WAVE DIGITAL BIQUADS THAT ARE FREE OF LIMIT CYCLES UNDER ZERO- AND CONSTANT-INPUT CONDITIONS.

It is shown that limit cycles under zero- as well as constant-input conditions can be eliminated in wave digital biquads proposed recently by employing the techniques of magnitude truncation and controlled rounding. A new universal wave digital biquad is derived from the feed-forward RC-active configuration, which realizes simultaneously a lowpass, a highpass, a bandpass, a notch and an allpass transfer function, and which is free of limit cycles under zero- and constant-input conditions. The structure uses four multipliers and two unit-delays and it is quite attractive for VLSI implementation.