A new type of integrated optical magnetic field sensor is presented in this paper. The proposed sensor consists of a Mach–Zehnder waveguide interferometer and a doubly loaded loop antenna. Such a structure can successfully avoid detection of the undesired electric field signal. The size of the sensor is $35\mathrm{mm}\times 6\mathrm{mm}\times 1\mathrm{mm}$ . The measurements show that the frequency response is from $2\mathrm{kHz}$ to $9\mathrm{GHz}$ , the dynamic range is $98\mathrm{dB}$ , and the minimum detectable magnetic field is $51.8\mathrm{\mu A}/\mathrm{m}$ at $1\mathrm{GHz}$ . Therefore, this sensing system can be used in electromagnetic compatibility measurements.