摘要
在无线通信终端中,低噪声放大器是射频接收系统中的第一级有源电路,对系统性能有重要影响。在深入分析噪声的基础上,提出一种采用共基差分输入结构的低噪声放大器,电路包括可控增益放大器和增益控制电路。该结构的低噪声放大器的输出电压直接反映到自动增益控制电路的输入端,根据输出电压幅值的大小,自动增益控制电路的输出电压反馈到低噪声放大器的增益控制电路比较器的输入端,进而影响放大器的总体增益。基于JAZZ 0.35μmBICMOS工艺设计放大器电路结构,并对电路进行了仿真和分析,结果表明设计的放大器可以更加有效地抑制噪声,低噪声放大器能提供25 dB的增益,噪声系数小于1 dB,灵敏度达到2μV。
In the wireless communication terminals, the low noise amplifier is the first level of active circuits in RF system, which has an important impact on the performance of system. After analyzing the noise in-depth, this paper afforded the low-noise amplifier with common-base differential input structure. The circuit included the controlled gain amplifier and gain control circuit. The output voltage of low-noise amplifier was directly connected to the input of AGC circuit. According to the output voltage amplitude, the AGC circuit output voltage was fed to the comparator input of the low noise amplifier gain control circuit, affecting the overall gain of amplifier. The circuit is designed and simulated based on the JAZZ 0.35 μm BICMOS process. The results show that the amplifier can effectively suppress the noise, low-noise amplifier can provide 25 dB gain, noise parameter is less than 1dB, and the sensitivity reaches 2μV.
出处
《电子设计工程》
2010年第8期182-184,188,共4页
Electronic Design Engineering
