1/4 1/4 (1+z -4) - (z -1+z -3)+1.25z -2 (1+z -12)-0.990234375(z -3+z -9)+2.572265625 z -6 1/4 (1+z -12)+0.25(z -3+z -9)+2.453125 z -6 1/4 4 (1+z -18)+2.078125(z -3+z -15)-0.828125 (z -6+z -12)-3.9921875 z -9 1 1-1.546875z -3+z -6 1/2 (1+z -12)+1.484375(z -3+z -9)+2.96875 z -6 (1+z -12)+2.59375(z -3+z -9)+3.987375 z -6 1/4 1/4 1/4 1/4 -4 1-1.609375z -3+z -6 1-1.6875z -3+z -6 -1 -3 (1+z )-0.75(z +z )+1.25z -2 1/4 1-1.8125z -3+z -6 1-2.0625z -3+z -6 (1+z -12)+3.4804687(z -3+z -9)+5.1875z -6 4 -6 -1 -5 -2 -4 (1+z )+2.41015625(z +z )+0.08984375(z +z )-2.82421875z -3 1/4 1+1.984375z -2+z -4 1/2 -2 1/2 1/2 1-0.375z -1+z -2 (1+z -12)+0.21875(z -3+z -9)-2.03125z -6 1/2 1+0.3125z -1+z -2 -4 1+2.1875z -1+z -2 1-0.625z -1+z -2 1/4 4 1/4 1/4 1-1.75z -1+z -2 1/2 1-z -1+z -2 (1+z -4)+3.546875(z -1+z -3)+5.2734375z -2 1/4 1-0.75z -1+z -2 10.0101101 1/2 1-z -1 1-2z -1+z -2 1-1.875z -1+z -2 1-z -3 (a) 0 0 Magnitude (dB) -40 -60 0.8 -80 0.85 0.9 0.95 1 (dB) 0.05 Target ωp = 0.8 rad/π Target δp = ±0.05 -20 -0.05 Target δs = -80 dB -100 -120 Target ωs = 0.74 rad/π -140 -160 0 0.1 0.2 0.3 0.4 0.5 ω /π 0.6 0.7 0.8 0.9 1 Highpass Wideband 121-Tap Filter [53] Optimally-Factored IFIR Cascade Implementation (b) Figure 10. (a) An optimally-factored implementation [46], [47], [57], [58] of the wideband filter specification in Example 3. (b) the magnitude plot for the fig. 10(a) optimally-factored implementation of the wideband filter specification in Example 3. fIrst quArtEr 2018 IEEE cIrcuIts ANd systEMs MAgAzINE 23