| 摘要 |
PURPOSE:To improve the C/N of the oscillator by connecting a bias voltage impression resistor to an oscillation transistor (TR) via a wire line being a component of a distributed constant type lowpass filter cutting off the band of the oscillating frequency. CONSTITUTION:The combined resistance of resistors R1, R2 when viewed from the TR shown an apparently high value because the low-pass filters 1, 2 are inserted. Similarly, the impedance as to a resistor R3 is apparently high because the impedance of the filter 3 is added. The apparent impedance of the bias resistor is increased without changing the actual bias point of the oscillation TR to reduce the effect of the bias resistor onto the oscillation resistor. Thus, the deterioration in the Q due to the oscillation load is prevented. Moreover, noise from the power supply is eliminated by the low-pass filter to improve the C/N ratio of the oscillator.
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