Measurement of Surface EM Field of Planar Circuit in Microwave Frequency

A field mapping system used in microwave frequency band is established for the purpose of surface field detection. A section of coaxial line with a protruded inner conductor is used as an electric probe, while a new compact CPW-type loop probe is designed as a magnetic probe. The electric probe used here has a very high sensitivity and could be used up to 18 GHz. The new designed magnetic probe has a very simple structure, compact size of 2.3X2.3 mm and good seIf resonance suppression characteristics, in order to verify the effectiveness of this field mapping system, the EM field distribution of a section of short circuited microstrip line is scanned. By comparing the measurement results with the theoretical ones obtained by 3D simulator (CST MWS), the good performance of the new proposed probes are validated.