Signal filter using ceramic resonators - each held between sides of notch in circuit board at its neutral points

摘要

The filter uses ceramic resonators (1..4), each fitting into a rectangular notch (6) formed in one edge of a circuit board (5). The individual resonators (1..4) are held at their resonation neutral points between the opposing sides if the notch (6) either directly, or via V-shaped projections (7) extending into the notch (6) from each side. A number of circuit paths (8) are formed on the surface of the circuit board (5), with the electrode layers of each resonator (1..4) coupled to the ends of respective circuit paths (8) extending up to the side edges of the notches (6) where these contact the resonator (1..4). Pref. the other end of each circuit path (8) widens out to form a terminal connection point (9,9',9") and the conductor paths (8) may be formed by a thin-film or printed circuit technique.