| 摘要 |
PURPOSE:To prevent central frequency from variation even if band width is changed by connecting three stages of inverted L-type impedance circuits in series and defining the size of a reactance element. CONSTITUTION:An input signal voltage V1 is divided by the inverted L-type circuit consisting of resistors R1, R2. Consequently, the influence exerted to the variation of the level of internal resistance included in a signal source is removed. A frequency characteristic is applied to the voltage generated in the resistor R2 in an inverted L-type circuit consisting of a capacitor C1 and a coil L1. Said circuit is a series resonance circuit. Since the size of the resistor R2 exerts an influence to Q, the band width can be easily changed by changing the resistance R2. The voltage generated in the coil L1 is applied to an inverted L-type circuit consisting of a coil L2 and a resistor R3. If the reactance of the coil L2 is made sufficiently larger than the value of the resistor R3, said circuit is actuated as an impedance converting circuit, reducing output impedance and forming stable impedance for a transmission line. |
