...) (17b) (17c) f is central frequency of digital filter in In bilinear transformation, if � � is small around the 0 sin� �t Q � � �t 0 0 q . (20) Substituting (20) into (17) and using (19), we can get =-=[16]-=- ��T a � 2 � ��T 0 (21a) 4cos �0T b � � 2 � ��T 1 (22b) 2 � ��T b � 2 � ��T 2 (22c) Let f f � � fT ( F is sampling frequency) which is s Fs a normalized frequency of called digital frequency, then �T ...