This thesis presents a quantitative study into the errors in measuring automotive vehicle radiated emissions using the CISPR~12 method. This method is based upon a limited set of tests, when compared to that used for many other commercial electrical devices. This research, details the errors introduced in recording the maximum amplitude of the radiated electric field from the vehicle by using the simplified method.
Two key differences between the CISPR~12 setup and other radiated emissions test methods were researched, in order to quantify the errors. These were: not scanning the receive antenna in height, and not rotating the vehicle through 360 degrees in the azimuth plane whilst the E-field is measured. It was concluded that the current CISPR12 method has the potential to under-estimate the maximum amplitude of the E-field by up to 30~dB.
Research was then performed to investigate alternative methods to those defined in CISPR~12. A number of approaches were considered before being subsequently discounted. The final alternative method considered was the `Test Wire Method', which was originally designed for performing tests on large, industrial machines.
The Test Wire Method, TWM, was initially used as a `proof of concept' that the approach could be used for testing a much smaller device than it was originally designed for. Once the method had been successfully used, and a reduction in the error compared to the CISPR~12 method confirmed, the TWM was then further developed into a novel, new measurement system, designated the MicroStrip Method. A small, near-field probe was designed which, along with the use of a calibration factor, allows for a closer approximation of the maximum amplitude of the radiated E-field to be recorded. Measurements performed on a range of vehicles, resulted in a reduction in the mean error of over 10~dB, compared to using the CISPR~12 method.
