1
Johan Samyn: Method and apparatus for checking the authenticity of documents. N V Bekaert, Foley & Lardner Schwartz Jeffery Schwaab Mack Blumenthal & Evans, April 11, 1989: US04820912 (149 worldwide citation)

A method and an apparatus for checking the authenticity of documents, such as banknotes or credit-cards. The documents comprise a number of randomly distributed conductive fibres of which the distribution is scanned by microwaves and the response is transformed into a digital coded signal. A digital ...


2
Devendra K Misra: Method and apparatus for measuring the permittivity of materials. The Board of Regents of the University of Wisconsin System, Foley & Lardner, August 3, 1993: US05233306 (120 worldwide citation)

A method and apparatus for determining the permittivity of a sample is disclosed. The method includes applying an AC electrical signal in the microwave frequency range via a coaxial probe having an end position near the sample and measuring the reflection coefficient of the sample. The complex permi ...


3
Lawrence E Larsen, John H Jacobi: Microwave time delay spectroscopic methods and apparatus for remote interrogation of biological targets. The United States of America represented by the Secretary of the Army, William G Gapcynski, Werten F W Bellamy, January 16, 1979: US04135131 (110 worldwide citation)

Remote interrogation of biological targets is accomplished in accordance h the present invention by method and apparatus wherein a microwave signal is generated which varies in frequency from a first frequency to a second frequency in a predetermined time period. The signal is divided into two signa ...


4
Wayne C Cannon, John T Barr IV: Vector network analyzer with integral processor. Hewlett Packard Company, Jeffery B Fromm, William C Milks III, March 28, 1989: US04816767 (105 worldwide citation)

An RF network analyzer is disclosed which is suitable for both laboratory and automated production measurements. An important feature of the invention is the ability of the user to completely specify the method of calibration to be used. In particular the user can select any three arbitrary RF stand ...


5
Gnanalingam Arjavalingam, Alina Deutsch, Gerard V Kopcsay, James K Tam: Methods for the measurement of the frequency dependent complex propagation matrix, impedance matrix and admittance matrix of coupled transmission lines. International Business Machines Corporation, Daniel P Morris, March 26, 1996: US05502392 (100 worldwide citation)

A method for completely characterizing coupled transmission lines by short-pulse propagation is described. The complex frequency-dependent propagation matrix, impedance matrix and admittance matrix for a set of n parallel transmission lines can be determined by comparing the properties of two sets o ...


6
Eric W Strid, Keith E Jones: System for setting reference reactance for vector corrected measurements. Cascade Microtech, Chernoff Vilhauer McClung & Stenzel, August 15, 1989: US04858160 (98 worldwide citation)

A system for calibrating vector corrected electrical measurements to adjust for distortion due to reactance in the measuring circuit, particularly that caused by variable positioning of a circuit element, such as probe or coupling. Initial error factors for directivity, source match, and frequency r ...


7
Vahe Adamian, Peter V Phillips, Patrick J Enquist, J Bradford Cole: Method and apparatus for linear characterization of multi-terminal single-ended or balanced devices. Agilent Technologies, November 25, 2003: US06653848 (91 worldwide citation)

A method and apparatus for characterizing a device under test (“DUT”) calibrates a multiport test set and measures S-parameters [S] of the DUT. The method and apparatus further involves determining elements of a scalar orthogonal matrix [M] corresponding to terminals of the DUT a ...


8
Paul Bryant, Martin Silverstein, Larry W Fullerton: Programmable active microwave ultrafine resonance spectrometer (PAMURS) method and systems. January 1, 2002: US06335625 (91 worldwide citation)

A preferred embodiment of the present invention includes a system for detecting a presence of a macromolecule having one or more resonant frequencies. The system includes a pulse generator (a T-wave generator in the most preferred embodiment) for generating a detection profile having a detection set ...


9
Strid Eric W, Jones Keith E: System for setting reference reactance for vector corrected measurements.. Cascade Microtech, September 20, 1989: EP0333521-A1 (87 worldwide citation)

A system is disclosed for calibrating vector corrected electrical measurements to adjust for distortion due to reactance in the measuring circuit, particularly that caused by variable positioning of a circuit element, such as a probe or coupling. Initial error factors for directivity, source match, ...


10
Arie Ariav: High-precision measuring method and apparatus. Nexense, G E Ehrlich, September 16, 2003: US06621278 (84 worldwide citation)

A method and apparatus of measuring a predetermined parameter having a known relation to the transit time of movement of an energy wave through a medium, by transmitting from a first location in the medium a cyclically-repeating energy wave; receiving the cyclically-repeating energy wave at a second ...