Spacecraft receiving antenna study: Outer planets atmospheric entry probe

A quadrifilar helix antenna was selected for the Pioneer spacecraft receiving antenna. A model was constructed for radiation pattern measurement at 2.2 GHz. Radiation patterns were measured with the model quadrifilar helix antenna mounted on a Pioneer spacecraft model and four different configurations were tested. The results show that the antenna location does not have a major effect on its patterns over the aft hemisphere but moving the antenna away from the spacecraft improves the antenna performance.