PatentDOI
Detection and ranging of material flaws using microwave transmission line reflectometry
Donald B. Mertens,Louis E. Gates,Ronald I Wolfson,William W. Milroy,Joseph P. Smalanskas +4 more
- Vol. 2448, pp 226-229
Reads0
Chats0
TLDR
In this article, a meandering transmission line (22) or coaxial cable is adhered to a dielectric substrate (20), where the microwave signals propagating through them are reflected at crossover points along the way creating a signature reflection wave.Abstract:
A structure integrity monitoring apparatus and method for use with certain structures such as air-frame structures. A meandering transmission line (22) or serpentine coaxial cable is adhered to a dielectric substrate (20). The dielectric substrate may be a composite panel of the air-frame structure. A microwave signal is introduced at one end of the transmission line (22) or coaxial cable and absorbed at the other end by an appropriate signal absorbing device. For use of the meandering transmission line (22), generally two conductors (22, 24) are affixed on opposite sides of the dielectric substrate (20). In this manner, an electric field created by the two conductors (22, 24) by the microwave signals propagating through them is confined within the dielectric substrate (20). As the signals travel down the transmission conductors (22, 24), they will be reflected at crossover points along the way creating a signature reflection wave. If the dielectric substrate is flawed, a perturbation in the electric field caused by the flaw will create a reflection of the microwave signal at the flaw area. When this reflection signal is compared with the signature signal, it can be determined where and if a flaw is present.read more
Citations
More filters
Patent
System interface fault isolator test set
Doru T. Roll-Mecak,Stanley Teich +1 more
TL;DR: In this article, a system interface fault isolator uses time domain reflectometry test techniques to isolate faults from only one end of a cable, a cable string or component without requiring removal of the cable or component from the system interface.
Patent
Method of finding faults in a branched electrical distribution circuit
TL;DR: In this article, a PN modulated signal is applied to an end of a network electrical distribution circuit and the signal produces a snapshot trace of energy reflected from various discontinuities along the circuit, including a fault.
Patent
Apparatus and method for nondestructive testing of dielectric materials
TL;DR: In this paper, an apparatus and method for the nondestructive inspection of dielectric materials are disclosed. The detection technique is based on interference between reflected and reference microwaves having substantially the same frequency.
Patent
Seal integrity detection system
Stephen A. Mastro,John K. Overby +1 more
TL;DR: In this paper, a TDR is used to detect changes in the impedance of a wire with integral coaxial waveguide, twisted pair wires, parallel ribbon wires or parallel wires.
Patent
Interferometric localization of irregularities
TL;DR: In this article, an apparatus and method for the nondestructive inspection of dielectric materials is described, where microwave signals are transmitted and reflected at each interface where the dielectrics constant changes (e.g., where there are delaminations, cracks, holes, impurities, or other defects).
References
More filters
Patent
Method and apparatus for locating and measuring wave guide discontinuities
TL;DR: In this paper, a wave guide discontinuity point is determined using time domain reflectometry from the time interval for the signal to reach the discontinuity and for the reflected wave totravel back along the wave guide and be detected.
Patent
Method and apparatus for digital time domain reflectometry
TL;DR: A digital time domain reflectometer includes a pulse generator for generating a test pulse to a cable under test and comparator circuits for determining whether a reflected voltage pulse exceeds user-selected bias values thus indicating an impedance mismatch as discussed by the authors.
Patent
Programmable broadband electronic tuner
Vahe A. Adamian,Peter Phillips +1 more
TL;DR: In this article, a programmable microwave network test device is used to establish a multitude of reflection and transmission coefficients determined by a set of digital inputs, which can be used to characterize a non-linear or linear device.
Patent
Apparatus for detecting and locating leakage in underwater structures
TL;DR: In this paper, a system for leak detection in underwater structures where each critical leakage test point is maintained dry by an enclosure and a test cable is led down through the series of enclosures in fluid-tight manner to support a test probe within the dry test point volume.