We herein formulate the concept of a generalized lock-in amplifier for the precision measurement of high frequency signals based on digital cavities. Accurate measurement of signals higher than 200 MHz using the generalized lock-in is demonstrated. The technique is compared with a traditional lock-in and its advantages and limitations are discussed. We also briefly point out how the generalized lock-in can be used for precision measurement of giga-hertz signals by using parallel processing of the digitized signals.
@article{arxiv.1308.5512,
title = {Generalized lock-in amplifier for precision measurement of high frequency signals},
author = {Siyuan Fu and Atsunori Sakurai and Liang Liu and Fredrik Edman and Tõnu Pullerits and Viktor Öwall and Khadga Karki},
journal= {arXiv preprint arXiv:1308.5512},
year = {2013}
}