Method capable of improving low-frequency flicker noise and high-gain characteristic and active mixer

Abstract

The invention discloses an active mixer with low-frequency flicker noise and a high-gain characteristic. In the prior art, a traditional Gilbert active mixer has the problems that flicker noise is loud, and compromise of noise and gain exists, so that the traditional Gilbert active mixer cannot meet the requirement of a present receiver to a high-performance mixer, especially to zero intermediate frequency receivers and low intermediate frequency receivers. Aiming at the defects, the active mixer with low-frequency flicker noise and the high-gain characteristic reduces the mixer flicker noise by reducing direct current which flows through a traditional Gilbert active mixer switch pipe, and by the adoption of input transconductance generated by the current, the contradictory problem that the flicker noise and the gain exist in traditional active mixer performance optimization is solved, so that the high-performance active mixer which is low in flicker noise and high in gain is achieved.

Description

technical field [0001] The invention relates to the field of frequency mixing, in particular to an active mixer with low flicker noise (1 / f noise) and high gain performance. Background technique [0002] The demand for portable wireless communication systems such as wireless local area network (LAN), wireless multimedia and home wireless control systems has grown significantly in recent years. With the scaling down of CMOS process feature size and the continuous improvement of circuit technology, more and more high-performance, highly integrated radio frequency chips (RFICs) have emerged, and these chips have been widely used. [0003] The receiver architecture mainly includes three architectures: superheterodyne, zero-IF, and low-IF. Now, with technological progress and integration requirements, the most mainstream receiver architecture is zero-IF architecture. figure 1 Represents a general zero-IF receiver block diagram. The zero-IF receiver is also called a direct-conv...

AI Technical Summary

Problems solved by technology

In the actual design, it is found that these methods of improving noise performance will affect other performances such as gain and linearity, and cannot effectively improve the performance of the mixer, especially the 1 / f noise performance. The traditional means of reducing the bias current flowing through the switch tube There is a trade-off between noise (flicker noise) and gain: reducing flicker noise requires reducing mixer bias current, while increasing gain requires increasing mixer bias current

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