Transistor Synthetic Inductor

Abstract

The invention provides a transistor synthesized inductor which comprises a direct-current blocking capacitor, a first trans-conductance amplifier, a second trans-conductance amplifier, a feedback transistor, a first current mirror and a second current mirror. The two trans-conductance amplifiers are respectively a positive trans-conductance amplifier and a negative trans-conductance amplifier and are connected in a crossed mode to form a gyrator, the gyrator gyrates an input capacitor of the second trans-conductance amplifier into an equivalent inductor. A current mirror feedback ring formed by the two current mirrors and the feedback transistor is connected between the input ends of the two trans-conductance amplifiers in a bridging mode and used for decreasing quality factor Q-value change caused by change of input signal amplitude. When the amplitude of an input signal of the transistor synthesized inductor changes, a Q-value is basically kept constant. The transistor synthesized inductor having the constant Q-value is used in a voltage control (current control) oscillator, and phase noise of the oscillator can be reduced.

Description

technical field [0001] The invention relates to the fields of radio frequency devices and integrated circuits, in particular to a transistor synthesis inductance. Background technique [0002] Inductors are one of the commonly used components in radio frequency integrated circuit (RFIC) designs. Since the transistor synthesis inductor does not use a metal layer that occupies a large area, the chip area is small, the inductance value is adjustable, the quality factor Q value is high and adjustable, and the production cost is low. Transistor synthetic inductance replaces the spiral inductance in the radio frequency circuit, and its adjustability can be used to reconfigure the performance of the circuit, and it can compensate the influence of process deviation, parasitic effect and other factors on the circuit performance. Therefore, the use of transistors to synthesize inductance has high practical application value. [0003] The synthesized inductance of the transistor is c...

AI Technical Summary

Problems solved by technology

On the other hand, when the input signal amplitude of the transistor composite inductance changes greatly, it will cause changes in the bias state of the transistor, and the quality factor Q value of the transistor composite inductor will change accordingly, thus affecting the performance of the radio frequency circuit

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