ITE Technical Report
Online ISSN : 2424-1970
Print ISSN : 1342-6893
ISSN-L : 1342-6893
25.73
Showing 1-18 articles out of 18 articles from the selected issue
  • Type: Cover
    Pages Cover1-
    Published: November 15, 2001
    Released: June 23, 2017
    CONFERENCE PROCEEDINGS FREE ACCESS
    Download PDF (14K)
  • Type: Index
    Pages Toc1-
    Published: November 15, 2001
    Released: June 23, 2017
    CONFERENCE PROCEEDINGS FREE ACCESS
    Download PDF (91K)
  • Akira SUGAWARA, Tadashi TAKANO, Eiji HANAYAMA, Yoshio KAMI
    Type: Article
    Session ID: ROFT2001-88
    Published: November 15, 2001
    Released: June 23, 2017
    CONFERENCE PROCEEDINGS FREE ACCESS
    In future, an ultra large space antenna which has a 1km class diameter will be needed. Such an antenna consists of many small aperture elements, because of advantage in transportation and construction of antenna parts. In the case of this antenna, there are physical openings between the array aperture elements. The openings lead to degrade the characteristics of the antenna. In this paper, in order to improve the characteristics of the aperture array antenna, we compose the antenna model which consists of two standard pyramidal horns with dipole elements. The validity of the experimental results and theoretical analysis method is shown.
    Download PDF (843K)
  • Koji TANAKA, Ken HIGUCHI, Susumu SASAKI
    Type: Article
    Session ID: ROFT2001-89
    Published: November 15, 2001
    Released: June 23, 2017
    CONFERENCE PROCEEDINGS FREE ACCESS
    We propose space experiments in order to verify significant technologies and to promote public awareness of the Solar Power Satellite(SPS). Some technical and engineering problems were still remained toward SPS. The main missions we proposed is wireless power transmission(WPT) experiment from Low Earth Orbit(LEO) to the ground using one satellite that can be launched by only one large launch vehicle such as the HII-A. The WPT technologies for SPS, which are the direct detection of rectenna sites, and the microwave beam control skill with high angular precision, will be verified and established. The large phased array antenna system that radiates the microwave with a power of around 400 kW was considered.
    Download PDF (759K)
  • Hiroshi MATSUMOTO
    Type: Article
    Session ID: ROFT2001-90
    Published: November 15, 2001
    Released: June 23, 2017
    CONFERENCE PROCEEDINGS FREE ACCESS
    The SSPS Committee started in FY 1998 and is held in every year. The SSPS is a huge solar power satellite which generates a several million kW by solar cells. The electric power is transmitted via microwave form the SSPS to the ground. A diameter of a transmitting antenna is 2.6 km and the antenna is active-phased array. The antenna is the largest in the human history for space and in the ground. We describe the recent state of the transmitting antenna and a future work.
    Download PDF (985K)
  • Naoki SHINOHARA, Hiroshi MATSUMOTO, Kozo HASHIMOTO
    Type: Article
    Session ID: ROFT2001-91
    Published: November 15, 2001
    Released: June 23, 2017
    CONFERENCE PROCEEDINGS FREE ACCESS
    A microwave power of a several million kW is transmitted from the SPS to the ground. Therefore, we have to take care of interferences to the other communication systems. The microwave power transmission(MPT) is different from the past antenna for communications because the diameter of TX and RX antenna are a several km and a power collection efficiency is over 90%. It is necessary to consider a counterplan to ISM band system(wireless LAN, Bluetooth, and DSRC)on the same frequency band. We describe a method of decrease of side lobes by a transmitting power distribution and an optimum of steps of the transmitting power distribution.
    Download PDF (657K)
  • Kenji UENO, Takeshi HATSUDA
    Type: Article
    Session ID: ROFT2001-92
    Published: November 15, 2001
    Released: June 23, 2017
    CONFERENCE PROCEEDINGS FREE ACCESS
    Harmonic radiation properties of power transmitting antennas on a solar power satellite have been studied theoretically considering planar array antennas of square arranged circular microstrip antennas. Although directive gains in near-axis region at harmonics are lower than at a fundamental frequency by several ten decibels, these gains are not too little to ignore. Calculated results will be applied to assessment of co-existence of a solar power satellite and other radio communication systems.
    Download PDF (624K)
  • Takeshi Hatsuda, Kenji Ueno
    Type: Article
    Session ID: ROFT2001-93
    Published: November 15, 2001
    Released: June 23, 2017
    CONFERENCE PROCEEDINGS FREE ACCESS
    The Solar Power Satellite/Station(SPS) system is considered as one solution for future energy problems. On the other hand, the congestion of the GSO is very severe and there are many existing satellites on the GSO. The SPS system with 2.45 GHz transmitter, 6.72 GW power and one km square antenna on the geostationary satellite orbit(GSO) are examined. The Interference assessment between SPS system and Fixed Satellites Service(FSS)/Fixed Terrestrial Service(FS) are carried out. The SPS antenna is assumed as patch array and 4.9, 12.25, 19.6, 29.4 GHz band spurious radiated antenna gains are used for interference calculations. As a result, interference constraints in 12.25 GHz band is relatively severe. Some strategies for relaxation of interference are discussed for co-existing between SPS and FSS/FS systems.
    Download PDF (1354K)
  • Yasushi MATSUMOTO, Naokazu HAMAMOTO, Akira SUGIURA
    Type: Article
    Session ID: ROFT2001-94
    Published: November 15, 2001
    Released: June 23, 2017
    CONFERENCE PROCEEDINGS FREE ACCESS
    GEO-based communication systems for handheld terminals can provide cost-effective and global communication infrastructure. In such a system, a 10m-class large deployable reflector antenna is necessary on the satellite, and the pointing accuracy of multiple narrow beams is important to stabilize the link quality. In this report, an electrical steering method is studied in order to reduce the pointing error of shaped antenna beams. A simple weight control algorithm of a defocused feed array is proposed for simultaneous steering of multiple beams. Numerical results are presented for an S-band deployable reflector antenna on Japanese Engineering Test Satellite VIII(ETS-VIII).
    Download PDF (731K)
  • Akihiro MIYASAKA, Akio TSUJIHATA, Kazuhisa YAMADA, Kiyotaka UCHIMARU
    Type: Article
    Session ID: ROFT2001-95
    Published: November 15, 2001
    Released: June 23, 2017
    CONFERENCE PROCEEDINGS FREE ACCESS
    A modular-mesh concept in which structure consists of several basic modules is an operative design procedure on large-sized reflector for space. The deployment feasibility study is one of the most essential issues for developing the large deployable reflector. In this paper, a modular-concept-based design shows compared with a test result on a small-scale reflector launched as a piggyback structure.
    Download PDF (1057K)
  • Kiyotaka Uchimaru, Teruaki Orikasa, Takashi Tsukashima, Akio Tsujihata ...
    Type: Article
    Session ID: ROFT2001-96
    Published: November 15, 2001
    Released: June 23, 2017
    CONFERENCE PROCEEDINGS FREE ACCESS
    Engineering Test Satellite-VIII(ETS-VIII) is a geostationary satellite which is scheduled to be launched in 2004 by H-IIA launch vehicle^<[1], [2], [3], [4]>. ETS-VIII is equipped with two Large Deployable Reflectors(LDR) to develop satellite communications technology for such as mobile communication with hand-held terminals. The most distinctive feature of LDR is an adoption of the module structure. LDR is an assembly of 14 independent hexagonal modules composed of deployable back structure and reflector surface. These Modules are connected using module connecting points on back structure. The locations of module connecting points are precisely measured prior to connection. These data are applied to SPADE(Simple Partitioning Algorithm based Dynamics of finite Element) model and the surface shape of multi-connected modules in orbit is simulated. This simulation is verified by the surface accuracy of partially connected modules.
    Download PDF (1369K)
  • Teruaki ORIKASA, Kiyotaka UCHIMARU, Akio TSUJIHATA, Akihiro MIYASAKA
    Type: Article
    Session ID: ROFT2001-97
    Published: November 15, 2001
    Released: June 23, 2017
    CONFERENCE PROCEEDINGS FREE ACCESS
    Large deployable reflector antenna of ETS-VIII is constructed by metal mesh which will deploy on orbit. This reflector is divided by 14 modules. In this complex construction of reflector, reflection performance and PIM performance(because reflector is constructed by metal wire)will be verified by testing. Electrical performance of partial engineering model which is constructed by 7 modules is measured by near field measurement. Reflection performance is confirmed by radiation pattern and PIM performance is confirmed by microwave holography. From these test results, we show that the reflection performance(radiation pattern)of reflector is excellent and PIM generation level of reflector is very small.
    Download PDF (1212K)
  • Toyoaki Uo, Tomoaki Toda, Tadashi Takano
    Type: Article
    Session ID: ROFT2001-98
    Published: November 15, 2001
    Released: June 23, 2017
    CONFERENCE PROCEEDINGS FREE ACCESS
    A shaped reflector antenna has a low tolerance to its various fabrication errors because its specific reflector shape needs high precision on the order of optical wavelength. This paper proposes a new design of optical antenna with a high tolerance against manufacturing errors by shaping a feeder-lens and a sub-reflector. Antenna parameters are optimized for each error and optical gain degradation. We compared the error tolerance of our optical antenna, a standard Cassegrain optical antenna, and a normal shaped reflectors optical antenna. The new optical antenna has better error tolerance than the normal shaped reflectors optical antenna and is competitive with the standard Cassegrain optical antenna. The designed new antenna's surface is so simple that the required manufacturing precision has become realistic.
    Download PDF (877K)
  • Yumi SENBOKUYA, Hiroaki TSUNODA
    Type: Article
    Session ID: ROFT2001-99
    Published: November 15, 2001
    Released: June 23, 2017
    CONFERENCE PROCEEDINGS FREE ACCESS
    The planar array antenna which is supported by the inflatable tubular ring has been developed as the satellite antenna to be deployed in space. The conductive non-woven fabrics are used as the circular patch antennas rather than the conventional copper leaves. This inflatable planar array antenna has been developed to be lighter and more foldable than the conventional planar array antenna which uses the polyamide film as the antenna plane of the planar array antenna and the copper leaves as the circular patch antennas. In this paper, the characteristics of the circular patch antennas which use the conductive non-woven fabrics and the conventional copper leaves are compared to determine if the conductive non-woven fabrics can be used as a material of the planar array antennas. Also the relationships between the antenna gain and the conductivity of the conductive non-woven fabrics are examined to find out the range of applicability of the conductive non-woven fabrics to patch antennas.
    Download PDF (785K)
  • Takafumi Asano, Tatsuro Yasumi, Nobuyuki Kaya, Hiroaki Tsunoda
    Type: Article
    Session ID: ROFT2001-100
    Published: November 15, 2001
    Released: June 23, 2017
    CONFERENCE PROCEEDINGS FREE ACCESS
    The microwave power transmission is a very useful technology. Especially, a flexible rectenna can have many applications as it can be freely transformed to fold flat. Two conductive non-woven fabrics are examined as a material of microwave transmission lines for the flexible rectenna in this paper. The result indicates that the efficiencies of the flexible rectenna with the two conductive non-woven fabrics are not so high as the rectenna with copper foil. We have to examine the characteristics of the conductive non-woven fabrics as microwave transmission lines for the design of the rectenna.
    Download PDF (657K)
  • Shinji SUESADA, Akihito WATANABE, Atsuhiro NISHIKATA
    Type: Article
    Session ID: ROFT2001-101
    Published: November 15, 2001
    Released: June 23, 2017
    CONFERENCE PROCEEDINGS FREE ACCESS
    Carbon Fiber Triaxial Woven Fabrics(C-TWF), which have been utilized for the antenna reflector of satellites, have been studied with respect to the microwave reflectivity characteristics of the oblique incident. And the conductive fiber non-woven fabrics(NWF) being expected as the large scale inflatable antenna material, have been studied and presumed that reflectivity. The microvave reflectivity for the C-TWF and NWF molding with resin, have the higher than the basic fabrics.
    Download PDF (716K)
  • David DELAUNE, Koichi ITO, Hiroyuki YOSHIMURA
    Type: Article
    Session ID: ROFT2001-102
    Published: November 15, 2001
    Released: June 23, 2017
    CONFERENCE PROCEEDINGS FREE ACCESS
    Recently, the demand for the mobile satellite communication has been increasing, and various communication services are in the planning stage. Different types of vehicle antennas, which are able to track satellites, have been studied. A candidate for this request is the beam tracking patch array antenna with a square shape. The advantages are its reduced bulk and low price. In this paper, we especially study two circularly polarized beam-switching array antennas respectively composed of 3 and 4 elements having a single-point feed in terms of numerical simulations. The numerical simulations have been performed in the 2.6 GHz frequency band reserved to the mobile satellite broadcasting. Good performances in terms of gain and axial ratio have been obtained.
    Download PDF (814K)
  • Type: Appendix
    Pages App1-
    Published: November 15, 2001
    Released: June 23, 2017
    CONFERENCE PROCEEDINGS FREE ACCESS
    Download PDF (84K)
feedback
Top