The determination of S-parameters from the poles of voltage-gain transfer function for RF IC design

Abstract

A method for estimating the -parameters of active circuits using hand analysis is introduced. This method involves the determination of -parameters from the poles of voltage-gain transfer function. It is found that the information on the frequency responses of input/output return loss, input/output impedance, and reverse isolation is all hidden in the poles or equivalently in the denominator of the voltage-gain transfer function of a circuit system. The method has been applied to three commonly used RF circuit configurations and one fabricated CMOS wide-band amplifier to illustrate the usefulness of the proposed theory.

Evaluation of Contactless Identification Card Immunity against a Current Pulse in an Adjacent Conductor

“…RFID cards damaged during tests and measurements were measured using contactless means using a vector network analyser to calculate their state after the damage. For calculations, mutual relations between measured scattering parameters and the theoretical transfer function of measuring fixture were taken from [39][40][41][42].…”

“…3 (the parameters to find are R 4 and C 2 ) was estimated from the absolute value of the theoretical transfer function of the measuring fixture (Figure 19) and the measured values of S 21 using the optimized Levenberg-Marquardt method for the following circuit parameters in Figure 19: R 1 = R 3 = 50 Ω, coupling factor k = 0.35, the inductance of the sensing coil L 1 = 0.78 µH, the inductance of the card coil L 2 = 4.9 µH, and the series resistance of the card coil R 2 = 2.24 Ω. Considering the definition of the transfer function and the scattering parameter S 21 , it was necessary to add an offset of 6 dB to the theoretical absolute value of the transfer function [41,42]. The regression result gives an estimation of R 4 = 745 Ω and C 2 = 33.7 pF.…”

Accurate Modeling of CCS Combo Type 1 Cable and Its Communication Performance Analysis for High-Speed EV-EVSE Charging System

“…However, the actual output port impedance of the DC supply equipment or the communication module's in/output port impedance has a respective value according to its preference. In order to derive the voltage transfer function for NEXT or FEXT from the S-parameter measurement obtained in a 50 Ω system, the conversion process should proceed as follows in (14a), (14b), and (14c) [57,58];…”