Curriculum Vitaes
  1. Researcher Search Results
  2. TOMIKI ATSUSHI

TOMIKI ATSUSHI

  (冨木 淳史)

Profile Information

Affiliation
Associate professor, Institute of Space and Astronautical Science, Department of Spacecraft Engineering, Japan Aerospace Exploration Agency
Degree
Dr. Eng.(Mar, 2007, Tokyo Denki University)
J-GLOBAL ID
200901094498520904
researchmap Member ID
6000005907
External link

Research Interests

 7

Research Areas

 3

Research History

 1

Papers

 40
  • Tatsuaki Hashimoto, Junji Kikuchi, Ryo Hirasawa, Kota Miyoshi, Wataru Torii, Naoki Morishita, Nobutaka Bando, Atsushi Tomiki, Shintaro Nakajima, Masatsugu Otsuki, Hiroyuki Toyota, Kakeru Tokunaga, Chikako Hirose, Tetsuo Yoshimitsu, Hiroshi Takeuchi
    Proceedings of the International Astronautical Congress, IAC, 2023-October, 2023  
    A 6U CubeSat “OMOTENASHI” was developed to be the world's smallest moon lander. It was launched by NASA's SLS Artemis-1 on November 16, 2022. However, because of the spacecraft anomaly, the battery was depleted and the communication with the spacecraft had been lost. After we gave up the moon landing experiment, we have been conducting a search and rescue operation till September 2023. But it was unsuccessful, unfortunately. In this article, the mission objective, the spacecraft design, the planed mission scenario, and the in-orbit operation results are presented. Additionally, lessons learned from the development and the in-orbit operation are presented.
  • Timothy Pham, Hiroshi Takeuchi, Atsushi Tomiki, Kathleen Harmon, Sami Asmar, Yoshihide Sugimoto, Taniguchi Sho, Tsutomu Ichikawa
    Proceedings of the International Astronautical Congress, IAC, 2023-October, 2023  
    This paper presents a collaborative effort between NASA and JAXA to make 3-way Doppler data from JAXA tracking stations available to the Artemis 1 navigation team to improve orbit determination. The paper describes the system configuration and concept of operation of this capability. Testing effort at the three JAXA's ground stations - the Uchinoura's 20-m and 34-m antennas and Usuda's 64-m antenna - are discussed. Both aspects of system testing are highlighted, first on the use of Artemis 1 recorded signal to ensure compatibility between ground and flight systems, and second on the tracking with the Lunar Reconnaissance Orbiter, as a substitute for Artemis before launch, to validate other key operational functions such as ephemeris processing, spacecraft tracking capability, data delivery, and interactions among multiple operational teams in different organizations. Results from actual support to Artemis 1's Orion spacecraft in November-December 2022 are also presented.
  • Timothy Pham, Hiroshi Takeuchi, Atsushi Tomiki
    ADVANCES IN COMMUNICATIONS SATELLITE SYSTEMS 2, 95 235-242, 2020  
    This chapter presents an ongoing effort in preparing JAXA Uchinoura station support to the Artemis 1 mission, scheduled for launch in late 2020. The system involves three key participants: JAXA ground station at Uchinoura, the Deep Space Network (DSN) components at the Jet Propulsion Laboratory, California, and the Artemis 1 mission navigation at the NASA Johnson Space Center, Texas.Demonstration of Uchinoura station support to the future Artemis signal relies on the use of a low-cost, highly-portable software-defined radio (SDR) test equipment as well as the tracking of the Lunar Reconnaissance Orbiter (LRO) spacecraft. Using the SDR equipment, we validated the compatibility of signal format between the Artemis flight radio and the Uchinoura ground station without having to send the flight equipment to the station. By tracking an ongoing operational spacecraft such as LRO, we were able to calibrate the performance of the system in real operational conditions. The measured Doppler noise of 0.03 Hz (1-sigma), or 0.002 m/s range rate at S-band, for Uchinoura station is deemed suitable to the Artemis 1 mission navigation needs.This chapter also discusses the test equipment capability and its performance. In addition to being low cost, the equipment offers many advantages compared to the traditional full-scaled test signal simulator. Chief among them is portability making system easy to set up and transport, and the fidelity of the test signal that it captures from spacecraft flight equipment. Some of the lessons learned, such as internal frequency stability of the test signal, are also reflected.
  • Tatsuaki Hashimoto, Junji Kikuchi, Ryo Hirasawa, Naoki Morishita, Nobutaka Bando, Atsushi Tomiki, Wataru Torii, Yuta Kobayashi, Shintaro Nakajima, Masatsugu Otsuki, Tetsuo Yoshimitsu, Tetsuya Yamada, Kota Miyoshi, Hiroyuki Toyota, Kakeru Tokunaga, Chikako Hirose, Toshinori Ikenaga, Aiko Nagamatsu, Hitoshi Morimoto
    Proceedings of the International Astronautical Congress, IAC, 2020-October, 2020  
    Copyright © 2020 by the International Astronautical Federation (IAF). All rights reserved. A 6U CubeSat “OMOTENASHI” will be the world's smallest moon lander which is launched by NASA SLS Artemis-1. Because of its severe mass and size limitation, it will adopt semi-hard landing scheme. That is, OMOTENASHI is decelerated from orbital velocity to less than 50 m/s by a small solid rocket motor and shock absorption mechanism has been developed to withstand the high-speed impact. Ultra small communication system (X-band and P-band) is also developed. It observes radiation environment of Earth and moon region with portable dosimeters. This paper shows the mission outline, the design, and the development results of OMOTENASHI.
  • Ikari Satoshi, Ito Takahiro, Oguri Kenshiro, Inamori Takaya, Sakai Shinichiro, Kawakatsu Yasuhiro, Tomiki Atsushi, Funase Ryu
    JOURNAL OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, 68(2) 89-95, 2020  
    <p>A Fault Detection, Isolation, and Recovery (FDIR) algorithm for attitude control systems is a key technology to increasing the reliability and survivability of spacecraft. Micro/nano interplanetary spacecraft, which are rapidly evolving in recent years, also require robust FDIR algorithms. However, the implementation of FDIR algorithms to these micro/nano spacecraft is difficult because of the limitations of their resources (power, mass, cost, and so on). This paper shows a strategy of how to construct a FDIR algorithm in the limited resources, taking examples from micro deep space probe PROCYON. The strategy focuses on function redundancies and multi-layer FDIR. These ideas are integrated to suit the situation of micro/nano interplanetary spacecraft and demonstrated in orbit by the PROCYON mission. The in-orbit results are discussed in detail to emphasize the effectiveness of the FDIR algorithm. </p>
More

Misc.

 150
  • Mori Yuya, Tomiki Atsushi, Kobayashi Takehiko, Murata Yasuhiro, Matsubara Hideo, Nakagawa Takao, Tahara Ken
    Technical report of IEICE. SANE, 114(48) 51-56, May 23, 2014  
    Space Infrared Telescope for Cosmology and Astrophysics (SPICA) is an infrared IR astronomical satellite to be launched in 2022. It is equipped with sensitive IR sensors, cooled down to 4.5K. It also consists of a high-power X-band transmitting antenna used for downlink to the earth. Since energy leakage should be stringently suppressed from the antenna to the IR sensors, it is necessary to evaluate electromagnetic shielding effectiveness (SE) of structural materials of the satellite, including carbon fiber reinforced plastics (CFRP), multi-layer insulator (MLI), and aluminium plates connected with rivets. The CFRP and MLI were found to yield SE equivalent to aluminium. The SE of the connected aluminium plates increased with decreasing spacings of the rivets. Chromate conversion coating, providing higher surface conductivity than anodized aluminium surface, also enhanced the SE.
  • TAKEUCHI Hiroshi, TOMIKI Atsushi, KOBAYASHI Yuta
    Technical report of IEICE. SANE, 114(48) 49-50, May 16, 2014  
    Delta-DOR (Delta Differential One-way Ranging) is an application of VLBI (Very Long Baseline Interferometry) technique which enables very precise angular position measurements for deep space spacecrafts. The technique play an essential role in the critical events such as a planetary orbit insertion, landing, and gravity assist operations. International space agencies had been working for the improvement of the measurement accuracy of the Delta-DOR, and the current accuracy of the measurement reaches a-few nano radian level. In this lecture, the principle of the technique are described and several techniques that provides the better Delta-DOR accuracy are introduced. In particular a sweeping tone technique which aims at a reduction of phase ripple error in the ground station transmit line are described in detail. This newly developed technique will be used for an asteroid exploration mission PROCYON that will be launched in 2014 as a sub payload mission of the Hayabusa-2.
  • Saito Hirobumi, Tomiki Atsushi, Akbar Prilando Rizki, Ohtani Takashi, Nishijo Kunitoshi, Hirokawa Jiro, Ando Makoto
    Proceedings of the IEICE General Conference, 2014(1) "SS-74"-"SS-75", Mar 4, 2014  
  • Watanabe Hiromi, Fukami Tomoya, Saito Hirobumi, Iwakiri Naohiko, Tomiki Atsushi
    Proceedings of the IEICE General Conference, 2014(1) 243-243, Mar 4, 2014  
  • WATANABE Hiromi, FUKAMI Tomoya, SAITO Hirobumi, IWAKIRI Naohiko, TOMIKI Atsushi
    Technical report of IEICE. SANE, 113(435) 31-36, Feb 20, 2014  
    A high-speed downlink communication system is required to meet various applications for nano/small satellites. Therefore, it is essential to implement a transmitter with small weight and power in such satellites. Our recent research has focused on an efficient system with the compact transmitter incorporating a powerful error correction on ground station receiver. Generally, an operation at nonlinear region of RF power amplifier provides a RF power amplifier with high energy efficiency. However, an amplitude-phase modulation, which is an efficient scheme in term of frequency band, requires high linearity. GaN-HEMT SSPA, which has high efficiency and linearity, and Digital-pre-distortion can provide better answer. Also, I'm developing a new measurement method to evaluate Pas and transmitter systems. We will demonstrate a high-speed down link communication system in "Hodoyoshi-4" satellite.
  • 小林雄太, 冨木淳史, 川崎繁男, 小島要, 新家隆広, 青木勝, 土屋慎二郎, 羽賀俊行, 奥野秀一, 石川雅澄, 神田泰明, 大森義智, 北島邦美, 野々村拓, 三田信, 伊藤大智, 小林大輔, 福島洋介, 船瀬龍, 川勝康弘
    宇宙科学技術連合講演会講演集(CD-ROM), 58th, 2014  
  • 冨木淳史, 小林雄太, 川崎繁男, 小島要, 新家隆広, 青木勝, 土屋慎二郎, 羽賀俊行, 奥野秀一, 石川雅澄, 神田泰明, 大森義智, 北島邦美, 野々村拓, 三田信, 伊藤大智, 小林大輔, 福島洋介, 船瀬龍, 川勝康弘
    宇宙科学技術連合講演会講演集(CD-ROM), 58th, 2014  
  • Yonemura Sho, Tomiki Atsushi, Toda Tomoaki, Kobayashi Takehiko
    Technical report of IEICE. SANE, 113(335) 35-40, Dec 2, 2013  
    JAXA has planned a light airplane ejected from a Mars orbiter for observing the residual magnetic fields near the surfaced and the exposed strata of Mars. An altimeter is indispensable to achieve the mission. It must be miniature and light weight to be equipped on the airplane flying in the thin atmosphere of Mars. For this propose, we have been developing an FM-CW radar for its accepted merits: easier signal processing and lower power consumption than a pulse radar. This paper presents the feasibility study of the radar and the results of ranging experiments using a breadboard model.
  • SAITO Hirobumi, TOMIKI Atsushi, AKBAR Prilando Rizki, OHTANI Takashi, NISHIJO Kunitoshi, HIROKAWA Jiro, ANDO Makoto
    Technical report of IEICE. SANE, 113(335) 169-174, Dec 2, 2013  
    We have started development of small synthetic aperture radar (SAR) compatible to 100kg class small satellites with about 3m ground resolution and multi-polarization, aiming for constellation SAR observations. This paper describes key technologies of this development such as deployable slot array antennas, waveguide feeder with a small gap at a deployment point, and GaN HEMT X band amplifier. Also we show an integration design result of this SAR system to 100kg class bus system.
  • FUKAMI Tomoya, WATANABE Hiromi, TOMIKI Atsushi, IWAKIRI Naohiko, SAITO Hirobumi, NAKASUKA Shinichi
    Technical report of IEICE. SANE, 113(335) 179-184, Dec 2, 2013  
    Recently small satellites start playing important roles in earth observation missions. It, however, is true that small satellites have drawbacks of sensor resolutions and down link data rate. As a solution to the latter drawback, we have developed novel communications system for 320 Mbps down link with 16QAM for small satellites with 50 kg class. We developed a new 2 W class GaN-HEMT X-band amplifier with high efficiency and small distortion, digital filter and pre-distortion processing with relatively low clock frequency in FPGAs. This paper describes our downlink system and evaluation result of the engineering model and the prototype model.
  • 57 6p, Oct 9, 2013  
  • 57 6p, Oct 9, 2013  
  • 57 6p, Oct 9, 2013  
  • 57 5p, Oct 9, 2013  Peer-reviewed
  • Fukami Tomoya, Tomiki Atsushi, Watanabe Hiromi, Iwakiri Naohiko, Saito Hirobumi, Nakasuka Shinichi
    Proceedings of the Society Conference of IEICE, 2013(1) 230-230, Sep 3, 2013  
  • Watanabe Hiromi, Fukami Tomoya, Tomoki Atsushi, Iwakiri Naohiko, Saito Hirobumi
    Proceedings of the Society Conference of IEICE, 2013(1) 229-229, Sep 3, 2013  
  • HIROSE Miyuki, TOMIKI Atsushi, TODA Tomoaki, KOBAYASHI Takehiko
    IEICE technical report. WBS, Wideband System, 113(117) 5-10, Jul 9, 2013  
    Ultra wideband (UWB) propagation was measured and characterized within spacecrafts, with a view to partly replacing onboard data buses with wireless connections. Adaptation of wireless technologies in spacecrafts could contribute to: reduction of cable weight (and launching cost as a result), more flexibility in layout of spacecraft subsystems, and reliable connections at rotary, moving, and sliding joints. However, multipath propagation in semi-closed metal enclosures, such as spacecrafts, restricts the transmission performance. To realize the above benefits, multipath propagation affecting the transmission performance must be scrutinized. Spatial distributions of UWB and narrowband propagation in frequency (from 3.1 to 10.6 GHz) and time domains were measured with a microwave vector network analyzer. While narrowband resulted in a number of dead spots (deep fading points) within the conductive enclosures, UWB yielded none. In this present paper, UWB channels within a small scientific satellite was measured and statistically analyzed, based on a modified Saleh-Valenzuela (SV) model [2], which modeled indoor UWB propagation channels. The modified SV model is based on a cluster concept of rays. The clusters, as well as the multipath components within a cluster, arrive according to Poisson processes with different rates. The received power of both the cluster and the rays within a cluster decays exponentially.
  • SAITO Hirobumi, TOMIKI Atsushi, AKBAR Prilando Rizki, OHTANI Takashi, NISHIJO Kunitoshi, SUMANTYO Josaphat Tetuko Sri, HIROKAWA Jiro, ANDO Makoto
    Technical report of IEICE. SANE, 113(88) 5-10, Jun 20, 2013  
    We have started development of small synthetic aperture radar (SAR) compatible to 100kg class small satellites with about 3m ground resolution and multi-polarization, aiming for constellation SAR observations. This technology enables us to realize high frequency SAR observations with only several hours observation interval. This paper describes key technologies of this development such as deployable slot array antennas, waveguide feeder with a small gap at a deployment point, and GaN HEMT X band amplifier. Also we show an integration design result of this SAR system to 100kg class bus system.
  • HIRAHARA Daichi, Ohikata YASUHIRO, TOMIKI Atsushi, Yoshimoto HIROMASA, SHINOHARA Suetsugu
    Technical report of IEICE. SANE, 113(88) 97-102, Jun 20, 2013  
    JAXA has the Satellite AIS demonstration experiment named SPAISE1 (SPace based AIS Experimentl) which is installed in Small demonstration Satellite 4 (SDS-4). We are now executing reception performance experiment from 30/May. Experimental studies on the delay characteristics of signal propagation must be conducted in order to achieve improved reception rate in the signal interference area. We have analyzed the detected AIS signals for measuring the SPAISE propagation delay profile with the replica signal in the 160 MHz band. This paper presents the results of the SPAISE propagation analysis.
  • TANAKA Koji, MAKI Ken-iciro, TOMIKI Atsushi, SASAKI Susumu, JOUDOI Daisuke, MAKINO Katsumi, IKEDA Hitoshi, FUJITA Tatsuhito, GOTO Daisuke, OHASHI Kazuo, SPS WG
    Technical report of IEICE. SANE, 113(88) 51-56, Jun 20, 2013  
    We have made a conceptual design of a long-distance wireless power transmission (WPT) experiment using a small scientific satellite, which is developed by ISAS/JAXA. The purposes of the WPT experiments are to demonstrate a precise directional control of microwave beam, which includes the direct detection of rectenna sites, and to clarify the propagation characteristics of intense microwaves in the plasma of the ionosphere. The sub-recurrent orbit at an altitude of 370 km is a prime candidate. Typical microwave power radiated from the transmission antenna with frequency of 5 GHz band is around 2kW. This level of microwave power injection will generate a power density above 1,000 W/m^2 within 40 m in the ionosphere. The onboard instrument that consists of plasma probes and wave receiver can measure effects of interaction between high power microwaves and plasma in ionosphere. The ground system is designed to evaluate the microwave beam characteristics such as the radiation pattern and microwave power. Wireless power transmission efficiency from space to the ground will be evaluated by analyses of the results of space demonstration experiments.
  • FUKAMI Tomoya, WATANABE Hiromi, TOMIKI Atsushi, IWAKIRI Naohiko, SAITO Hirobumi, NAKASUKA Shinichi
    Technical report of IEICE. SANE, 113(16) 1-6, Apr 25, 2013  
    Recently small satellites start playing important roles in earth observation missions. It, however, is true that small satellites have drawbacks of sensor resolutions and down link data rate. As a solution to the latter drawback, we have developed novel communications system for 320 Mbps down link with 16QAM for small satellites with 50 kg class. We developed a new 2 W class GaN-HEMT X-band amplifier with high efficiency and small distortion, digital filter and pre-distortion processing with relatively low clock frequency in FPGAs. This paper describes the transmitter design and evaluation result of the engineering model.
  • YOSHIMITSU Tetsuo, KUBOTA Takashi, TOMIKI Atsushi, ADACHI Tadashi
    Technical report of IEICE. SANE, 113(16) 35-39, Apr 25, 2013  
    Japan has decided to launch the second sample return mission "Hayabusa-2" to the Near Earth asteroid 1999JU3 in 2014. The predecessor spacecraft "Hayabusa" made a great success when it returned to the Earth in June 2010 with a capsule containing some particles obtained around the S-type asteroid "Itokawa." The authors installed a tiny hopping rover called "MINERVA" into Hayabusa spacecraft. The rover was deployed at the vicinity of the asteroid in 2005, but failed to make a surface exploration since the human operator on the ground made a critical failure in deploying the rover. The second spacecraft also involves a plan to have a tiny rover system which will make a surface exploration over the 1km-sized asteroid. With the past experience in developing a rover, the authors are again working to install some rover packages to Hayabusa-2. The total concept is the same but this time multiple rovers are considered. Many of the aspects of the mother spacecraft come from the heritage of the previous explorer which was build using the technologies more than ten years ago. But the rover system is a completely brand-new one, based on the lessons learned from the previous rover system. Since the target asteroid parameters are different from the previous target, the rover design has to be made from the beginning. We also face to the another technically challenging matters arisen from the point of the distance from the Sun as well as the surface cruel temperature of low-albedo body. This paper describes the system configuration of the rover system currently designed and developed for the launch in 2014.
  • Yonemura Sho, Tomiki Atsushi, Toda Tomoaki, Kobayashi Takehiko
    Technical report of IEICE. SANE, 113(16) 23-28, Apr 25, 2013  
    This report presents a preliminary study of the radar altimeter for an airplane cruising in the Mars' atmosphere. Furthermore it presents the states of BBM (Bread Board Model) development and a plan for an experiment using the Mars-like terrestrial ground.
  • Matsubara Akihisa, Tomiki Atsushi, Toda Tomoaki, Kobayashi Takehiko
    Proceedings of the IEICE General Conference, 2013(1) 282-282, Mar 5, 2013  
  • Fukami Tomoya, Iwakiri Naohiko, Tomiki Atsushi, Saito Hirobumi
    Proceedings of the IEICE General Conference, 2013(1) 302-302, Mar 5, 2013  
  • Watanabe Hiromi, Fukami Tomoya, Saito Hirobumi, Iwakiri Naohiko, Tomiki Atsushi, Osman Ceylan
    Proceedings of the IEICE General Conference, 2013(1) 303-303, Mar 5, 2013  
  • Kobayashi Yuta, Tomiki Atsushi, Narita Shinichiro, Nunomura Hitoshi, Shigeta Osamu, Itoh Masanobu, Aoki Masaru, Kawasaki Shigeo
    Proceedings of the IEICE General Conference, 2013(1) 301-301, Mar 5, 2013  
  • 白澤洋次, 川崎繁男, 竹内央, 松浦周二, 富木淳史, 加持勇介, 小林正規, 松井孝典, 大野剛, 松本純, 林直宏
    宇宙科学技術連合講演会講演集(CD-ROM), 57th, 2013  
  • 松浦周二, 冨木淳史, 磯部直樹, 村田泰宏, 松原英雄, 川田光伸, 中川貴雄, 土井靖生
    日本天文学会年会講演予稿集, 2013, 2013  
  • KATO Yuichi, KOBAYASHI Takehiko, KAGOSHIMA Kenichi, TAKEDA Shigeki, TOMIKI Atsushi, TODA Tomoaki
    IEICE technical report. Antennas and propagation, 112(285) 77-82, Nov 8, 2012  
    Dual (X and Ka) band downlink operation is demanded scientific satellite missions, to facilitate much higher data rate and to increase the available radio channels. A combinations of a corrugated horn (for X band) and a disk-on-rod antenna (for Ka band) have used as a primary feed for a satellite-borne dual-band reflector antenna, but its volume was not satisfactorily small. The anothers proposed a combination of a sequential four-element array of rectangular microstrip antennas fed with L-shape probes for X band and a four-element array of helical antennas for Ka-band, to realize a small-volume, light-weight circular-polarized primary radiator. This paper reports the performances-VSWR, XPD, and radiation patterns of a prototype radiator.
  • WATANABE Hiromi, FUKAMI Tomoya, TOMIKI Atsushi, SAITO Hirobumi, IWAKIRI Naohiko
    Technical report of IEICE. SANE, 112(229) 153-158, Oct 3, 2012  
    A high-speed downlink communication system is required to meet different applications for nano/small satellites. Therefore, it is essential to implement a power- and weight-limited transmitter in such satellites. Our recent research has focused on an efficient system with the limited transmitter incorporating a powerful ground station receiver. Generally, an operation at nonlinear region provides a RF power amplifier with high energy efficiency. However, an amplitude-phase modulation, which is an efficient scheme in term of frequency band, requires high linearity. Digital pre-distortion on the transmitter is known as a powerful complementary nonlinearity of power amplifier. We are developing pre-distortion scheme for nano/small satellite transmitter. And we developed a new measurement method to evaluate the transmitter system. We will report the results of evaluation of the new transmitter engineering model. The results indicate that the new PA performances are suitable for multi-level modulation high-speed downlink system with pre-distortion such as 16-QAM system. Therefore, the power amplifier with high efficiency can be implemented.
  • HAMADA Shinichiro, TOMIKI Atsushi, TODA Tomiaki, KOBAYASHI Takehiko
    Technical report of IEICE. SANE, 112(229) 89-94, Oct 3, 2012  
    Experimental evaluation of ultra wideband (UWB) wireless transmission was carried out with a view to replacing wired interface buses in spacecrafts. Application of wireless technologies within the spacecrafts could contribute to reduction in cable weight (and launching cost as a result), reduction in the cost of manufacture, more flexibility in layout of spacecraft subsystems, and reliable connections at rotary, moving, and sliding joints. However, multipath propagation in semi-closed conductive enclosures, such as spacecrafts, restricts the link performance. This paper addresses the effects of apertures perforated on the outer surface of satellites on the UWB propagation and transmission for low-(4.2-4.8GHz) and high-band (7.4-7.9GHz) UWB. The larger total area of apertures resulted in lower UWB propagation gains, shorter delay spreads, and (slightly) higher link throughput.
  • KOBAYASHI Yuta, TOMIKI Atsushi, NARITA Shinichiro, KAWASAKI Shigeo
    Technical report of IEICE. SANE, 112(229) 101-105, Oct 3, 2012  
    This research proposes an X-band high efficiency onboard SSPA for deep space missions by focusing on GaN HEMT whose remarkable material properties, such as high thermal conductivity, wide band gap, and high breakdown voltage, are suitable for high power and high efficiency applications. To develop a high efficiency onboard SSPA is one of the great issues when we consider some missions toward Mars, Jupiter, and much farther planets because of the requirements of both ultra-long distance communication and low power consumption. In this paper, results of preliminary design and evaluations of some trial productions using COTS device will be shown.
  • FUKAMI Tomoya, TOMIKI Atsushi, WATANABE Hiromi, IWAKIRI Naohiko, SAITO Hirobumi, NAKASUKA Shinichi
    Proceedings of the Society Conference of IEICE, 2012(1) 264-264, Aug 28, 2012  
  • WATANABE Hiromi, SAITO Hirobumi, TOMIKI Atsushi, IWAKIRI Naohiko, FUKAMI Tomoya
    Proceedings of the Society Conference of IEICE, 2012(1) 265-265, Aug 28, 2012  
  • WATANABE Hiromi, TOMIKI Atsushi, IWAKIRI Naohiko, FUKAMI Tomoya, SAITO Hirobumi, NAKASUKA Shinichi
    Technical report of IEICE. SANE, 112(107) 111-116, Jun 21, 2012  
    A high-speed downlink communication system is required to meet different applications for nano/small satellites. Therefore, it is essential to implement a power- and weight-limited transmitter in such satellites. Our recent research has focused on an efficient system with the limited transmitter incorporating a powerful ground station receiver. To overcome signal distortion at the cost of some limitations of the transmitter, an SCCC turbo equalization system equipped with nonlinear distortion compensation techniques in the receiver has been developed. However, digital predistortion on the transmitter is known as a powerful complementary nonlinearity of power amplifier. We are developing predistortion scheme for nano satellite transmitter. We evaluate performances of the new GaN-HEMT power amplifier. The results indicate that the new PA performances are suitable for multi-level modulation high-speed downlink system with predistortion such as 16-QAM system.Therefore, the power amplifier with high efficiency can be implemented
  • NAKADAI Mitsuhiro, IWAKIRI Naohiko, SAITO Hirobumi, TOMIKI Atsushi
    Technical report of IEICE. SANE, 112(17) 29-34, Apr 19, 2012  
    In Recent year, small satellites have been developed by universities and companies to investigate Earth environment. High-speed downlink communication system for small satellites is required to realize different kind of applications. We have developing the system which is optimized to reduce a load of transmitter and signal distortion caused by the transmitter. To achieve a low power consumption and high-speed communication, optimum pre-distortion must be selected. This paper shows that the method can be determined by a index related with received symbols mean power and symbol distances.
  • HIRAHARA Daichi, TOMIKI Atsushi, TODA Tomoaki, SAITO Hirobumi
    Technical report of IEICE. SANE, 112(17) 41-46, Apr 19, 2012  
    The more technologies advance, the higher mission achievements are demanded in small satellite missions. In this study, we have been developing an S-band transponder for small satellites of Category-A missions (such as the lunar orbiter, halo orbiter and Lagrange point missions). It has dimensions of 110×110×90 mm^3, weighs about 1kg, consumes less than 10W, and use of COT devices. In this paper, we will discuss the RF property that obtained phase noise of PCM (NRZ-L)-PSK/PM, error vector magnitude of BPSK and QPSK, bit error rate of the PCM (NRZ-L)-PSK/PM, and spectrum of each moderation mode (PCM (NRZ-L)-PSK/PM, PCM (Biφ-L)-PM, BPSK, QPSK) on our new transponder.
  • Kato Yuichi, Izima Hiroko, Kobayashi Takehiko, Kagoshima Kenichi, Ikeda Kazuki, Tomiki Atsushi, Toda Tomoaki
    Proceedings of the IEICE General Conference, 2012(1) 92-92, Mar 6, 2012  
  • NAKADAI Mitsuhiro, IWAKIRI Naohiko, TOMIKI Atsuhi, SAITO Hirobumi
    Proceedings of the IEICE General Conference, 2012(1) 330-330, Mar 6, 2012  
  • K. Kagoshima, S. Takeda, Kazuki Ikeda, T. Kobayashi, Y. Kato, H. Iijima, A. Tomiki, T. Toda
    2012 IEEE ANTENNAS AND PROPAGATION SOCIETY INTERNATIONAL SYMPOSIUM (APSURSI), 2012  
    A compact X/Ka bands feeder antenna has been proposed for a Cassegrain type reflector antenna board on a planetary exploration satellite. A sequentially rotated array in X band and a helical array in Ka band are employed for realizing the circular polarization. In the X band array, the unique feeding method has been developed for reducing cross polarization level of the sequential array and in the Ka band array, the compact configuration has been realized by positioning it within the space of the X band elements..
  • IWAKIRI Naohiko, TOMIKI Atsushi, MIZUNO Takahide, SAITO Hirobumi, NAKASUKA Shinichi
    Technical report of IEICE. SANE, 111(239) 17-22, Oct 10, 2011  
    A high-speed downlink communication system is required to meet different applications for nano/small satellites. Therefore, it is essential to implement a power- and weight-limited transmitter in such satellites. Our recent research has focused on an efficient system adopting CCSDS 131.0-R signaling formats with the limited transmitter incorporating a powerful ground station receiver. To overcome signal distortion at the cost of some limitations of the transmitter, an SCCC turbo equalization system equipped with nonlinear distortion compensation techniques in the receiver has been developed. We simulate the system using practical distortion models to determine the performances of BER and synchronization.
  • TODA Tomoaki, TOMIKI Atsushi, Kobayashi Yuta
    Proceedings of the Society Conference of IEICE, 2011(1) 251-251, Aug 30, 2011  
  • NAKADAI Mitsuhiro, IWAKIRI Naohiko, TOMIKI Atsushi, SAITO Hirobumi
    Proceedings of the Society Conference of IEICE, 2011(1) 252-252, Aug 30, 2011  
  • AWANO Johta, TODA Tomoaki, TOMIKI Atsushi, KOBAYASHI Yuta, TAKATA Noboru
    IEICE technical report, 111(7) 7-12, Apr 14, 2011  
    High reliability S-band communication and X-band communication for fast mission data transmission are both required for many satellite users. But for small satellite users, it is difficult to use both the S-band and the X-band transponder in order to limitation of on-borad power, area, mass and so on. By these current conditions, we start concept study of the multi-band transponder for category-A region.
  • TODA Tomoaki, TOMIKI Atsushi, Ishii Nobuaki
    Proceedings of the IEICE General Conference, 2011(1) 258-258, Feb 28, 2011  
  • IKEDA Kazuki, Sato Keigo, KAGOSHIMA Ken-ichi, OBOTE Shigeki, TOMIKI Atsushi, TODA Tomoaki
    Proceedings of the IEICE General Conference, 2011(1) 176-176, Feb 28, 2011  
  • Kobayashi Yuta, Tomiki Atsushi, Toda Tomoaki, Kobayashi Takehiko
    Proceedings of the IEICE General Conference, 2011(1) 313-313, Feb 28, 2011  
  • IMAMURA Takeshi, TODA Tomoaki, TOMIKI Atsushi, HIRAHARA Daichi, HAYASHIYAMA Tomoko, MOCHIZUKI Nanako, YAMAMOTO Zen-ichi, ABE Takumi, IWATA Takahiro, NODA Hirotomo, FUTAANA Yoshifumi, ANDO Hiroki, HAEUSLER Bernd, PAETZOLD Martin, NABATOV Alexander
    Earth, Planets and Space, 63(6), 2011  
  • ICHIKAWA Tatsuya, MATSUBARA Akihisa, TOMIKI Atsushi, TODA Tomoaki, KOBAYASHI Takehiko
    IEICE technical report, 110(308) 19-24, Nov 19, 2010  
    The replacement of wired data buses among space-borne subsystems with wireless connections enhances onboard component layouts, reduces a connecting cable mass, and enables higher-speed data bus connections. We have proposed to apply Ultra Wideband (UWB) technologies to a spacecraft inner closed space filled with bus and science instruments. While narrowband resulted in a number of dead spots (deep fading points) within the conductive enclosures like inside of spacecraft, UWB yielded none. This implies the UWB systems have an advantage over narrowband ones from a viewpoint of reducing fading margins. We measured spatial distributions of UWB and narrowband propagation in frequency (from 3.1 to 10.6 GHz) and time domains with a mockup of REIMEI satellite, UWB monopole antennas, and a microwave vector network analyzer. We also investigated spatial distributions of data throughputs inside REIMEI using commercially available UWB devices. The influences of polarization of UWB antennas on the above propagation and throughputs characteristics have also been evaluated for this report. They are so small and limited that the polarization is not a factor needing careful wireless link designs and layout considerations.

Professional Memberships

 1

Research Projects

 4

Industrial Property Rights

 10
More
To the list screen