Superconductors made for satellite-talk.

Superconductors made for satellite-talk

As the skies get more crowded with electromagnetic signals of the kilo- and megahertz frequencies, satellite communications researchers want to ease the crunch by building circuitry that operates at much faster, gigahertz frequencies -- billions of cycles per second.

Scientists at NASA's Lewis Research Center in Cleveland have used the superconducting material yttrium-barium-copper sulfate to make a simple experimental circuit, which operates in the 33- to 37-gigahertz frequency range. That's fast enough to transmit the contents of roughly 50 multi-volume encyclopedias in a second. The researchers made the device by blasting a small piece of the superconducting material with a laser to produce an atomic vapor of precisely the correct composition, which was then deposited onto a nearby lanthanum aluminate support chip, explains research team leader Kul B. Bhasin. They then used chemical etching and photolithography techniques to produce a simple and precise pattern consisting of a circle--which can resonate at the superhigh frequencies--and a few lines about 75 microns wide that nearly touch the circle.