A variable gain 2.4-GHz CMOS low noise amplifier employing body biasing

In this paper, a variable gain CMOS low noise amplifier (LNA) suitable for WiMAX (Worldwide Interoperability for Microwave Access) applications, 2.4 GHz, is reported. The design concept is based on the novel idea of body biasing. In high mode gain the cascode LNA, implemented in a 0.13µm CMOS standard process and supplied under 1.1V, exhibits a power gain of 15.44 dB, a 2.87 dB noise figure (NF), and −4.62 dBm of third order intercept point (IIP3) for a 4.64 mA current consumption and a bulk to source Voltage, VBS, of 0.3V. Tuning VBS to −0.55V, the LNA operates in the low gain mode, achieving 8.23 dB of power gain, 5 dB NF and 6.63 dBm IIP3 under a constrained power consumption of 1.1 mW.