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Abstracts - Nice 2002
Review of work at IAPP
Igor Minin
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Prof. Minin's slides were in his absence presented by Chairman Juan Mosig. Diffraction mm-wave lens and 3D radomes probably also alumina. See www.sinor.ru/~iapp. Lowcost mm-wave omni-directional antennas.
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On maximum available Directivity of conformal arrays
P-S Kildal, Z Sipus and N Herscovici
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Formula for peak Directivity of planar array:
Dmax = etagrating lobe etaefficiency etaspillover 4 pi/lambda2 Area.
Asymptotic cylindrical and projected planar reference arrays. Pattern shape depends on radius of cylinder. Optimum excitations also depend on radius. Correction to GO phase. We don't reach the projected aperture limit. Hessel and Sureau's realized Gain includes mismatch, loss and surface wave. There may be 1.2 dB difference between Gain and Directivity for cylindrical array. Tuning impedances of individual elements improve gain by 0.5 dB.
Increasing the bandwidth of a microstrip patch antenna with a thick superstrate
Custodio Peixeiro
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Presented at URSI in San Antonio last June. Dielectric lens about 20 lambda diameter fed by patch. Plexiglass with epsilonr = 2.50 and Ensemble simulation results. Bandwidth may increase from 3% to 8%, but the Gain may decrease substantially. Half-power beamwidth can change a lot in the H plane. Experimental results confirm predicted bandwidth results. Increasing the dielectric constant can increase the impedance bandwidth very much, but the Gain goes down. The impedance bandwidth is defined as VSWR less than 2.
Modelling of geometric detail in FDTD
Ian Craddock
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Introduces Univ. of Bristol. FDTD work since 1985. Usually no fine details in FDTD analysis. Conformal meshes for conformal arrays. See JINA paper 177 by Dominique Paul. Hybrid FDTD for larger antennas. Radar systems for breast tumor detection detecting difference in dielectric constants. Bandwidth 40%. Microwaves are well suited for breast tumor detection. Mark Beach works on MIMO systems with simulation. E-mail: Ian.craddock@bristol.ac.uk.
Some recent developments in the modelling of integrated antennas
A. Alu, F. Bilotti and L. Vegni
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Antenna analysis and design. Chiral and Meta materials. Conformal antenna field solution exploiting the Borgnis potential theory. Interesting isomorphism transforming between curved and planar structures. High impedance groundplanes suppress surface waves. Polygonal patch antennas with analytical entire domain basis functions in cooperation with Alenia Spazio.
Antennas for W-CDMA supported by more than 2MEuro over 4 years in Italy. Active Integrated Antennas for W-LAN.
Leaky wave antennas realized with artificial surfaces
Stefano Maci
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In this talk, the concepts of surface/grazing wave suppression and leaky wave excitation mechanisms for high-impedance artificial surfaces are comparatively investigated with the help of both rigorous and simplified models, with the objective to suggest new arrangements and technological solutions for leaky wave antennas.
Full-wave analysis giving equivalent circuit with network parameters depending on angle of incidence in TE and TM scan plane. FSS, AMS (artificial magnetic surfaces) and LWA (leaky wave antenna). Truncation of periodic structure. Solution by Ensemble.
Wide band sparse array antennas - Challenges/proposals
Ioan Lager
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Preoccupations of IRCTR and contributions to COST. 19 scientist incl. 3 full professors and 1 guest professor, 6 engineers and measurement facilities. Work in antennas, telecommunications transmission, remote sensing and radar. See Web site at irctr.et.tudelft.nl
The WISE (wideband sparse element array) mainly for radar. Made portfolio of radiators for ultra wideband applications. Cooperation with METU and Romanian military institute. Ioan Lager joined Delft in 1998.
ASC Technical Contribution (multibeam) to COST 284
Peter Balling
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Conformal antenna research at FGAN-FHR
Bernhard Wierig
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Conformal array demonstrator system: Simultaneous measurements of embedded element patterns to test and evaluate beamforming algorithms.
Antenna modelling techniques and pattern synthesis. Finite Element Methods for infinite arrays and arbitrarily shaped scatterers. Hybrid BEM/MM boundary element method/mode matching for waveguide elements. Cylindrical sector arrays with wedge shaped elements. Systematic investigation of radome parameters varying permittivity (sidelobes increase with epsilonr).
Multiband internal terminal antenna: optimization of properties
Pawel Kabacik, Robert Hossa and Arkadiusz Byndas
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Different bands may have different pattern requirements. Cost differences as small as 10% are important. Stacked patch provides more degrees of freedom in the design than single layer, but there is little flexibility in resonant frequency tuning. PIFA type feed is good as it is close to 50 Ohm, which should be standard. Single layer are low cost, compatible with nanosecond technology, but provides only few resonance frequencies.
Fractal antennas has self similarity. They have a low number of resonances. The lowest resonance has a poor impedance.
Saab Ericsson Space Technical Contribution to COST 284
Per Ingvarson
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500-600 people in Gothenburg with mechanical branch in Linköping and Austrian daughter company. Ascat slotted waveguide array for METOP. Advanced C-band SAR module in cooperation with LEMA and IDS. 3000 ICO elements - microstrip radiator without dielectric. New element includes filter in antenna. GRAS antenna for METOP.
Rosetta 2m reflector with dichroic subreflector for S and X band. Siral interferometer antenna for Cryosat. 7 arcsec bending accuracy. Gregorian shaped reflector antenna. Active Ka-band Rx feed - Multikara feed study - in cooperation with Alcatel, Beacon tracking antenna in CFRP and pin diode switches.
Considerations on antennas for broad-band communication space-based systems
Antoine Roederer
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Rain-fade mitigation for 10-15 dB fades at 20 GHz. Correct scan aberrations with gain and sidelobe control. One feed per beam is not the preferred solution. A few feeds per beam as in the Ka-band Rx multikara project. Tx is more complex. Matrix-based solutions may be used. TWTAs are preferred because of efficiency, but need to be linearised.
Antenna development roadmap. Multiple beam shaped reflectors or with reconfigurable surface.
Terminal antenna development roadmap for satellites. Advanced terminals with scanning beams.
On the polarisation states of mobile terminals
Jussi Rahola
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Total field and vertical and horizontal components can be shown, or CP components can be shown.
New ideas on visualization: Plot total field and indicate polarization state on top. Polarization states change with frequency, but remain similar around 2 GHz for small elements. Head absorbs. Both efficiency and pattern are important.
Dual frequency active amplifier antenna with resistive equalization
Daniel Segovia Vargas
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Centered stacked patches can reach bandwidths of 18%. Displacing the patch in the E plane doubles the bandwidth of the original patch. Example with 10mm displacement. 10 dB amplifier gain from 1.2 to 2.3 GHz. EIRP increased by 7-10 dB and 25% wider band with amplifier and resistive equalisation compared to passive system. Return loss is better than 10 dB with amplifier.
Future work will increase the bandwidth and improve the equalisation. The resistive equalistion probably costs 2 dB.
JINA 2002 PAPERS RELATED TO COST 284
COST: 'Cooperation Scientifique & Technique' on antennas - Results and perspectives
A. Roederer, J. Mosig (Invited paper)
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The paper presents recent and planned antenna activities in the "COST" framework of European Co-Operation in the Field of Scientific and Technical Research, supported by the European Commission.First, some key achievements of the Antenna COST Action 260 on "Smart Antennas: Computer-Aided Design & Technology" (1997-2001) are presented. This includes new modelling techniques and technologies for multi-frequency antennas, conformal arrays, and smart beam-forming.
Then, the main objectives and domains of research of Antenna COST Action 284 (2002-2006) on "Innovative Antennas for Emerging Terrestrial & Space-based Applications", are outlined.
COST 284 will continue some of the developments of COST 260, in particular in the field of conformal antennas. It also will address antenna challenges of emerging terrestrial and space-based multimedia communications, remote sensing, localisation and intelligent transportation. Such applications will require multi-function integrated or conformal antennas with multi-band and reconfiguration capabilities, up to millimetre waves and even beyond. Some of the first achievements and plans of participants in COST 284 will be outlined in the paper.
The T-match: an integrated match for CPW-fed slot antennas
Daniel Llorens del Río, Julien Perruisseau-Carrier and Juan R. Mosig
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A new, compact way to match slot antennas to a coplanar waveguide (CPW) feed is presented. Added to its advantages of flexibility, reduced size and increased bandwidth of the matched antenna, a good analytical approximation of its behavior is possible. An equivalent circuit and procedures for its design are presented. As a demonstration of the possibilites of the method, a set of T-matched antennas has been built and measured at S-band.
Main effects of chiral loading materials in microstrip antennas
Filiberto Bilotti and Lucio Vegni
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The paper describes the main effects of chiral materials employed as substrates for microstrip patch antennas. An extended variational formulation and a hybrid finite element boundary integral numerical method have been jointly applied to simulate cavity backed patch antennas with chiral loading media. Strong reduction of the antenna dimensionas compared to the isotropic case and good wide-band performances have been found to be the main effects of chiral substrates. Finally, the effects of chiral superstrates on conventional patches have been also pointed out through several numerical results.
Innovative wide-band planar monopole antenna for multi-service mobile systems
Marta Cabedo-Fabrés, Miguel Ferrando-Bataller, Alejandro Valero-Nogueira
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The resonance frequency of broadband planar monopoles with different shapes is investigated. A novel compact wide-band planar monopole antenna suitable for use in multi-service wireless devices is proposed. By adding a shorting pin to an arrow tip planar monopole, a great improvement in the bandwidth performance is achieved, while retaining good radiation characteristics.
Pattern synthesis using phase-only control radiated by planar arrays with a large number of elements
A. Trastoy, F. Ares-Pena and J. Vassal'lo
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A method for synthesizing antenna patterns from planar arrays with a high number of elements is presented. This method allows to synthesize antenna patterns radiated by planar arrays with a fixed amplitude distribution using just the phase of the radiating elements. An example of a shaped-beam pattern radiated by a rectangular grid, circular boundary planar array with more than 11.000 elements will be shown.
Hybrid cylindrical-Cartesian FDTD with application to conformal antenna arrays
Dominique L. Paul, Ian J. Craddock, Chris J. Railton, Greg Ball, Paul N. Fletcher and James Watts
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New results from a hybrid Cylindrical/Cartesian FDTD algorithm are presented. The technique, which is very easily introduced into a standard FDTD code without extra computational cost, permits a dramatic increase in the flexibility of the basic FDTD algorithm. It is shown to be particularly well suited to the analysis of facetted conformal antenna arrays, giving a very accurate picture of the far field pattern and of all coupling effects, even between distant elements of the array.
Characteristics of a wideband antenna array
B. Carlegrim, S. Hagelin, R. Gunnarsson, L. Pettersson and R. Ericksson
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We have studied array apertures with tapered slot elements and broadband beamforming networks. The design and evaluation of a 2-6 GHz dual polarized array consisting of two orthogonal, linearly polarized, arrays is reported. Comparisons between simulated and measured results are made.
Experimental design of passive and active microstrip reflectarrays
Francesco Venneri, Luigi Boccia, Giovanni Angiulli, Giandomenico Amendola and Giuseppe Di Massa
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In contrast to the numerical techniques conventionally used to analyse and design microstrip reflectarrays, in this paper a fully experimental approach is proposed. The overall procedure relies on the possibility to estimate the reflection phase of the single reflectarray cell by measuring the scattering characteristics of a small set of identical elements. This method, valid only when the mutual coupling can be ignored, has been successfully applied to both active and passive microstrip reflectarrays. For the passive case, the phase of the field scattered by patches with different sizes has been experimentally retrieved. In a second assessment, the phase curve of a varactor loaded microstrip antenna has been characterised. To prove the effectiveness of the proposed technique the experimentally generated data have been used to design two small reflectarrays. The measured radiation patterns are presented and discussed.
Near-field phase retrieval from intensity-only measurements on a cylindrical helix
Sandra Costanzo and Giuseppe Di Massa
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An amplitude-only measurement strategy is proposed to recover the near-field phase on a cylindrical helix. A recently designed probe, performing near-field intensity-only measurements, is used in conjunction with the helicoidal scanning to significantly reduce the data acquisition time and the complexity of the near-field equipment. Numerical simulations on a uniformly spaced array of dipoles are presented to validate the method.
Array antennas coupling model for multimode radiators
Manuel Sierra-Peréz, Daniel Segovia-Vargas, Manuel Sierra-Castañer and Oscar Moreno
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This paper introduces a mathematical model of coupling and radiation field in array antennas that allows an easy antenna analysis and design. The model is based in the linear behaviour of antennas and in the option to separate the radiated field structure in a reduced number of modes. Special attention can be paid to resonant printed antennas. Printed antenna radiation field can be described through a reduced number of modes, usually one or two, to reach high accuracy in the radiated field computation.
Coupling compensation in a microstrip patch array
José Luis Masa Campos and Manuel Sierra Perez
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In the design process of array antennas, coupling is one of the most important elements to be counted. The real feeding radiated coefficients can be quite different from the theoretical ones because of this effect. In this paper, a compensation method is presented allowing matching each element from the array, thanks to the measurement of some its parameters.
Interference between dual CP and dual LP satellite networks
Peter Balling, Eric Villette, Anthony Baker and Richard Barnett
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A simple method based upon earth station gain templates and the concept of "effective length" is used to assess the aggregate interference between closely spaced dual polarized satellite networks using different polarization types. An asymmetry exists between the downlink and the uplink.
Dual band on-chip-carrier active integrated antenna
G. Ma, P. Gardner and P.S. Hall
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Abstract: An on-chip-carrier active integrated antenna is introduced as an alternative structure for the MMIC on-chip antenna. The idea is to build the antenna on cheap and thick substrates, and the circuit including all the active devices and circuitry on the MMIC materials and then to form this into a single chip carrier device for surface mounting. The antenna is positioned on the top layer of the chip case, and the circuit is laid on the lower layer. Through a slot, power is coupled from the antenna to the MMIC layer and vice versa. The advantages of this structure are low manufacturing cost, compact size and relatively high gain. In addition, this configuration can reduce the interference between the antenna and the circuit, and could achieve optimum performances both for the antenna and circuit.
Comparison of different theoretical horn antenna types used as cluster feeds in reflector systems with multiple beams
Omid Sotoudeh, Per-Simon Kildal and Per Ingvarson
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We have developed a simple numerical test bed for elements in cluster feeds for multiple-beam antennas. In this test bed we can very fast compute the performance of different elements with respect to their directive gains in the middle of a beam and in the weakest point between neighboring beams. This can be done for multiple beam antennas with one, three or four reflectors. The test bed is in this paper used to compare some different theoretical horn antenna types, such as a normal TE11 smooth walled horn, a dual-mode horn and a hard horn. The latter is a horn with a uniform aperture distribution and turns out to have better performance than the other horns considered.
Application of a two-dimensional Physical Optics model in the analysis of microstrip antennas on a finite ground plane
Vladimir Volski and Guy A. E. Vandenbosch
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A two-dimensional (2D) physical optics model for a magnetic line source located near the edge of a semi-infinite structure is applied to investigate the radiation characteristics of a microstrip patch antenna located on a finite ground plane. The 2D model is coupled with the 3D model using a relationship between the incident field at the edge of the finite ground plane and the amplitude of the magnetic line source. The incident field at the edge is expressed in terms of so-called expansion waves. Our formulation to take the diffraction effects into consideration is simple and not time-consuming because it involves only analytical expressions. The experimental results are in good agreement with the proposed model.
Design considerations for quadband antennas integrated in personal communications devices
Marta Martinez Vazquez and Oliver Litschke
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The rapid evolution of the mobile phone market requires the development of terminals, which can operate within different networks, and implement different standards. In most cases, these terminals feature multiband antennas. In this paper, some investigations on the influence of the casing on the matching and efficiency performance of a novel internal, quadband patch antenna are presented. The content of this work falls within the research framework of COST284.
Possibility of spherical semiactive antenna
Leo Vaskelainen
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The motivation of this paper is to demonstrate, that the concept of semiactive array can be applied also to spherical or other three-dimensional conformal arrays. In that kind of antenna the beam can be directed to almost any direction. General phase synthesis techniques can be used with minor modifications to design several types of shaped or contoured beams to different directions.
Decomposition of a finite-by-infinite array using two approximate semi-infinite arrays
Christophe Craeye
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The simulation of finite-by-infinite antenna arrays provides insight into the effects of array truncation. The exact solution to such a problem can be seen as the superposition of the infinite array and two Approximate Semi-Infinite Array (APSIA) solutions. The APSIA problem can be computed in a recursive way for arrays of increasing sizes. A fast single-sweep approximation for the APSIA problem is developed and the results are compared to the exact solution in the case of an array of tapered-slot antennas. The recursive approach automatically yields the solutions for all finite arrays of smaller sizes.
A 70 GHz Cassegrain antenna using a Fresnel reflector
Giovanni Aulisio, Helena Palacios and Juan Vassal'lo
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A prototype of a new Cassegrain antenna, with a Fresnel flat reflector, working at 70 GHz, has been manufactured and measured. Its development and results are presented in this paper.
Design of shaped beam reflectarray for direct broadcast satellites
J. Agustin Zornoza and José A. Encinar
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A phase-only synthesis method based on the Intersection Approach has been applied to design contoured beam reflectarrays with very large number of elements (>10,000). Two different coverages have been synthesised, the first one covers all Europe and The Canary Islands and the second one South America and Florida. For both coverages, an elliptical flat reflectarray was designed with an offset feed that illuminates the reflectarray with a Ð15 dB amplitude taper. For the case of America, an improvement on the frequency response, from 13 GHz to 14 GHz, was obtained by applying a broadband optimisation for a three-layer reflectarray.
Effective diversity gain of two parallel dipoles: Theory and measurement in reverberation chamber
Kent Rosengren and Per-Simon Kildal
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Two parallel dipoles are often used as a reference case for measuring diversity gain. The present paper shows how to calculate the radiation efficiency and effective diversity gain of two parallel dipoles and how they depend on dipole spacing. We treat the case when both dipoles are connected to receivers with input impedance 50 Ohm and the results are verified by measurements of effective diversity gain in a reverberation chamber.
A novel highly linear amplifier active antenna
L. Cabria, J.A. Garcia, A. Tazon, A. Mediavilla and J. Vassal'lo
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In this paper, a novel highly linear amplifier active antenna is presented. In the proposed approach, the antenna serves as an in-phase power combiner of two HEMT-based amplifier branches. The auxiliary branch is added for cancelling the third order intermodulation distortion (IMD3) current of the main branch, without diminishing its gain.
UMTS smart antenna design and implementation
M. Sierra-Perez, L. De Haro, M. Calvo, J.L. Fernández, B. Galocha, E. García, R. Rodríguez and M.S. Castañer
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Adaptive type smart antennas does not usually operate on the deployed UMTS systems, although UTRA-UMTS preview their operation and they also could improve capacity specially in a multiservice environment. This paper describes the implementation of a simplified version of an adaptive antenna, that can be applied to standard Node-Bs, both in the up and down links.
Frequency-tunable internal antenna for mobile phones
Outi Kivekäs, Jani Ollikainen and Pertti Vainikainen
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New approaches are needed for improving the performance of small antennas to fulfill the multiband operation requirements of future wireless mobile communications terminals. In this paper, a novel low-loss frequency tuning circuit for mobile handset antennas is proposed. The presented design takes into account several factors that affect the practical mobile handset antenna design, such as the biasing limitations and distortion of the switching component as well as the effect of the mobile handset-sized ground plane. An antenna prototype that is capable of switching between the US cellular and GSM systems at 800-900 MHz frequency range was designed and measured. The antenna was positioned on a metallized printed circuit board (PCB) having size equal to that of a typical mobile phone. The tuning circuit, consisting of transmission line sections and an SPDT (single-pole, double-throw) FET switch, was fabricated directly on the substrate of the PCB. The designed antenna has high radiation efficiency and low distortion in both system bands.
Multiple spherical wave expansions to characterize radiated fields of mobile phones
T.A. Laitinen, P. Vainikainen and T. Koskinen
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In this paper we first present theoretical considerations that multiple spherical wave expansion (SWE) technique could be used to characterize the radiated fields of longitudinal structures, i.e. a mobile phone whose chassis is relatively long, with a smaller number of basis function compared to a single SWE technique. We then perform a simulation for a mobile phone, whose chassis is relatively long, and show that the number of basis functions required to characterize the field of the mobile phone is smaller when the multiple SWE technique is used compared to the single SWE technique. The result is important in that the number of basis functions ultimately determines the number of measurement locations that is required in practice to characterize the radiated field.
Estimation of Signal Correlation in Antenna Arrays
I. Salonen and P. Vainikainen
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The correlation between signals received with different antenna elements is an important parameter in an adaptive array. In this paper it is shown that when the signal DOA distribution is uniform the signal correlation can be calculated using measured S-parameters of the antenna input ports. When the spread of the angle of arrival is known, the scattering parameters allow also to estimate the correlation level.
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