Design and Test of 3-D Printed Spherical Ground Planes for Monopole Antennae

This paper presents the design and test of 3-D printed spherically-shaped ground planes for monopole antennae used in space probe applications. Two monopole antennae with spherical ground planes operating at 880 MHz and 1.33 GHz were designed and fabricated using additive manufacturing. Results were compared to a conventional ground plane antenna as well as alternative spherical ground plane antennae using copper-wrapped incandescent light bulbs. The simulated and measured results were in good agreement. The radiation patterns of the spherical ground monopoles are similar to that of a standard monopole antenna provided the sphere radius is set to less than 0.15λ. The use of 3-D printing allows the antenna designer ample flexibility in accurately modeling arbitrarily-shaped ground planes at low cost.