Selex assesses lightning protection systems for Radar with CST MWS

Ing. Americo Dominicis of Selex-SI in collaboration with Prof. A.Orlandi of University of L’Aquila investigated the impact of a lightning strike on a mobile 3D radar using CST MICROWAVE STUDIO (CST MWS)iii. Such a unit consists of three separate parts, an antenna pallet unit (APU), the power generator group and the equipment shelter group, which are only connected by cables and the soil. After identifying the most adverse position of the lightning channel with respect to the APU, the induced current as a function of the ground resistance – reflecting different soil conditions - was simulated.

The specification of the splip ring ground channel is a direct result. Further studies were carried out after extracting an equivalent circuit model from the full 3D simulation of the APU using Thevenin’s theorem. The application of 3D simulation to this complex problem resulted in a better understanding of the impact of a lighting strike on the various components of a mobile radar unit and therefore in the improved design of the LPS. “Protecting a mobile Radar unit from lightning strike is a very demanding task,” commented Americo Dominicis, Selex-SI. “CST MWS, in particular its time domain simulation capabilities, helped us to understand the impact of various parameters on the specification of an LPS before running expensive, time-consuming tests.” “The investigation of a lightning strike on a complex system such as a mobile radar is a challenging problem,” said Dr. Martin Timm, Marketing Director, CST. “Using 3D simulation to extract a circuit model that replaces the lightning induced fields by a equivalent voltage source is an intriguing idea which has been applied successfully in the design of this lightning protection system.”