EMI antenna calibration using the antenna impedance measurement

A newly developed EMI antenna calibration method named antenna impedance method is theoretically investigated on the antenna arrangements and the attainable accuracy. This calibration method requires only antenna impedance measurements on an antenna under calibration above a metal ground plane at various antenna heights. The paper briefly reviews the theoretical basis of the method and the experimental results obtained by this method. Then, an appropriate height range for the antenna scanning is investigated by using the method of moments. In addition, the achievable accuracy of this calibration method is evaluated by taking into account the error in antenna impedance measurements. It is concluded that the accuracy of the antenna impedance method is around 0.3 dB or less for the almost all frequencies from 30 to 1000 MHz. It is comparable to the standard antenna method that is commonly used for EMI antenna calibration at many national standard institutes.