2017 Antenna Measurement Techniques Association Symposium (AMTA)最新文献

{"title":"Correction of non-ideal probe orientations for spherical near-field antenna measurements","authors":"R. Cornelius, D. Heberling","doi":"10.23919/AMTAP.2017.8123692","DOIUrl":"https://doi.org/10.23919/AMTAP.2017.8123692","url":null,"abstract":"Spherical near-field scanning is a standard method to measure the radiation characteristic of an antenna under test (AUT). Due to the required near-field to far-field transformation of the measured data, an accurate position and orientation of the probe during the measurement is crucial. This might be difficult to achieve if, for example, a robotic arm system is used to position the probe. Different methods for correction of non-ideal measurement positions have been presented in the past. In contrast, the related non-ideal probe orientations in a spherical near-field measurement system have not been comprehensively analyzed due to the assumption that the error is small since the probe receiving pattern is typically broad (e.g. an open-ended waveguide). In this paper, it is shown that non-ideal probe orientations can be included in the spherical near-field to far-field transformation. This is achieved by additional rotations of the probe receiving coefficients in the probe response calculation. The introduced pointwise higher-order probe correction scheme allows an exact spherical wave expansion of the radiated AUT field. The proposed method is used to investigate the error due to non-ideal probe orientations by simulation and measurement. The presented results can be used to estimate the error due to non-ideal probe orientations. It is verified that the error is typically small compared to other error sources in a practical measurement even if a directive higher-order probe is used. Nevertheless, including the probe orientation generally improves the accuracy of the measurement result.","PeriodicalId":405864,"journal":{"name":"2017 Antenna Measurement Techniques Association Symposium (AMTA)","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125208915","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dual-polarized probe with full octave bandwidth and minimum scattering for planar near field measurements","authors":"A. Giacomini, V. Schirosi, R. Morbidini, L. Foged, J. Estrada, J. Acree, L. Tancioni","doi":"10.23919/AMTAP.2017.8123716","DOIUrl":"https://doi.org/10.23919/AMTAP.2017.8123716","url":null,"abstract":"Dual-polarized probes with wide-bandwidth operational capabilities are highly desirable for time-efficient Planar Near-Field (PNF) measurements [1]-[3]. However, sometimes the performance tradeoffs necessary to achieve the desired operating bandwidth make such probes impractical for many applications. Traditional probes are often bandwidth limited, and their electrical size can be an undesired source of scattering in PNF measurements, in particular if the probe-AUT distance is small [4]-[5]. An innovative, octave-band probe has recently been presented combining wide bandwidth, near constant directivity, low cross-polarization, and minimum scattering [6]. In this paper, the probe design is discussed in detail, including technical and implementation trade-offs. Several probes have been manufactured at L/Ku-band band, and test results are presented. The probe design is fully scalable, even beyond Ka-band. The scattering properties of the probe (in terms of measurement perturbation) are assessed by numerical simulation and compared to standard rectangular open-ended waveguides.","PeriodicalId":405864,"journal":{"name":"2017 Antenna Measurement Techniques Association Symposium (AMTA)","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125596584","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"On the design of door-less access passages to shielded enclosures","authors":"V. Rodriguez","doi":"10.23919/AMTAP.2017.8123693","DOIUrl":"https://doi.org/10.23919/AMTAP.2017.8123693","url":null,"abstract":"RF shielded enclosures have been common features in laboratories and manufacturing areas for over 70 years. They provide a quiet environment where RF measurements can be performed without interference from outdoor sources and are used to keep potentially classified frequencies and modulations from leaking out. In general, these shielded rooms have shielded doors to maintain the shielding integrity of the enclosure until they are opened. In some cases, to maintain the shielding integrity as personnel moves from the inside to the outside of the room and vice-versa, dual shielded doors with a small vestibule between them are used. However, the presence of multiple doors increases the time to access the enclosure. To solve this, some enclosures are designed featuring access passages to maintain the shielding integrity over a broad frequency without the use of doors. Although this type of access has been around for over 40 years, its design has never been discussed in the literature. In this paper, a door-less access is analyzed and some design rules are presented. The limitations of these accesses are also presented. While clearly they do not have the shielding performance of a shielded door, they are ideal for certain applications.","PeriodicalId":405864,"journal":{"name":"2017 Antenna Measurement Techniques Association Symposium (AMTA)","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128029730","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nonredundant near-field-far-field transformation from probe positioning errors affected bi-polar data","authors":"F. D’Agostino, F. Ferrara, C. Gennarelli, R. Guerriero, M. Migliozzi","doi":"10.23919/AMTAP.2017.8123690","DOIUrl":"https://doi.org/10.23919/AMTAP.2017.8123690","url":null,"abstract":"This work provides the experimental assessment of an efficient technique which allows the correction of known positioning errors in a near-field — far-field (NF-FF) transformation with bipolar scan requiring a minimum number of NF data. The NF-FF transformation uses a 2-D optimal sampling interpolation expansion, obtained by modeling the antenna under test with an oblate ellipsoid and applying the nonredundant sampling representations to the voltage measured by the probe, to accurately reconstruct the NF data needed by the classical plane-rectangular NF-FF transformation from the voltages samples at the points fixed by the representation. These unknown uniform samples are efficiently retrieved from the acquired positioning errors affected ones by applying a singular value decomposition based procedure. The so developed NF-FF transformation allows the accurate evaluation of the antenna far field from a nonredundant number of positioning errors affected NF data acquired through a bi-polar scanning. Some experimental results, carried out at the Antenna Characterization Lab of the University of Salerno and confirming the effectiveness of the proposed technique, are shown.","PeriodicalId":405864,"journal":{"name":"2017 Antenna Measurement Techniques Association Symposium (AMTA)","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128645486","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterization of a photonics E-field sensor as a near-field probe","authors":"B. Walkenhorst, V. Rodriguez, J. Toney","doi":"10.23919/AMTAP.2017.8123720","DOIUrl":"https://doi.org/10.23919/AMTAP.2017.8123720","url":null,"abstract":"In this paper, we explore the possibility of using a photonics-based E-field sensor as a near-field probe. Relative to open-ended waveguide (OEWG) probes, a photonics probe could offer substantially larger bandwidths. In addition, since it outputs an optical signal, a photonics probe can offer signal transport through optical fiber with much lower loss than what can be achieved using RF cables. We begin with a discussion of the theory of the device followed by a summary of results of a photonics sensor that was tested in a spherical near-field (SNF) range. In these tests, data were collected with the photonics probe in the test antenna position to characterize various probe parameters including polarization discrimination, probe gain, effective dynamic range, and probe patterns. Results are presented along with discussions of some of the advantages and disadvantages of using a photonics probe in a practical system based on the lessons learned in the SNF testing.","PeriodicalId":405864,"journal":{"name":"2017 Antenna Measurement Techniques Association Symposium (AMTA)","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124536546","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ka-band measurement results of the irregular near-field scanning system PAMS","authors":"A. Geise, T. Fritzel, M. Paquay","doi":"10.23919/AMTAP.2017.8123702","DOIUrl":"https://doi.org/10.23919/AMTAP.2017.8123702","url":null,"abstract":"The portable antenna measurement system PAMS was developed for arbitrary and irregular near-field scanning. The system utilizes a crane for positioning of the near-field probe. Inherent positioning inaccuracies of the crane mechanics are handled with precise knowledge of the probe location within the transformation algorithm. The probe position and orientation is tracked by a laser while the near-field is being sampled. Far-field patterns are obtained by applying modern multi-level fast multipole techniques. The measurement process includes full probe pattern correction of both polarizations and takes into account channel imbalances. Because the system is designed for measuring large antennas the RF setup utilizes fiber optic links for all signals from the ground instrumentation up to the gondola, at which the probe is mounted. This paper presents results of the Ka-band test campaign in the scope of an ESA/ESTEC project. First, the new versatile approach of characterizing antennas in the near-field without precise positioning mechanics is briefly summarized. The setup inside the anechoic chamber at Airbus Ottobrunn, Germany is shown. Test object was a linearly polarized parabolic antenna with 33 dBi gain at 33 GHz. The near-fields were scanned on a plane with irregular variations of over a wavelength in wave propagation. Allowing these phase variations in combination with a non-equidistant sampling grid gives more degree of freedom in scanning with less demanding mechanics at the cost of more complex data processing. The setup and the way of on-the-fly scanning are explained with respect to the crane speed and the receiver measurement time. Far-fields contours are compared to compact range measurements for both polarizations to verify the test results. The methodology of gain determination is also described under the uncommon near-field constraint of coarse positioning accuracy. Finally, the error level assessment is outlined on the basis of the classic 18-term near-field budgets. The assessment differs in the way the impact of the field transformation on the far-field pattern is evaluated. Evaluation is done by testing the sensitivity of the transformation with a combination of measured and synthetic data.","PeriodicalId":405864,"journal":{"name":"2017 Antenna Measurement Techniques Association Symposium (AMTA)","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133340032","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Verification of spherical mathematical absorber reflection suppression in a combination spherical near-field and compact antenna test range","authors":"S. Gregson, A. Newell, P. Betjes, C. Parini","doi":"10.23919/AMTAP.2017.8123721","DOIUrl":"https://doi.org/10.23919/AMTAP.2017.8123721","url":null,"abstract":"This paper presents the results of a recent study concerning the computational electromagnetic simulation of a spherical near-field (SNF) antenna test system in the presence of a compact antenna test range (CATR). The plane-wave scattering matrix approach [1, 2] allows many of the commonly encountered components within the range uncertainty budget, including range reflections, to be included within the model [3]. This paper presents the results of simulations that verify the utility of the spherical mathematical absorber reflection suppression (S-MARS) technique [3, 4] for the identification and subsequent extraction of artifacts resulting from range reflections. Although past verifications have been obtained using experimental techniques this paper, for the first time, corroborates these findings using purely computational methods. The use of MARS is particularly relevant in applications that inherently include scatterers within the test environment. Such cases include instances where a SNF test system is installed within an existing compact antenna test range (CATR) as is the configuration at the recently upgraded Queen Mary University of London (QMUL) Antenna Laboratory [5, 6]. Thus, this study focuses on this installation with results of CEM simulations being presented. The method enables a quantitative measure of the levels of suppression offered by the MARS system.","PeriodicalId":405864,"journal":{"name":"2017 Antenna Measurement Techniques Association Symposium (AMTA)","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116655428","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Broadband additive spiral antenna","authors":"T. Lam","doi":"10.23919/AMTAP.2017.8123700","DOIUrl":"https://doi.org/10.23919/AMTAP.2017.8123700","url":null,"abstract":"A novel low cost and high performance miniaturized broadband Additive Spiral Antenna (ASA) technology (patent pending) has been developed. Unlike other conventional spiral designs, this new spiral antenna leverages Additive Manufacturing (AM) 3D zig-zag shapes to achieve an efficient slow wave radiation structure for extending spiral's low frequency performance without size increases. Conversely, this 3D additive structure allows a significant antenna miniaturization for the given frequency band, without gain bandwidth performance degradations. As a result, an initial 4″ prototype ASA has been successfully designed and tested with the measured gain bandwidth performance approaching the Chu's fundamental limit for the given antenna size. More importantly, the ASA aperture size is significantly reduced by more than 50% with excellent transmit and receive gain efficiency and power handling capabilities. This paper describes the ASA prototype design and the antenna near field and far field compact range measurement results to demonstrate Additive Manufacturing technology can enhance antenna performance that otherwise not realizable with conventional fabrication techniques.","PeriodicalId":405864,"journal":{"name":"2017 Antenna Measurement Techniques Association Symposium (AMTA)","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129955284","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Measurements of low gain VHF antennas in spherical multi-probe NF system","authors":"A. Giacomini, F. Saccardi, V. Schirosi, F. Rossi, L. Foged, S. Dooghe, A. Gandois","doi":"10.23919/AMTAP.2017.8123717","DOIUrl":"https://doi.org/10.23919/AMTAP.2017.8123717","url":null,"abstract":"The accurate characterization of low-gain antennas at VHF frequencies is challenging. Such antennas can be tested outdoors for convenience or in very large and thus expensive indoor Far-Field (FF) ranges [1]. Indoor Near-Field (NF) systems are often considered a better cost compromise for such measurements, mainly due to the relaxed requirements on chamber size. However, reflectivity issues and other source of errors such as truncation can compromise the measurement accuracy [2]. Multi-probe NF systems in spherical geometry are optimal measurement solutions for the low frequency characterization of low directivity antennas such as most antennas in automotive applications [3,4,5]. In this paper, we present VHF-band measurements of a low directivity antenna in a hemispherical and quasi full-3D multi-probe system. The VHF antenna in this study is an array element, which has been developed for space applications [6-7]. The different measurements reported are part of the technology development activity of the antenna. For each antenna measurement, the gain and pattern accuracies are investigated by comparison with full wave simulations.","PeriodicalId":405864,"journal":{"name":"2017 Antenna Measurement Techniques Association Symposium (AMTA)","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128023526","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermal testing of small antennas in multi-probe spherical near-field systems","authors":"A. Giacomini, R. Morbidini, L. Foged, J. Acree, J. Estrada, E. Szpindor, P. Iversen","doi":"10.23919/AMTAP.2017.8123715","DOIUrl":"https://doi.org/10.23919/AMTAP.2017.8123715","url":null,"abstract":"Temperature changes cause thermal expansion of antenna materials and will have an important impact on antenna performances. In some applications, it is sufficient to calculate the antenna deformation by mechanical analysis and determine the RF impact by EM analysis tools. However, if the environmental conditions of the final antenna are stringent and considered critical as in the case of military and civil applications like space and aeronautics, the thermal performance of the antenna must be determined by experiment [1]-[2]. Based on the preliminary results discussed in [3], this paper present a simple and effective method for thermal testing of antennas in a spherical near field range based on multi probe technology [4]-[9]. The antenna is maintained inside an RF transparent thermally insulated container including the local heating and cooling equipment. The fast testing provided by the multiprobe system allows one to measure the temperature dependence of the antenna at several different temperatures within the investigation range. The method will be illustrated for the cold measurement case with temperatures below −100°C but the extension to the full cold to hot temperature range is trivial.","PeriodicalId":405864,"journal":{"name":"2017 Antenna Measurement Techniques Association Symposium (AMTA)","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115522650","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}