一款高增益宽带低噪声放大器的设计

Design of a high-gain,broadband and low-noise amplifier

采用0.5μm GaAs E-PHEMT工艺设计了一款0.5~5 GHz高增益宽带低噪声放大器芯片。该放大器采用三级共源结构,运用负反馈技术有效地进行了输入输出阻抗匹配,针对高频增益不足问题,在共栅晶体管的栅极到地之间增加栅极电容,提高了高频增益,改善了增益平坦度,拓展了带宽。同时,放大器前两级应用电流复用技术,大大降低了电路功耗。仿真结果表明:在工作频带内,最大增益可达36.6 dB,增益平坦度为±0.4 dB,输入输出回波损耗均小于-10 dB,噪声系数小于0.9 dB,输出功率1 dB压缩点最大可达15.4 dBm,OIP3最高可达34.1 dBm,芯片版图尺寸为0.65 mm×0.87 mm。

A 0.5-5 GHz high-gain,broadband and low-noise amplifier chip was designed using 0.5μm GaAs E-PHEMT process.A three-stage common source structure was adopted,and the negative feedback technology was used to effectively match the input and output impedance.Aiming at the problem of insufficient high-frequency gain,the gate capacitance is increased between the gate of the common-gate transistor and the ground,resulting in the improvement of the high-frequency gain,gain flatness and bandwidth.At the same time,the current multiplexing technology was applied to the first two stages of the amplifier,which greatly reduces the power consumption of the circuit.The simulation results show that in the working frequency band,the maximum gain can reach 36.6 dB,the gain flatness is±0.4 dB,the input and output return loss are less than-10 dB,the noise figure is less than 0.9 dB,the maximum output power 1 dB compression point can reach 15.4 dBm,OIP3 can reach up to 34.1 dBm,and the layout size of chip is 0.65 mm×0.87 mm.