The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 19, 1996
Filed:
Nov. 28, 1994
Gerd Stange, Nortorf, DE;
Nu-Tech GmbH, , DE;
Abstract
An apparatus and a method for the measurement of the complex dielectric constant of a material by evaluating the amount of detuning introduced by the presence of the material. In order to simplify the circuitry required for measurement and evaluation according to the invention there are provided two rf resonators (8, 8') of the same construction, each of them comprising a dielectric solid state resonator (1, 1') in a case having a first conductive section (2, 2') and a second section (3, 3'), which is permeable for alternating fields. Both the rf resonators are positioned to each other in such a way as to provide a shielding effect by their conductive case sections (2, 2') against mutual interference and to have their sections permeable for electromagnetic fields (3, 3') facing towards the material to be measured. The operating rf frequency coupled to both the rf resonators and/or the resonance frequencies of the rf resonators (8, 8') are selected in such a way that, in the absence of the material to be measured, the common operating frequency is centered between the resonance frequencies of the rf resonators (8, 8'). On the basis of the measured amplitude values of the rf signals received in both the rf resonators and their sum and difference values the complex dielectric constant may be determined. Therefore, the need of a complete sampling of the resonance curves of the rf resonators is eliminated.