Novel low-complexity broadband variable gain amplifier

Abstract

The invention discloses a novel low-complexity broadband variable gain amplifier. The novel low-complexity broadband variable gain amplifier comprises an active load circuit, a current source circuit, a differential input circuit, a gm-boost circuit and a gain control circuit. The active load circuit is respectively connected with the gm-boost circuit and the differential input circuit; and the current source circuit is respectively connected with the differential input circuit, the gm-boost circuit and the gain control circuit. The novel low-complexity broadband variable gain amplifier can realize a dB linear relationship of input and output without an index generation circuit, efficiently enhances equivalent input transconductance of VGA through the gm-boost circuit, enables the VGA to have relatively high linearity and a relatively wide dB linearity range, and also greatly expands the broadband of the VGA under the precondition of not adding the VGA power consumption through the active load circuit. The novel low-complexity broadband variable gain amplifier can be widely applied to an amplifier product.

Description

technical field [0001] The invention relates to the technical field of electronic circuits, in particular to a novel low-complexity broadband variable gain amplifier. Background technique [0002] VGA is a variable gain amplifier. In an analog integrated circuit system, VGA can adjust different signal gains according to different control voltages. In the fields of wireless communication transceiver system, human body medium communication, disk access circuit and weak signal processing, due to the influence of factors such as communication distance, transmission path and blocking fading, the dynamic range of the received signal is large. Therefore, in order to ensure better stability of the received signal, the adjustable characteristic of the gain of the receiving system becomes particularly important. VGA can adjust the output gain according to the feedback signal, and stabilize the received signal near a predetermined amplitude. The linearity, dB linear range and bandwid...

AI Technical Summary

Problems solved by technology

The existing VGA usually increases its linearity and dB linear range by adding a relatively complex exponential generating circuit, which increases the complexity of the circuit and the area of ​​the chip, and increases the production cost of the chip.

In order to increase the bandwidth of VGA, most VGAs achieve the goal by increasing the consumption current, which greatly increases the power consumption of the system.

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