title: Broadband microwave spectroscopy in Corbino geometry at 3He temperatures.
abstract: A broadband microwave spectrometer has been constructed to determine the complex conductivity of thin metal films at frequencies from 45 MHz to 20 GHz working in the temperature range from 0.45 K to 2 K (in a (3)He cryostat). The setup follows the Corbino approach: a vector network analyzer measures the complex reflection coefficient of a microwave signal hitting the sample as termination of a coaxial transmission line. As the calibration of the setup limits the achievable resolution, we discuss the sources of error hampering different types of calibration. Test measurements of the complex conductivity of a heavy-fermion material demonstrate the applicability of the calibration procedures.
authors.affiliation: 1. Physikalisches Institut, Universität Stuttgart, 70550 Stuttgart, Germany.
authors.forename: Katrin
authors.initials: K
authors.lastname: Steinberg
authors.forename: Marc
authors.initials: M
authors.lastname: Scheffler
authors.forename: Martin
authors.initials: M
authors.lastname: Dressel