Capacitance correction factor of Equivalent Capacitor Substitution Method (ECSM) for monopole antenna calibration

Free space methods for electromagnetic compatibility (EMC) antenna calibrations at Open Area Test Site (OATS) are not suitable for monopole antennas due to corresponding large wavelengths in low-frequency bands. As an alternative, the Equivalent Capacitor Substitution Method (ECSM) is commonly adopted now. In this paper, a major uncertainty factor of capacitance accuracy is investigated by simulation. As a remedy, a capacitance correction factor providing accurate capacitance calculation is proposed, which greatly decreases the total uncertainty. With a self-developed capacitance extraction tool, such correction process can be easily implemented in practical measurements.