The Experts below are selected from a list of 297 Experts worldwide ranked by ideXlab platform
A. Ferrero - One of the best experts on this subject based on the ideXlab platform.
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Simple technique for measuring source Reflection Coefficient while characterizing active devices
IEEE Transactions on Microwave Theory and Techniques, 2002Co-Authors: G. Madonna, A. FerreroAbstract:The measurement of the source Reflection Coefficient is fundamental for noise, as well as large-signal testing of microwave active devices. This paper describes a simple yet rigorous technique for fast and accurate determination of a source Reflection Coefficient when a load-source pull test set is used. The solution consists in measuring the waves at the device-under-test reference plane under two different bias conditions. We have proven that these measurements give enough information to compute the source Reflection Coefficient with accuracy suitable for most applications. Experimental results are presented and compared to data obtained with more conventional techniques.
G. Madonna - One of the best experts on this subject based on the ideXlab platform.
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Simple technique for measuring source Reflection Coefficient while characterizing active devices
IEEE Transactions on Microwave Theory and Techniques, 2002Co-Authors: G. Madonna, A. FerreroAbstract:The measurement of the source Reflection Coefficient is fundamental for noise, as well as large-signal testing of microwave active devices. This paper describes a simple yet rigorous technique for fast and accurate determination of a source Reflection Coefficient when a load-source pull test set is used. The solution consists in measuring the waves at the device-under-test reference plane under two different bias conditions. We have proven that these measurements give enough information to compute the source Reflection Coefficient with accuracy suitable for most applications. Experimental results are presented and compared to data obtained with more conventional techniques.
Krzysztof Wincza - One of the best experts on this subject based on the ideXlab platform.
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theoretical limits and accuracy improvement of Reflection Coefficient measurements in six port reflectometers
IEEE Transactions on Microwave Theory and Techniques, 2013Co-Authors: Kamil Staszek, Slawomir Gruszczynski, Krzysztof WinczaAbstract:A complete analysis of the influence of six-port reflectometer parameters on the measurement accuracy is presented. A theoretical limit of the Reflection-Coefficient measurement has been investigated and is derived analytically. Moreover, for a set of six-ports reported in the literature, the numerical analysis of magnitude and phase measurement errors in a wide range of Reflection-Coefficient magnitude is presented. Furthermore, the modified six-port reflectometer utilizing a 4 × 4 Butler matrix and featuring scalable circle center distribution is proposed, and its advantage is discussed. The impact of power detectors uncertainty on an arbitrary six-port calibration procedure is presented. The performance of the proposed reflectometer has been verified in a wide frequency range of 2-3 GHz by measurements of a Reflection Coefficient having small magnitude. The obtained results are in agreement with the theoretical predictions, confirming the usefulness of the presented analysis.
T.l. Marzetta - One of the best experts on this subject based on the ideXlab platform.
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Reflection Coefficient (Schur parameter) representation for convex compact sets in the plane
IEEE Transactions on Signal Processing, 2003Co-Authors: T.l. MarzettaAbstract:We obtain a one-to-one relation between the shape and orientation of a convex compact planar set and a complex-valued Reflection Coefficient (Schur (1917) parameter) sequence, such that (1) the Reflection Coefficient magnitudes are less than or equal to one, (2) if any Reflection Coefficient has a magnitude equal to one, then all subsequent Reflection Coefficients are equal to zero, and (3) the first Reflection Coefficient is equal to zero. Three additional independent parameters specify the position of the set in the plane, and the size of the set (specifically its circumference). For a finite duration Reflection Coefficient sequence, if the last nonzero Reflection Coefficient has a magnitude that is less than one, then the boundary of the set is an infinitely differentiable convex curve. The boundary is a convex polygon if and only if the magnitude of the last Reflection Coefficient is equal to one; the number of sides of the polygon is equal to the index of the last Reflection Coefficient. Almost all planar convex compact sets have Reflection Coefficient sequences of infinite duration. Such sets can be accurately approximated with convex compact sets that are generated from relatively small numbers of Reflection Coefficients.
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Reflection Coefficient representation for convex planar sets
Proceedings 1998 International Conference on Image Processing. ICIP98 (Cat. No.98CB36269), 1998Co-Authors: T.l. MarzettaAbstract:We combine certain results from two disparate areas, kinematics and geophysics, to obtain a convenient representation for the class of convex compact planar sets, in terms of a sequence of complex valued Reflection Coefficients. This gives a one-to-one relation between any convex compact planar set S and any set of parameters comprising: a) the coordinates of a reference point in /spl Sscr/, b) the circumference of the set, and c) a complex Reflection Coefficient sequence, {k/sub 1/, k/sub 2/,...}, such that 1) k/sub 1/=0, 2) |k/sub n/|/spl les/1, /spl forall/n, 3) if |k/sub N/|=1 for some N then k/sub n/=0, /spl forall/n>N. For a finite duration Reflection Coefficient sequence, where k/sub n/=0, /spl forall/n>N, if 0
E.l. Holzman - One of the best experts on this subject based on the ideXlab platform.
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Phased-array radiator Reflection Coefficient extraction from computer waveguide simulator data when grating lobes are present
IEEE Transactions on Antennas and Propagation, 2000Co-Authors: E.l. HolzmanAbstract:Commercially available finite-element software that solves Maxwell's equations for arbitrary three-dimensional bounded structures has enabled phase-array radiator designers to perform waveguide simulator modeling of phased-array radiating elements on the computer very efficiently. Published work on waveguide simulator design has concentrated on array performance in the absence of grating lobes, a requirement for many radar applications. For such simulators, the Reflection Coefficient of each propagating mode at the waveguide simulator port gives the radiator Reflection Coefficient at a discrete scan angle. However, the design of limited scan arrays can lead to selection of an array element spacing that allows grating lobes in real space. When a waveguide simulator is modeled on the computer, and a grating lobe is present, the two waveguide modes representing the main lobe and the grating lobe will propagate in the waveguide simulator and they will be coupled together. The simulator port-Reflection Coefficient of either mode is not the true Reflection Coefficient seen by the radiating element. We describe a method for extracting the Reflection Coefficient of the radiating element from the waveguide simulator data when one or more grating lobes are present.
