Microwave field vector detector based on the off-resonant spin rectification effect

Normal microwave (MW) electromagnetic field detectors convert microwave power into voltages, which results in loss of the vector characteristics of the microwave field. In this work, we developed a MW magnetic field (h-field) vector detector based on the off-resonant spin rectification effect. By measuring and analyzing the angle dependence of the rectification voltages under off-resonant conditions, we can extract the three components of the h-field. As an initial test of this method, we obtained the h-field distributions at 5.4 GHz generated by a coplanar waveguide with sub-wavelength resolution. Compared to methods using ferromagnetic resonance, this technique offers a faster and more convenient way to determine the spatial distribution of the h-field, which can be used for MW integrated circuit optimization and fault diagnosis.