Optimized Design of Helical Antenna with Parasitic Patch for L-band Satellite Communications

A new small, low-profile and light-weight helical antenna element was designed for L-band satellite communications. The novelty of the antenna is that its input impedance matching has been improved by adjusting the copper strip matching stub, while its circular polarization performance has been enhanced by changing the parasitic radiation patch loaded in the front of the antenna. The optimal antenna structure for INMARSAT application has been fabricated and measured. The proposed antenna can produce a gain of higher than 9 dB, a 3-dB axial ratio bandwidth of nearly 15%, and a |S11| < −15 dB impedance bandwidth of nearly 19%. A good agreement between measurements and simulations is obtained. The proposed antenna is compact in size and easy to tune. It provides a promising antenna element for antenna array applications.