Lower-power-supply-voltage high-conversion-gain passive mixer

Abstract

The invention discloses a lower-power-supply-voltage high-conversion-gain passive mixer, which comprises an input transconductance amplification stage, a switch mixing stage and an output transimpedance amplification stage. The input transconductance amplification stage adopts a push-pull transconductance structure. In order to satisfy the requirement of 0.6V power supply voltage, a common-mode negative feedback circuit based on two stages of common-source amplifiers is provided to enable transconductance-stage common mode bias voltage to be equal to fixed grid-source voltage. The switch mixing stage is used for modulating radio-frequency current output by the transconductance amplification stage and outputting medium-frequency current signals through low-pass filtering. The output transimpedance amplification stage is used for absorbing the medium-frequency current output by the switch mixing stage and outputting a mirror, and finally medium-frequency output voltage is obtained on a load resistor. Moreover, a transimpedance amplifier under low power supply voltage is provided. The transimpedance amplifier is based on a negative feedback structure, the output of low input impedance within a medium frequency band is realized, and the current utilization efficiency and the port isolation are improved. The lower-power-supply-voltage high-conversion-gain passive mixer with the structure has the advantages of low power consumption, high conversion gain and good port isolation.

Description

technical field [0001] The invention relates to a mixer, in particular to a passive mixer with high conversion gain under low power supply voltage. Background technique [0002] In the RF signal receiving chain, the role of the mixer is to down-convert the input RF signal to an intermediate frequency or baseband for processing by subsequent modules. Considering the entire receiving chain, the mixer should have a high conversion gain to suppress the impact of the noise of the subsequent intermediate frequency amplifier circuit and filter circuit on the noise figure of the entire receiving chain. In addition, the mixer itself should have good port isolation to reduce the local oscillator leakage at the intermediate frequency. With the continuous improvement of CMOS technology, the power supply voltage is continuously reduced, and complex issues are constantly raised for the design of the mixer. In recent years, silicon solar cells have been more and more applied to circuit s...

AI Technical Summary

Problems solved by technology

[0003] Mixers can be divided into active mixers and passive mixers. Active mixers not only provide the function of mixing, but also have the function of amplifying the signal, which can effectively suppress the more serious IF circuit noise. , but the active mixer itself has a large noise, especially in the zero-IF receiver structure, its flicker noise will bring a certain impact, while the passive mixer has no quiescent current, and its flicker noise is also greatly reduced smaller, and passive mixers are usually more linear than active mixers

[0004] In the classic frequency mixing structure, when the RF voltage is converted into RF current in the transconductance stage, the signal received by the receiver is generally very small, and the transconductance value of the traditional transconductance stage circuit is generally only the transconductance value of the input transistor. Its transconductance value is limited at low bias current, and the conversion gain is low

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