A novel design method of EMC anechoic chamber using phase and magnitude deviation

EMC(Electro Magnetic Compatibility) tests have been inevitable for electronic products of recent years. Most of the products are tested in anechoic chamber or open site, but in an experiment, it is susceptible to error caused by reflections from the wall because absolute free space could not be achieved with absorber. Then an evaluation value for constructing a better condition of anechoic chamber in which the error is reduced, is required. To design high performance measurement environment and anechoic chamber, we propose an evaluation value using the phase difference between direct wave and reflected wave. The value is introduced with the investigation of the error source by ray-tracing method. The results using proposed value for locating the transmitting point show that it is possible to improve the measurement environment by calculation. Moreover this indicates that the better design of anechoic chambers can be obtained by this value.