A wideband voltage-controlled oscillator with wideband harmonic tunability

Abstract

This invention discloses a broadband harmonic-tunable voltage-controlled oscillator (VCO), relating to the field of radio frequency integrated circuit design technology, to solve the technical problems of narrow tuning range and phase noise degradation caused by the design of existing LC oscillators. The broadband harmonic-tunable VCO of this invention includes an LC resonant unit, a negative resistance unit, a head resonant unit, and a tuning transformer unit. The second terminal of the negative resistance unit is connected to the power supply ground, and the first terminal is connected to the second terminal of the LC resonant unit. The input terminal of the head resonant unit is connected to the power supply voltage, and the output terminal is connected to the first terminal of the LC resonant unit. The input terminal of the tuning transformer unit is connected to a first control voltage. The tuning transformer unit resonates at the first harmonic frequency of the VCO output frequency. The tuning transformer unit and the head resonant unit simultaneously act on the first and second harmonics. The oscillation frequency is adjusted by magnetic tuning controlled by the first control voltage to obtain a broadband adjustable range.

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