2.4 GHz Active Inductor Based Single to Differential LNA for WLAN Applications

Abstract

This paper presents a source degenerated cascode LNA design using a regulated cascode active inductor (AI). The AI has an inductance value of up to 6.28 nH, a Q-value of up to 4750, and a resonant frequency of up to 9.758 GHz. The proposed AI replaces the passive source degenerated inductor and load inductor in the LNA. Further, an active balun is used to have a differential signal at the LNA output to support the mixer stage. The gain and noise figure of the LNA is 22.2 and 5.6 dB respectively. The 3rd order input intercept (IIP3) value is 1.92 dBm and the return losses at the input port and two output ports are less than −10 dB. The power consumption of the circuit is 27 mW at a 1.8 V supply and the figure of merit (FoM) is 9.17. The area occupied by the AI is 39 × 72 µm2 and balun-LNA is 0.872 × 0.62 mm2. The complete proposed circuit is meant for wireless local area network (WLAN) applications in the 2.4 GHz frequency band.