Broadband active inductor with high Q value

Abstract

The invention provides a broadband active inductor with a high Q value. The active inductor comprises a first trsanscondutance amplifier, a second trsanscondutance amplifier, an active feedback resistor, a variable capacitor, a first current source, a second current source, and a shunting branch. The two trsanscondutance amplifiers are connected end to end so as to form a gyrator. By means of the gyrator, the input capacitance of the first trsanscondutance amplifier gyrates to be equivalent inductance. The first current source supplies current to the second trsanscondutance amplifier. The second current source supplies current to the first trsanscondutance amplifier. A voltage-modulated composite transistor with common-emitter and common-base structure is applied to the negative-trsanscondutance amplifier so that the output impedance of the amplifier is increased, thereby reducing zero point frequency and widening a bandwidth. The active feedback resistor and the variable capacitor improve a quality factor Q, an equivalent inductance value, and the adjustability of the quality factor Q and the equivalent inductance value. By means of the coordinated adjustment of the gate voltage of each transistor and the capacitance value of the variable capacitor, the active inductor achieves a broad band, a high Q value, and the adjustability of the bandwidth and the Q value.

Description

technical field

[0001] The invention relates to the technical field of radio frequency integrated circuits, in particular to a wide-band, high-Q active inductor. Background technique

[0002] Inductors are important components in radio frequency integrated circuits, and are widely used in various radio frequency circuits such as filters, bandpass filters, and low noise amplifiers. Usually, on-chip passive spiral inductors are used in these circuit designs, but they have low Q value, low self-resonant frequency, large area, high manufacturing cost, unfavorable integration, and non-tunable Q value and inductance value. and other defects. For this reason, it is proposed to use active devices to synthesize active inductors to replace spiral inductors to solve these problems.

[0003] Active inductors are synthesized with small-sized transistors, so the size of active inductors is relatively small, and can be reduced correspondingly with the reduction of transistor size, which ...

Images