how I can determine the frequency of an analog signal?

[kathalebm]

Frequency measurement

I would like to know how I can determine the frequency of an analog signal.

 

[srizbf]

Re: Frequency measurement

i dont know whether it is just for measuring or calculating using a processor.

if just measure:
use a scope. find the period. and measure the freq.
modern dso can display that value also.

if for using a processor to calculate:

method is same.

measure the period between the similar instants.
e.g, use zero cross detector . you know the half period . and calculate
the freq.

if the exact environment is specified somebody will help.

srizbf
1stjune2010

 

[micard]

Frequency measurement

you can perform Fourier analyses and obtain the power spectra.

Then you will know the base frequency of your signal

 

[kathalebm]

Re: Frequency measurement

Am working with 484-pin Actel FPGA, but I do not know how I can implement the zero cross detector. Do you have an idea on this?

 

[kathalebm]

Re: Frequency measurement

Hi All,
I was working with 484-pin Actel FPGA but I realized that its not possible to connect an external signal as clock that can be used to modify the sampling frequency of the ADC. I changed the idea of using that FPGA and now I'm looking for a circuit that can measure the analog signal. I want a circuit that can measure frequency in the region of GHz. If anyone knows then can help me plz.