Accurate phase measurements of broadband Multitone signals using a specific configuration of a Large Signal Network Analyzer

Accurate measurements of time domain waveforms at microwave frequencies are performed using the harmonic sampling principle. This principle used in the large signal network analyzer (LSNA) enables to transform a measured RF spectrum into an IF spectrum which is then digitized by ADCs. Unfortunately in this principle IF spectrum bandwidth is limited to 10MHz due to the need of high dynamic range ADCs (14bits). In this paper, we propose a new method that enables to accurately measure the phase relationships and the amplitudes of the spectral components of broadband microwave signals. Measurements of a 62MHz bandwidth multitone signal at L band have been performed and are shown. The extension of the proposed method to wider bandwidth is absolutely possible. Furthermore the application of the proposed technique to other harmonic samplers than those used in the LSNA is also possible