Signal frequency bandwidth limitation, fast pulse shaping,separation between telecommunications signals, and suppressionof unwanted carrier and disturbance frequencies areamong the most important jobs of filter circuits. Whileactive filters with operational amplifiers and switched capacitorfilters are used for lower frequency applications,passive filter versions dominate the application spectrum atfrequencies above 5MHz. Now, however, a new active filterdesign has been developed that makes use of the open looppole and delay time of an operational amplifier. The filtercircuits consist of OPA660s, which provide the necessarybandwidth and allow access to the first open-loop pole andinternal amplifier delay time.