设计了一种2.4 GHz低功耗可变增益跨阻放大器。该放大器为两级放大结构,主要应用于电流模式发射机后端的电流-电压信号转换及放大。第一级放大使用电流复用结构,第二级放大使用共源共栅差分结构。通过控制第一级的跨阻式反馈电阻的大小及第二级偏置电压的大小,在基本不影响输入、输出匹配的情况下,可以得到连续15 dB的增益变化范围。在2.4 GHz及高增益模式下,增益可达18.27 dB,噪声仅为1.061 dB,功耗也仅为6.38 mW。 A 2.4 GHz low power variable gain transimpedance amplifier is designed. The amplifier is a two-stage amplification structure, mainly used in the current-mode transmitter rear-end current-voltage signal conversion and amplification. The first stage uses a current-multiplexing structure and the second stage uses a cascode structure. By controlling the size of the first stage of the transimpedance feedback resistor and the magnitude of the second stage bias voltage, a continuous 15 dB gain variation range can be obtained without substantially affecting the input and output matching. In 2.4 GHz and high gain modes, the gain is up to 18.27 dB, the noise is only 1.061 dB, and the power dissipation is only 6.38 mW.