并发双频段低噪声放大器的设计与仿真

Design and Simulation of Concurrent Dual Band Low Noise Amplifier

针对低噪声放大器(LNA)工作频段单一的问题,提出一种以新型匹配结构为基础的并发双频段LNA设计方法。首先将两频点的输入输出阻抗利用串联微带线变换到等电导圆上;再通过在匹配频点处阻抗等效为所需要电纳,同时在另一个频点等效为开路的特定并联微带线枝节将两频点同时匹配到50Ω。最后基于这种匹配结构对适用于WIFI(2.4GHz)、LTE-Hi(3.5GHz)[1]的双频点三级LNA进行了设计与仿真。仿真结果表明,三级级联LNA在这两个频段噪声系数均小于1d B;增益大于40d B;输入输出回波损耗均大于20d B,能同时稳定工作在两个频段。

Aiming at the problem of operating band single in low noise amplifier（ LNA）. A design method of concurrent dual band LNA based on a novel matching structure is proposed. First two frequency of input and output impedance using series microstrip transform to conductance circle; and then through the frequency equivalent impedance matching to the susceptance,and in another frequency equivalent open circuit specific parallel microstrip stub to the frequency and matched to 50 ohms. Finally,the design and Simulation of WIFI（ 2. 4GHz） LTE-Hi（ 3. 5GHz）[1]single stage and three stage LNA are carried out based on the matching structure. The simulation results show that the noise figure of the three stage cascade LNA is less than 1d B,the gain is greater than 40 d B,and the input and output return loss is greater than 20 d B,and it can work stably at two frequency bands simultaneously.