10 Bodc Plots 214 'l'dde 10.2: Table of values of f ( j w ) , dainping ancl phase Frcyueitry U) w =0 H(yw) 1 10 -=- n w = (1 w>a -20 dB 0" M 1 x-=a 10 Ja a N N 3d (*I LL, Pharc < 0.1tr w < a to about Damping ou 20 dH -23 dB -45' -20 dB/'decarle > 1OCX M -90" = O.1a At this frequency the phase has the value p(.70.1(~,) = arg H(.jO.la) = O.ln ~ arcl,an -= - arctaii0.1 = -6" The magnitude of the fr~quencyresponse first varies significantly from the value at w =- at the cnt-off frequency w = a,ailcl is given by ii t j to u ) ~so , that, it is (hen decaying reciprocal to w hi the doiiblc logaritllrnic representation, because of log IH(ju)l = - log LJ, liirear relationship between log lSS(,jw)I arid log U ) is oblainrtl Incrrasing the