Improved double Gilbert structure radio-frequency orthogonal upper frequency mixer

Abstract

The invention discloses an improved double Gilbert structure radio-frequency orthogonal upper frequency mixer. The frequency mixer comprises a transconductance level circuit, a switching level circuit and a tail current source circuit. Silicon germanium double pole-complementary metal oxide semiconductor process technology is adopted in the integral circuit; and the frequency mixer combines the advantages of a bipolar device and a complementary metal oxide semiconductor, and can improve the conversion gain at the same time of effectively reducing circuit noise. The transconductance level circuit has a parallel-connection structure of three pairs of transconductances, and improves the linearity of the frequency mixer at the same time of increasing the transconductance parameter of the transconductance level. The switching level circuit works in an ideal switching state according to the simulation result. A current injection mode is also adopted in the circuit, and partial current is extracted at the emitter of the switching level so that the current of the switching level is low enough and the hot noise and the flicker noise of the circuit are effectively reduced. According to the design, the frequency mixer works at 1.95GHz and can be applied in personal communication service and wideband code division multiple access communication systems.

Description

technical field [0001] The invention belongs to the technical field of radio frequency integrated circuit design, specifically a silicon germanium bipolar-complementary metal oxide semiconductor (SiGe BiCMOS) improved dual-Gilbert structure radio frequency quadrature up-mixer working at 1.95 GHz . Background technique [0002] In recent years, with the popularization of the Internet, wireless communications such as wireless LAN, Bluetooth, and CDMA have developed rapidly, and the monolithic integration of RF transceivers in CMOS technology has long been a hot spot for development. And now the ever-increasing low power consumption, low noise and low cost have put forward higher standards for wireless communication design. Using SiGe BiCMOS process to design and fabricate radio frequency chip (RFIC) is one of the research hotspots in today's international integrated circuits. Researchers from different countries and regions have done a lot on silicon germanium radio frequency...

AI Technical Summary

Problems solved by technology

However, in the actual RF transmitter application, if the gain of the up-mixer is high enough, the pressure on the lower power amplifier can be greatly reduced, but when the gain of the up-mixer is high, the linearity usually cannot reach the ideal value case

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