Active inductance type voltage-controlled oscillator

Abstract

The invention discloses an active inductance type voltage-controlled oscillator, which mainly comprises an LC resonance circuit and a negative resistance circuit; the LC resonance circuit mainly comprises a first active inductor, a second active inductor and a capacitor; the negative resistance circuit comprises a first NMOS (N-channel metal oxide semiconductor) transistor, a second NMOS transistor and a bias current source; the first NMOS transistor and the second NMOS transistor are connected in a crosswise coupling method, the bias current source is adjusted for changing the magnitude of negative resistance, and lost energy of the LC resonance circuit is supplemented; the active inductors and the capacitor form the equivalent LC resonance circuit; by adjusting the inductances of the active inductors, the tuning of center frequency of the oscillator is realized. The active inductance type voltage-controlled oscillator disclosed by the invention has the advantages that tuning bandwidth of the circuits is large, simple and convenient effects are realized, and the chip area is saved.

Description

technical field [0001] The invention relates to the technical field of integrated circuits, in particular to an active inductive voltage-controlled oscillator. Background technique [0002] Oscillators are one of the most important circuits in electronic systems. At present, there are two main implementation methods of their circuits, namely, ring voltage-controlled oscillators and inductor-capacitor voltage-controlled oscillators. As far as academic reports published in the past are concerned, CMOS In designs where the operating frequency of the oscillator can reach hundreds of MHz to tens of GHz, a passive LC topology is used directly or indirectly to meet the requirement of a higher operating frequency in the design. The on-chip passive inductor is made of metal wires wound on the Si substrate. Due to the limited thickness of the interconnection wire of the on-chip passive inductor, the metal loss of the coil is relatively large, and the skin effect is very significant. ...

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Problems solved by technology

The on-chip passive inductor is made of metal wires wound on the Si substrate. Due to the limited thickness of the interconnection wire of the on-chip passive inductor, the metal loss of the coil is relatively large, and the skin effect is very significant. The coupling with the silicon substrate is very strong. Although the introduction of an external ground can shield the loss to a certain extent, the existence of these two loss mechanisms makes the inductance quality factor of the CMOS process low, generally only about a dozen, and passive It is difficult to adjust the inductance, and it occupies a large area of ​​the chip circuit, which increases the cost of integrated circuit manufacturing. At present, the passive LC structure on the chip is used, and it is still difficult to meet the performance indicators required by the communication system.

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