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针对实际产品中ESD保护产生的寄生效应对低噪声放大器噪声性能的影响,通过详细的理论分析,提出了一种具有ESD保护的低噪声放大器的噪声优化方法,并给出了具体的设计公式。采用该优化方法设计的低噪声放大器可以接近或等于单个晶体管的最小噪声系数。在0.25μm CMOS工艺下进行了仿真,仿真结果表明设计的低噪声放大器可以在不同的功耗下接近最小噪声系数,从而验证了提出的噪声优化方法的有效性。 相似文献
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This paper proposes a sigma-delta fractional-N frequency synthesizer-based multi-standard I/Q carrier generation system.With reasonable frequency planning,the system can be used in multi-standard wireless communication applications(GSM,WCDMA,GPRS,TD-SCDMA,WLAN(802.11a/b/g)).The implementation is achieved by a 0.13μm RF CMOS process.The measured results demonstrate that three quadrature VCOs(QVCO) continuously cover the frequency from 3.1 to 6.1 GHz(65.2%),and through the successive divide-by-2 prescalers to achieve the frequency from 0.75 to 6.1 GHz continuously.The chip was fully integrated with the exception of an off-chip filter.The entire chip area is only 3.78 mm~2,and the system consumes a 21.7 mA@1.2 V supply without output buffers.The lock-in time of the PLL frequency synthesizer is less than 4μs over the entire frequency range with a direct frequency presetting technique and the auxiliary non-volatile memory(NVM)can store the digital configuration signal of the system,including presetting signals to avoid the calibration process case by case. 相似文献
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提出一种应用于功率放大器的高精度温度补偿电路,采用硅二极管与电阻串并联的方法实现功率放大器的温度补偿,保证功率放大器在不同温度下均可以正常稳定地工作,且电路结构简单、易于调试。应用PCB板实现了具有温度补偿的功率放大器电路,测试结果表明在-40~80℃的温度范围内,功率放大器的静态电流只有3.8%的变化。因此该方法可以实现在较宽的温度范围内对功率放大器进行有效的高精度温度补偿,可以广泛应用于功率放大器、特别是对温度补偿量要求较高的功率放大器及大功率放大器的设计中。 相似文献