Dynamic Feedback CMOS LNA, for UWB WLAN Transform-Domain Receiver Loss of Orthogonality

This paper addresses the selectivity problem, for the ultra-wide band (UWB), transform-domain receiver loss of orthogonality. A novel selective, low-power, multi-block low noise amplifier (LNA) for UWB, wireless local area network (WLAN) is proposed. When using a dynamic feedback with a specific inductive load range values, the UWB WLAN LNA is reduced to a simple second order circuit with zero at the origin, witch not only ensure a perfect stability over all the UWB frequency band, but almost. doubles the small signal gain, when reducing the frequency band between the two poles. In this design, the gain improvement add robustness to adjacent interference, lowers the noise figure by over than 1dB in the 5-6 GHz frequency range, and 2dB in the highest frequency band, witch leads to better use of the excellent linearity, selectivity, and impedance matching of the common-gate LNA. Experimental results indicate 27dB small signal gain at 5.6GHz, the noise-figure (NF) varies from 3.86dB to 2.78dB in the 5-6 GHz frequency range, drawing 3.9mA from 1.8v.