Fourier-Reihe — Rechteckschwingung
A square wave can be built entirely from sine waves, which seems unlikely until you watch it happen. This simulation adds harmonics one at a time and the flat tops emerge from the accumulating curves.
So benutzt du diese Simulation
- Add harmonics one at a time
- Adjust individual harmonic amplitudes
- Compare the sum with the ideal square wave
Worauf du achten solltest
- Only odd harmonics contribute to a square wave
- The approximation improves quickly at first, then very slowly
- The overshoot at each edge never disappears, only narrows
Die Physik dahinter
Fourier's theorem states that any periodic waveform is a sum of sinusoids at multiples of the fundamental frequency. A square wave needs only the odd harmonics, with amplitudes falling as 1/n. No finite number of terms is ever exact — an overshoot near each edge, the Gibbs phenomenon, persists no matter how many harmonics are added.