| 摘要 |
PURPOSE:To make the resonance frequency of a resonance circuit variable so that various frequency bands can be set with one semiconductor device by constituting the resonance circuit of a capacitor, inductor and FET whose source and drain are connected in parallel with the inductor. CONSTITUTION:A peaking circuit is constituted of a capacitor 4, inductor 3, and FET 5 which is connected in parallel with the inductor 3. Since the capacity between the source and drain of the FET 5 is variable due to a gate bias, the resonance frequency of the peaking circuit can be changed by changing the gate bias. Accordingly, the frequency band of a negative feedback amplifier can also be changed by changing the gate bias only without changing the parts constituting the circuit. Moreover, since the fluctuation, etc., of the characteristics between each semiconductor device can be eliminated due to the variable resonance frequency, a semiconductor device always having stable characteristics can be obtained. |
