Compact piezoelectric ceramic filter - comprises series oscillators held along junction line of insulated substrate

摘要

A piezo-electric ceramic filter has several ceramic oscillators held at oscillation junction points on an insulated substrate. The oscillators (1, 1a, 1b, 1c, 1d) are formed as series oscillators retained along the junction line. The oscillators can be formed as rectangular plates suspended in slots (10) of the insulated substrate (4) by means of their leads (6) at least two neighbouring positions of the junction line. The electrodes can be galvanically connected to a wiring board (5) installed on the substrate. The wiring board has connecting points, e.g. input terminal (7), output terminal (8) and earth terminal (9). This forms a compact filter insensitive to vibration. It is esp. suitable as an i.f. filter in broadcast receivers.