title: Precision waveguide system for measurement of complex permittivity of liquids at frequencies from 60 to 90 GHz.
abstract: We describe a variable path length waveguide setup developed to accurately measure the complex dielectric permittivity of liquids. This is achieved by measuring the complex scattering parameter of the liquid in a waveguide section with a vector network analyzer in combination with an E-band frequency converter. The automated measurement procedure allows fast acquisition at closely spaced intervals over the entire measurement bandwidth: 60-90 GHz. The presented technique is an absolute method and as such is not prone to calibration errors. The technique is suited to investigate low-loss as well as high-loss liquids in contrast to similar setups described previously. We present measurements for a high-loss liquid (water), an intermediate-loss sample (ethanol), and for nearly loss-less n-octane. Due to the available phase information, the present data have an improved accuracy in comparison with literature data.
authors: FOM Institute AMOLF, Amsterdam, The Netherlands.
authors: J
authors: J
authors: Hunger
authors: I
authors: I
authors: Cerjak
authors: H
authors: H
authors: Schoenmaker
authors: M
authors: M
authors: Bonn
authors: H J
authors: HJ
authors: Bakker