基于Cascode级间匹配的多频段LNA设计

A Multi-Band Cascode LNA with Inter-Stage Matching Network

提出了一种Cascode级间匹配电路,能够优化Cascode放大器的噪声系数、增益及高频稳定性。应用该电路,设计了一款多频段射频低噪声放大器(LNA)。采用0.25μm GaAs工艺进行实现,输入、输出阻抗匹配网络采用片外元件。测试结果表明,通过重配置片外元件的参数,该LNA可工作于0.7~1.1 GHz、1.6~2.1 GHz、2.3~2.8 GHz这三个频段,增益分别为25±2 dB、19.5±0.5 dB和18±1 dB,噪声系数分别低于0.6 dB、0.7 dB和0.9 dB,OIP3均大于30 dBm。该LNA对于GSM/WCDMA/LTE通信基站以及L/S频段接收机等设备具有一定的应用价值。

An inter-stage matching circuit for cascode structure was proposed, which could enhance cascode amplifier’s noise performance, gain and high frequency stability. Applying the circuit, a low noise amplifier(LNA) was designed and implemented in a 0.25 μm GaAs process with input/output matching networks achieved off-chip. Through reconfiguring components of input/output matching networks, the proposed LNA could be used in the three frequency bands of 0.7~1.1 GHz, 1.6~2.1 GHz and 2.3~2.8 GHz. Measurement results showed that the LNA had a gain of 25±2 dB, 19.5±0.5 dB and 18±1 dB respectively in the three frequency bands mentioned above, with a noise figure less than 0.6 dB, 0.7 dB and 0.9 dB respectively. And the LNA’s OIP3 s were larger than 30 dBm in the all three frequency bands. Therefore, the LNA possessed an application prospect for GSM/WCDMA/LTE base stations and L/S band receivers.