A digital filter is required to have a cut off frequency  100 Hz  and sampling frequency of  1000 Hz.What is the analog domain cut off frequency?.Assume that BLT Method is used.Select one:628 radian/sec649.84 radian/sec100 radian/sec642.84 radian/sec

To find the analog domain cut off frequency, we can use the bilinear transform (BLT) method.

The BLT method relates the analog frequency to the digital frequency using the formula:

ωa = (2/T) * tan(ωd * T/2)

where ωa is the analog frequency, ωd is the digital frequency, and T is the sampling period.

In this case, the cut off frequency in the digital domain is 100 Hz and the sampling frequency is 1000 Hz. Therefore, ωd = 100 Hz and T = 1/1000 s.

Substituting these values into the formula, we get:

ωa = (2/(1/1000)) * tan(100 * (1/1000) / 2)

Simplifying further:

ωa = 2000 * tan(0.05)

Using a calculator, we find that tan(0.05) is approximately 0.049979.

Therefore:

ωa ≈ 2000 * 0.049979

ωa ≈ 99.958 radian/sec

So, the analog domain cut off frequency is approximately 99.958 radian/sec.

Therefore, the correct answer is 100 radian/sec.