高低增益双通路射频低噪声放大器的设计

High and Low Gain Dual-Channel RF Low Noise Amplifier Design

介绍了一种应用于VHF频段跳频通信系统接收机的低噪声放大器(LNA)。根据跳频通信系统抗扰要求高,适应能力强的特殊要求,确定具有高、低增益双通路的设计方案,而后对LNA电路进行稳定性分析;并使用Agilent公司的ADS软件对基于U310场效应管和2N5031晶体管的LNA电路进行仿真设计;最后在仿真的基础上,设计出LNA的电路实物,测试结果表明,该LNA电路增益为:高增益>20dB、低增益>8dB,噪声系数<3dB,带内纹波<1.5dB,工作稳定并有一定裕量。

A tow-noise amplifier（LNA）applied in the receiver of VHF frequency-hopping communication system is introduced. According to the specific requirements of the frequency-hopping communication system such as high-disturbance-rejection and strong adaptability, the design of high and low gain dual-channel LNA circuit is identified. And then we analyzed the stability of LNA; simulate and designed the LNA based on U310 FET and 2N5031 transistor by designing and simulating software ADS of Agilient co. Finally the actual circuit of LNA was designed on the basis of simulation,the results of test show that,the gain of the LNA is high-gainS〉20 dB,low-gain〉8 dB, NF〈3 dB, band ripple〈1. 5 dB. It works steadily. All figures are required and better than that of their requirements.