Plasmonic Nanoclusters with Rotational Symmetry: Polarization-Invariant Far-Field ResponsevsChanging Near-Field Distribution

ACS Nano ◽  
2013 ◽  
Vol 7 (12) ◽  
pp. 11138-11146 ◽  
Author(s):  
Mohsen Rahmani ◽  
Edward Yoxall ◽  
Ben Hopkins ◽  
Yannick Sonnefraud ◽  
Yuri Kivshar ◽  
...  
Keyword(s):  
Field Distribution ◽  
Rotational Symmetry ◽  
Near Field ◽  
Far Field

Far-Field and Near-Field Distribution of GaN-Based Photonic Crystal LEDs With Guided Mode Extraction

2009 ◽  
Vol 15 (4) ◽  
pp. 1234-1241 ◽  
Author(s):  
Chun-Feng Lai ◽  
Jim-Yong Chi ◽  
Hao-Chung Kuo ◽  
Hsi-Hsuan Yen ◽  
Chia-En Lee ◽  
...  
Keyword(s):  
Photonic Crystal ◽  
Field Distribution ◽  
Near Field ◽  
Far Field ◽  
Guided Mode ◽  
Mode Extraction

scholarly journals Measurement uncertainty caused by distance errors during in situ tests of wind turbines

2019 ◽  
Vol 17 ◽  
pp. 19-25
Author(s):  
Cornelia Reschka ◽  
Sebastian Koj ◽  
Sven Fisahn ◽  
Heyno Garbe
Keyword(s):  
Electromagnetic Field ◽  
Measurement Uncertainty ◽  
Field Distribution ◽  
Wind Turbines ◽  
Near Field ◽  
Observation Point ◽  
Far Field ◽  
In Situ Tests ◽  
Electromagnetic Emissions

Abstract. During the assessment of the electromagnetic emissions of wind turbines (WTs), the aspects of measurement uncertainty must be taken into account. Therefore, this work focuses on the measurement uncertainty which arises through distance errors of the measuring positions around a WT. The measurement distance given by the corresponding standard is 30 m with respect to the WT tower. However, this determined distance will always differ e.g. due to unevenness of the surrounding ground, leading to measurement uncertainties. These uncertainties can be estimated with the knowledge of the electromagnetic field distribution. It is assumed in standard measurements, that the electromagnetic field present is a pure transversal electromagnetic field (far field). Simulations of a simplified WT model with a hub height of 100 m shows that this assumption is not effective for the whole frequency range from 150 kHz to 1 GHz. For frequencies below 3 MHz the field distribution is monotonically decreasing with the distance from the WT since it behaves like an electrical small radiator. Whereas for frequencies above 3 MHz, where the investigated model forms an electrical large radiator, the field distribution becomes more complex and the measurement uncertainty of the field strength at the observation point increases. Therefore, this work focuses on investigations where the near field becomes a far field. Based on the simulation results, a method for minimizing the uncertainty contribution caused by distance errors is presented. Therefore, advanced measurement uncertainty during in situ test of WTs can be reduced.

scholarly journals NEAR AND FAR FIELD OPTICAL PATTERNS FORMATION BY ROTATIONAL SYMMETRY MASKS: APPLICATION TO OPTICAL SPATIAL SOLITON GENERATION

2012 ◽  
Vol 15 ◽  
pp. 113-119
Author(s):  
ANAHIT BADALYAN ◽  
PAYTSAR MANTASHYAN ◽  
VAHRAM MEKHITARYAN ◽  
VARSENIK NERSESYAN ◽  
RAFAEL DRAMPYAN
Keyword(s):  
Rotational Symmetry ◽  
Near Field ◽  
Single Mode ◽  
Optical Diffraction ◽  
Spatial Soliton ◽  
Far Field ◽  
Single Mode Laser ◽  
Beam Formation ◽  
Different Types ◽  
Soliton Generation

In this report we present the formation of necklace type optical beams from Gaussian beam by rotational symmetry masks. The detailed studies of space evolution of the optical beam formation from the near field to the far field by the use of 7-fold symmetry mask and a single mode laser beam were performed. Different types of necklace beams with different numbers of "pearls" periodically or quasi-periodically situated along the different radii rings were observed during the space evolution of the optical diffraction pattern.

Magnetic Tag Antenna for UHF Near-field and Far-Field RFID Applications

2015 ◽  
Vol 5 (2) ◽  
pp. 119
Author(s):  
Mondher Dhaouadi ◽  
M. Mabrouk ◽  
T. Vuong ◽  
A. Ghazel
Keyword(s):  
Near Field ◽  
Far Field ◽  
Rfid Applications
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