抄録
This paper investigates frequency-dependent parameters of a counterpoise which are identified from measured voltages and currents by a numerical optimization technique. Based on the investigation, the frequency characteristics of the impedance and the admittance are made clear. Then, Sunde's formulas of the frequency-dependent impedance and admittance, which are not widely used because of requiring iterative calculations to determine the final values, are compared with the measured results. It appears that Sunde's iterative formulas show a similar trend to the frequency-dependent parameters identified from the measured results, and can be adopted in a frequency lower than 100kHz. However above the frequency, the formula is case sensitive and is not reliable.
