A novel disk type support structure installed in a quadrifilar helical antenna for satellite application

We propose a new type of support structure for helical antennas which are made of rolled cylindrical film resin substrate. The structure is composed of a rod arranged on the cylinder axis and disks fixed to it, which have a function that holds the cylindrical film, at specific intervals. This structure suppresses deterioration in antenna performances under adverse conditions of satellite application with vibrations. The configuration is found to be optimum in which the disks are arranged from the position that fell down from the helical upper end by 0.25 λ_g along the helical element. Here, λ_g is guide wavelength along the helical element.