| 摘要 |
PURPOSE:To simplify the constitution of a band pass filter BPF by providing an LC parallel resonance circuit between a junction of two IC series resonance circuits connected in series to each other and its earth and securing connection between inductances of both LC series resonance circuits together with addition of a trap at a point having a higher frequency than a pass band. CONSTITUTION:An LC series resonance circuit consisting of an inductance L1 and a capacitor C1 is connected in series to an LC series resonance circuit consisting of an inductance L2 and a capacitor C2. Then an LC parallel resonance circuit consisting of an inductance L3 and a capacitor C3 is set between the junction of both LC series resonance circuit and an earth E. The connection is secured between inductances L1 and L2 to produce the mutual inductance, and a trap is added at an optional point having a higher frequency than a pass band. Thus the constitution of a BPF can be simplified. |
