# Impedance and Transmission

#### S-parameters, reflection/transmission loss calculators and electronic Smith charts.

## 3D Smith Chart

*Andrei A. Muller (PhD), Alin Moldoveanu (PhD), Victor Asavei (PhD), Cristian Fleischer*

The 3D Smith Chart is the first commercially available software tool that enables new capabilities for RF/microwave designers that were not available using the original Smith chart introduced in 1939. First proposed in 2011, the 3D Smith Chart can represent both active and passive microwave circuits on a spherical plot. Using the mathematical concept of the Riemann sphere, the extended reflection coefficient plane is transformed into the surface of the unit sphere. Since the 3D Smith Chart compiles the whole complex plane, all possible loads can be plotted on the chart, which is not possible on the traditional Smith chart. Lossy lines with complex characteristic impedances can also be represented.

Purchase Required

## AppCAD Design Assistant for Microsoft Windows

*Avago Technologies*

AppCAD is a free Design Assistant Tool for Microsoft Windows

- S-Parameter Analysis and Plotting
- Active Circuit Bias Design
- Cascade Noise and IP3 Analysis
- Transmission Line Analysis
- Signals and Systems
- Complex Math Engineering Calculator

Free Download

## Microwave Impedance Calculator

*Rogers Corporation*

This software is intended to assist with microwave circuit design in predicting the impedance of a circuit made with Rogers High Frequency circuit materials. The software also has some capabilities for predicting transmission line losses as well. The user will select the circuit materials and the circuit construction, after which the software will determine the predicted impedance and other electrical information.

The calculator uses well known closed form equations to determine impedance and loss of a given circuit model. The loss calculation is divided into conductor loss and dielectric loss. With specific circuit designs, the calculator also predicts other properties such as wavelength in the circuit, skin depth and thermal rise above ambient.

Free (Requires Registration)

## Reflectometer Calculator

*MDL*

The Reflectometer Calculator allows engineers to input any one of three known values, (Reflection Coefficient (p), VSWR or Return Loss), to quickly convert to the other unknown values. This tool allows the user to put their System or Component’s performance in perspective. Users can quickly convert to numbers they are comfortable using to determine the System or Component’s RF efficiency. The calculator will even provide engineers with a window of uncertainty for measurements taken with less than perfect systems (Coupler Directivity).

Free

## RSplot

*RS Microwave Company*

RSplot simulator plots and analyses S-parameter files. It is a simple to use application that does not require installation (application is in exe form). RSplot is suitable to plot multiport S-parameter files in rectangular formats.

Free Download

## Smith Chart Matching Web App

*Besser Associates*

Use this handy Smith Chart web app to create matching networks. Easiest tool to use: drag elements right on the chart! Supports multiple frequencies, transmission line elements, etc.

Free Online (Registration Recommended)

## SParamViewer

*Teledyne Lecroy*

SParamViewer is a tool for plotting S-parameters

Features

- Reads standard Touchstone format S-parameter files
- Zoom in for more detail
- Copy and Paste S-parameter data as images, text or Microsoft Excel® format

Free Download

## Z-S-Y-A Parameter Conversion Calculator

*Daycounter, Inc*

This calculator converts between Z-, Y- and S-parameters. S-parameters are a function of the characteristic impedance. All impedances are expressed in rectangular form (R+Xj).

Free Online

## VSWR/Return Loss Calculator

*Pasternack*

Pasternack's VSWR/Return Loss Calculator finds VSWR, Return Loss, Mismatch Loss, and the Reflection Coefficient given any one of the listed input types.

Free Online

## The Smith Chart

#### Pegasus Technologies

This site comprises a comprehensive array of tutorials and related tools, including explanations, examples, references and charting applications.

Free