Gilbert mixer with folding structure

Abstract

The invention belongs to the technique area of the wireless communication receptor system related to the Gilbert mixer with folded structure. The mixer is the symmetric structure composed of the MOS tubes M1 and M2, M3 and M4, M5 and M6 as well as the resistors R1 and R2. The character is that the MOS tubes M3-M6 are PMOS tubes. The invention increases one degrees of freedom of the power consumption in the designing circuits, weakens the crossrelation among the noise, linearity and the conversion gain. Thus, the three targets can be optimized respectively. The cost paid directly for the optimization is the power consumption in the stead of deteriorating other targets.

Description

technical field [0001] The invention belongs to the technical field of wireless communication receiver systems, in particular to the design of a mixer used for the front end of a wireless communication transceiver system. Background technique [0002] In the past ten years, the development and research of radio frequency integrated circuits (RFICs) have developed rapidly, which is mainly due to the prosperity of the wireless communication market. These wireless applications include pagers, cordless phones, radio frequency identification (RFID), analog and digital cellular mobile phones, and the Global Positioning System (GPS). At the same time, with the popularity of the Internet at an astonishing speed all over the world, some emerging short-distance, high-speed wireless communication systems—Wireless Local Area Network (WLAN) have also begun to develop rapidly in the past two years, mainly including IEEE802.11 series, HyperLAN , Bluetooth, HomeRF, etc. The development of...

AI Technical Summary

Problems solved by technology

According to the principle of circuit analysis, in order to reduce the output noise of the circuit, it is necessary to reduce the quiescent current flowing through the tubes of M3~M6 of the local oscillator, but because the traditional Gilbert (Gilbert) structure uses M1 and M2 and M3~ The M6-phase stacked circuit structure reduces the current flowing through M3~M6, and at the same time reduces the current flowing through M1 and M2, and reduces the latter's current, which will cause the conversion gain of the circuit to decrease and linearity. degree of deterioration

That is to say, conversion gain, linearity and noise must be sacrificed at the expense of each other in order to obtain their own improvement, which is why the traditional Gilbert (Gilbert) mixer cannot obtain satisfactory performance in many indicators. s reason

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