The ONION method: A reflection coefficient measurement technique for thick underwater acoustic panels

1989 ◽  
Vol 85 (3) ◽  
pp. 1029-1040 ◽  
Author(s):  
Jean C. Piquette
2020 ◽  
pp. 59-63
Author(s):  
A.S. Bondarenko ◽  
A.S. Borovkov ◽  
I.M. Malay ◽  
V.A. Semyonov

The analysis of the current state of the reflection coefficient measurements in waveguides at millimeter waves is carried out. An approach for solving the problem of reproducing the reflection coefficient measurement scale is proposed. Mathematical equations, which are the basis of the reflection coefficient measurement equation are obtained. The method of determining the metrological performance of reflection coefficient unit’s reference standards is developed. The results of electrodynamic modeling and analytical calculations by the developed method are compared. It is shown that this method can be used for reproducing the reflection coefficient unit in the development of the State primary standard.


1991 ◽  
Vol 34 (12) ◽  
pp. 1245-1248
Author(s):  
G. A. Vedyushkin ◽  
M. G. Chernyshov

2013 ◽  
Vol 64 (3) ◽  
Author(s):  
Rashidah Che Yob ◽  
Norhudah Seman

This article presents the reflection coefficient measurement by using a wideband multi-port reflectometer for microwave imaging application of human head. The configuration of the proposed wideband multi-port reflectometer is formed by passive components, which are four couplers and two power dividers operating from 1 to 6 GHz. The investigation is successfully done through simulation using the Agilent’s Advanced Design Systems (ADS) software and practical measurement in laboratory. An error correction method with three standards of match, open and short load is then applied to the constructed wideband multi-port reflectometer to remove its imperfect characteristics. The wideband characteristics of proposed reflectometer are analyzed and verified across the designated frequency band.  Its operation in reflection coefficient is tested with the chosen device under test (DUT).


Author(s):  
Julie Garvey ◽  
David Newport ◽  
Tara Dalton

This paper considers division of amplitude interferometry as a means to extract fluid information from micro-systems. Initially the phase measurement technique is analysed and the measurement limitations of mixing measurement are assessed. Accurate phase measurements are then made of the concentration in a 3 dimensional channel flow. A mini sized channel with tow fluid flows at Reynolds numbers of 0.848 and 0.0848 is numerically analysed. The same channel is experimentally tested and the results for the mixing concentration gradients in channel flow are compared with those obtained numerically. The requirement for experimental measurement for accurate measurement of binary liquid diffusion is observed by the variation between experimental and numerical results. The diffusion coefficient measurement verifies PMI as a means of mixture measurement, or more broadly as a phase measurement technique for small-scale, or micro scale, fluidic analysis. PMI’s potential is finally discussed as a measurement technique for concentration, and hence fluidic analysis of micro channel mixing.


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