| 摘要 |
PURPOSE:To prevent the generation of associated vibration, by cascading outer circumferences of electromechanical vibrators. CONSTITUTION:Of mechanical filters composed of coaxial ceramic 1 and metal vibrator 2 arranged, outer circumference parts of metal vibrators are coupled by several couplers 3. Couplers 3 are connected to several points at intervals of a certain angle. Symmetric flection vibration with nodal circles of metal vibrator 2 has various modes. A main mode used for the mechanical filter is mode (alpha10), and several other associated vibrations are caused. Associated vibrations in modes (alpha01) and (alpha11), having frequencies sufficiently different from that of mode (alpha10), can sufficiently be suppressed by the input-output transformer of the filter. Modes (alpha02) and (alpha03) are close to mode (alpha10). Mode (alpha02) has polarity at every angle of 90 deg., and mode (alpha03) at every angle of 60 deg.. For the purpose, coupler 3 is arranged at each circular measure where those vibrations are suppressed. |
