DC BIAS CIRCUIT AND THE RADIO FREQUENCY RECEIVER CIRCUIT USING THE SAME

摘要

The present invention presents a DC bias circuit including a first biasing circuit and a second biasing circuit. The first biasing circuit includes a first biasing transistor and a first biasing resistor for providing a first bias voltage to an output transistor of the mixer circuit. The first biasing transistor and the output transistor are the same type of transistor and have equal channel lengths. The second biasing circuit includes a second biasing transistor and a second biasing resistor for providing a second bias voltage to an input transistor of the common gate amplifier circuit. The second biasing transistor and the input transistor are the same type of transistor and have equal channel lengths. When the input transistor and the output transistor all operate in a saturation region, alternating current signals output from the mixer circuit is unrelated to a threshold voltage of the output transistor.

主权项

1. A DC bias circuit for DC biasing a mixer circuit and a common gate amplifier circuit, the DC bias circuit comprising:
a first biasing circuit, comprising a first biasing transistor and a first biasing resistor, wherein the first biasing transistor and the first biasing resistor provide a first DC bias voltage to an output transistor of the mixer circuit so that the output transistor operates in a saturation region; and wherein the first biasing transistor and the output transistor are the same type of transistor and have equal channel lengths; and a second biasing circuit, comprising a second biasing transistor and a second biasing resistor, wherein the second biasing transistor and the second biasing resistor provide a second DC bias voltage to an input transistor of the common gate amplifier circuit so that the input transistor operates in the saturation region; wherein the second biasing transistor and the input transistor are the same type of transistor and have equal channel lengths; and wherein when the input transistor and the output transistor all operate in the saturation region, a plurality of alternating current signals output from the mixer circuit is unrelated to a threshold voltage of the output transistor, and the alternating current signals is unrelated to a threshold voltage of the input transistor.