Time filter

Source Type

Sierra-Castaner M.,Technical University of Madrid | Saccardi F.,Microwave Vision Italy MVI | Foged L.J.,Microwave Vision Italy MVI
AMTA 2016 Proceedings | Year: 2016

Some antennas require rapid validation at a reduced measurement distance while maintaining sufficient accuracy in the determination of pertinent antenna parameters such as gain. In particular, for cellular base station antennas in production phase the measurement time can be a limitation. In these cases, a rapid check of the radiation performance in the two main planes is sufficient. Other examples are phase arrays with high degree of steering that would require considerable measurement time for characterizing all steering positions. This paper presents a near-field antenna test procedure providing single or double main plane patterns including the gain. The procedure is applicable to antennas, with separable excitation in the two main planes. The test set-up is based on an azimuth positioner and near to far-field transformation based on expansion in cylindrical modes. The paper shows results for gain measurements. Near to far-field transformation is performed using the cylindrical modes expansion assuming a zero-height cylinder. This allows the use of a FFT in the calculation of the far field pattern including probe correction. In the case of gain, the near to far-field transformation factor is calculated for bore sight direction, taking advantage of the separable excitation properties of the antenna. This factor is used in the gain calculation by comparison technique. © 2016 AMTA.


Mioc F.,Microwave Vision Italy MVI | Saporetti M.,Microwave Vision Italy MVI | Sabbadini M.,European Space Agency | Del Muto M.,StepOver
2016 10th European Conference on Antennas and Propagation, EuCAP 2016 | Year: 2016

This paper presents the application to satellite antenna modelling of a common format for the exchange of geometry and associated data. The EDX development has been a core activity of the EAML team in collaboration with the Working Group on Software of the European Association on Antennas and Propagation (EurAAP). The implementation of the Structures Data Dictionary in Data Dictionary Language is discussed together with an application example relevant to the Emerald satellite facsimile. © 2016 European Association of Antennas and Propagation.


Foged L.J.,Microwave Vision Italy MVI | Scialacqua L.,Microwave Vision Italy MVI | Saccardi F.,Microwave Vision Italy MVI | Quijano Araque J.L.,National University of Colombia | Vecchi G.,Polytechnic University of Turin
IEEE Antennas and Propagation Magazine | Year: 2014

A number of interesting applications of the equivalent-current/source method (EQC) have recently been presented for antenna design and diagnostics. The Dual-Equation formulation has been proven to be superior in terms of accurately reconstructing sources on, or very near, the AUT structure, and is the only formulation directly applicable for diagnostics [1]. The maximum antenna size that can be handled by this method is limited by memory and running time constraints, due to the construction and solution of the linear system describing the problem. This paper reports the enhancement of the Dual-Equation formulation by the integration of the Fast Multipole Method, which allows dealing efficiently with large antennas. © 2014 IEEE.


Morales M.J.L.,Technical University of Madrid | Saccardi F.,Microwave Vision Italy MVI | Castaner M.S.,Technical University of Madrid | Foged L.J.,Microwave Vision Italy MVI
2016 10th European Conference on Antennas and Propagation, EuCAP 2016 | Year: 2016

This paper presents a comparison between two different echo reduction techniques applied to one-single cut antenna measurements. These techniques are based on modal filtering and time filtering. The first technique uses a post-processing of the far field one-single cut so as to obtain a modal expansion of cylindrical modes and to cancel the effect of spurious signals. The second one is based on filtering echoes out in time domain by applying a Fourier Transform to get a signal in which some spurious contributions can be filtered out. Such techniques are applied on the single cut measurements of a wideband horn (MVI SH2000) performed in a semi-anechoic chamber and on the measurements of a dipole (MVI SD1900) performed in a MVG spherical multi-probe system (StarLab). A smart combination of both methods is also applied in order to improve the results of the post processing with respect each different method. © 2016 European Association of Antennas and Propagation.


Drioli L.S.,European Space Agency | Foged L.J.,Microwave Vision Italy MVI | Saccardi F.,Microwave Vision Italy MVI | Scialacqua L.,Microwave Vision Italy MVI
2015 9th European Conference on Antennas and Propagation, EuCAP 2015 | Year: 2015

In this paper data coming from a GNSS satellite measurement campaign will be used to perform an advanced analysis regarding the interaction between antennas, satellite structure and appendages. © 2015 EurAAP.


Foged L.J.,Microwave Vision Italy MVI | Saccardi F.,Microwave Vision Italy MVI | Mioc F.,Microwave Vision Italy MVI | Iversen P.O.,Orbit FR Inc.
2016 10th European Conference on Antennas and Propagation, EuCAP 2016 | Year: 2016

Spherical Near Field (NF) measurements are widely used in order to accurately characterize the radiating performance of antennas. The main drawback of this type of measurement is the acquisition time that, depending on the electrical size of the Antenna Under Test (AUT), could be very long. This is due to the fact that, in order to correctly evaluate the Far Field (FF) with the NF/FF transformation [1]-[3], the NF has to be sampled over the full sphere with a sampling density that increases with the dimension of the so called AUT minimum sphere [3]. In many spherical NF measurement scenario, it is not possible to locate the AUT in the origin of the measurement sphere resulting in a larger minimum sphere, which implies a denser sampling and a longer acquisition time. An innovative NF/FF technique that allows to drastically reduce the samples density in offset spherical NF measurement is presented in this paper. © 2016 European Association of Antennas and Propagation.


Foged L.J.,Microwave Vision Italy MVI | Saccardi F.,Microwave Vision Italy MVI | Giacomini A.,Microwave Vision Italy MVI
2016 10th European Conference on Antennas and Propagation, EuCAP 2016 | Year: 2016

Probe Correction (PC) in Spherical Near Field (SNF) measurements is typically performed involving the so called first order PC algorithm [1]-[3] which assumes probes with limited |μ|=1 spherical wave spectrum. Lot of effort is typically put in the developments of probes with such requirement [4]-[5] but their design is in many case very challenging especially for wide-band applications. In order to have less restrictions in the selection of the probe, different full probe correction techniques have been recently proposed [6]-[9]. In this paper the accuracy and limitation of the first and higher order PC algorithms are investigated considering the SNF measurement of a wideband horn measured with a first order probe and with a standard gain antenna with higher modal content. The full PC algorithm here considered is based on the modification of the spherical basis functions that are properly elaborated taking into account the effect of the probe. © 2016 European Association of Antennas and Propagation.


Scialacqua L.,Microwave Vision Italy MVI | Foged L.J.,Microwave Vision Italy MVI | Saccardi F.,Microwave Vision Italy MVI | Mioc F.,Microwave Vision Italy MVI
2016 10th European Conference on Antennas and Propagation, EuCAP 2016 | Year: 2016

Electromagnetic models of measured antenna can be accurately computed by the inverse source technique, implemented in the MVG software INSIGHT [1-5]. The measurement processing is based on the expansion of the measured field using equivalent currents [7-10]. A recently created link enable the INSIGHT to export the electromagnetic model to a number of commercial Computational Electromagnetic (CEM) solvers [11-16]. In flush-mounted antenna applications, the antenna measurement and the data processing has to be carefully performed. This paper discuss the source antenna measurement, post processing and successive link to commercial CEM solvers for numerical simulations of the antenna characteristic within a large complex environment, with particular attention to the accuracy of the near field radiation when the measured source is flush-mounted in the simulation scenario. © 2016 European Association of Antennas and Propagation.


Foged L.J.,Microwave Vision Italy MVI | Scialacqua L.,Microwave Vision Italy MVI | Saccardi F.,Microwave Vision Italy MVI | Mioc F.,Microwave Vision Italy MVI
2015 9th European Conference on Antennas and Propagation, EuCAP 2015 | Year: 2015

Computational Electromagnetics (CEM) solvers are important engineering tools in the characterization and optimization of antenna placement on large and complex platforms. The accuracy of the source representation has a strong influence on the simulation accuracy of such antenna systems. It is customary to use domain decomposition technique based on the near field description of the local domain in such cases. This allows a separate modelling of the radiating antenna with high level of detail. The source is subsequently used in the numerical simulation of the entire system. Due to the conclusiveness and high data reliability, measured antennas are attractive as accurate antenna model in numerical simulations. Inverse source or the equivalent current/source method (EQC) provides an accurate near-field representation of any radiating device in terms of equivalent electric and magnetic currents [1-8]. This technique establish accurate electromagnetic 3D models, maintaining the near-field (NF) and far-field (FF) properties of the measured device. The equivalent model of the measured device is importable in commercial CEM solvers in form of a near-field Huygens Box [1-3]. In this paper, applications of measured sources in complex scenarios are reported using commercial CEM solvers. Both free-standing and flush mounted antennas are investigated. The accuracy of the method is investigated by comparison with measurements and/or full-wave simulation of the full structure. © 2015 EurAAP.


Foged L.J.,Microwave Vision Italy MVI | Giacomini A.,Microwave Vision Italy MVI | Saccardi F.,Microwave Vision Italy MVI | Scialacqua L.,Microwave Vision Italy MVI
2015 9th European Conference on Antennas and Propagation, EuCAP 2015 | Year: 2015

Classical probe corrected Spherical Near Field (SNF) measurement assumes probes with limited μ=1 spectrum [1]-[3]. This requirements is needed to fully compensate the effect of the probe during the NF/FF transformation [3]. If the probe spectrum contains higher order modes, a residual error will affect the measured pattern (probe modal truncation). This requirement leads to challenging probe designs, especially if the required bandwidth is wide and/or there is a limitation on the acceptable physical dimension. Consequently, in many practical cases, higher order spherical modes are unavoidable and the design task is to minimize their impact on the probe quality. In this paper, the source of higher order spherical modes of the MVI SP1100 L-band probe is investigated by post-processing the calibration data from NF measurement. Reconstructed equivalent currents associated to higher order modes have been computed on a conformal geometry encompassing the probe using MV-INSIGHT processing [6]. Using a combination of spherical mode filtering and equivalent currents, the origin of such higher order modes is evidenced. Knowledge of these sources are useful to improve future probe designs. © 2015 EurAAP.

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