A Low-Power Noise Reduction Technique for Broadband CMOS Low-Noise Amplifiers

A broadband input matching technique for low noise amplifiers (LNAs) is presented which exploits an active feedback network to achieve better noise performance. The presented matching scheme is compared to the common-gate and conventional noise canceling structures. The noise performance of the presented technique is similar to that of the conventional noise canceling technique with much less power consumption. In contrast to the traditional noise cancellation circuit, the proposed LNA does not degrade the linearity and its IIP3 is similar to the simple common-gate LNA. The proposed technique is applied to an LNA operating in 2~6.5 GHz bandwidth. The circuit is designed in a 0.18 μm RF CMOS technology with a 1.8 V power supply. This LNA achieves an IIP3 of +5.4 dBm, 17 dB voltage gain, and 2.5 dB noise figure while consuming 7.6 mW power. KeywordsUltra wideband (UWB), low noise amplifier, noise cancellation, low power.