FDTD modeling and experiments of microfabricated coplanar waveguide probes for electromagnetic compatibility applications

We present the design, fabrication and experiment of a miniature nonresonant probe based on a coplanar waveguide dedicated to near-field imaging for electromagnetic compatibility applications. Our modeling approach, based on the Finite Difference Time Domain and Finite Element Method, proves that this probe is sensitive to the longitudinal component of the electric field. In addition to its compatibility with integrated circuits, this probe is suitable for wide frequency band applications since it is produced from a micro-metric coplanar line which has no cut-off frequency. We achieved prototypes using the clean room techniques. Using this probe on a precision X-Y scanning table, two-dimensional images of micro-strip line and electric dipole antenna have been successfully constructed. Simulations and measurements results on a microstrip line have shown that the probe is mainly sensitive to the normal electric field. The estimated sensitivity is 30 μV/(V/m).