Some uses of piezo-electric lead titanate zirconate

The use of a piezo-electric ceramic, lead titanate zirconate, in frequency-sensitive networks is examined. The design procedure for ladder filters is outlined; band-pass filters with pass bands between 2 and 20% with a pole of attenuation on either or both sides of the pass band are possible, using materials at present available, within the frequency range 50¿500 kc/s. Within this range, 3-terminal devices (transformers) can be designed which are suitable for interstage coupling in transistor circuits. The elimination of spurious pass bands in these transformers is discussed.