Sensitivity analysis of variable band-pass wave digital filters
Rajni Billa, Subhash Chandra Gupta · International Journal of Electronics · 1976
The paper presents the sensitivity studies of band-pass variable wave digital filters (WDF). A time-domain definition of sensitivity is introduced which is specially suited for higher-order filters specified only in terms of numerous difference equations and is valid for any filter with specified parameters. This definition avoids the problem of evaluating the transfer functions or pole-zero locations in terms of variable parameters. Using this definition, the sensitivity of the WDF is evaluated and compared with a direct form implementation for three different kinds of coefficient approximations. In one of the cases studied, the WDF is about 5 bits better than the direct form. The sensitivity evaluations also indicate possible instability of the filter.