| 摘要 |
PURPOSE: To realize the filter having a required attenuation characteristic in a narrow space by laminating MCFs(monolithic crystal filter) and piezoelectric oscillators in many stages to constitute the filter. CONSTITUTION: The signal inputted to a terminating electrode 120a of an MCF 101 successively oscillates split electrodes 105a and 106a, and the signal from the electrode 106a is grounded by external electrodes 127a, 127b, and 130, a chip capacitor 109, and a connection external electrode 131. Meanwhile, the signal passes electrodes 127a and 127b and flows to a terminating electrode 121b, split electrodes 106b and 105b, and a terminating electrode 120b on a piezoelectric substrate 104 of the other MCF 102 and is finally outputted to the outside from external electrodes 128a and 128b. By this constitution, the surface mounted type multistage connection filter is miniaturized. Parts just above and just below leading-out electrodes which connect respective stages are constituted except on the same size face, and propagation of unnecessary signals is prevented through floating capacities between inter-stage terminals of each device to prevent the occurrence of spurious and the degradation of attenuation characteristics. |
