An Apparent Discrepancy Between Impedance Mismatch Factors for Near-Field and Far-Field Measurements
Author: Doren W. Hess
In making accurate measurements of antenna gain one must correct for the impedance mismatches between (1) the signal generator and transmitting antenna, (2) between the receiving power sensor and the receiving antenna and (3) between the signal generator and receiving power sensor. This is true for both far-field gain measurements and near-field gain measurements. It has recently come to our attention that there is a lack of clarity as to the form the mismatch factor should take when correcting near-field measured data. We show that a different form of impedance mismatch factor is to be used with the voltage domain equations of near-field than has been used with the power domain Friis transmission equation.