Validation of intermediate level circuit models (ILCM) of a generic system through measurement

A combined work programme is currently being undertaken to develop and validate suitable modelling and empirical tools to enable the prediction of interference upset to systems. This is a collaboration between the University of York (development of ILCM modelling techniques), and QinetiQ (model validation). The modelling effort and validation exercise centres on a system known as GENEC, a simplified modular representation of a generic missile system. The paper focuses on the RF measurement techniques that were undertaken as part of the collaborative programme to validate the York ILCM frequency domain models. The ILCM method treats the enclosure as a waveguide with forward and reverse propagating waves for each mode. As such, the technique has been applied to the computation of coupling between currents on short monopole antennas located within GENEC, and also to the coupling between internally located monopoles and incident plane waves via the apertures in the GENEC enclosure. The measurement techniques that were used to validate the monopole to monopole coupling scenario are the main topic of the paper. It is found that intermediate circuit level models of the dominant coupling modes within an enclosure can provide very rapid and accurate predictions when compared to measurement.