EMI analysis of automotive vehicles and its suppression techniques

This paper describes the EMI emission from systems and its suppression techniques. Some measured results for radiated emission from automotive vehicles are also shown. Electrical noise radiated from automotive vehicles can cause interference in radio receivers installed in the vehicle and also in receivers remotely located. In automotive ignition systems, the ignition circuit is essentially a spark generator. Each discharge in the spark plug gap produces a train of pulses. The frequency spread in this broadband type of disturbance may be from very low frequencies to above 1000 MHz.