Emission source for compatibility testing of wireless networks in the below-deck environment on ships

Abstract

Wireless communications technology is being deployed in Navy ships and submarines. Prior to installing wireless systems, shipboard testing must be conducted to verify electromagnetic compatibility in the below-deck environment between the wireless system and sensitive onboard electronics. An electromagnetic environment (EME) generator is being developed that can be used for conducting compatibility testing from 900MHz to 18GHz in a single test, eliminating the need for expensive individual compatibility tests for each new wireless technology and frequency. This EME generator can create an electromagnetic emission with spectra and waveforms that bound the spectra and waveforms of digitally modulated wireless signals. All of the factors that cause a wireless signal to interfere with nearby electronics are operator controlled in the EME generator, and set to conservative values for conducting compatibility testing. Spectrum and signal analysis measurements and susceptibility tests of a common test article were conducted for both 802.11(N/G) wireless and EME generator emission sources in the multipath environment of the NSWC Dahlgren reverberation chamber. Results indicate that the EME generator will enable evaluation of high-frequency EMI effects to legacy shipboard electronic systems, and provide valuable compatibility information as wireless systems continue to move to higher frequencies, wider bandwidths, and higher aggregate power.