Nyquist App vs Smith Chart Touch

In this app, you can practice the Nyquist stability criterion. With the Nyquist stability criterion, you can determine the stability of the closed loop based on the frequency response of the open loop, without explicitly calculating the poles of the closed loop. This app was developed at the Institute for Systems Theory and Automatic Control of the University of Stuttgart and accompanies the course "Einführung in die Regelungstechnik" at the University of Stuttgart. Nevertheless, the content and tasks are self-contained, and we encourage all interested in this topic to play with the app and practice the Nyquist stability criterion.

Smith Chart Touch is the essential Smith chart tool for RF and microwave engineers, students, and hobbyists. Design and analyze impedance matching networks interactively — directly on your device. Build your circuit by adding components one by one and watch the matching path update on the Smith chart in real time. Tap any component to edit its value, drag on the chart to tune it visually, or type exact numbers — the chart and inputs stay in sync at all times. Circuit Components: Series resistor, inductor, and capacitor Parallel resistor, inductor, and capacitor Transmission line (length in wavelengths) Open and short stub (parallel) Smith Chart Modes: Impedance (Z) chart Admittance (Y) chart Immittance (ZY) combined chart Key Features: Fully interactive: drag on the chart or type values — both update each other instantly Multiple projects with custom names and colors per circuit path Example circuits included to get started quickly Clean, dark UI optimized for readability Who is it for? Smith Chart Touch is built for electrical engineers working with RF circuits, antenna design, amplifier matching, and transmission line theory. It is also a great learning companion for students studying microwave engineering.