Even Tinier Cell Phones On The Horizon
WASHINGTON (UPI) -- Researchers at the U.S. National Institute of Standards and Technology have developed a tiny, novel device for generating tunable microwave signals. Described in the Jan. 16 issue of Physical Review Letters, the device measures just a few micrometers square and is hundreds of times smaller than typical microwave signal-generators used today in cell phones, wireless Internet devices, radar systems and other applications.
The NIST device consists of two magnetic films separated by a non-magnetic layer of copper. As an electric current passes through the first magnetic film, the electrons in the current align their spins to match the magnetic orientation in the film. But when the now aligned electrons flow through the second magnetic film, the process is reversed. This time the alignment of the electrons is transferred to the film. The result is that the magnetization of the film rapidly switches direction, or oscillates, generating a microwave signal that can be tuned from less than 5 gigahertz (5 billion oscillations per second) to greater than 40 GHz.
WASHINGTON (UPI) -- Researchers at the U.S. National Institute of Standards and Technology have developed a tiny, novel device for generating tunable microwave signals. Described in the Jan. 16 issue of Physical Review Letters, the device measures just a few micrometers square and is hundreds of times smaller than typical microwave signal-generators used today in cell phones, wireless Internet devices, radar systems and other applications.
The NIST device consists of two magnetic films separated by a non-magnetic layer of copper. As an electric current passes through the first magnetic film, the electrons in the current align their spins to match the magnetic orientation in the film. But when the now aligned electrons flow through the second magnetic film, the process is reversed. This time the alignment of the electrons is transferred to the film. The result is that the magnetization of the film rapidly switches direction, or oscillates, generating a microwave signal that can be tuned from less than 5 gigahertz (5 billion oscillations per second) to greater than 40 GHz.
Charles Mims
Never trust a computer you can't lift. - Stan Masor
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