Low-consumption high-gain down-conversion mixer

Abstract

Disclosed is a low-consumption high-gain down-conversion mixer. The low-consumption high-gain down-conversion mixer is provided with a current source unit, an input transconductance unit, a switch unit and a load unit. An output of the current source unit is connected with the input transconductance unit, a radio frequency input signal is inputted between the input transconductance unit and the current source unit, and the input transconductance unit amplifies the radio frequency signal and outputs the same to the switch unit via two pairs of cross-coupling reinforcing signals. A local oscillation input signal is input into the switch unit, an output of the switch unit is connected with the load unit, the load unit further reinforces the output signal through positive feedback, and a differential medium-frequency output signal is output between the load unit and the switch unit.

Description

technical field [0001] The present invention relates to frequency conversion circuits in various wireless transmitters, especially a low-power consumption high-gain down-mixer, which can be applied to radio frequency transceiver chips, such as wireless local area network (WLAN), wireless sensor network (WSN), Global positioning system (GPS), radio frequency identification system (RFID), Bluetooth system, mobile communication system, mobile digital TV (CMMB, TMMB) and other transceiver chips. Background technique [0002] The down-mixer is generally used as a frequency conversion circuit of various wireless receivers. Its function is to convert high-frequency signals into low-frequency signals that are beneficial to signal processing. For most radio frequency receiving systems, the down-mixer is a necessary Indispensable module. In order to prolong the service life of the system battery, it is hoped that each module in the receiver reduces power consumption, and on the basis...

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Problems solved by technology

[0005] The second is the low gain. The gain of the traditional Gilbert mixer depends largely on the size of the transconductance of the transconductor and the size of the load impedance, but in the case of low power consumption, the transconductance of the transconductor will be very small , the gain improvement brought by increasing the ordinary resistive load is also very limited

[0006] The third is that the noise figure is large. Traditional Gilbert mixers input signals from the grid end, and the input impedance seen from the grid end is very large, which matches the output impedance of the previous stage circuit (usually more than 100 ohms) or 50 ohms. Poor, resulting in a large noise figure, difficult to meet the needs of the system

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