By Alexander Hellemans

It’s well understood that a dipole or monopole metal antenna’s length has to be at least one eighth of the wavelength of the wireless signal in order to transmit enough power. For transmission in the gigahertz range, where most mobile communication takes place, wavelengths between 15 and 30 centimeters had set a limit for miniaturization of transmitter and receiver antennas even as the silicon chips on which they must be integrated got ever smaller.

Now researchers have found a way to reduce the size of GHz antennas by modifying an existing technique, the use of antennas made from a dielectric or insulating material instead of a conductor.  In a proof of concept experiment, researchers at the department of engineering at the University of Cambridge and at the National Physical Laboratory in Teddington, Middlesex, UK, have shown that they can reduce the size of a GHz antenna without significant transmission loss by using dielectric materials as the radio wave emitting material.  They reported the results earlier this month in Physical Review Letters.  …[Read more]