S-band high-linearity, low-noise and low-gain down-conversion active mixer

The invention discloses an S-band high-linearity, low-noise and low-gain down-conversion active mixer. The structure of the mixer is based on a Gilbert-type unit. The invention further discloses a local oscillator drive circuit so as to provide a good local oscillator input signal and improve overall circuit performance. The mixer has the advantages of low power consumption, high linearity and low noise, and linearity and noise performance of the mixer are improved under the condition of low gain.