A low voltage, low power RF CMOS LNA for bluetooth applications using transmission line transformers

This work presents the design and implementation of a 1.2V - 1.8V, 2.5 GHz LNA in a mixed-signal 0.18 µm CMOS technology. A standard differential cascode structure was used with off-chip transmission line transformers. A model for the transmission line transformer is presented that shows matching between the LNA and transformer is critical for optimum results. The LNA consumes 2mA at 1.8V while achieving a gain of 8.9dB, a noise figure of 3.22dB and an IIP3 of -5.6 dBm.