Determination of geometric properties of SNOM tips by means of combined far-field and near-field evaluation

1999 ◽  
Author(s):  
Soenke Seebacher ◽  
Wolfgang Osten ◽  
Werner P. O. Jueptner ◽  
Vadim P. Veiko ◽  
Nikolay B. Voznesensky
Keyword(s):  
Near Field ◽  
Field Evaluation ◽  
Far Field ◽  
Geometric Properties

Determination of geometric properties of SNOM tips by means of far-field evaluation

2000 ◽  
Author(s):  
Soenke Seebacher ◽  
Wolfgang Osten ◽  
Werner P. O. Jueptner ◽  
Vadim P. Veiko ◽  
Nikolay B. Voznesensky
Keyword(s):  
Field Evaluation ◽  
Far Field ◽  
Geometric Properties

scholarly journals Far-Field Reconstruction from Transient Near-Field Measurement Using Cylindrical Modal Development

2009 ◽  
Vol 2009 ◽  
pp. 1-7 ◽  
Author(s):  
R. Rammal ◽  
M. Lalande ◽  
E. Martinod ◽  
N. Feix ◽  
M. Jouvet ◽  
...  
Keyword(s):  
Field Measurement ◽  
Near Field ◽  
Accurate Determination ◽  
Ultra Wideband ◽  
Far Field ◽  
Field Radiation ◽  
Measurement Base ◽  
Large Frequency ◽  
Near Field Measurement

The aim of this work is to get far field radiation patterns for any radiating source from transient acquisition, in a large frequency range. An outdoor transient Ultra-Wideband near-field measurement base will be installed, a single time pulse radiated by the source will cover the desired spectrum, and the accurate determination of far field radiations will be accomplished by means of cylindrical waves' modal development. This method uses simplified test equipments, easy to be installed, and it reduces measurement costs.

scholarly journals A Generalized Approach for Computation of Near Field Radiation Pattern of an Antenna

2014 ◽  
Vol 2014 ◽  
pp. 1-18
Author(s):  
Preetham Shankpal ◽  
Varun Arur ◽  
Govind Kadambi ◽  
James Shuttleworth
Keyword(s):  
Radiation Pattern ◽  
Near Field ◽  
Circular Waveguide ◽  
Field Analysis ◽  
Far Field ◽  
Magnetic Dipoles ◽  
Underlying Principle ◽  
Field Radiation ◽  
Conical Horn

A generalized procedure in the form of an analytical formulation for the determination of radiation pattern of an antenna at any arbitrary distance which covers the near field as well as far field is presented in this paper. With the prior knowledge of either the current or field distribution on the radiating aperture, the proposed near field analysis is generic and can be applied for wide variety of antenna elements. The underlying principle of the generalized procedure is tantamount to considering the radiating aperture as an array of point electric and magnetic dipoles. The validity and novelty of the proposed new approach have been substantiated considering an open ended circular cylindrical waveguide and a conical horn as case studies and treating the far field as a special case of near field with pertinent distance criterion. The effect of change in the distance of observation ranging from reactive near field to far field on the radiation patterns of these antennas has also been discussed. The simulation studies reveal that the depicted normalized phase patterns of both the circular waveguide and conical horn follow the changes in the profile of the corresponding amplitude patterns.

scholarly journals Non-redundant Spherical Near-Field to Far-Field Transformation for a Volumetric Antenna in Offset Configuration

2019 ◽  
Vol 13 (1) ◽  
pp. 19-29 ◽  
Author(s):  
Francesco D’Agostino ◽  
Flaminio Ferrara ◽  
Claudio Gennarelli ◽  
Rocco Guerriero ◽  
Massimo Migliozzi
Keyword(s):  
Near Field ◽  
Measurement Techniques ◽  
Data Gathering ◽  
Experimental Tests ◽  
Precise Determination ◽  
Far Field ◽  
Interpolation Algorithm ◽  
Classical Technique ◽  
Field Transformation

Background: The development of fast Near-Field (NF) measurement techniques allowing the precise determination of the Far-Field (FF) radiation features of an antenna is becoming more and more challenging nowadays. Objective: The goal of the article is the development of an NF To FF Transformation (NFTFFT) with spherical scan for offset mounted volumetric Antennas Under Tests (AUTs) requiring, unlike the classical technique, a reduced set of NF data, that is of the same amount as for the onset mounting case, thus making data gathering faster. In fact, the number of NF data needed by the standard approach may considerably increase in this case, since the size of the smallest sphere surrounding the AUT and centered at the center of the measurement sphere rises. Methods: This goal has been achieved by profitably exploiting the non-redundant sampling representation of electromagnetic field and assuming a volumetric AUT as contained in a sphere. An optimal sampling interpolation algorithm is then employed to precisely reconstruct the input NF data for the traditional spherical NFTFFT from the reduced set of the collected ones. Conclusion: The numerical simulations and experimental tests demonstrate the effectiveness of the developed approach accounting for an offset mounting of the AUT.

Far-field evaluation directly from helicoidal near-field data

2012 ◽  
Author(s):  
Francesco D'Agostino ◽  
Flaminio Ferrara ◽  
Claudio Gennarelli ◽  
Rocco Guerriero ◽  
Massimo Migliozzi
Keyword(s):  
Field Data ◽  
Near Field ◽  
Field Evaluation ◽  
Far Field
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