An innovative spherical NF/FF transformation algorithm for offset measurements based on a Translated Spherical Wave Expansion (TSWE) has been recently proposed. In this paper we investigate by experiment the echo reduction properties of offset AUT measurements using TSWE.
In this paper, a wide-band numerical model of the measured antenna is presented, improving the accuracy of the coupling assessment. The finding are supported by radiated and conducted measurement on the single element and the array configuration.
Probe correction in standard spherical near field measurements are typically limited to probes with |μ|=1 spherical wave spectrum when performing spherical wave expansion. The design of such probes is often a trade-off between achievable performance, modal purity and bandwidth. Compensation techniques for probes with higher or full order modal spectrum have recently been proposed.
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.
In this paper, the QZ cross-polar reduction properties of the CXR feed is measured in a standard corner-fed CATR in both orthogonal polarization over the full 1.6:1 bandwidth. The advantages of the CXR in general measurement scenarios are investigated by measurement of an antenna with low cross-polarization level at different QZ positions and frequencies.
Dual polarized wideband probes are convenient for accurate and time efficient Planar Near Field (PNF) antenna testing -. Traditional probe designs are often bandwidth limited and electrically large leading to high scattering - in PNF measurements with short probe-AUT distances.
Probe correction in Spherical Near Field (SNF) measurements is typically performed during the NF/FF transformation. This requirement leads to challenging probe designs, especially if the required bandwidth is wide. For this reason, in many practical cases, higher order spherical modes can be radiated.
The polarization purity of an antenna system is an important performance parameter, particularly in dual-polarized systems, where depolarization can prevent operating objectives from being achieved. Accurate polarisation testing requires a significantly higher polarisation purity of the test system than of the test object.
Integration of antenna measurements in numerical simulations, based on the equivalent current technique, has been validated in previous activities. A link, enabling the export of an accurate numerical model, derived from the measured antenna pattern, to a number of commercial Computational Electromagnetic (CEM) solvers has been created and validated.
Accurate numerical models of a given antenna can be derived from measurements using the inverse source technique. Using this technique, measured antenna patterns can currently be imported and used as numerical sources in a number of commercial Computational Electromagnetic (CEM) solvers.
Electromagnetic simulation allows engineers to investigate the performance of antennas in a wide range of different environments which may be inaccessible or infeasible to measure. However, it is often the case that a suitable model of the antenna is not available for the simulation, especially for off-the-shelf antennas with geometries that are protected by intellectual property.
In this paper an advanced analysis regarding the interaction between antennas installed on a spacecraft is presented. In particular, data coming from a GNSS satellite near field measurement campaign have been considered and the MV-INSIGHT software has been used to perform the analysis.
In this paper is demonstrated the accurate representative electromagnetic models of measured antennas based on the MVG software INSIGHT processing, implementing the inverse source technique. The measurement processing is based on the expansion of the measured field using equivalent currents.
This paper describes a new procedure allowing the use of measured antenna sources in commercially-available numerical computational environments. The procedure is fully general and can be used with common antennas in complex environments of arbitrary shape and complexity.
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.
This paper reviews recent developments in multi-probe antenna measurements technology and show new application examples. In particular, the results of a challenging measurement of a VHF low-directive antenna performed in a hemispherical multi-probe system are reported.
A multi-probe array (MPA) spherical near-field antenna measurement system, comprised of OTS equipment, has been developed for testing UHF antennas mounted of an aircraft rotodome. The spherical probe radius is 5 meters, which accommodates a 24 ft. diameter rotodome.