A 30 μW 2.4-GHz LNA With 5.6 dB NF Exploiting Trifilar Transformer Coupling for Smart AIoT Electronics

K.-C. Tai, K.-W. Cheng (National Cheng Kung University, Taiwan)

A 30 μW 2.4-GHz low-noise amplifier (LNA) exploiting complementary current reuse and trifilar transformer coupling is presented for ultra-low-power smart electronics and always-on wireless receivers. The proposed architecture passively boosts the effective transconductance of a stacked NMOS/PMOS input pair without increasing dc power, thereby enabling an effective tradeoff among gain, noise figure, linearity, and energy efficiency. A gm/ID-based design methodology and complementary-bias optimization are further adopted to improve current efficiency and linearity under a 0.6-V supply. Implemented in TSMC 90-nm CMOS, the LNA achieves a voltage gain of 13.8 dB, a noise figure (NF) of 5.6 dB, and an input third-order intercept point (IIP3) of -6.2 dBm at 2.4 GHz while consuming only 30 μW. With a compact core area of 0.71×0.52 mm2, the proposed design is well suited for always-on wireless sensing, AIoT nodes, and future battery-operated smart electronic systems.