Title: Quantization of Impedance Stability in Frequency Domain
Abstract: A method based on Sample Standard Deviation (SSD) is suggested here to quantify impedance stability in frequency domain. Firstly, impedance instability factor, δ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">T</sub> , is introduced as an indicator of that could be used for impedance stability quantifications of measured or simulated impedance data of Radio Frequency (RF) and high-power devices. The method is used then for a generic real/imaginary impedance trajectory as an example to clarify calculation process. Finally, the introduced approach has been used to quantify impedance stabilities in some RF devices such as stable impedance antenna of 5G in-band full duplex (IBFD) transceivers, microstrip low-pass filter and hybrid coupler. Also, suitable efficiency of the method to follow up correct design direction to smoothen impedance of an antenna is realized.