射频低噪声放大器提高三阶交截点方法探讨

Discussion on Improving the Third Order Intersection Point of Radio Frequency Low Noise Amplifier

随着现代通信技术的进步,特别是4G,5G等无线移动通信的高速发展,多正交振幅调制(QAM)等高频谱利用率的调制方式得到广泛应用,对无线通信系统提出了更高、更严格的线性要求。射频低噪声放大器(RF LNA)作为射频前端(RF FEM)的第1个有源器件,其非线性特征直接影响系统的信号质量和动态范围。以3阶交调为例,低噪声放大器需要足够的输入3阶交截点,以确保即使在强干扰信号下也能提供预期的性能。基于3阶非线性模型,该文简要分析了3阶交调的理论模型,梳理了提高3阶交截点的方法,归纳研究了近年来相关的研究成果与进展,并展望了未来的发展趋势。

With the progress of modern communication technology, especially the rapid development of 4G, 5G and other wireless mobile communications, modulation methods with high spectrum efficiency such as multiQuadrature Amplitude Modulation(QAM) have been widely used, which puts forward higher and stricter linear requirements for wireless communication systems. The Radio Frequency Low Noise Amplifier(RF LNA)is the first active device of the RF Front-End Module(RF FEM), and the signal quality and dynamic range of the system are directly affected by the the nonlinear characteristics of the LNA. Taking the 3rd-order intermodulation as an example, a sufficient input 3rd-order intercept point is required in LNA to ensure expected performance even with strong interfering signals. Based on the 3rd-order nonlinear model, in this article, the theoretical model of the 3rd-order intermodulation is analyzed briefly, the methods to improve the 3rd-order intercept point are sorted out, the relevant research results and progress in recent years are summarized and studied, and the future development trend is prospected.