A multi-step phase calibration procedure for closely spaced multi-tone signals

Abstract

In this work we present a novel phase calibration procedure suitable for the waveform reconstruction of closely spaced multi-tone signals. The proposed multi-step calibration approach is based on the phase alignment of the calibration error terms measured with different frequency grids generated by the harmonic phase reference. The method achieves a reduction in the needed multiplication order of the phase reference to cover the intended measurement frequency range. The calibration procedure is implemented on an Agilent PNA-X platform, which uses external hardware extensions, e.g. low frequency bridges, for the accurate measurement of the baseband frequency components.