Terahertz wireless makes big strides in paving the way to technological singularity

Medical AI and doctors at earth stations could remotely conduct a zero-gravity operation aboard a space plane connected via terahertz wireless links.(CREDIT ©HIROSHIMA UNIVERSITY, NICT, PANASONIC, AND 123RF.COM)

https://www.eurekalert.org/pub_releases/2019-02/hu-twm021419.php

Hiroshima, Japan, February 19, 2019--Hiroshima University, National Institute of Information and Communications Technology, and Panasonic Corporation announced the successful development of a terahertz (THz) transceiver that can transmit or receive digital data at 80 gigabits per second (Gbit/s). The transceiver was implemented using silicon CMOS integrated circuit technology, which would have a great advantage for volume production. Details of the technology will be presented at the International Solid-State Circuits Conference (ISSCC) 2019 to be held from February 17 to February 21 in San Francisco, California [1].

The THz band is a new and vast frequency resource expected to be used for future ultrahigh-speed wireless communications. IEEE Standard 802.15.3d, published in October 2017, defines the use of the lower THz frequency range between 252 gigahertz (GHz) and 325 GHz (the "300-GHz band") as high-speed wireless communication channels. The research group has developed a single-chip transceiver that achieves a communication speed of 80 Gbit/s using the channel 66 defined by the Standard. The research group developed a 300-GHz-band transmitter chip capable of 105 Gbit/s [2] and a receiver chip capable of 32 Gbit/s [3] in the past few years. The group has now integrated a transmitter and a receiver into a single transceiver chip. 

"We presented a CMOS transmitter that could do 105 Gbit/s in 2017, but the performance of receivers we developed, or anybody else did for that matter, were way behind [3] for a reason. We can use a technique called 'power combining' in transmitters for performance boosting, but the same technique cannot be applied to receivers. An ultrafast transmitter is useless unless an equally fast receiver is available. We have finally managed to bring the CMOS receiver performance close to 100 Gbit/s," said Prof. Minoru Fujishima, Graduate School of Advanced Sciences of Matter, Hiroshima University.

"People talk a lot about technological singularity these days. The main point of interest seems to be whether artificial superintelligence will appear. But a more meaningful question to ask myself as an engineer is how we can keep the ever-accelerating technological advancement going. That's a prerequisite. Advances in not only computational power but also in communication speed and capacity within and between computers are vitally important. You wouldn't want to have a zero-grav operation on board a space plane without real-time connection with earth stations staffed by medical super-AI and doctors. After all, singularity is a self-fulfilling prophecy. It's not something some genius out there will make happen all of a sudden. It will be a distant outcome of what we develop today and tomorrow," said Prof. Fujishima.

"Of course, there still is a long way to go, but I hope we are steadily paving the way to such a day. And don't you worry you might use up your ten-gigabyte monthly quota within hours, because your monthly quota then will be in terabytes," he added.

Panasonic Develops A Gallium Nitride (GaN) Terahertz Detector with High Sensitivity

                                                               GaN (Gallium Nitride) Terahertz Detector

http://phys.org/news/2010-06-panasonic-gallium-nitride-gan-terahertz.html

Panasonic today announced the development of a new terahertz (THz) detector using a Gallium Nitride (GaN) transistor. The detector exhibits the world highest sensitivity at room temperature. The GaN-based THz detector is applicable to a variety of security or analyzing systems, which will greatly help the wide-spread use of such THz applications in the future

The GaN detector forms a so-called plasma wave of the electrons, in which the electron density is fluctuated as a wave. The plasma wave resonates with the incident THz wave, which is detected as an electric signal at the GaN transistor. The use of GaN with high electron velocity effectively increases the amplitude of the plasma wave and the extracted electric signal.

The detector uses the gate electrode itself as a dipole antenna free from the loss in the transmission lines. In addition, the source and the drain electrodes of the GaN transistor are designed to work as parasitic elements for the antenna, which effectively confine the incident THz wave in the vicinity of the gate. Note that the employed metal-oxide-semiconductor (MOS) gate structure reduces the gate leakage current suppressing the leakage of the plasma wave around the gate antenna. The choice of the material together with a novel antenna structure successfully increases the sensitivity of the THz detector.

The fabricated THz detector using Panasonic's proprietary GaN technologies achieves a very high sensitivity of 1100 V/W at room temperature, while a conventional detector utilizing thermal conversion requires cooling of the device down to -270°C to maintain high enough sensitivity. The developed GaN-based THz detector free from such cooling systems can make the THz systems very compact keeping high sensitivity.

Applications for 9 domestic and 1 overseas patents have been filed. These research and development results have been presented at 68th Device Research Conference, held in South Bend, Indiana, U.S. from June 21 to 23, 2010.

 Explore further: Gallium Nitride Power Transistor for Wireless Base Stations

IEDM papers hint at future of imaging

Embedded sensor: CCD plus CMOS benefits

Leading research teams have presented a raft of innovations in the field of imaging sensor chips at the IEEE-organized 2014International Electron Devices Meeting (IEDM).

http://optics.org/news/5/12/30
Taking place in San Francisco this week, the conference is regarded as a key event in the dissemination of semiconductor device research, with key players from the giant chip makers and leading university groups taking part.

While most of the conference sessions focus on electronic device design and manufacture, a handful of them are dedicated to developments in photonics technologies – largely new types of sensors for imaging applications.

Among them were a silicon detector capable of operating in the increasingly important far-infrared range – a part of the spectrum usually regarded as being well beyond the range of any conventional silicon chips.

Devised by a multinational team from Texas, Germany and Lithuania, the Schottky barrier diodes – made using a normal CMOS process - were able to detect at 9.74 THz.

“The detector exhibits 14 times higher responsivity near 10 THz than the highest previously reported for electronic detection,” they wrote. “This work also suggests electronic detection beyond 10 THz and potential for affordable imaging in the infrared range using foundry CMOS.”

In the same session, a collaboration involving Panasonic and others said that new and highly sensitive photodetectors based on thin-film crystalline selenium could “open the door” to next-generation, ultrahigh-definition imaging systems.

Laminated onto a CMOS circuit, the photodiodes showed an external quantum efficiency of more than 50 per cent between 350 nm and 600 nm, dropping off to zero in the red end of the spectrum at around 690 nm.

DNA sequencing roadmap
A team from Belgian electronics research base IMEC – always a major contributor at IEDM – described a new imager platform combining both the light sensitivity of CCD and the speed of CMOS sensor technologies.

“The time delay integration (TDI) imagers use a light-sensitive CCD imaging part with a column-based CMOS readout, combining the best technologies for both integration of light-induced charges and a fast readout,” wrote the team in its paper.

The team believes that the device, the first of its kind, will enable “beyond state-of-the-art” performance for industrial inspection and Earth observation applications, once it is combined with a backside illuminated imager platform also under development at IMEC.

A separate session saw Annette Grot from US-based Pacific Biosciences reveal details of a roadmap for the light sensors required for massively parallel DNA sequencing. Recent advances in both CCD and CMOS sensors have been part of the reason behind a huge drop in the cost of one of the main approaches to DNA sequencing, which marks base nucleotides with fluorescent “tags”.

Key sensor characteristics for this application include resolution, sensitivity and frame-rate, Grot says, adding that future advances could help continue what has been an exponential decrease in DNA sequencing cost.

Equipment from Pacific Biosciences, as well as sequencing specialist Illumina and ThermoFisher use a free-space optical system to relay fluorescence signals generated on the sample plate to the image sensor. Grot says that, ideally, the resolution of the sensor should match or exceed the optical resolution of the collection path.

Elsewhere, a Japanese team highlighted what it claimed to be the first demonstration of 3D-integrated CMOS image sensors featuring in-pixel analog/digital converters. The 64-pixel device made by a collaboration between NHK’s research labs and the University of Tokyo was able to capture video images with a dynamic range of 80 dB and excellent linearity, the team said.

Researchers Submit Patent Application, "Method for Polarizing a Terahertz Electromagnetic Wave Using a Polarizer", for Approval

By a News Reporter-Staff News Editor at Electronics Newsweekly -- FromWashington, D.C., VerticalNews journalists report that a patent application by the inventors TAKAHASHI, Kohei (Osaka, JP); KANNO, Tsutomu (Kyoto, JP); SAKAI, Akihiro (Nara, JP); 

http://www.4-traders.com/news/Researchers-Submit-Patent-Application-Method-for-Polarizing-a-Terahertz-Electromagnetic-Wave-Using--17940291/

YAMADA, Yuka (Nara, JP), filed on October 1, 2013, was made available online on February 6, 2014.

The patent's assignee is Panasonic Corporation.

News editors obtained the following quote from the background information supplied by the inventors: "The present invention relates to a method for polarizing a terahertz electromagnetic wave using a polarizer.

"Terahertz electromagnetic wave is an electromagnetic wave having a frequency of 0.1 THz or more. JP 2009-052920 A, Itsunari Yamada et. al., 'Terahertz wire-grid polarizers with micrometer-pitch Al gratings', Optics Letters, 2009, Vol. 34, No. 3, p.p. 274-276, and Lei Ren et. al., 'Carbon Nanotube Terahertz Polarizer', Nano Letters, 2009, Vol. 9, No. 7, p.p. 2610-2613 disclose a method for polarizing a terahertz electromagnetic wave."

As a supplement to the background information on this patent application, VerticalNews correspondents also obtained the inventors' summary information for this patent application: "One non-limiting and exemplary embodiment provides a novel method for polarizing a terahertz electromagnetic wave using a polarizer.

"Additional benefits and advantages of the disclosed embodiments will be apparent from the specification and Figures. The benefits and/or advantages may be individually provided by the various embodiments and features of the specification and drawings disclosure, and need not all be provided in order to obtain one or more of the same.

"In one general aspect, the techniques disclosed here feature; a method for polarizing an electromagnetic wave having a frequency of not less than 0.1 THz and not more than 0.8 THz using a polarizer, the method comprising: a step (a) of preparing the polarizer; wherein the polarizer comprises a sapphire single crystalline layer, and a Ca.sub.xCoO.sub.2 crystalline layer, the Ca.sub.xCoO.sub.2 crystalline layer is stacked on the sapphire single crystalline layer, a surface of the Ca.sub.xCoO.sub.2 crystalline layer has a (010) surface orientation, and the Ca.sub.xCoO.sub.2 crystalline layer has a thickness of not less than 2 micrometers and not more than 20 micrometers; and a step (b) of irradiating the polarizer with the electromagnetic wave having a frequency of not less than 0.1 THz and not more than 0.8 THz to output an output wave having only a component parallel to a c-axis direction of the sapphire single crystalline layer.

"These general and specific aspects may be implemented using a system, a method, and a computer program, and any combination of systems, methods, and computer programs.

Panasonic Develops A Gallium Nitride (GaN) Terahertz Detector with High Sensitivity

June 23, 2010

Panasonic today announced the development of a new terahertz (THz) detector using a Gallium Nitride (GaN) transistor. The detector exhibits the world highest sensitivity at room temperature. The GaN-based THz detector is applicable to a variety of security or analyzing systems, which will greatly help the wide-spread use of such THz applications in the future.

The GaN detector forms a so-called plasma wave of the electrons, in which the electron density is fluctuated as a wave. The plasma wave resonates with the incident THz wave, which is detected as an electric signal at the GaN transistor. The use of GaN with high electron velocity effectively increases the amplitude of the plasma wave and the extracted electric signal.
The detector uses the gate electrode itself as a dipole antenna free from the loss in the transmission lines. In addition, the source and the drain electrodes of the GaN transistor are designed to work as parasitic elements for the antenna, which effectively confine the incident THz wave in the vicinity of the gate. Note that the employed metal-oxide-semiconductor (MOS) gate structure reduces the gate leakage current suppressing the leakage of the plasma wave around the gate antenna. The choice of the material together with a novel antenna structure successfully increases the sensitivity of the THz detector.
The fabricated THz detector using Panasonic's proprietary GaN technologies achieves a very high sensitivity of 1100 V/W at room temperature, while a conventional detector utilizing thermal conversion requires cooling of the device down to -270°C to maintain high enough sensitivity. The developed GaN-based THz detector free from such cooling systems can make the THz systems very compact keeping high sensitivity.
Applications for 9 domestic and 1 overseas patents have been filed. These research and development results have been presented at 68th Device Research Conference, held in South Bend, Indiana, U.S. from June 21 to 23, 2010.
Source: Panasonic