Spherical Near Field (NF) measurements are widely used in order to accurately characterize the radiating performance of antennas. The main drawback this type measurement is acquisition time that, depending on electrical size Antenna Under Test (AUT), could be very long. This due fact correctly evaluate Far (FF) with NF/FF transformation [1]-[3], NF has sampled over full sphere a sampling density that increases dimension so called AUT minimum [3]. In many spherical scenario, it not possible...

Recently, significant efforts from different research groups have been aimed at the problem of reconstructing extreme near field radiated by an antenna measured data. Among proposed solutions, inverse-source or Equivalent-Current/Source Method (EQC), based on discretization integral equations, has attracted considerable attention, due to a host promising applications in design and diagnostics. The integral-equation approach constitutes complement more-established tools, such as plane-wave...

Electromagnetic analysis of antennas in complex scenarios require accurate numerical modelling solvers. A fundamental requirement to achieve truthful results is the representation/modelling source antenna. However, many practical cases a full-wave representation physical antenna either unfeasible or unavailable format required by desired computational electromagnetic (CEM) tool. This paper describes an innovative procedure enabling measured data be used as sources commercially-available...

Near-field-to-far-field transformation algorithms have been developed during the last decades of century. Spherical near-field measurements are nowadays most accurate technique for characterizing one antenna. However, drawbacks is requirement a full spherical acquisition. This means large number scans, especially very antennas, requiring long measurement time. paper presents several techniques performing single-cut near-to-far-field transformation. An explanation each algorithm, and...

Recent use of measured data as near field sources in Computational Electro Magnetic (CEM) tools has opened the possibility to represent antennas numerical simulations, even when antenna characteristics and geometry are unknown therefore cannot be included a full wave model [1-4]. The source consists an equivalent current representation antenna, which is prepared by inverse method from radiation pattern [5-9]. This link bringing together simulations measurements been validated proper...

The ground-based automatic identification system (AIS) is a coastal tracking and messaging used by vessels for maritime traffic monitoring. European SAT-AIS initiative aims at providing space-based complementary to extend the range of existing AIS high seas via very frequency (VHF) satellite constellation. Miniaturized Antenna (AISMAN) activity concentrates on development VHF array antenna minisatellite platforms in low Earth orbit. Array element volume minimization mass reduction are...

In this paper, early performance assessments on a newly developed plane wave generator (PWG) at millimeter frequencies are reported for the first time. The PWG is integrated in an automated system suitable 5G testing. Far-field radiation from devices such as pattern, beam pointing, and typical over-the-air (OTA) parameters can be measured 3D space. Devices positioned quiet zone (QZ) using RF transparent positioner. Live person testing feasible, chair placed that device including head upper...

This paper presents a comparative investigation of two versatile error-mitigation techniques, applicable to general antenna near-field measurement scenarios with echo signals unknown origin. Both techniques are based on spatial filtering the measured field, taking advantage priori knowledge antenna's size. The first approach takes spatial-filtering properties spherical-wave expansion field. second is reconstruction equivalent currents, and implements as direct consequence selected size shape...

A fast spherical near-field to far-field transformation using single cuts is introduced in this paper. It based on calculating the Cylindrical Modal Coefficients of each individual ring and processing them independently, considering as cylinders zero height applying probe correction. The reconstruction cut obtained through an inverse Fast Fourier Transform. This procedure provides opportunity perform real time transformations due its low acquisition time. a useful tool for applications which...

Modern antennas and applications are expanding the frequency range towards both lower higher frequencies while demanding very rapid development testing cycles. A fast, reliable accurate way to exhaustively determine antenna device performance is based on near-field measurement techniques combined with probe array technology. This paper reviews recent developments in multi measurements technology show new application examples. In particular, results of a challenging VHF low-directive...

Accurate electromagnetic models of measured antennas are available from the expansion field using equivalent currents. The constructed model is importable in commercial Computational Electromagnetic (CEM) solvers form a Huygens Box. In flush-mounted antenna applications, measurement sited locally relevant scenario and subsequent data processing require special attention. This paper, discuss details appropriate characterization source for numerical computation flush mounted scenarios. Post...

The Plane Wave Generator (PWG) is an array of elements generating approximately plane wave over a finite volume in the test area called Quiet Zone (QZ). condition can be achieved close proximity to with suitably optimized complex coefficients. PWG thus achieve far-field testing conditions manner similar Compact Antenna Test Range (CATR) but reduced distance QZ [1–2]. As complete system has advantage physical size compared CATR equivalent capabilities, particular at lower frequencies. In...

Automotive antenna measurements are increasingly demanding. Modern cars equipped with a large number of integrated antennas, spanning wide frequency range for applications. Integrated antennas strongly coupled the structure, final testing thus performed on vehicle to accurately determine performance. The physical and electrical size typical cars, impose different measurement challenges while performing radiated in automotive Spherical Near Field (SNF) ranges. At higher frequencies, coupling...

Antennas installed in modern cars are often highly integrated. In such cases, the entire vehicle is contributing to radiated field, particular at lower frequencies as VHF. The complete characterization of full thus typically required. For down 70 MHz, a widely accepted and cost effective solution multi-probe spherical Near Field (NF) system which scanning area truncated below horizon minimize dimensions. order emulate proper freespace condition hemisphere, ground floor covered with absorbing...

Electromagnetic models of measured antenna can be accurately computed by the inverse source technique, implemented in MVG software INSIGHT [1-5]. The measurement processing is based on expansion field using equivalent currents [7-10]. A recently created link enable to export electromagnetic model a number commercial Computational (CEM) solvers [11-16]. In flush-mounted applications, and data has carefully performed. This paper discuss measurement, post successive CEM for numerical...

The development and validation of a Plane Wave Generator (PWG) suitable for 5G testing at frequencies below 6 GHz have been reported in recent publications. There is an obvious interest to further develop the successful PWG technology higher employed by other communication systems. In this paper, we report on dual polarized millimeter wave frequencies. A representative demonstrator has manufactured tested. consists twelve identical elements distributed two concentric rings using corporate...

Additive manufacturing is becoming a popular alternative to traditional techniques as it has reached suitable maturity and accuracy for microwave applications. The main advantage that the can be performed directly from three-dimensional CAD model, available numerical simulation of antenna, without significant modifications. This highly desirable feature, in particular time cost critical applications such prototyping small quantities antennas. In this letter, we investigate repeatability...

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

The calibration of the antenna measurements system is a fundamental step which directly influences accuracy any power-related quantity device under test. In some types systems, can be more challenging than in others, and selection proper method critical. this paper, truncated spherical near-field ranges typically used for automotive tests investigated, considering both absorbing conductive floors. analyses are carried out 12:1 scaled multi-probe system, allowing access to "true", full-sphere...

This paper presents a comparative investigation of two different but highly suitable techniques for the accurate determination full sphere pattern an antenna from truncated spherical near field measurements. The first approach is based on iterative procedure which exploits band-limitedness properties radiated to correctly reconstruct data [1]. second was described in [2] and determining set equivalent currents that radiate same known area thus extrapolate unknown fields area. study performed...

This paper presents an investigation of a new technique for the accurate determination full sphere pattern antenna from truncated spherical near field measurements. The approach was first described in [2] and is based on determining set equivalent currents that radiate same known area thus extrapolate unknown fields area. study performed actual measured near-field data to investigate effectiveness realistic measurement scenarios.

In this paper, two filtering techniques for the suppression of range reflections in antenna measurements are compared based on simulated and measured data. The spherical modal is expansion field wave functions. Range suppressed by removing unwanted modes before transforming back to far-field. direct low-pass technique employs band limitation radiation pattern function directly. higher order components angular spectrum. Both methods require a or spectral separation between wanted part be...