Two-dimensional mapping of the microwave potential on MMICs using electrooptic sampling

An accurate technique for mapping the two-dimensional microwave potential in microwave circuits has been developed and tested. Using the direct electooptic sampling technique and a de-embedding algorithm to remove substrate-variation-induced measurement errors, accurate two-dimensional potential maps with a dynamic range of 50 dB and spatial resolution of 10 μm are obtained. De-embedding of the microwave potential from the measured, electrooptically modulated signal is achieved by deducing the substrate parameters from the measured average reflected optical power. Once the substrate is characterized, the microwave potential can be calculated from the electrooptic signal. The de-embedding procedure technique was successfully tested on a through-line and an open-end line of a through-reflect-line (TRL) microstrip calibration standard