A ring antenna for dual-sense circular polarization

A design of dual circularly polarized antenna is proposed. By two dual L-shaped probe structure, dual-sense circular polarization (CP) for radio astronomy is achieved. The dual L-shaped probes are place in the radial direction of a circular ring to obtain both right hand circular polarization (RHCP) and left hand circular polarization (LHCP). According to our simulation results, the proposed antenna element could achieve -10dB-level of |S₁₁| and more than -20dB-level of isolation in frequency range of 1.4 - 1.7 GHz. The antenna element broadside gain is approximately 8.5 dBic. The axial ratio (AR) below 3dB is more than 300 MHz in each circular polarization state. The details of simulation results for the proposed design are presented and discussed.