Chiral antenna element as a low backscattering sensor

For an antenna to operate as a sensor without disturbing the device under test, it should not backscatter any power toward the sensing direction. Here we propose a sensor antenna with such properties, that is very simple to manufacture. The antenna element is basically composed of two loaded wires that have been wound from the center to form two canonical chiral particles. One chiral particle is a combination of a loop and two wires, effectively a magnetic and an electric dipole, respectively. It is the appropriate combination of the dipoles, two electric and two magnetic altogether, that makes the operation possible. In this paper we study the scattering properties of the chiral antenna element. It is observed that whereas the antenna is able to receive power from the main beam direction, the scattered field is directed in the opposite direction with a Huygens' pattern and very little backscattering, that makes it suitable for sensor applications. Scattering from the antenna has in-plane isotropy respective to the plane of the elements, and works similarly for both TM and TE incident waves.