2021 Volume 18 Issue 12 Pages 20210185
A new measurement method is proposed in this letter to improve the accuracy of electromagnetic parameters measurement with air coaxial line, especially in low frequency band. The new method measures reflection parameters of the air coaxial line with terminal short-circuited and open-circuited, then the impedances from the specimen section to terminal are calculated. Combined with the impedance equations established based on the transmission line theory, the complex permittivity and complex permeability of the specimen are derived. Compared with the classic Nicolson-Ross-Weir (NRW) method, the method proposed achieves better accuracy in low frequencies, which is proved in this letter through comparative measurements.
