Practical Filter Design Part 9

PRACTICAL FILTER DESIGN PART 9 by H. Baggott Following last month"s discussion of Chebishev filters with a ripple of 0.1 dB in the pass band, this month"s article deals with Chebishev networks with a 0.5 dB ripple. These have an even steeper cut-off profile than the 0.1 dB types but, as explained last month, the ringing becomes more pronounced. As in previous articles, five tables are given that contain all the information for the calculation of Chebishev filters with a 0.5 dB ripple in the pass band. As was the case with Table 11, Table 15 can not be used for the computation of an even-order section with equal input and output impedances. For It sections, the table is valid for a ratio of 2:1, whereas for T sec- tions the ratio is 1:2. It all depends on which resistance is used as a reference. nCl L1 2 0.1564 0,3347 3 0.2966 0.2038 4 0.1345 0.4329 5 0.2876 0.2073 6 0.1321 0.4304 7 0.2848 0.2063 8 0.1313 0.4284 0.02589 0.2056 10 0.1309 0.4273 LI Cl L OM even order C2 L2 L(;) LI MI...