Reverberation Chamber Techniques for Determining the Radiation and Total Efficiency of Antennas

2012 ◽  
Vol 60 (4) ◽  
pp. 1758-1770 ◽  
Author(s):  
Christopher L. Holloway ◽  
Haider A. Shah ◽  
Ryan J. Pirkl ◽  
William F. Young ◽  
David A. Hill ◽  
...  
Keyword(s):  
Total Efficiency ◽  
Reverberation Chamber

scholarly journals Diversity Performance of Multiantenna Systems for UMTS Cellular Phones in Different Propagation Environments

2008 ◽  
Vol 2008 ◽  
pp. 1-10 ◽  
Author(s):  
A. Diallo ◽  
C. Luxey ◽  
P. Le Thuc ◽  
R. Staraj ◽  
G. Kossiavas
Keyword(s):  
Correlation Coefficient ◽  
Antenna System ◽  
Diversity Gain ◽  
Total Efficiency ◽  
Cellular Phones ◽  
Radiation Patterns ◽  
Reverberation Chamber ◽  
The Mean ◽  
Antenna Systems ◽  
Diversity Antenna

We present the evaluation of the diversity performance of several two-antenna systems for UMTS terminals. First, a two-antenna system with poor antenna-to-antenna isolation is described. Then, with the help of a neutralization technique, we introduced an optimized structure with high antenna-to-antenna isolation. The key parameters for an efficient diversity performance are then discussed, some of them being actually dependent on the propagation environment (uniform, indoor, outdoor, and outdoor-to-indoor chosen here). All these parameters, the total efficiency, the envelope correlation coefficient, the mean effective gain, the diversity gain, and the effective diversity gain, are computed with the help of the simulated radiation patterns of both antenna systems. Next, these key parameters are measured in a reverberation chamber to validate the simulations we achieved in the uniform environment. The comparison of the performance of the two prototypes is especially showing the usefulness of using a neutralization technique for enhanced diversity antenna systems.

Research on Characteristics of Field Uniformity in Reverberation Chamber Using Two TX Antennas

2012 ◽  
Vol E95.B (7) ◽  
pp. 2386-2392
Author(s):  
Jung-Hoon KIM ◽  
Tae-Heon JANG ◽  
Sung-Kuk LIM ◽  
Songjun LEE ◽  
Sung-Il YANG
Keyword(s):  
Reverberation Chamber ◽  
Field Uniformity

The Field Uniformity Analysis in a Triangular Prism Reverberation Chamber with a QRD

2011 ◽  
Vol E94-B (1) ◽  
pp. 334-337 ◽  
Author(s):  
Jung-Hoon KIM ◽  
Hye-Kwang KIM ◽  
Eugene RHEE ◽  
Sung-Il YANG
Keyword(s):  
Triangular Prism ◽  
Reverberation Chamber ◽  
Field Uniformity

Fundamental Propagation Characteristics of Stirrer-Less Reverberation Chamber for MIMO-OTA Measurements

2014 ◽  
Vol E97.B (10) ◽  
pp. 2083-2092 ◽  
Author(s):  
Yoshio KARASAWA ◽  
Ichiro OSHIMA ◽  
Fatahuddin TAMRIN ◽  
Yui SAKAMOTO ◽  
Rizwan ARIF ◽  
...  
Keyword(s):  
Propagation Characteristics ◽  
Reverberation Chamber

Outlet Surface Area Influence in Spiral Casing Design on Centrifugal Fan Performance

2020 ◽  
Vol 5 (1) ◽  
pp. 37-41
Author(s):  
Ardit Gjeta ◽  
Lorenc Malka
Keyword(s):  
Surface Area ◽  
Static Pressure ◽  
Total Efficiency ◽  
Centrifugal Fan ◽  
Recovery Coefficient ◽  
Fan Performance ◽  
Parameter Variations ◽  
Set Up ◽  
Spiral Casing ◽  
Pressure Recovery Coefficient

In this paper, the effect of the outlet surface area of the spiral casing on the performance of a centrifugal fan was investigated using open source CFD software OpenFOAM [1]. An automized loop with RANS and data post-processing is set up using Matlab, for allowing a large number of parameter variations. The effect was analyzed as a function of total pressure loss and static pressure recovery coefficient and on total efficiency as well.

Field testing CFD-based predictions of storage chamber gross solids separation efficiency

1999 ◽  
Vol 39 (9) ◽  
pp. 161-168 ◽  
Author(s):  
Virginia R. Stovin ◽  
Adrian J. Saul ◽  
Andrew Drinkwater ◽  
Ian Clifforde
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Settling Velocity ◽  
Separation Efficiency ◽  
Flow Patterns ◽  
Total Efficiency ◽  
Separation Performance ◽  
Storage Chamber ◽  
Solids Separation ◽  
Simulated Flow

The use of computational fluid dynamics-based techniques for predicting the gross solids and finely suspended solids separation performance of structures within urban drainage systems is becoming well established. This paper compares the result of simulated flow patterns and gross solids separation predictions with field measurements made in a full size storage chamber. The gross solids retention efficiency was measured for six different storage chambers in the field and simulations of these chambers were undertaken using the Fluent computational fluid dynamics software. Differences between the observed and simulated flow patterns are discussed. The simulated flow fields were used to estimate chamber efficiency using particle tracking. Efficiency results are presented as efficiency cusps, with efficiency plotted as a function of settling velocity. The cusp represents a range of efficiency values, and approaches to the estimation of an overall efficiency value from these cusps are briefly discussed. Estimates of total efficiency based on the observed settling velocity distribution differed from the measured values by an average of ±17%. However, estimates of steady flow efficiency were consistently higher than the observed values. The simulated efficiencies agreed with the field observations in identifying the most efficient configuration.

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