Determine the alias frequency that results from sampling fi

Determine the alias frequency that results from sampling f_i at sample rate f_g. f_1 = 60 Hz; f_s = 90 Hz f_1 = 16 Hz; f_s = 8 Hz f_1 = 10 Hz; f_s = 90 Hz

Solution

Aliased frequency is the absolute difference between the actual signal frequency and the nearest integer multiple of the sampling frequency

Aliased frequency = |(n*fs)-f)|

a) |( 1 * 90) - 60 | = 30 Hz

b) | (2 * 8) - 16 | = 0 Hz

c)| (1 * 90) - 10 | = 80 Hz