Optimal use of redundant information in multiport reflectometers by statistical methods

Abstract

Multiport reflectometers permit the determination of both the amplitude and phase of coherent microwave signals from the measurement of power alone. A feature of the multiport technique is that it creates a set of mutually dependent estimates for the value of the unknown reflection coefficient Γ. The paper concerns a statistical method which generates a best linear unbiased estimator for reflection coefficient Γ, based on the criterion of minimum variance; such an estimator has many useful general properties. In addition to providing a single best estimator for Γ, the method also gives its standard deviation, a direct measure of its probable error, and such a measure of system performance can constitute a valuable diagnostic in multiport-reflectometer networks.