Convert digital filter to transfer function
[num,den] = tf(d)
Design a 6th-order highpass FIR filter with a passband frequency of 75 kHz and a passband ripple of 0.2 dB. Specify a sample rate of 200 kHz. Compute the coefficients of the equivalent transfer function.
hpFilt = designfilt('highpassiir','FilterOrder',6, ... 'PassbandFrequency',75e3,'PassbandRipple',0.2, ... 'SampleRate',200e3); [b,a] = tf(hpFilt)
b = 0.0003 -0.0019 0.0048 -0.0064 0.0048 -0.0019 0.0003
a = 1.0000 4.0580 7.5656 8.1243 5.2561 1.9348 0.3164
num— Numerator coefficients
Numerator coefficients, returned as a row vector.
den— Denominator coefficients
Denominator coefficients, returned as a row vector.