Contactless electromagnetic field mapping system on planar circuits in EMC/EMI investigations

A contactless EM field mapping system on microwave planar circuits in the ultra-wideband (UWB) 1 to 12 GHz has been successfully established for the EMC/EMI problem. By using a small coaxial and loop-type probes, 2D field distributions in UWB-BPF are measured. The upper limit of the operating frequency and the spatial resolution for the measurement system will be clarified. Electromagnetic near field distributions above UWB bandpass filter were measured to validate the effectiveness of probes. In addition, the application of this system was extendedly studied to experimentally determine the effective dielectric constant in the microstrip, coplanar waveguide and slotted line.