Simple FIR Digital Filters Thus, the gain G() at @=@ is approximately 3 db less than the gain at o=0 As a result, a is called the 3-dB cutoff frequency To determine the value of o we set o(e)2=cos(00/2)=2 which yields o=兀 8 Copyright C 2001, S K. MitraCopyright © 2001, S. K. Mitra 8 Simple FIR Digital Filters • Thus, the gain G(w) at is approximately 3 dB less than the gain at w = 0 • As a result, is called the 3-dB cutoff frequency • To determine the value of we set which yields w= wc wc wc wc = p/ 2 2 2 2 1 0 | ( )| = cos (w / 2) = w c j c H e