Showing papers by "Toshihiko Kosugi published in 2005"
TL;DR: A rectangular-waveguide output UTC-PD module integrating a HEMT power amplifier has been developed for operation in the 125-GHz band and exhibits maximum output power of more than 14 dBm with nearly flat frequency dependence.
Abstract: A rectangular-waveguide output UTC-PD module integrating a HEMT power amplifier has been developed for operation in the 125-GHz band. The fabricated module exhibits maximum output power of more than 14 dBm with nearly flat frequency dependence in the 115-135GHz range. A 10-Gbit/s error-free wireless transmission at 125GHz with a minimum sensitivity of −34 dBm for a bit-error-rate of 10−12 is also demonstrated using the fabricated module.
14 citations
01 Jan 2005
TL;DR: A 10-Gb/s wireless link system that uses a 120-GHz-band sub-terahertz electro-magnetic waves and is composed of all-electronic devices using InP-HEMTs is presented.
Abstract: This paper presents a 10-Gb/s wireless link system that uses a 120-GHz-band sub-terahertz electro-magnetic waves. In the transmitter, photonic techniques are used for generation, modulation, and emission of the sub-THz signals, while the receiver is composed of all-electronic devices using InP-HEMTs
14 citations
01 Jan 2005
TL;DR: In this article, the authors review recent progress in photonic devices for millimeter-wave (MMW) wireless links, imaging, and sensing, and describe key devices, including photonic MMW sources, high-speed photonic transmitters, and Electro-Optic (EO) sensors.
Abstract: We review recent progress in photonic devices for millimeter-wave (MMW) wireless links, imaging, and sensing. O/E conversion of optical signals that are modulated at high-frequency is suitable for generating high frequency radio waves with wide frequency tunability. Electro-optic (EO) measurements enable a wide bandwidth and low invasiveness. This paper highlights a MMW wireless links, MMW imaging, sensing, and measurements, and describes key devices, including photonic MMW sources, high-speed photonic transmitters, and EO sensors.
3 citations
TL;DR: In this paper, a pre-amplifier integrated UTC-PD module with a rectangular-waveguide output port for operation in the 120 GHz band has been realized, achieving an 8 dB increase in the output power, resulting in an equivalent response as high as 1.0 A/W.
Abstract: A pre-amplifier integrated UTC-PD module with a rectangular-waveguide output port for operation in the 120 GHz band has been realised. The integrated amplifier achieves an 8 dB increase in the output power, resulting in an equivalent responsivity as high as 1.0 A/W. A 10 Gbit/s error-free wireless transmission at 125 GHz has also been demonstrated using the fabricated module.
3 citations
TL;DR: In this paper, a dual-gate AlGaN/GaN high-electron-mobility transistors on SiC substrates for high-power mixers were demonstrated.
Abstract: We have demonstrated dual-gate AlGaN/GaN high-electron-mobility transistors on SiC substrates for high-power mixers and examined DC and up-conversion RF measurements with drain-source bias voltages (VDS) to analyze the possible output level. The 0.7 × 300 µm-gate device exhibited the maximum transconductance of 47 mS, maximum RF power of 19.6 dBm and up-conversion gain of 11 dB at 2 GHz when VDS = 15 V. For VDS of over 15 V, the devices occasionally broke down, because, although the device can handle more drain current, but the voltage swing reached the breakdown voltage of about 30 V. These results indicate that a Watt-class output mixer can be easily achieved with this simple dual-gate structure. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
2 citations