Single-ended input and differential output parallel dual-frequency low noise amplifier and design method thereof

Abstract

The invention discloses a single-ended input and differential output parallel dual-frequency low noise amplifier (LNA) and a design method thereof. The LNA can be applied to a digital TV, wireless communication and a navigation receiver and mainly comprises an input matching network, a main amplification circuit, an output network and a single-ended to differential circuit. The main amplification circuit adopts a cascode structure and has favorable reverse isolation degree; the input matching network enables the LNA to realize impedance matching and noise matching simultaneously in input stage and dual frequency ranges, and thus the noise performance of the circuit is improved at the same time of ensuring the maximum power transmission; and the singled-ended to differential circuit ensures that the LNA can be directly cascaded with a front-end antenna and a rear-end mixer circuit and easy to integrate. The LNA disclosed by the invention not only has a simple design, but also ensures that the system power consumption and area are reduced due to parallel dual-frequency receiving.

Description

technical field [0001] The invention belongs to the field of deep submicron RF CMOS integrated circuits, and in particular relates to a parallel dual-frequency low-noise amplifier with single-end input and differential output and a design method thereof. Background technique [0002] The RF front-end amplifies, mixes, and converts the signal received by the antenna to complete the conversion from the RF signal to the baseband signal. The low-noise amplifier is generally at the forefront and plays an extremely important role in the sensitivity of the receiver. It needs to provide enough gain to amplify the signal and its own noise figure is small, thereby suppressing the contribution of the subsequent stage circuit to the overall noise, and ensuring that the signal in the channel has a sufficient signal-to-noise ratio; at the same time, its gain cannot be too large, In order to prevent the nonlinear distortion caused by the overload of the post-stage mixer; for the maximum p...

AI Technical Summary

Problems solved by technology

[0004] The first is to use two sets of independent narrowband amplifiers to match in different frequency bands respectively. Such a circuit design is simple and easy to implement, but it needs to establish multiple links, which will inevitably increase the size, power consumption and cost. It is also inconvenient to switch between frequency bands

[0005] The second is the broadband amplifier, which needs to achieve sufficient gain, low enough noise figure and good input impedance matching in the entire frequency band, thus greatly increasing the difficulty of design

However, the disadvantages of doing this are: First, the balun is difficult to integrate on-chip, and usually needs to introduce off-chip components, which will affect the integration level and system cost, and will bring 1-3dB loss, which will affect the sensitivity of the system; Low-loss high-performance baluns are usually narrow-band and cannot be used for dual-band reception. Broadband baluns suitable for dual-band reception not only have higher losses, but also introduce greater noise to the system

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