Standards and test procedures for the immunity of vehicle electronic systems to electromagnetic interference : improvements in test methods. Stage IV. Prepared for Department of Transport DOT, Vehicle Standards and Engineering VSE3.

This report describes a programme of research to examine test methods for the immunity of vehicle electronic systems to radio frequency disturbance. A number of problems have been identified including resonance, standing waves and frequency response. Recommendations have been made to improve these methods including the use of damping materials, the test method itself, system safety, integrity levels and software requirements. The effect of radio frequency disturbances on different electronic circuits has been examined including how the levels of disturbances are distributed within the electronic circuit. Different types of transmission, including modulated signals, have been used to investigate their effects on electronic circuits. Existing test methods have been studied in detail and a number of improvements proposed. In particular, the GTEM cell is a major development of the standard cell offering far superior wideband performance, the 800 mm stripline can be significantly improved using damping materials and an improved method for bulk current injection has been suggested. The report recommends the use of four test methods for immunity to radio frequency disturbances. These are the full-scale chamber test, the 800 mm stripline, the GTEM cell and bulk current injection when performed on the vehicle. Recommendations have been proposed for electromagnetic compatibility, EMC, testing over the range of vehicle applications. These include the basic immunity and emissions requirements together with transient, electrostatic discharge, low frequency fields, specific problems with radio transmitters and software. (A)