Photoconductive probing and computer simulation of microwave potentials inside a SiGe MMIC

Electrical potentials inside a SiGe MMIC are measured at frequencies up to 20 GHz using a micro-machined photoconductive sampling probe and compared with values predicted using microwave CAD software. The results illustrate that this combination of simulation and in-circuit measurement technique is a powerful tool for performing diagnostics of the microwave performance of Si-based RF circuits. The methodology can be used for applications such as fault isolation and validation of device models, as well as for investigation of the sensitivity of performance to process variations.