Loss sensitivities in singly and doubly terminated filters

The loss of a conventional doubly terminated filter is far less sensitive than the loss of a singly terminated filter to errors in the component values. This property, first pointed out in 1966, has motivated many new high quality RC-active and digital filter design techniques. It is not so widely appreciated, however, that this superiority of the doubly terminated filter also holds for errors in the terminating resistances as well as for errors in the components inside the filter. The nature of these sensitivities in both types of filter is discussed in some detail, and Illustrated by means of a numerical example.