Electromagnetic Design of Planar Ablatable Radome Using Inhomogeneous Planar Layer Model

Radome in a high-velocity airborne platform experiences a steep ascent in temperature, affecting its electromagnetic performance. This paper uses the inhomogeneous planar layer model to design a novel radome wall and analyze its performance under dynamic temperature ranges. The model considers the dielectric wall a combination of several layers with different dielectric properties to account for the variation in temperature along thickness of the radome. Outer coating of ablative material is provided to protect the radome wall experiencing elevated temperature levels for high-speed airborne applications. To overcome the issue of total internal reflection at higher angles of incidence, an additional layer of the same ablative material is applied to the inside of the radome wall. Power transmission coefficient, insertion phase delay and power reflection coefficient are calculated using the equivalent transmission line method. The performance of the resulting radome wall is compared with that of the monolithic radome wall designed at a constant temperature.