Broadband programmable gain amplifier with high-precision dB linear characteristic

Abstract

The invention discloses a broadband programmable gain amplifier with a high-precision dB linear characteristic, which comprises a first gain amplification unit GM1, a second gain amplification unit GM2, a feedback amplification unit GMf, an MOS (Metal Oxide Semiconductor) tube differential pair M3, an MOS tube differential pair M4, an MOS tube differential pair M5, an MOS tube differential pair M6, an MOS tube differential pair M7, a common-mode feedback circuit CMFB1 and a common-mode feedback circuit CMFB2, according to the broadband programmable gain amplifier, precise dB linear gain control is achieved through a near pseudo-exponential function by means of the binary weighted switch technology, and an additional exponential generation circuit is not needed; the change of the voltage gain is determined by the ratio of the transconductance values of the MOS transistors of the same type, so that the gain of the circuit is insensitive to the change of process, voltage and temperature; the wide-3dB bandwidth, the precise dB linear characteristic and the wide gain adjusting range can be achieved.

Description

technical field [0001] The invention belongs to the technical field of radio frequency receivers, in particular to a wideband programmable gain amplifier with high-precision dB-linear characteristics. Background technique [0002] In recent years, with the development of big data analysis and artificial intelligence, the requirements for signal processing rate have increased rapidly, and the bandwidth of received signals has continued to increase. This requires an automatic gain control (Automatic Generation Control, AGC) amplifier to accommodate a wide range of signal bandwidth, operating frequency and power requirements. AGC amplifiers are widely used in modern communication and signal processing systems, and can be used in software-defined radios or the latest automotive radar systems, millimeter-wave imaging, local area networks (LANs), and wide dynamic range optical receivers. Based on different gain tuning mechanisms, variable gain amplifiers in AGC amplifiers can be ...

AI Technical Summary

Problems solved by technology

At present, some digitally controlled variable gain amplifier circuits are also discussed in the literature, but none of them achieve high-precision dB linear gain control while achieving very high bandwidth

Traditional closed-loop based digitally controlled variable gain amplifiers have severe limitations in high frequency applications due to the need to draw large currents and have sufficient resistive loads to drive

Digitally controlled variable gain amplifiers controlled by variable transconductance are more popular in high frequency applications, but process-voltage-temperature variations can cause their step size to be uneven, increasing gain error

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