![]() The matrix allows for a powerful and scalable linear tool that can be used to isolate and study certain port characteristics in an n-port network. In this format the rows and columns represent the number of ports present. These complex numbers arise from a mathematical representation known as a scattering matrix. On its own, Moku:Lab is capable of measuring S 12 or S 21 of a 2-port system, but not the S 11 and S 22. ![]() Moku:Lab’s FRA is capable of driving a DUT with a swept sine wave into a system’s input port and extracting the amplitude and phase response at a system’s output port. The first number is the output port (emerging) and the second number is the input port (applied) as depicted in this figure below.įor example, S 22 represents the reflected power (magnitude and phase) of the system from port 2 at a certain frequency. Notice that the four S-parameters for this 2-port network have subscripts relating the ports that are under consideration. Below is a figure representing a 2-port DUT network along with all the signal paths captured by S-parameters.įigure 1: S-parameter representation in a 2-port network The beauty of S-parameters is that we can fully understand a DUT by just analyzing the transmitted and reflected signals as described by its S-parameters. This box can contain a multitude of system variables: resistors, filters, integrated circuits, or transmission lines, the details of which are hidden. S-parameter characterization of a Device Under Test (DUT) treats that DUT as a black box with one or more ports, where signals can both enter and exit any port. ![]() Since we care mainly about power gain or loss we will focus on the magnitude as a function of frequency. S-parameters are complex numbers, meaning they have both imaginary and real parts, thus can represent both magnitude and phase. We will visualize transmission line problems and impedance matching with Smith charts. We will be exploring this parameter in depth and showcasing its implementations when analyzing systems and filters at high frequencies using Moku:Lab’s Frequency Response Analyzer. In other words, it helps describe how RF energy propagates through a multi-port network. It is used to describe the reflection/transmission characteristics of a port network system. One useful parameter when designing at high frequencies is the S-parameter, or “Scattering parameter”. This reflection is suboptimal in RF design as it reduces transmission quality and efficiency. Any mismatch in impedance along the transmission lines of an RF system will result in signal reflection. This phenomenon of reflection is analogous to dealing with high frequency signals (hundreds of MHz or GHz) in the RF world. This time, when you shout your voice is reflected by the wall and echoes back at you. Next, imagine doing the same thing, but the hallway is truncated with a wall. The sound travels into the abyss with no discontinuity and eventually just fades into nothingness. Imagine shouting into a long, endless hallway. In this application note, Moku:Lab’s Frequency Response Analyzer is used in conjunction with an RF directional coupler for a complete S-parameter characterization of a two port network. Using the rational function fitting method, you can model backplanes, interconnects, and linear components, and export them as Simulink ® blocks, SPICE netlists, or Verilog ®-A modules for time-domain simulation.Transmission and reflection signal information is vital when designing and validating RF components and systems. The RF Budget Analyzer app lets you analyze transceiver chains in terms of noise, power, and nonlinearity and generate RF Blockset™ models for circuit envelope simulation. You can also de-embed, check, and enforce passivity, and compute group and phase delay. You can analyze S-parameters convert among S, Y, Z, T, and other network parameters and visualize RF data using rectangular and polar plots and Smith ® Charts. The toolbox provides functions for analyzing, manipulating, and visualizing RF data. Components can be specified using measurement data such as Touchstone files, network parameters, or physical properties. RF Toolbox lets you build networks of RF components such as filters, transmission lines, matching networks, amplifiers, and mixers. ![]() The toolbox supports wireless communications, radar, and signal integrity applications. RF Toolbox™ provides functions, objects, and apps for designing, modeling, analyzing, and visualizing networks of radio frequency (RF) components.
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