| 摘要 |
PURPOSE:To attain low distortion at a large amplitude by connecting a coil bypassing an envelope frequency component in parallel with a resistor for preventing the oscillation of a gate bias circuit of an amplifier using GaAs FET. CONSTITUTION:A resistive element 1 is a resistor R giving a small resistance at a microwave frequency band and a large resistance at an envelope frequency band (near 100MHz) lower than the microwave frequency band with respect to a reactive element 3. A capacitive element 2 is a capacitor C which blocks a frequency component near DC. The reactive element 3 is a coil L giving a large impedance at the microwave frequency band and giving a small impedance at the envelope frequency band with respect to the resistance R. Thus, the microwave component of an input signal prevents the oscillation of the FET depending on the resistor R and the capacitor C and the effect by the envelope component on the gate voltage is excluded because the resistor R is bypassed by the coil L.
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