On the use of three-dimensional TEM cells for total radiated power measurements

2002 ◽  
Author(s):  
M. Klingler ◽  
S. Egot ◽  
J.-P. Ghys ◽  
J. Rioult
Keyword(s):  
Three Dimensional ◽  
Radiated Power ◽  
Power Measurements

scholarly journals Correction for Neutral Pressure-Driven Signal in Radiated Power Measurements on Proto-MPEX

2020 ◽  
Vol 48 (6) ◽  
pp. 1649-1654
Author(s):  
Seungsup Lee ◽  
Matthew Reinke ◽  
Theodore Biewer ◽  
David Donovan ◽  
Jamie Coble
Keyword(s):  
Radiated Power ◽  
Power Measurements ◽  
Pressure Driven

scholarly journals Radiation Characteristics of 3D Resonant Cavity Antenna with Grid-Oscillator Integrated Inside

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
L. A. Haralambiev ◽  
H. D. Hristov
Keyword(s):  
Spectral Power ◽  
Resonant Cavity ◽  
Three Dimensional ◽  
Spectral Power Density ◽  
Measured Data ◽  
Radiation Characteristics ◽  
Power Combining ◽  
Radiated Power ◽  
Lateral Cavity ◽  
Directive Gain

A three-dimensional (3D) rectangular cavity antenna with an aperture size of 80 mm×80 mm and a length of 16 mm, integrated with a four-MESFET transistor grid-oscillator, is designed and studied experimentally. It is found that the use of 3D antenna resonant cavity in case of small or medium gain microwave active cavity antenna leads to effective and stable power combining and radiation. The lack of lateral cavity diffraction and radiation helps in producing a directive gain of about 17 dB and radiation aperture efficiency bigger than 75% at a resonance frequency of 8.62 GHz. Good DC to RF oscillator efficiency of 26%, effective isotropic radiated power (EIRP) of 5.2 W, and SSB spectral power density of −82 dBc/Hz are found from the measured data. The 3D antenna cavity serves also as a strong metal container for the solid-state oscillator circuitry.

Effect of Drive Location on Vibro-Acoustic Characteristics of Submerged Double Cylindrical Shells with Damping Layers

2013 ◽  
Vol 387 ◽  
pp. 59-63
Author(s):  
Chao Zhang ◽  
De Jiang Shang ◽  
Qi Li
Keyword(s):  
Annular Plate ◽  
Cylindrical Shells ◽  
Three Dimensional ◽  
Plane Motion ◽  
Superposition Method ◽  
Annular Plates ◽  
Radiated Power ◽  
Modal Superposition Method ◽  
Viscoelastic Theory ◽  
Vibration And Sound Radiation

Based on the modal superposition method, the analytical model of vibration and sound radiation from submerged double cylindrical shells with damping layers was presented. The shells were described by the classical thin shell theory. The damping layers were described by three-dimensional viscoelastic theory. The annular plates, connecting the double shells, were analyzed with in-plane motion theory. For different drive locations of radial point force on the inner shell, the sound radiated power and the radial quadratic velocity of the model were calculated and analyzed. The results show that making the drive location near the annular plate helps to reduce the sound radiated power and radial quadratic velocity of model, and making the drive location far from the middle of model also helps to reduce the sound radiated power. The drive applied on the location of annular plate causes high similarity of vibrations from inner shell and outer shell.

On the use of 3-D TEM cells for total radiated power measurements

2002 ◽  
Vol 44 (2) ◽  
pp. 364-372 ◽  
Author(s):  
M. Klingler ◽  
S. Egot ◽  
J.-P. Ghys ◽  
J. Rioult
Keyword(s):  
Radiated Power ◽  
Power Measurements

A Boundary Element Approach to Optimization of Active Noise Control Sources on Three-Dimensional Structures

1991 ◽  
Vol 113 (3) ◽  
pp. 387-394 ◽  
Author(s):  
K. A. Cunefare ◽  
G. H. Koopmann
Keyword(s):  
Boundary Element ◽  
Noise Control ◽  
Noise Source ◽  
Active Noise Control ◽  
Three Dimensional ◽  
Control Technique ◽  
Optimization Analysis ◽  
Radiated Power ◽  
Active Noise ◽  
Control Source

This paper presents the theoretical development of an approach to active noise control (ANC) applicable to three-dimensional radiators. The active noise control technique, termed ANC Optimization Analysis, is based on minimizing the total radiated power by adding secondary acoustic sources on the primary noise source. ANC Optimization Analysis determines the optimum magnitude and phase at which to drive the secondary control sources in order to achieve the best possible reduction in the total radiated power from the noise source/control source combination. For example, ANC Optimization Analysis predicts a 20 dB reduction in the total power radiated from a sphere of radius α at a dimensionless wavenumber ka of 0.125, for a single control source representing 2.5 percent of the total area of the sphere. ANC Optimization Analysis is based on a boundary element formulation of the Helmholtz Integral Equation, and thus, the optimization analysis applies to a single frequency, while multiple frequencies can be treated through repeated analyses.

The β'-α' Interaction: a Study of early Stages of Phase Separation in a Fe-20%Cr-6%Al-0.5%Ti Alloy

2011 ◽  
Vol 172-174 ◽  
pp. 315-320
Author(s):  
Carlos Capdevila ◽  
Michael K. Miller ◽  
K.F. Russell ◽  
J. Chao ◽  
F.A. López
Keyword(s):  
Phase Separation ◽  
Atom Probe Tomography ◽  
Temporal Evolution ◽  
Theoretical Calculations ◽  
Three Dimensional ◽  
Atom Probe ◽  
Early Stages ◽  
Β Phase ◽  
Α Phase ◽  
Power Measurements

The temporal evolution of the microstructure resulting from phase separation into Fe-rich (α), Cr-rich (α¢), and Fe(Ti,Al) (β¢) phases of a Fe-20Cr-6Al-0.5Ti alloy has been analyzed by thermoelectric power measurements (TEP). The early stages of decomposition and the evolution of the three-dimensional microstructure have been analyzed by atom probe tomography (APT). The roles of Cr, Al, and Ti during the decomposition process have been investigated in terms of solute partitioning between the phases. Analysis of proximity histograms revealed that significant Al and Ti partitioning occurs, which is consistent with theoretical calculations. The results indicate that as the α-α¢ phase separation proceeds, Al and Ti are rejected into the α phase, which causes the β¢ phase to nucleate on the surface of the α¢ phase.

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