Folding double balance active mixer of K wave band

Abstract

The invention relates to the mixer technology, and specifically relates to a folding double balance active mixer of K wave band. The folding double balance active mixer of K wave band includes a first balance-imbalance converter T1, a second balance-imbalance converter T2, a first transconductance amplification circuit, a second transconductance amplification circuit, a first current source circuit, a second current source circuit, a switch level circuit, a load level circuit, a first buffer circuit and a second buffer circuit. The folding double balance active mixer of K wave band solves the compromise problem between structural noise, gain and linearity of a traditional mixer, and can effectively improve the overall performance index of the mixer. The folding double balance active mixer of K wave band can improve the gain and reduce the noise. The folding double balance active mixer of K wave band obtains the relatively ideal switching performance and greater output amplitude space, and can expand the linearity of the circuit. The folding double balance active mixer of K wave band can further improve the gain and the noise performance by eliminating the influence of parasitic capacitance. Moreover, when the folding double balance active mixer of K wave band drives the post 50 ohm load, the signal amplitude cannot be attenuated.

Description

technical field [0001] The invention belongs to the technical field of mixers, in particular to a K-band folding double-balanced active mixer. Background technique [0002] With the rapid development of intelligent transportation, radar sensors are more and more widely used in automotive driving assistance systems. 24GHz radar sensors have quickly become the most widely used in automotive driving assistance systems due to their advantages such as small beam angle, high sensitivity, and small size. radar sensor. As a key module responsible for frequency conversion in the radar sensor system, the mixer plays a very important role, and its performance directly determines the performance of the overall system. Designing a high-performance mixer is of great significance to the development of modern automotive radar sensor systems. [0003] The design of the mixer generally adopts a double-balanced active structure, but the traditional double-balanced circuit is a multi-layer st...

AI Technical Summary

Problems solved by technology

[0003] The design of the mixer generally adopts a double-balanced active structure, but the traditional double-balanced circuit is a multi-layer stacked structure, which occupies a lot of voltage space and is difficult to design with low voltage and low power consumption

The noise and linearity of the mixer are mainly determined by the transconductance stage circuit. In order to improve the noise and linearity, it is necessary to provide a large bias current for the circuit, but the large current will cause a large voltage drop at the load stage, which will cause the switching stage transistor When entering the linear region, the circuit cannot work normally; the use of source inductance negative feedback technology can effectively improve the linearity without introducing thermal noise, but it will significantly reduce the gain; increasing the swing of the local oscillator signal can increase the gain, but Large local oscillator signals will indirectly introduce flicker noise through transistor parasitic capacitance, and at the same time produce more serious local oscillator signal crosstalk

It can be seen that the traditional double-balanced circuit structure faces a difficult trade-off between noise, gain and linearity, and it is difficult to meet the requirements of high-performance design.

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