Rf parameters and rf measurement equipment support getting started. For multilayer pcb s the stackup wizard button would be used to define the number of copper layers, cores and prepreg s. Sparameter techniques another important advantage of s parameters stems from the fact that traveling waves, unlike terminal voltages and currents, do not vary in magnitude at points along a lossless transmission line. Figure 3 shows examples of typical forward s parameter plots.
S21 or s12 represents power coupled from one port to another, a useful parameter for determining coupled power from one antenna to another. While y parameters utilize input and output voltages and currents to characterize the operation of a twoport network, s parameters use normalized incident and reflected. Ansys high frequency structure simulator hfss tutorial. S parameters depend upon the network and the characteristic impedances of the source and load used to measure it, and the frequency measured at. Part i discusses the fundamental background needed to understand the concept of sparameters. Sparameters are important in microwave design because they. Scattering parameters or s parameters the elements of a scattering matrix or s matrix describe the electrical behavior of linear electrical networks when undergoing various steady state stimuli by electrical signals. It might help for you to have the program open while you read this tutorial. Vna vector network analyzer is used to measure s parameters of active and passive microwave components. Flowjo basic tutorial flowjo is software for the analysis of flow cytometry data. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext.
Rf basics, rf for nonrf engineers dag grini program manager, low power wireless. The s parameters for a twoport network are defined using the reflected or emanating waves, b1 and b2,as the dependent variables, and the incident waves, a1and a2, as the independent variables figure 3. Sparameters depend upon the network and the characteristic impedances of the source and load used to measure it, and the frequency measured at. The next screen is for configuration of drill spans.
Sep 28, 2015 for the love of physics walter lewin may 16, 2011 duration. This white paper will create a strong foundation of test and measurement science related to sparameter measurements and analysis. S zl nov 06, 2014 the smatrix for an nport network contains n2 coefficients sparameters, each one representing a possible inputoutput path. Problem description getting started create the 3d model analysis setup plot s parameters vs. This report develops the scattering parameter concept and defines the sparameters of a generalized linear two port network. This tutorial will quickly introduce you to flowjo using an example experiment, where a fitc anticd8 reagent is titrated to determine the most economical concentration for staining in future experiments. Cable television integrated circuits are usually designed to interface with 75. The background needed for the study of sparameters consists of two fundamental topics. Sparameter techniques hp application note 951 hp memory. By multiport network, we could be referring to, for example, a cable or a microstrip line. Again, for our proposed 2layer board the only possibility is thruhole so there is no action required. Following a demonstration of the strategy used to convert sparameters to conventional two port parameters, it addresses the utility of sparameters in the analysis of active networks. This tutorial explains how to measure s parameters without a fancy vector network analyzer vna. Ansys high frequency structure simulator hfss tutorial august 16, 2018 1.
Pdf containing the equations used to convert fluidic units to equivalent electrical units for use with ltspice. For high frequencies, it is convenient to describe a given network in terms of wavesrather than voltages or currents. Sparameters have magnitude and phase typically, magnitude is measured in db, phase is measured in degrees. The wanted signal is corrupted by the phase noise tail of the transmitter.
S parameters come in a matrix, with the number of rows and columns equal to the number of ports. August 16, 2018 2 agenda overview of hfss capabilities and key features. S parameters allow highfrequency verification of rf switch models. Thus s 11 refers to the ratio of the amplitude of the signal that reflects from port.
The toolbox of established matrix mathematics is directly applicable to the matrices that are the equivalent of the port equations of the parameter sets. The sparameter of a 1port device is referred to as the refl ection coeffi cient in other words, sparameters are the expansion of the refl ection coeffi cient to more than two ports. For microwave integrated circuits mics planar transmission lines such as the microstrip line have. Active components include transistors, amplifiers etc. At high rf and microwave frequencies direct measurement of y, z, or h parameters is difficult due to. S 11 is the input reflection coefficient with the output port terminated by a matched load.
All you need are a scope and function generator capable of measuring and producing frequencies in the desired range. Scattering parameters consider a twoport device with a scattering matrix at some specific frequency. The s parameters can be measured by embedding the twoport network the deviceundertest, or, dut in a transmission line whose ends are connected to a network analyzer. Useful matrix operations certain simple matrix operations are useful in manipulating and evaluating sparameter matrices. Eee 194 rf sparameter matrices 5 we find that it is simply s. The average power can be obtained by taking one half of the real component of the complex power. Its important to realize that although we associate s parameters with high. I will write many more tutorials explaining some of the program s insandouts, my favorite variations and how to get particular results. For the s parameter subscripts ij, j is the port that is excited the input port, and i is the output port.
Part ii to appear in the next issue of in compliance magazine explains the s parameters use in emc measurements and testing the background needed for the study of s parameters consists of two fundamental topics. Ansys hfss tutorial simulate and analyze an example of trace and via tianjian lu 02014 tianjian lu ece 546. Part i discusses the fundamental background needed to understand the concept of s parameters. A11 the s parameter is a ratio, so it is basically a nondimensional parameter.
When these s parameters are aligned in a matrix form a11, it is referred to as an s matrix scattering matrix. Each part of the puzzle has been created the pieces now fit together seamlessly. A11 the s parameter is a ratio, so it is basically a nondimensional parameter no unit. The business entity formerly known as hp eesof is now part of agilent technologies and is known as agilent eesof. Either way, simulation data results in an s matrix in the data set for the specified range and points. Sparameter simulation feburary 2011 advanced design. The measurement is direct and only involves measurement of relative quantities such as the swr or the location of the. Forward s parameters can be measured by driving the input and terminating the output. Agilent deembedding and embedding sparameter networks. This is the sort of practical application in which sparameters. This is part 1, in which well discuss basic commands, shortcuts and the translation editor tool found in apophysis.
While yparameters utilize input and output voltages and currents to characterize the operation of a twoport network, s parameters use normalized incident and reflected. X parameters are a generalization of s parameters and are used for characterizing the amplitudes and relative phase of harmonics generated by nonlinear components under large input power levels. For the s parameter s ij the j subscript stands for the port that is excited the input port, and the i subscript is for the output port. Here, scattering refers to the way traveling currents or voltages are affected when they meet a discontinuity in a. Hybrid parameters also known as h parameters are known as hybrid parameters as they use z parameters, y parameters, voltage ratio, and current ratios to represent the relationship between voltage and current in a two port network h parameters are useful in describing the inputoutput characteristics of circuits where it is hard to measure z or y parameters such as a transistor.
S parameter measurements basics for high speed digital engineers frequency dependent effects are becoming more prominent with the increasing data rates of digital systems. S scattering parameters are used to characterize electrical networks using matched impedances. Part ii to appear in the next issue of in compliance magazine explains the sparameters use in emc measurements and testing. Scattering parameters rf and microwave circuits university of. Sparameter measurements basics for high speed digital engineers frequency dependent effects are becoming more prominent with the increasing data rates of digital systems. The matrix elements s11,s12,s21,s22 are referred to as the scattering parameters or the sparameters. In their most basic sense, s parameters refer to the ratio of voltage out versus voltage in. S parameters zss 11 s 21 s 12, and s 22 zs 11, and s 22 the z 0 50 ohms. For the love of physics walter lewin may 16, 2011 duration. S parameters are easier to measure at high frequency.
Differential and mixed mode s parameters can also be obtained from corresponding tdr oscilloscope data. Sparameter that is incident at port jdetected at port i is described as. While passive components include attenuators, cables, isolators, couplers, filters, circulators, bridges, antennas, transformers, duplexers, diplexers, triplexers, switches etc. The parameters are useful for several branches of electrical engineering, including electronics, communication systems design. For microwave integrated circuits mics planar transmission lines such as the microstrip line have become very important. After that the solutions are posted and there will be no credit. S parameter that is incident at port jdetected at port i is described as. Part ii to appear in the next issue of in compliance magazine explains the s parameters use in emc measurements and testing. S11 is known as the return loss, or how much power is reflected from the transmitter to an antenna. Sparameters allow highfrequency verification of rf switch. This means that scattering parameters can be measured on a device located at some distance from the. Learn practical sparameter design techniques for rf and microwave applications to assist continued development of new high frequency circuit designs. X parameters are also referred to as the parameters of the polyharmonic distortion phd nonlinear behavioral model.
Figure 1 shows that for port 1, the s 11 parameter reveals the forward. S parameters in fact, all the parameter sets benefit from the matrix toolbox. The sparameter scattering parameter expresses device. Enable browser cookies for improved site capabilities and performance. The content of the s parameter design seminaris as follows. An antenna radiates power, but the direction in which it radiates matters much. A typical network analyzer can measure s parameters over a large frequency range. Differential circuit topology is commonlyused as an implementation method, with the goal of enhancing the data carrying capable of the physical layer. Functions reference format in the subsequent two chapters, each function is described using the following structure. Network characterization sparameters are basically a means for characterizing nport networks.
Ansys high frequency structure simulator hfss tutorial august 16, 2018 1 mark jones pacific northwest national laboratory 82118. Sparameters are a useful method for representing a circuit as a black box. X parameters are the mathematically correct superset of s parameters, applicable to both largesignal and smallsignal conditions, for linear and nonlinear components. S parameter simulation controller default sweep variable freq sweep plan can also be used see next slide. Tdt results in insertion loss s21, tdr in return loss s11. The series resistance of the line increases as the f also note. Sparameter simulation controller default sweep variable freq sweep plan can also be used see next slide. For a more detailed defi nition, please refer to the textbooks 1 to 5.
The network could be a coax cable, passive antenna, active amplifier, microwave filter, etc. According to the standard definition, the ratio of maximum radiation intensity of the subject antenna to the radiation intensity of an isotropic or reference antenna, radiating the same total power is called the directivity. Spectre circuit simulator reference september 2003 2 product version 5. The measurement is direct and only involves measurement of relative quantities such as the swr or the. Phase noise is a key parameter for transceivers cc1020. When measuring s parameters on an active circuit you must include all of the biasing components as part of the two port circuit. S parameters, on the other hand, are usually measured with the device imbedded between a 50. The general equations for these waves as a function of the s parameters is shown below.
Say that the transmission line connected to port 2 of this. S scattering parameters scattering, or s, parameters are another extremely useful design aid that most manufacturers provide for their higher frequency transistors. Scattering parameters or s parameters the elements of a scattering matrix or s matrix describe the electrical behavior of linear electrical networks when undergoing various steady state stimuli by electrical signals the parameters are useful for several branches of electrical engineering, including electronics, communication systems design, and especially for microwave engineering. S parameters are usually displayed in a matrix format, with the number of rows and columns equal to the number of ports. Forward sparameters can be measured by driving the input and terminating the output.
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