A High Linearity Low Noise Transconductance Amplifier

Abstract

The invention discloses a low-noise transconductance amplifier, in particular a differential input / output structure. The circuits on the left and right sides both include two complementary common source stages, a feedback stage and a load stage including complementary source followers and resistors; After the differential RF input signal enters the input ports Vin+ and Vin‑, it is converted into a current signal by the two NMOS / PMOS complementary common source tubes on the left and right, respectively, and transmitted to the output nodes IO+, IO‑; the left and right sides are output The current is converted into a differential output voltage signal through the left and right load stages respectively. The differential output voltage signal is converted into a current signal after passing through the left and right feedback stages and flows into the input ports Vin+ and Vin‑ to achieve input impedance matching. Both the forward path and the feedback path adopt the complementary symmetrical structure of NMOS / PMOS transistors to achieve current multiplexing and good linearity. The invention can significantly improve the small-signal and large-signal linearity and anti-blocking of the transconductance amplifier in a wide frequency band. ability to interfere.

Description

technical field [0001] The invention belongs to the field of integrated circuits, in particular to a high-linearity and low-noise transconductance amplifier. Background technique [0002] In recent years, people's urgent demand for high data rate has greatly stimulated the research, development and application of multi-mode and multi-band RF receivers. Traditional multi-mode multi-band receivers use separate optimized receiving front-end circuits for each frequency band, resulting in larger chip area and power consumption (shortening battery life). At the same time, in the face of extremely large out-of-band interference (such as 0dBm out-of-band interference specified in the GSM standard), it is common to use off-chip bulky surface acoustic wave (SAW) filters, such as figure 1 As shown in (a), this further increases the board size and overall cost. In order to reduce hardware cost as much as possible and achieve single-chip integration, figure 1 The non-SAW transceiver s...

AI Technical Summary

Problems solved by technology

However, the inherent second-order nonlinear interaction of the feedback circuit deteriorates the linearity of traditional active feedback low-noise amplifiers, which cannot meet the increasingly stringent linearity performance requirements of today's wireless systems

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