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Toshihiko Kosugi

Bio: Toshihiko Kosugi is an academic researcher from Nippon Telegraph and Telephone. The author has contributed to research in topics: Amplifier & Monolithic microwave integrated circuit. The author has an hindex of 20, co-authored 95 publications receiving 1632 citations.


Papers
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Journal ArticleDOI
TL;DR: In this article, a 120-GHz-band wireless link that uses millimeter-wave photonic techniques was developed, which achieved error-free transmission of OC-192 and 10-GbE signals over a distance of more than 200 m with a received power of below -30 dBm.
Abstract: A 120-GHz-band wireless link that uses millimeter-wave (MMW) photonic techniques was developed. The output power and noise characteristics of 120-GHz-band MMWs generated by converting a 125-GHz optical subcarrier signal were evaluated. It was then shown that the noise characteristics of the 125-GHz signal generated with these photonic technologies is sufficient for 10-Gb/s data transmission. We constructed a compact 120-GHz-band wireless link system, and evaluated its data transmission characteristics. This system achieved error-free transmission of OC-192 and 10-GbE signals over a distance of more than 200 m with a received power of below -30 dBm.

300 citations

Journal ArticleDOI
TL;DR: In this paper, the authors investigated the maximum output power of these devices and compared the phase noise of MMW signals generated by high-speed uni-traveling carrier photodiodes (UTC-PD) and InP high-electron mobility transistor (HEMT) millimeter-wave (MMW) monolithic integrated circuits (MMICs).
Abstract: Our progress in 120-GHz-band wireless link technologies enables us to transmit 10-Gbit/s data transmission over a distance of more than 1 km The 120-GHz-band wireless link uses high-speed uni-traveling carrier photodiodes (UTC-PD) and InP high-electron mobility transistor (HEMT) millimeter-wave (MMW) monolithic integrated circuits (MMICs) for the generation of MMW signals We investigate the maximum output power of these devices and compare the phase noise of MMW signals generated by UTC-PDs and InP HEMT MMICs We describe the antennas we used and their operation technologies Finally, we investigate the dependence of transmission distance on availability using the statistical rain attenuation data The calculation results show that the 120-GHz-band wireless link can transmit 10-Gbit/s data over a distance of 1 km with availability of 99999%

136 citations

Journal ArticleDOI
TL;DR: In this article, a 120-GHz-band mm-wave monolithic integrated circuits (MMICs) were fabricated using 0.1-mum-gate InP-HEMTs and coplanar waveguides.
Abstract: We have developed a 120-GHz-band wireless link whose maximum transmission data rate is 11.1 Gbit/s. The wireless link uses millimeter-wave monolithic integrated circuits (MMICs) for the generation of a 120-GHz-band millimeter-wave wireless signal. The MMICs were fabricated using 0.1-mum-gate InP-HEMTs and coplanar waveguides. The wireless link can handle four kinds of data rate for OC-192 and 10-Gbit Ethernet standards with and without forward error correction (FEC). We succeeded in the error-free transmission of a 10-Gbit/s signal over a distance of 800 m. The introduction of FEC into the 120-GHz-band wireless link decreased the minimum received power for error-free transmission, and improved the reliability of the link.

129 citations

Journal ArticleDOI
TL;DR: In this paper, the transmission characteristics of a 120 GHz-band millimeter-wave wireless link are described and the effects of transmitting 120GHz-band optical subcarrier signals through single-mode fibers were theoretically and experimentally investigated.
Abstract: The transmission characteristics of a 120-GHz-band millimeter-wave wireless link are described. The wireless link uses photonic technologies for generation, modulation, and transmission of millimeter-wave signals. This configuration enables set up of the photonic millimeter-wave generator and transmitter core separately; therefore, the wireless link can be used as a kind of radio-over-fiber system. The effects of transmitting 120-GHz-band optical subcarrier signals through single-mode fibers were theoretically and experimentally investigated. It was confirmed that the time shift of the code edges, because of chromatic dispersion, limits the transmission distance. A data stream at 10-Gbit/s was successfully transmitted over the 120-GHz-band millimeter-wave wireless link, with a bit error rate (BER) below 10-12 over a distance of 250 m. The results also demonstrated the stability of the wireless link, which satisfied the 10-Gb Ethernet standard under clear weather conditions.

87 citations

Proceedings ArticleDOI
28 Oct 2010
TL;DR: 120-GHz-band wireless equipment that can transmit 10-Gbit/s data signal over a distance of more than 5 km is developed and a millimeter-wave amplifier that integrates 0.08-µm-gate-length InGaAs/InP composite-channel high-electron-mobility transistors is used to increase the output power.
Abstract: We have developed 120-GHz-band wireless equipment that can transmit 10-Gbit/s data signal over a distance of more than 5 km. In order to increase the output power of the120-GHz-band wireless equipment, we used a millimeter-wave amplifier that integrates 0.08-µm-gate-length InGaAs/InP composite-channel high-electron-mobility transistors. The output power of the wireless equipment becomes 16 dBm. The wireless equipment can handle data rates of 1 Mbit/s to 11.1 Gbit/s and transmit 10-Gbit/s-class data signals with and without forward error correction (FEC). We conducted wireless data transmission experiments over a distance of 4.8 km and 5.8 km and succeeded in the error-free data transmission of 10-Gbit/s data with FEC.

72 citations


Cited by
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Journal ArticleDOI
TL;DR: An overview of the status of the terahertz technology, its uses and its future prospects are presented in this article, with a focus on the use of the waveband in a wide range of applications.
Abstract: Research into terahertz technology is now receiving increasing attention around the world, and devices exploiting this waveband are set to become increasingly important in a very diverse range of applications. Here, an overview of the status of the technology, its uses and its future prospects are presented.

5,512 citations

Journal ArticleDOI
TL;DR: In this paper, the state-of-the-art technologies on photonics-based terahertz communications are compared with competing technologies based on electronics and free-space optical communications.
Abstract: This Review covers the state-of-the-art technologies on photonics-based terahertz communications, which are compared with competing technologies based on electronics and free-space optical communications. Future prospects and challenges are also discussed. Almost 15 years have passed since the initial demonstrations of terahertz (THz) wireless communications were made using both pulsed and continuous waves. THz technologies are attracting great interest and are expected to meet the ever-increasing demand for high-capacity wireless communications. Here, we review the latest trends in THz communications research, focusing on how photonics technologies have played a key role in the development of first-age THz communication systems. We also provide a comparison with other competitive technologies, such as THz transceivers enabled by electronic devices as well as free-space lightwave communications.

1,238 citations

Journal ArticleDOI
TL;DR: The current progress of terahertz-wave technologies related to communications applications are examined and some issues that need to be considered for the future of THz communications are discussed.
Abstract: Recent changes in how people consume multimedia services are causing an explosive increase in mobile traffic. With more and more people using wireless networks, the demand for the ultra-fast wireless communications systems is increasing. To date, this demand has been accommodated with advanced modulation schemes and signal-processing technologies at microwave frequencies. However, without increasing the carrier frequencies for more spectral resources, it may be quite difficult to keep up with the needs of users. Although there are several alternative bands, recent advances in terahertz-wave (THz-wave) technologies have attracted attention due to the huge bandwidth of THz waves and its potential for use in wireless communications. The frequency band of 275 ~ 3000 GHz , which has not been allocated for specific uses yet, is especially of interest for future wireless systems with data rates of 10 Gb/s or higher. Although THz communications is still in a very early stage of development, there have been lots of reports that show its potential. In this review, we will examine the current progress of THz-wave technologies related to communications applications and discuss some issues that need to be considered for the future of THz communications.

1,072 citations

Journal ArticleDOI
TL;DR: A wireless sub-THz communication system near 237.5 GHz with one to three carriers and up to 100 Gbit/s with state-of-the-art active I/Q-MMIC at the Rx is demonstrated.
Abstract: A wireless communication system with a maximum data rate of 100 Gbit s−1 over 20 m is demonstrated using a carrier frequency of 237.5 GHz. The photonic schemes used to generate the signal carrier and local oscillator are described, as is the fast photodetector used as a mixer for data extraction.

1,037 citations

Journal ArticleDOI
TL;DR: The goal of this paper is to provide a comprehensive review of wireless sub-THz and THz communications and report on the reported advantages and challenges of using sub-terahertz andTHz waves as a means to transmit data wirelessly.
Abstract: According to Edholm’s law, the demand for point-to-point bandwidth in wireless short-range communications has doubled every 18 months over the last 25 years It can be predicted that data rates of around 5–10 Gb/s will be required in ten years In order to achieve 10 Gb/s data rates, the carrier frequencies need to be increased beyond 100 GHz Over the past ten years, several groups have considered the prospects of using sub-terahertz (THz) and THz waves (100–2000 GHz) as a means to transmit data wirelessly Some of the reported advantages of THz communications links are inherently higher bandwidth compared to millimeter wave links, less susceptibility to scintillation effects than infrared wireless links, and the ability to use THz links for secure communications Our goal of this paper is to provide a comprehensive review of wireless sub-THz and THz communications

991 citations