  Broadband ferromagnetic resonance (bbFMR) spectroscopy is an established
experimental tool to quantify magnetic properties. Due to frequency-dependent
transmission of the microwave setup, bbFMR measurements in the frequency domain
require a suitable background removal method. Here, we present a measurement
and data analysis protocol that allows to perform quantitative frequency-swept
bbFMR measurements without the need for a calibration of the microwave setup.
The method, its limitations and advantages are described in detail. Finally the
method is applied to evaluate FMR spectra of a permalloy thin film. The
extracted material parameters are in very good agreement with those obtained
using a conventional analysis in field-space.
