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5. PRODUCT OF 2 SINUSOIDAL SIGNALS HAVING
FREQUENCIES OF 10 KHZ AND 80 KHZ
5.1. DISPLAY OF THE PRODUCT SIGNAL WITH DELAYED TIME BASE
We use the cursors to measure the frequency of the 80 kHz product signal (remark: the hardware frequency counter indicates
40.0 kHz because the triggering level is adjusted on the peaks of the product signal).
Configuration of the oscilloscope:
Time base range M = 1.0 ms
Memory Depth = Normal
Acquisition : Samples
Display : Vectors
Then the low frequency of the product signal, 10 kHz:
The FFT of the product signal shows two spectral components having the same amplitude, one at the F = 90 kHz sum frequency
(10 kHz + 80 kHz) and the other at the F = 70 kHz difference frequency (80 kHz - 10 kHz).
