Electromagnetic design of advanced sandwich radomes

Sandwich radomes are being utilized with numerous secondary surveillance radars (SSR) and in weather radar applications. System performance requirements place increasing demands on radome design with tighter specifications as a direct consequence of the rapid growth and advancement of modern radar and communication systems. Radomes used in these modern systems require low transmission loss and improved boresight shift, cross-polarization, sidelobe degradation and reflection than was previously achieved. In most of these applications, the panels are designed with a quasirandom configuration that is optimized for minimum transmission loss over moderate bandwidths. The joints between each panel of these advanced sandwich radomes are tuned with frequency selective elements to reduce the scattering level and achieve high transmissivity (>95%). To obtain a high performance radome, one should consider both reducing the scattering from the individual joints and optimizing the joint geometry. The basic parameter which determines the scattering characteristics of a radome joint is the induced field ratio (IFR). The IFR is the ratio of the forward field scattered by the joint to the field that would be radiated by the geometrical shadow area of the joint containing that incident field if the joint was not present. IFR measurement results for a tuned radome joint are illustrated.<<ETX>>