Yuichi Kado

10-Gbit/s Wireless Link Using InP HEMT MMICs for Generating 120-GHz-Band Millimeter-Wave Signal

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.

Heteroepitaxial growth of SrO films on Si substrates

Epitaxial growth of SrO thin films onto Si(111) and (100) substrates by means of molecular‐beam epitaxy has been demonstrated. The orientation relationships between epitaxial SrO and Si were found to be (111)SrO//(111)Si and [112]SrO//[112]Si, (100)SrO//(100)Si and [011]SrO//[001]Si. The composition of the grown films was Sr:O=1:1. In addition, it has been shown that it was possible to grow layers with no Si surface oxidation and no noticeable interdiffusion at the interfaces. These SrO films possess a low dielectric constant (3.0) and a high breakdown field (5×106 V/cm).

Experimental 0.25-/spl mu/m-gate fully depleted CMOS/SIMOX process using a new two-step LOCOS isolation technique

This paper describes the fabrication process of quarter-micrometer-gate fully depleted CMOS/SIMOX devices, which is characterized by a new lateral isolation technique that can easily achieve 30-nm-class surface planarization and 0.2-/spl mu/m-class isolation with no degradation of device characteristics. The distinctive feature of this isolation technique is to use high-temperature two-step LOCOS oxidation. The CMOS/SIMOX devices have 50-nm-thick body regions and dual N/sup +//P/sup +/ poly-Si gates so that they can surely operate in a fully depleted mode. By applying the CMOS/SIMOX process to the fabrication of a CMOS ring oscillator, which is formed on a gate array designed with a 1.2-/spl mu/m wiring pitch, short delay times of 30 and 45 ps/stage have been achieved at supply voltages of 2 and 1 V, respectively. This result demonstrates that the present process is useful for the fabrication of a high-speed VLSI circuit operated at a low supply voltage below 2 V. >

Suppression of parasitic bipolar action in ultra-thin-film fully-depleted CMOS/SIMOX devices by Ar-ion implantation into source/drain regions

This paper proposes a new technique that can effectively suppress the parasitic bipolar action (PBA) in ultrathin-film fully-depleted (FD)nMOSFETs/SIMOX with a floating body. In this technique, recombination centers are created in the source and drain (S/D) regions by deep Ar-ion implantation. They act to reduce the number of holes that accumulate in the body region by increasing the hole current flowing from the body region into the source region. Consequently, the rise of the body potential is lowered, and the parasitic bipolar action can be suppressed. A 0.25-/spl mu/m gate nMOSFET/SIMOX fabricated with an Ar dose of 2/spl times/10/sup 14/ cm/sup -2/ exhibited excellent improvements in electrical characteristics: a reduction in the off-leakage current of over two orders of magnitude and an increase in the drain-to-source breakdown voltage beyond 0.6 V.

Terahertz wireless communication link at 300 GHz

We present a terahertz wave wireless link operating at 300 GHz which has a potential for use in ultra fast future wireless services in short range. Terahertz wave was generated and modulated with photonic technologies in the transmitter, allowing us to use radio on fiber system concept as well. For the receiver, we used a Schottky barrier diode detector integrated with a planar antenna. With the link, error free data transmission at 12.5 Gbps was experimentally demonstrated. Taking the performance margin of the transmitter and receiver into consideration, we believe that even up to 20-Gbps data can be transmitted.

120-GHz-Band Wireless Link Technologies for Outdoor 10-Gbit/s Data Transmission

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 99.999%.

Transmission Characteristics of 120-GHz-Band Wireless Link Using Radio-on-Fiber Technologies

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.

5.8-km 10-Gbps data transmission over a 120-GHz-band wireless link

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.

A 1-GHz/0.9-mW CMOS/SIMOX divide-by-128/129 dual-modulus prescaler using a divide-by-2/3 synchronous counter

An extremely low-power CMOS/SIMOX divide-by-128/129 dual-modulus prescaler that operates at up to 1 GHz and dissipates 0.9 mW at a supply voltage of 1 V is presented. The prescaler is capable of 2-GHz performance with dissipation of 7.2 mW at 2 V. This superior performance is primarily achieved by using an advanced ultrathin-film CMOS/SIMOX process technology combined with a circuit configuration that uses a divide-by-2/3 synchronous counter. Using these same technologies, a single-chip CMOS phase-locked-loop (PLL) LSI that uses the developed prescaler was fabricated. It can operate at up to 2 GHz while dissipating only 8.4 mW at a supply voltage of 2 V. Even at a lower supply voltage of 1.2 V, 1-GHz operation can be obtained with a corresponding power consumption of 1.4 mW. These results indicate that the high-speed and very-low-power features of CMOS/SIMOX technology could have an important impact on the development of future personal communication systems. >

10-Gbit/s MMIC wireless link exceeding 800 meters

We have developed a 120-GHz-band wireless link that uses MMICs for the generation, modulation, and amplification of 125-GHz signals. We succeeded in the error-free (BER=10-12) transmission of a 10-Gbit/s signal over a distance of 800 m, and the maximum transmission distance was estimated to be about 2 km.