Classroom design demonstrations for complex IIR filters

An environment for exceptionally fast design of FIR and IIR filters by pushbutton and easy drag-and-drop manipulations is described. Filter gain and phase credentials are immediately available to the designer, along with the facility to simply sketch the desired filter characteristics. The design flow for a specimen complex FIR and IIR realization of an arbitrary combination of gain and group delay is presented in detail, and a subsequent phase compensation filter is also shown. A varied selection of other design examples emphasizes the flexibility and abundance of choice afforded the user.