing research purpose, the measuring principle and frequency characteristic of electrically small loops are analyzed in this paper. A numerical model of electrically small loop is founded, and the pulse receiving characteristics are obtained by simulation. Then, the B-dot sensor is designed, and a pulsed magnetic field measuring system is constructed. The results show that the sensor's upper cut-off frequency exceeds 720 MHz when the ring radius is less than 20 mm, and the system calibrated risetime is less than 1 ns. The measuring system is used to measure the magnetic field generated by a HEMP simulator. It shows that the system can measure pulsed magnetic field with fast risetime, and it can also be applied to measure other pulsed magnetic field with high magnitude.