Low-Cost Radar Cross Section Measurement With a Resin-Made Model Coated With Conductive Paste

This study aims to provide practical information regarding the development of a cost-effective test model for low-cost radar cross Section (RCS) measurements. Two major possible approaches for reducing the manufacturing cost of a model are replacing the molding material with an inexpensive one and measuring a scaled-down model with a higher operating frequency. In this study, the former was achieved using a resin-made model coated with a conductive paste to imitate a complete metallic model. According to the scaling laws, the entire geometry, including the surface roughness of the model because of the conductive paint, must be appropriately scaled down. Because this roughness scaling is practically infeasible, we experimentally prove that, if an appropriate molding material is selected, shape-only scaling is valid without roughness scaling. As a preliminary study, two types of polyurethane resins with different densities were tested for their suitability for RCS measurements, and the resin with the higher density was shown to be appropriate for the RCS test model. Based on this preliminary study, 1/20- and 1/40-scale aircraft models were manufactured using aluminum or polyurethane resin, and their RCS values were measured to demonstrate that almost equivalent RCS patterns could be obtained. Therefore, low-cost RCS testing was achieved using the resin-made scaled model.