Modern wireless systems are increasingly incorporating adaptability to operate at low power under varying channel conditions and to increase yield under severe process variation. Effective adaptation requires built in tuning knobs in the RF front end circuits. Due to the sensitive nature of RF circuits traditional turning knobs affect more than one specification simultaneously. To ensure optimal adaptation it is beneficial to have carefully designed tuning knobs that allows independent control of important specifications. In this paper the design of an inductorless RF LNA is discussed whose specifications can be traded off independently/orthogonally of each other for reduced power consumption. Two built in tuning knobs are introduced for orthogonal adaptation of Gain and linearity. The proposed LNA, designed in 0.18µ CMOS achieves a 14 dB Gain and 30 dB OIP3 control range as its power consumption goes down by 20×.
['Shreyas Sen', 'Marian Verhelst', 'Abhijit Chatterjee']
Orthogonally tunable inductorless RF LNA for adaptive wireless systems