A new robust method for six-port reflectometer calibration

Abstract

Abstract-A new robust method for finding the parameters of Engen's six-port-to-four-port reduction algorithm for sixport reflectometer calibration has been developed. Like other previously published methods, it uses a minimum of five loads with an unknown but constant absolute value of the reflection coefficient and unknown but well-distributed phases. However, the quality of the parameter estimates is improved, especially in noisy environments, by efficiently eliminating cases in which these earlier methods may become ill-conditioned. The new method has been used successfully to calibrate a newly developed six-port reflectometer in GaAs MMIC technology working between 1.3 GHz and 3.0 GHz.Index Terms-Calibration procedure, network analysis, reflection coefficient measurement, six-port reflectometer, S-parameter measurement.

A Novel Design of a Robust Ten-Port Microwave Reflectometer With Autonomous Calibration by Using Neural Networks

“…Another possibility is described in [8] where five loads with the same module are used for the calibration, eliminating ill-conditioned configurations.…”

“…Additionally, uncertainty of connectors, transmission lines or diodes, may increment the final error in measurements, which is more relevant when high power levels are considered. Other techniques for the calibration of diodes' effects have been proposed, such as linear approximation around the working frequency [8], [11], inclusion of a correction factor depending on temperature [12] or sliding terminations for the calibration of both the diode and the six-port [13].…”

Six-Port-Based Architecture for Phase Noise Measurement in the UWB Band

“…A good solution to improve the phase noise measurement of this new architecture is the utilization of a six-port demodulator (see Figure 3). Six-port demodulators can work with low input power levels and their calibration has been widely studied [12]. The six-port architecture has been previously implemented in [13], for W-band phase noise measurements, but using a reference oscillator, obtaining good accuracy in phase noise measurement of one-port and two-port systems.…”

“…This architecture uses neither reference oscillator nor a phase shifter for quadrature adjustments. Moreover, the existence of powerful calibration strategies for six-port demodulators [12] and their good performance for low input power levels make the use of this structure advantageous against traditional mixers.…”

A new methodology for in situ calibration of a neural network-based software sensor for S-parameter prediction in six-port reflectometers

“…In Ref. [19] five loads with the same module are used for the calibration, in order to eliminate ill-conditioned configurations. In this way, the numerical solution can be graphically represented in the complex plane of impedances, by means of three circles, whose intersection gives the desired solution for S 11 .…”