The Design of Active Distributed Filters

In a recent book, P. M. Chirlian covers the main filter synthesis techniques using distributed resistance-capacitance networks.1 This paper takes a more practical design-oriented approach. Consistent with the original terminology of Wyndrum, 2 we call the uniform distributed EC network URC. The aim here is to design active distributed filters with minimal circuit element complexity. We consider the two basic types of URC shown in Figure 1, the single URC, and the common ground high-pass double URC. The low-pass filters are synthesized with a single URC and a Linvill realization3 and the high-pass filters by a common ground high-pass double URC and a Yanagisawa realization.4 605 606 T H E BELL SYSTEM TECHNICAL JOURNAL, M A Y - J U N E 1068 r0L AA/V © (a) CQL © © rnL. CNL :r0L © (b) Fig. 1 -- The circuit symbols for (a) the single D.C.R. and (b) the cross-connected double D.C.R.