Pioneering research on exploration of undeveloped electromagnetic waves using photonics technologies and their application to wireless communications

Photonic techniques for measuring high-frequency electrical signals and radio waves

Fig.1 Photonic techniques for measuring high-frequency electrical signals and radio waves

Block diagram of a 120-GHz-band wireless link using photonic techniques in the transmitter

Fig.2 Block diagram of a 120-GHz-band wireless link using photonic techniques in the transmitter

Block diagram of a wireless link system for uncompressed multi-channel transmission of high-definition television (HDTV) signals

Fig.3 Block diagram of a wireless link system for uncompressed multi-channel transmission of high-definition television (HDTV) signals

    Demand is increasing for higher data rate in wireless communications in order to keep up with the remarkable speed-up of fiber-optic networks such as Ethernet LANs. One of the most direct and easiest ways to achieve a higher data rate of >10 Gbit/s is to increase carrier frequencies to sub-terahertz frequency of over 100 GHz. Tadao Nagatsuma, Akihiko Hirata, and Toshihiko Kosugi had devoted their effort to challenges to use electromagnetic waves at over 100 GHz for the breakthrough in the capability of wireless communications, and had succeeded in the realization of a practical high-speed wireless link system with a world-record capacity of over 10 Gbit/s. In particular, they had established a basis for the generation and detection of electromagnetic waves at frequencies from 100 GHz to 1 THz using photonics technologies. One real-world application having a big impact on the society is the 120-GHz-band millimeter-wave wireless link featuring the above transmission capacity. The 120-GHz-band wireless link had been successfully applied to the uncompressed multi-channel transmission (maximum 6 channels) of high-definition television (HDTV) signals without any latency.

    Tadao Nagatsuma had developed basic technologies for the photonic generation and detection of over-100-GHz radio waves, and had led the long-term research on the communications applications. As for measurement/testing technologies, he had established a photonic measurement technique referred to as an electro-optic (EO) sampling for the development of high-frequency electronic/photonic devices, circuits and modules including antennas, which are key components in wireless systems. It should be emphasized that there has been no progress in component technologies without this measurement technology. In addition, he had rendered lots of services in the academic societies relating to the interdisciplinary areas, which combine electronics and photonics, and/or radio waves and fiber optics from their birth to the present.

    Akihiko Hirata had contributed to the system-oriented development of 120-GHz-band wireless link, and to getting a license of experimental radio station from the Japanese government, which was the first one operating at over-100-GHz band. He had demonstrated how practical the 120-GHz-band link is through numerous field trials in collaboration with broadcasting industries. Particularly, most crucially significant technologies he devised are a highly stable and frequency-tunable optical sub-carrier signal generator, and a millimeter-wave transmitter which consists of the optical subcarrier generator, the high-frequency photodiode, and the antenna.

    Toshihiko Kosugi had been involved in the development of millimeter-wave integrated circuits (MMICs) based on high-performance InP HEMT technology for the 120-GHz-band transmitter and receives. Notably, a high-output power (>10 mW) amplifier in the transmitter and a highly-sensitive MMIC receiver had brought about the increase in the transmission distance to more than 1 km.

    In addition to their continuous effort on the development of components and systems, they had appealed practicality of the 120-GHz-band wireless link at several international exhibitions such as International Broadcast Equipment Exhibition (InterBEE 2005, Makuhari), National Association of Broadcasters (NAB 2006, Las Vegas), International Broadcasting Convention (IBC 2006, Amsterdam) and Beijing International Radio Film & Television Exposition (BIRTV 2007, Beijing).

    The IEICE granted the Achievement Award to Tadao Nagatsuma, Akihiko Hirata, and Toshihiko Kosugi who had contributed to the above accomplishment and outcome in 2007.



Publications

[1] T. Nagatsuma, M. Shinagawa, N. Saburi, A. Sasaki, Y. Royter, and A. Hirata、1.55-micron Photonic Systems for Microwave and Millimeter-wave Measurement、2001、IEEE Trans. Microwave. Theory Tech., vol.49, no.10, pp.1831-1839, October 2001
[2] T. Nagatsuma、Exploring Sub-Terahertz Waves for Future Wireless Communications (Plenary Talk)、2006、Proc. Int. Conf. Infrared and Millimeter Waves/Terahertz Electronics, p.4, September 2006
[3] A. Hirata, T. Kosugi, H. Takahashi, R. Yamaguchi, F. Nakajima, T. Furuta, H. Ito, and T. Nagatsuma、120-GHz-Band Millimeter-Wave Photonic Wireless Link for 10-Gbit/s Data Transmission、2006、IEEE Trans. Microwave. Theory Tech., vol.54, no.5, pp.1937-1944, May 2006

Related Researches

Category

Communication
(Communication)

Events in World

no data.
Page Top