Low-noise passive frequency mixer

Abstract

The invention discloses a low-noise passive frequency mixer. The low-noise passive frequency mixer comprises a low-noise transconductance amplifier stage, a switch frequency mixing stage and a transimpedance amplifier stage. The low-noise transconductance amplifier stage mainly adopts a cross coupling master-slave noise cancellation technology, a main transconductance conduit adopts a cross coupled structure to double an equivalent transconductance value, an appropriate transconductance value is provided through the main transconductance conduit and the noise of the main transconductance conduit is lowered through a master-slave structure; the switch frequency mixing stage is used for modulating and filtering radiofrequency currents output from the low-noise transconductance amplifier stage and outputting intermediate frequency currents; the transimpedance amplifier stage consists of a full-differential operational transconductance amplifier and a load resistor; the operational transconductance amplifier is based on a feed-forward compensation technology, and a consequent pole point in a transfer function of the amplifier is offset by a zero point introduced to a feed-forward stage of the operational transconductance amplifier, so that a large unity-gain bandwidth is achieved; the load resistor is used for converting the intermediate frequency currents into intermediate frequency voltage signals which are then output, by virtue of a voltage-current negative-feedback connection way. The low-noise passive frequency mixer has the characteristics of low noise, high gain and low power consumption.

Description

technical field [0001] The invention relates to a frequency conversion receiver, in particular to a low-noise passive mixer. Background technique [0002] With the continuous development of wireless communication technology, devices such as mobile phones, global positioning systems and wireless broadband networks play an increasingly important role in people's daily lives. For these systems, low power consumption and low cost are extremely important indicators. Direct conversion receivers are widely used in modern mobile communication systems due to their low power consumption and low cost. The CMOS process is also increasingly favored by people for its low production cost and high integration. However, there are still many disadvantages of direct conversion receivers under CMOS technology, especially their poor noise performance, and with the continuous progress of CMOS technology towards small size, transistors under deep sub-micron CMOS technology will produce greater f...

AI Technical Summary

Problems solved by technology

The traditional operational transconductance amplifier adopts a two-stage cascaded structure based on Miller compensation. In order to obtain a large enough gain-bandwidth product and make the closed-loop feedback loop stable, this method needs to consume a lot of power. There are gains, bandwidths and Defects of mutual restriction of phase margin

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