ABSTRACT
The wave active filter (WAF) design method is an alternative approach to the simulation of resistively terminated LC ladder filters. The initially proposed WAFs employed a large number of operational amplifiers (opamp), but later developments resulted in more economical structures employing one opamp per storage element. These canonic structures are very similar to the structures of generalized impedance converters filters but, in some cases, they may use two opamps fewer than the latter. The sensitivity of WAFs is low, as low as the sensitivity of the other ladder simulation methods. Also, WAFs can be easily compensated in order to improve their useful frequency range. Another important feature of these active filters is that they provide two signal outputs that are power complementary. The development of WAFs was followed by the introduction of the linear transformation active filters which work on the same principles.
