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IBM Shows 155GHz Graphene Transistor

IBM has reached a new milestone in its research of graphene transistors. We learned over a year ago that IBM had achieved a radio-frequency graphene transistor with the cut-off frequency of 100 GHz. Now IBM has cranked it up even higher – hitting 155 GHz.

Graphene is a single atom-thick layer of carbon atoms bonded in a hexagonal honeycomb-like arrangement. This two-dimensional form of carbon has unique electrical, optical, mechanical and thermal properties and its technological applications are being explored intensely by IBM.

While the 155 GHz number is mighty impressive, it's not really the sort of transistor that's going to be immediately of interest to those looking for the next big personal computing technology.

IBM's work on the graphene transistor is part of the DARPA program to develop high performance radio transistors. Graphene is better suited to analog signals, as it does not have the discrete on/off characteristics of silicon.

Read more from Computerworld.

  • WyomingKnott
    ... as it does not have the discrete on/off characteristics of silicon.
    Someone enlighten me here. I thought that transistors were originally analog devices for many years. They had to be re-designed to be on-off devices. Am I wrong?
    Reply
  • galland
    You're right, today's transistors are like a faucet that is used only at full close or full open but still have many intermediate positions
    Reply
  • dogman_1234
    I thought the transistor was suppose to be an on/off switch? I congratulate the engineers at IBM, yet the transistor itself is not all that complete.
    Reply
  • hoofhearted
    Can we communicate with Aliens on their radio frequencies now?
    Reply
  • TeraMedia
    I wonder how small these things are. Graphene is a single-layer sheet of carbon like the article says, but you can stack layers on top of each other like a pile of paper. Is the transistor based on just a single layer, and if so, what surface area is required? Even a transistor involving 10 hexagons in each direction would only have dimensions of 2.46 nm on a side (one carbon bound is 1.42 Angstroms, and there are sqrt(3) bond-lengths per hexagon).
    Unfortunately it sounds like these are more akin to bipolar transistors than cmos in terms of their electrical characteristics, so the amount of current required to turn and keep one "on" rather than "off" would be prohibitive on a chip-wide scale. But if I wanted a radio with a 3mm wavelength, these could be used in the amplifier circuit if the gain is high enough.
    Reply
  • spiketheaardvark
    one commentTeraMediaI wonder how small these things are. .
    The advantages of graphene do not come from transistor size but the fact that it's a superconductor at normal temps. Because it's a much better conductor anything built with it produces much less heat. This allows them to get to these high frequencies.
    Reply
  • jeph_gag
    A transistor is used as an ON/OFF switch in digital application. But it's used as an amplifier in analog application.
    Reply
  • zzz_b
    The transistor can be in the active region, saturation region and cut-off region. So, it is an analog device, but in the saturation region is fully on, while in the cut-off region is off. These regions are used for the "digital" signal.
    I guess most of you guys know only how to play Cryis. :-(
    Reply
  • f-gomes
    In IE9, comments don't work. The button does nothing. One has to use compatibility view in order to post a comment. Come on guys, it has been more than a month, now.
    Reply
  • scook9
    zzz_bThe transistor can be in the active region, saturation region and cut-off region. So, it is an analog device, but in the saturation region is fully on, while in the cut-off region is off. These regions are used for the "digital" signal.I guess most of you guys know only how to play Cryis. :-(We are not ALL electrical engineers afterall haha
    Reply