Circularly Polarized Receiving Antenna Incorporating Two Helices to   Achieve Low Backscattering
  We propose to use an antenna composed of two orthogonal helices as a low-scattering sensor. The vector effective length is derived for the antenna using the small dipole approximation for the helices. The antenna can transmit and receive circular polarization in all directions with the Huygens' pattern. We observe that the antenna geometry does not backscatter, regardless of the polarization, when the incidence direction is normal to the plane of the helices. Scattered fields, scattered axial ratio, and the scattering cross section are presented. We show that the zero-backscattering property holds also for the antenna when it is capable to receive all the available power with conjugate loading. The approximate analytical model is validated with full-wave simulations. 
Antti O. Karilainen and Sergei A. Tretyakov
physics.class-ph