Calibration of biconical antennas using the standard antenna method

Antenna arrangements for calibration of EMI biconical antennas are theoretically investigated using the method of moments. It is found that, below the resonance frequency around 70 MHz of a biconical antenna, the standard antenna method yields antenna factors monotonously approaching a far-field value with increasing the antenna separation distance. At higher frequencies, however, the calibration provides different antenna factors strongly depending on the antenna arrangements. It is recommended that a lower transmitting antenna height is preferable to the calibration of biconical antennas. An EMI biconical antenna under calibration should be positioned far from a transmitting antenna with a separation distance increased with the measurement frequency.