Independent RF measurements
Investigate unknown components and circuits by examining their full frequency response, R, X and the Smith chart. For an antenna, compare resonance with minimum SWR and investigate whether an inductor or capacitor can improve a reactive load match to 50 ohms.
Practical examples also include coaxial cables, passive networks, common-mode chokes and a 1:49 transformer. The aim is not simply to produce a graph, but to choose a measurement strategy, assess the result and justify your conclusion technically.
View it along the transmission line In the interactive explanation of reflection, phase and S11 you can see how the measurement plane, electrical cable length and forward and reflected waves are related.
AntennasMatchingCoaxCommon-mode chokes
After this module you can
- choose an appropriate measurement strategy independently
- investigate unknown loads systematically
- assess an antenna using S11, impedance and SWR
- match a reactive load towards 50 + j0 ohms
- investigate electrical cable length and velocity factor
- assess the frequency-dependent behaviour of a common-mode choke