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4. PRODUCT OF 2 SINE WAVES HAVING FREQUENCIES
OF 100 KHZ AND 800 KHZ
4.1. DISPLAY OF THE PRODUCT SIGNAL WITH DELAYED TIME BASE
We use the cursors to measure the frequency of the product signal, F = 800 kHz (Remark: the hardware frequency counter indicates 399.996 kHz
because the triggering level is adjusted on the peaks of the product signal);
Configuration of the oscilloscope:
Time base range M = 100 µs
Memory Depth = Normal
Acquisition : Samples
Display : Vectors
Then the low frequency of the product signal F = 100 kHz
The FFT of the product signal shows spikes at the sum frequency (900 kHz = 800 kHz + 100 kHz) and at the difference frequency
(700 kHz = 800 kHz - 100 kHz)
Using a bandpass filter centred on 700 kHz, then on 900 kHz, we are going to be able to isolate these 2 spectral components.
