Center-Fed Circularly Polarized Omnidirectional Open-Helical Element Optimization

A Circularly Polarized Omnidirectional Open-Helical Antenna element was designed and optimized. This element consists of 2 dipoles wrapped in a helical shape to force circular polarization. The element was first modeled in ANSYS HFSS and optimized by running parametric simulations to determine the proper angle, trace width, and scaling factor. The element was then etched onto a flex circuit and a circular PCB was used to feed it from the center of the helix. This element had a center frequency of 907 MHz, a bandwidth of 55 MHz, a minimum cross polarization rejection of 11.93 dB, and a total gain of 1.45 dBi. Right and left-hand circular elements can be combined to transmit and receive a signal having any possible polarization on the Poincaré Sphere.