MadSci Network: Engineering

Re: How is hypersound (7 ghz +) produced?

Date: Wed Jul 11 10:25:17 2001
Posted By: Ronald Fisch, Physics, Washington University
Area of science: Engineering
ID: 993956769.Eg

According to the Encyclopaedia Britannica, hypersound is
defined to be sound waves of frequencies greater than 10 terahertz
(10^13 hertz).  So 7 gigahertz (7*10^9 hertz) sound waves would then be
in the ultrasound range of frequencies.

Ultrasound is produced by electromechanical tranducers.  Tranducers are of
two types, piezoelectric materials (such as quartz), or magnetostrictive
materials (which are certain types of ferromagnetic materials).  These
tranducers can convert an electromagnetic wave into a sound wave, or vice

So to create a 7 gigahertz ultrasound wave using a quartz transducer,
one would apply a 7 gigahertz electrical signal across the quartz crystal.
And one must connect the quartz crystal to the medium in which you want
the ultrasound to propagate.

It is straightforward to generate such a 7 GHz electrical signal using
readily available semiconductor devices.  I do not believe that it is
possible to make a motor with such a high RPM.  Even in the megahertz
range, signals are generated electronically rather than mechanically.

Current Queue | Current Queue for Engineering | Engineering archives

Try the links in the MadSci Library for more information on Engineering.

MadSci Home | Information | Search | Random Knowledge Generator | MadSci Archives | Mad Library | MAD Labs | MAD FAQs | Ask a ? | Join Us! | Help Support MadSci

MadSci Network,
© 1995-2001. All rights reserved.