Near-field measurement of stochastic electromagnetic fields

Stochastic electromagnetic fields with Gaussian amplitude probability distribution can be fully described by auto- and cross correlation spectra of the field components. The cross correlation spectra have to be known for the pairs of field components taken at different spatial points. Integrated electric dipole and magnetic loop probes together with active electronics in AlGaAs/GaAs-HEMT and SiGe:C-HBT technologies are presented. While the probes allow for a spatial resolution in the 100 μm range, integrated amplifiers provide about 30 dB gain over a bandwidth of about 10 GHz.