By SPA
Islamabad : A Pakistani scientist working at the Institute of Space Technology has invented the world’s lowest profile omni-directional antenna with dual polarization that does not require a ground plane.
Dr. Muhammad Amin listed in biographical directory published by Marquis “Who’s Who in the World” of the year 2008 has invented the antenna that has adequate signal strength.
The antenna can generate equal vertical and horizontal electric field components and has a helical shape with feed at the centre of the helical section of one side.
A part of vertical electric field generated at the transmitter can turn into horizontal because of the scattering environment.
An antenna capable of receiving or generating equal amplitudes of electric fields both in horizontal and vertical directions would improve reception by providing diversity.
The simplest form of such an antenna is a crossed dipole which consisted of two dipoles orientated at 90o to each other. The crossed dipole provides equal vertical and horizontal electric field over narrow regions and its height would be approximately half wavelength.
Many applications such as in mobile handsets and aerodynamic surfaces at jet speeds the antenna has to be low profile either to appeal the aesthetics or to reduce air resistance.
In addition equal amplitude of electric field both in vertical and horizontal directions is required in all directions for reliable communication.