Broadband characterization of optoelectronic components to 65 GHz using VNA techniques

This paper discusses the typical uncertainties associated with characterizing high-speed photodiodes to 65 GHz when using a vector network analyzer (VNA) measurement technique. We analyzed the accuracy of the technique by comparing measurements of two reference standards that had previously been calibrated using electro-optic sampling (EOS) and heterodyne methods. The results of the comparison show very good correlation to the direct characterizations. Typical uncertainties were less than 1.0 dB at frequencies up to 50 GHz and less than 2 dB at 65 GHz. The dominant sources of uncertainty come from the noise floor in the VNA above 50 GHz (depending upon signal level) and the base uncertainty in the reference-standard calibration.