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Re: Square wave excitation

> As to a different query about other harmonics in a square wave, such 
> a signal will contain the primary frequency and odd harmonics. That 
> is, a 1 KHz wave will also contain 3KHz, 5KHz, 7KHz, and so on. 
> Fortunately, the magnitude of each sucessive harmonic is less than 
> the previous one, with the largest percentage being that of the 
> primary frequency.

Actually, depending on the actual waveform (duty cycle, waveshape, 
etc...), you could have a fairly complicated Fourier spectrum, not 
necessarily just the odd harmonics.  What I was wondering was 
whether the abundance of harmonics would interfere with the tuning 
process.  Since you would see lots of "mini-resonances" at nominal 
oscillator frequencies lower than the primary resonant frequency as the 
harmonics present in the square wave come into resonance, would the 
fundamental resonance still be clearly visible over and above all the 
harmonic resonances?  I imagine it would work, but there would just be 
a lot of smaller tuning dips before you hit the big dip at the fundamental 
frequency.  Any practical experience with this (Chip?)?


Steven Roys (sroys-at-radiology.ab.umd.edu)