Spectrum analysis question

Thread Starter

drao

Joined Mar 11, 2012
16
For fill factor=1/2 , periodic rectangular signal,i have to calculate Ak/A1 (db), Ak is the harmonic of order k of the signal.
Ak/A1=1/k when k is odd and 0 when k us even ,And i have the following formula in my textbook:
Ak/A1(db)=20lg(Ak/A1)=nk-n1=nk because n1=0 but what is nk when Ak/A1=0???We also set n1=0 from spectrum analyzer when we measured the signal.
Im very confused about this.
 

Thread Starter

drao

Joined Mar 11, 2012
16
it is 0 becauyse ak/a1=1/k* (sin(kpi/2))/sin(pi/2) and Ak with k even are all 0.This happens when the signal is periodic rectangular and the fill factor is 1/2.
I know, that one is easy, but the others :D.
 
Last edited:

Papabravo

Joined Feb 24, 2006
21,160
it is 0 becauyse ak/a1=1/k* (sin(kpi/2))/sin(pi/2) and Ak with k even are all 0.This happens when the signal is periodic rectangular and the fill factor is 1/2.
I know, that one is easy, but the others :D.
So tell me what 1/k is equal to for k=1?
Now tell me what the log(1) is equal to.
 
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