Antenna scattering measurements using a scaled 3-D printed spacecraft model

A method to measure an antenna's performance when mounted to an electrically large and complex-shaped spacecraft is described. In the past, either time-intensive numerical simulations or antenna range measurements of an expensive full-scale model of the spacecraft were used to determine the antenna's performance. An alternative method fabricated a reduced-size scaled spacecraft model using 3-D printing processes. The antenna is also reduced in size by the same scale factor as the spacecraft, but the frequency of operation is increased. This combination of a reduced model and increased radiation frequency is equivalent to the full-scale model in terms of scattering. This approach was used to characterize the degradation of an X-Band low gain antenna (LGA) on NASA's Solar Probe Plus (SPP) Spacecraft. The spacecraft and antenna model were reduced in size by a factor of 4.51 and the radiation frequency was scaled upwards by 4.51, from X-Band to Ka-Band. The model was then measured in a compact antenna range and compared to numerical simulation using HFSS.