Hybrid multilevel plane wave based near-field far-field transformation utilising combined near- and far-field translations

Abstract. The radiation of large antennas and those operating at low frequencies can be determined efficiently by near-field measurement techniques and a subsequent near-field far-field transformation. Various approaches and algorithms have been researched but for electrically large antennas and irregular measurement contours advanced algorithms with low computation complexity are required. In this paper an algorithm employing plane waves as equivalent sources and utilising efficient diagonal translation operators is presented. The efficiency is further enhanced using simple far-field translations in combination with the expensive near-field translations. In this way a low complexity near-field transformation is achieved, which works for arbitrary sample point distributions and incorporates a full probe correction without increasing the complexity.

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Near-field far-field transformation exploiting the benefits of plane wave expansion and diagonal translation operators

2007 European Microwave Conference ◽

10.1109/eumc.2007.4405254 ◽

2007 ◽

Cited By ~ 1

Author(s):

Carsten H. Schmidt ◽

Martin M. Leibfritz ◽

Thomas F. Eibert

Keyword(s):

Plane Wave ◽

Near Field ◽

Far Field ◽

Plane Wave Expansion ◽

Wave Expansion ◽

Field Transformation ◽

Translation Operators

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

The Open Electrical & Electronic Engineering Journal ◽

10.2174/1874129001913010019 ◽

2019 ◽

Vol 13 (1) ◽

pp. 19-29 ◽

Cited By ~ 3

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.

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