Minimising performance degradation due to non linearities and improving EMC design of multi radiosets [HF-VHF]

In a multi radio set configured land mobile vehicle platform, there are two major issues arising that lead to degradation in system performance There is non linearity in wireless communication system design that gives rise to inter modulation EMI[IMI]and cross modulation EMI [CMI] when systems are operated in close proximity which are mainly responsible for reduction in communication system performance. Another important factor contributing for reduction in system performance is inadequate EMC design in the multi radio sets. Again under this category there are two issues, one inherent to the basic radio set design either HF or VHF or both and another that is external to the system that is physical limitations in the installation platform. The later part can be due to several technical parameters such as co siting factor, emitter sources other than radio sets, external sources independent of the platform so on and so forth . These two key issues are briefly addressed in this paper and an analysis is carried out to minimise the performance degradation. Also a few EMC design guidelines are arrived with specific attention to system configuration or system design in the vehicle platform where it operates.[EMI due to non communication equipment and external emitter sources such as radar, communication installations, other dense vehicular platforms etc are not considered in this analysis].