Prof. Robert Nevels ¡¡¡¡
Prof. Marlene Pontes¡¡¡¡¡¡
Prof. Joshua Le-Wei Li
Prof. Ya-Qiu Jin ¡¡¡¡¡¡¡¡
Prof. Wei Hong ¡¡¡¡¡¡¡¡¡¡¡¡Prof. ZHANG Minggao
Dr. Ingemar H?ggstr?m
Prof. Robert Nevels, Texas A&M University, USA
One of the most exciting aspects of the electromagnetic field is that as new frequency ranges and materials become available we must completely redesign both our antennas and the circuits that operate in the these environments while facing a new set of engineering challenges. Where do we learn about these new developments except at conferences and symposia like ISAPE? The Antennas and Propagation Society (AP-S) is honored to be a part of this conference and to share the fundamental knowledge and information presented here with the rest of the world through our online Xplore database. I will present some other opportunities in terms of chapter support, Distinguished Lecturer visits and travel support to our North American Conference that AP-S and the Institute of Electrical and Electronic Engineers (IEEE) governing organization provide. Also, the theme of this conference which is based on its name, The International Symposium on Antennas, Propagation and Electromagnetic Theory, rests on the fundamental principles of wireless wave theory. I will discuss briefly my experience with the origin of the phrase ¡®Wireless Technology' and its wider implications in bringing together the many disciplines of engineering. Rarely has one technological idea become so widely recognized so quickly. Not only is it used by a large portion of our international community, it has been voted one of the top two most important technologies of the next 10 years, an honor It shares with the internet.
In this presentation I will review some of the most interesting problems and opportunities that the higher frequency ranges present to the antenna engineer.
Welcome to the International Symposium on Antennas, Propagation and Electromagnetic Theory.
Prof. Marlene Pontes,CETUC-PUC/Rio
"Review on Rain Attenuation on Radio Links"
The ever-increasing exhaustion at the frequency spectrum for communications systems due to the
continuing expansion of the available services and the demand for new ones requires the use of
increasingly higher frequencies, well above 10 GHz. Propagation of electromagnetic waves through the
atmosphere at these frequencies is heavily affected by hydrometeors, specially rain.
When rainfall is present in the propagation path, the flux of power is attenuated by the raindrops present
within the first Fresnel zone. The attenuation in the wave amplitude is dependent on the wave frequency,
rainfall temperature, the complex index of refraction of water (due to the chemical composition of rain
water, raindrops can be considered as low loss dielectrics) and the distribution of raindrop sizes.
Two mechanisms are at work when rain attenuation occurs: absorption and scattering. Although
hydrometeor scattering is the major limiting factor in the EHF band (>30GHz), hydrometeor absorption is
the dominant phenomenon causing power loss in the lower spectral part between 10GHz and 30GHz.
Attenuation due to rainfall along a path may be calculated by integrating the specific attenuation over the
path length if the rainfall rate variation along the path is known.
Rainfall rate is inhomogeneous in space and time. Rain cells are known to cluster frequently within rain
regions sometimes called small mesoscale areas. Rain gauge records show short intervals of higher rain
rate imbedded in longer periods of lighter rain. Weather radar observations show small areas of higher rain
rate imbedded in larger regions of lighter rain. Terrestrial links exceeding 10 km and satellite links may,
therefore, traverse more than one rain cell within a rain region. In addition, influence of the lower intensity
rainfall surrounding the cell must be taken into account in the attenuation calculations. The linear extent of
these regions increases with decreasing rain intensity and may be as large as several tens of kilometers.
The main difference in the various methods developed for predicting rain attenuation statistics from
rainfall rate measurements is in the models used to describe the time-space structure of rainfall rate.
The ¡°synthetic storm method¡±, for instance, generates attenuation statistics by converting rain rate/time
profiles recorded at a point to rain rate/distance profiles, using the translation velocity of the rain pattern,
estimated as the wind speed.
All other methods make use of cumulative distributions of rainfall rate measured at a point. Some methods
derive the statistical profile of rain along the path assuming a single cell of suitable shape or a statistical
distribution of sizes for cells of a particular shape. Other methods characterize the statistical rain profile
simply by a reduction coefficient, which may be derived from the spatial correlation function of rainfall,
from measurements using rapid response rain gauges displaced along a line or from a semi-empirical law.
Multiplying point rain rate by this reduction coefficient gives the equivalent path-averaged rain rate.
An alternative procedure is to apply the reduction coefficient to the actual path length, which yields an
equivalent path length over which the rain intensity may be assumed to be constant. This type of procedure
is currently adopted in the method in Recommendation ITU-R P.530.
As it is obvious from what has been presented above, numerous modeling and prediction methods have
been developed which have provided good agreement with experimental observations. The great majority
of the methods are, in fact, compared with the results of local measurements and therefore biased towards
the local conditions.
As far as a global model is concerned, however, only a handful has been found to produce adequate
results. These global methods are of a semi-empirical nature, i.e., they combine theoretical and
meteorological data from several locations. The end results are tested against a set of goodness of fit
This work will deal with a review of the prediction models, from the classical to the state of the art. This
review includes the methodology currently adopted in ITU-R Recommendation P.530, applied to
terrestrial systems, and in ITU-R Recommendation P.618, applied to satellite systems.
Prof. Joshua Le-Wei Li, National University of Singapore , Singapore
Joshua Le-Wei Li (S'91-M'92-SM'96-F'05)
was born in
Nanjing, China . He received his B.Sc. degree in Physics from Xuzhou Normal University (XNU), Xuzhou , China ,
in 1984; M.Eng.Sc. degree in Electrical Engineering from China Research Institute of Radiowave Propagation (CRIRP),
Xinxiang, China, in 1987; and Ph.D. degree in Electrical Engineering from
Monash University , Melbourne, Australia, in 1992, respectively.
In 1992, he was a Research Fellow with Department of Electrical & Computer Systems Engineering at Monash University , sponsored by Department of Physics at La Trobe University , Melbourne , Australia . Since 1992, he has been with the Department of Electrical & Computer Engineering at the National University of Singapore where he is currently a Professor and the Director of NUS Centre for Microwave and Radio Frequency . In 1999-2004, he was seconded with High Performance Computations on Engineered Systems (HPCES) Programme of Singapore-MIT Alliance (SMA) as a SMA Faculty Fellow. In May-July 2002, he was a Visiting Scientist in the Research Laboratory of Electronics at Massachusetts Institute of Technology (MIT), Cambridge, USA; in October 2007, an Invited Professor with University of Paris VI, France; and in January and June 2008, an Invited Visiting Professor with Institute for Transmission, Waves and Photonics at Swiss Federal Institute of Technology, Lausanne (EPFL) in Switzerland. He was selected by Chinese Thousand Talent Scheme (Qian-Ren Ji-Hua) as a National Professor at the University of Electronic Science & Technology of China where she serves as Founding Director of Institute of Electromagnetics. His current research interests include electromagnetic theory (e.g., dyadic Green's functions), computational electromagnetics (e.g., pre-corrected fast Fourier transform - P-FFT method and adaptive integral method -AIM), radio wave propagation and scattering in various media (e.g., chiral media, anisotropic media, bi-anisotropic media and metamaterials), microwave propagation and scattering in tropical environment, and analysis and design of various antennas (e.g., loop and wire antennas and microstrip antennas). In these areas, he has (co-)authored 2 books [namely, Spheroidal Wave Functions in Electromagnetic Theory (New York: Wiley, 2001) and Device Modeling in CMOS Integrated Circuits: Interconnects, Inductors and Transformers (London: Lambert Academic Publishing)], 48 book chapters, over 310 international refereed journal papers (of which more than 150 papers were published in IEEE Transactions and Letters, and the remaining in Optics Express, Physical Review E or B , Radio Science , IEE Proceedings , and JEWA etc), 48 regional refereed journal papers, and over 350 international conference papers.
Dr. Li was a recipient of a few awards including 2 best paper awards from the Chinese Institute of Communications and the Chinese Institute of Electronics, the 1996 National Award of Science and Technology of China , the 2003 IEEE AP-S Best Chapter Award when he was the IEEE Singapore MTT/AP Joint Chapter Chairman, and the 2004 University Excellent Teacher Award of National University of Singapore. He has been a Fellow of IEEE since 2005 and a Fellow of The Electromagnetics Academy since 2007 (member since 1998) and was IEICE Singapore Section Chairman between 2002-2007. As a regular reviewer of many archival journals, he is an Associate Editor of Radio Science and International Journal of Antennas and Propagation ; an Editorial Board Member of Journal of Electromagnetic Waves and Applications (JEWA), the book series Progress In Electromagnetics Research (PIER) by EMW Publishing, International Journal of Microwave and Optical Technology , and Electromagnetics journal; and an Overseas Editorial Board Member of Chinese Journal of Radio Science , Frontiers of Electrical and Electronic Engineering in China (for selected papers from Chinese Universities by Springer), and Science China: Information Sciences . He was also a Guest Editor of a Special Section on ISAP 2006 of IEICE Transactions on Communications, Japan . He is an Advisory Professor at State Key Laboratory of Electromagnetic Environments, Beijing (2002-); a Guest Professor at both Harbin Institute of Technology, Harbin (2003-2010) and Southeast University, Nanjing (2004-); and an Adjunct Professor at both Zhejiang University, Hanzhou (2004-2006) and University of Electronic Science and Technology of China, Chengdu (2006-); all in China. He also serves as a member of various International Advisory Committee and/or Technical Program Committee of many international conferences or workshops, in addition to serving as a General Chairman of ISAP2006, MRS09-Meta09, and IWM2010 and TPC Chairman of PIERS2003, iWAT2006, APMC2009, and ISAPE2010.
"Sommerfeld Integrals for Planar Layered Media in EM Theory "
The radio wave propagation in a planar stratified medium, for instance, excited by a vertical electric dipole over the
earth, has been a subject of many years. When this classical problem is solved, the Sommerfeld integrals will occur and
there is no way of avoiding the evaluation of the Sommerfeld integrals for either numerical or closed form solutions.
To evaluate the Sommerfeld integrals, some well-known approaches such as steepest saddle-point method, branch cut method
and curve fitting approximations will have to be employed to obtain some approximate solutions.
Along this first line, King and Sandler derived the analytical formulas for the fields at all points of a three-layered planar geometry, and an extensive discussion about a trapped surface waves were made. Wait pointed out that the authors overlooked the trapped surface wave which can be excited by the source when the coating dielectric layer is low-lossy and the substrate is a highly conducting half-space. King and Sandler replied that their formulas were derived systematically and rigorously subject only to conditions (3a) and (3b) in their paper. In another work by Zhang and Pan, the discussion is summarized and the properties of the trapped surface wave are re-examined. They derived a set of modified analytical formulas where the contributions of the trapped surface wave and the lateral wave were given explicitly. They pointed out that the trapped surface wave can be efficiently excited when the dipole is near the surface and that both the lateral wave and the trapped surface wave cannot be ignored in the far region. Furthermore, it is pointed out that the trapped surface wave is affected significantly by the conductivity of an imperfect conductor. The method is extended to a horizontal dipole near the surface of a planar perfect conductor coated with a one-dimensionally anisotropic medium or a uniaxial layer in 2005.
In fact, the flat earth can be treated as a radially stratified sphere when its core radius is electrically very large; so the solution to the problem can be that of summing up the spherical harmonics in spherical coordinates system. By inspection, the solution to the flat problem should be the same as that to the spherical one when the radius of the earth is electrically very large. Along the second line, the layered spherical earth model takes into consideration of the earth curvature. The fields are expressed by spherical harmonics series which is usually poor in convergence although the solution is exact. In order to overcome the poor convergence problem, several research works have focused on the accelerated summation of the spherical harmonics. Johler and Lewis calculated the fields at an extremely low frequency (ELF) directly from zonal harmonics series, using the Kummer's transformation with an averaging process for a sharply bounded ionosphere model. Johler further improved the convergence of the harmonics series by using the modified zonal harmonics and geometric series. In addition to the zonal harmonics series solutions, several asymptotic methods were also explored using the Watson's transform ation. Sommerfeld in 1949 derived the field expressions for a perfectly conducting earth. Wait in 1956 and Fock in 1965 derived the formulas of the fields radiated by a dipole in the presence of a homogeneous earth with a compact notation for the Hankel function of the order one-third. The boundary conditions at the surface of the sphere were specified by surface impedance. Some recent progress is made and summarized.
Both of the planar and spherical earth models can be simplified under certain approximations, for instance the residue series approach. Therefore, their accuracy and validation range need to be studied in detail. In addition, it is not difficult to find that there exist in literature a number of results of radiated electric and magnetic fields derived for the planar stratified media, they are, however, not straightforwardly verified or validated for the accuracy. Due to this reason, some interests have been shown along the first line. It was indicated that to obtain the closed form solutions or the fast convergent solution, some conditions must be applied, as very well summarized by Collin. In fact, some other research works were also done earlier to look into the lateral wave properties. The properties of total field presented in are shown to fluctuating in near zone versus the horizontal distance while the asymptomatic forms given in cannot predict such effects.
In this talk, both of these asymptotic, approximate, and exact models in planar and spherically multilayered geometries are re-visited and three sets of results are compared each other with the results recently obtained. For the convenience of the comparison, it is assumed that the earth is a perfect conductor coated with one layer of dielectric. After the comparison is made, solutions to the Sommerfeld integrals are obtained using the spherical multipole expansions. Techniques on accelerating these series will be briefed as well.
Prof. Ya-Qiu Jin, Fudan University , China
Ya-Qiu Jin graduated from Peking University , Beijing , China in 1970, and received the M.S., E.E., and Ph.D. degrees from the Massachusetts Institute of Technology, Cambridge , USA in 1982, 1983 and 1985, respectively. All the degrees are from electrical engineering.
He was a Research Scientist with the Atmospheric and Environmental Research, Inc., Cambridge MA, USA (1985); a Research Associate with the City University of New York (1986-1987); a Visiting Professor with the University of York, U.K. (1993-1994) sponsored by the U.K. Royal Society; a Visiting Professor with the City University of Hong Kong (2001); and a Visiting Professor with Tohoku University, Japan (2005). He held the Senior Research Associateship at NOAA/NESDIS awarded by the USA National Research Council (1996). He is currently a Te-Pin Professor of Fudan University, Shanghai , China , and the founder Director of the Key Laboratory of Wave Scattering and Remote Sensing Information (MoE, Ministry of Education). He has been appointed as the Principal Scientist for the China State Key Basic Research Project (2001-2006) by the Ministry of National Science and Technology of China to lead the remote sensing program in China .
He has published more than 600 papers in refereed journals and conference proceedings and 12 books, including Electromagnetic Scattering Modeling for Quantitative Remote Sensing (World Scientific, 1994), Information of Electromagnetic Scattering and Radiative Transfer in Natural Media First volume 1983-2000 (Science Press, 2000), Theory and Approach for Information Retrieval from Electromagnetic Scattering and Remote Sensing (Springer, 2005)]. He is Editor of Wave Propagation, Scattering and Emission in Complex Media (World Scientific and Science Press, 2004) and Co-Editor of the book Selected Papers on Microwave Lunar Exploration in Chinese Chang'E-1 Project (Science Press, 2010) and SPIE Volume 3503 Microwave Remote Sensing of the Atmosphere and Environment . His main research interests include scattering and radiative transfer in complex natural media, microwave remote sensing, as well as theoretical modeling, information retrieval and applications in atmosphere, ocean, and Earth surfaces, and computational electromagnetics.
Dr. Jin is the IEEE Fellow, the member of IEEE GRSS AdCom, Chair of IEEE Fellow Evaluation Committee in GRSS, IEEE GRSS Distinguished Speaker, and an Associate Editor of IEEE Transactions on Geoscience and Remote Sensing (GRS). He received IEEE GRSS Education Award in 2010.
He is Co-Chair of Technical Committee of IGARSS2011, ISAPE2000 and 2010, and Chair of JURSE2009 and several international conferences. He is the Founder Chairman of IEEE GRSS Beijing Chapter (1998-2003) and received the appreciation for his notable service and contributions toward the advancement of IEEE professions from IEEE GRSS.
He received the China National Science Prize in 1993, the first-grade Science Prizes of MoE in 1992, 1996 and 2009, and the first-grade Guang-Hua Science Prize in 1993 among many other prizes.
¡°Scattering and Emission Models and Simulations for Lunar Exploration¡±
Abstract :China successfully launched its first lunar exploration satellite Chang-E 1 (CE-1) on October 24, 2007. A multi-channel (3.0, 7.8, 19.35 and 37 GHz) microwave radiometer was, for the first time in lunar exploration, used for the purpose of measuring the microwave thermal emission from the lunar surface.
This paper presents the research works on the modeling, data-image simulation and data validation for lunar exploration in both passive/active microwave remote sensing.
As the first part, the works on Chinese Chang-E (CE-1) lunar program, including brightness temperature simulation (Tb) of lunar surface media, CE-1 data validation and retrieval of lunar regolith layer thickness from multi-channel CE-1 Tb data, and evaluation of global inventory of Helium -3 in lunar regolith, are reported.
As the second part of this paper, scattering modeling and numerical image simulations of the randomly cratered lunar surface/subsurface structures for synthetic aperture radar (SAR) imagery and high frequency (HF) radar range echoes are presented.
Prof. Wei Hong, Southeast Univeristy, China
"Research Advances in Antennas for Satellite Mobile Communications"
Abstract : In this presentation, the recent research advances in multibeam antennas and phased array antennas for satellite mobile communications in the State Key Laboratory of Millimeter Waves (SKLMMW), Southeast University , are reviewed.
Prof. ZHANG Minggao,
China Research Institute of Radiowave Propagation
Professor ZHANG Minggao is an Academician of the Chinese Academy of Engineering (CAE) and a professor of the China Research Institute of Radiowave Propagation (CRIRP). He has been studying the radio wave propagation prediction of the ground and earth-space radio communications for a long time. As the former leader, he has led teams to attend the ITU-R meetings for many times and made significant revisions and supplements for ITU-R recommendations.
"A discussion on diffraction prediction in Recommendation ITU-R P.1812 "
Abstract: By comparing with the analytical theoretical results of the ground wave propagation, it shows that in ITU-R P.1812 recommendation, the existing diffraction prediction will lead to unbearable errors in ray paths at sea level or smooth ground surface. Also, it shows that compatible obstacle diffraction algorithm and spherical diffraction algorithm is necessary. Through accuracy analysis and checking computation, we propose a spherical diffraction algorithm which is suitable to engineering applications. By using analysis in the extreme case and interpolation technique, we propose a synthetic diffraction algorithm by combining the obstacle diffraction algorithm and spherical diffraction algorithm. Also, a method is presented for dealing with the characteristic parameters affecting the synthetic algorithm.
Dr. Ingemar Haggstrom , EISCAT, Sweden
Ingemar Haggstrom is the Senior Scientist at EISCAT, Sweden.
EISCAT, the European Incoherent Scatter Scientific Association, is established to conduct research on the lower, middle and upper
atmosphere and ionosphere using the incoherent scatter radar
technique. This technique is the most powerful ground-based tool for
these research applications and EISCAT operates three radar
systems in Northern Europe. They are also being used as a coherent
scatter radar for studying instabilities in the ionosphere, as well as for
investigating the structure and dynamics of the middle atmosphere
and as a diagnostic instrument in ionospheric modification
experiments with the Heating facility.
Ingemar H?ggstr?m have been doing research as a user of EISCAT
at the Swedish Institute of Space Physics, Kiruna since 1982. In 1990
he graduated at the institute in a thesis titled ¡°Incoherent scatter
studies of upper atmosphere dynamics and coding technique¡±. He has
lead of the geophysical observatory within the institute, with
instruments all over Sweden and has been visiting Professor at
National Institute of Polar Research in Tokyo, Japan. In 2001 he
joined EISCAT, and have since been at the headquarters of EISCAT
in Kiruna, Sweden.
He is currently chairing the Incoherent Scatter Working Group of
URSI, setting up jointly strategies between all IS radars over the world
and deciding jointly measurement campaigns, the World Days of
incoherent scatter. He is a member of the ITU group IUACF, the
Scientific Committee on Frequency Allocations for Radio Astronomy
and Space Science.
EISCAT_3D,an European three-dimensional imaging radarfor atmospheric and geospace research.
Abstract: EISCAT_3D will be Europe's next-generation radar for the study
of the high-latitude atmosphere and geospace, located in northern Scandinavia. EISCAT_3D's capabilities go well beyond anything currently available to the international research community. The facility will
consist of several very large phased-array antenna
transmitters/receivers and multiple receiver sites, distributed over at
least three countries and comprising up to 100,000 individual antenna
elements. This new type of volumetric imaging radar represents a
significant enhancement to the European Research area. EISCAT_3D will be
capable of making measurements from the middle atmosphere to the
magnetosphere and beyond, contributing to the basic environmental and
applied science that underpins the use of space by contemporary society.
International Union of Radio Science
Chinese Institute of Electronics
China Research Institute of Radiowave Propagation (CRIRP)