Laboratory 1 — spectrum of a square wave

Week 5 · report due in two weeks

Aim. Measure the harmonic content of a square wave and compare it with the Fourier series prediction.

Equipment. Function generator, oscilloscope, spectrum analyser, coaxial cables, 50 Ω terminations.

Procedure.

1. Set the generator to 1 kHz square wave, 1 V peak-to-peak.
2. Record the amplitudes of the first five harmonics.
3. Repeat with a 10 kHz square wave and note where the measurement departs from the prediction.
4. Explain the departure: instrument bandwidth, cable loss, or something else.

Report. Two pages: table of measured and predicted amplitudes, one figure, and a short discussion of the discrepancy. Hand in at the office or by email.