An Inductorless Wideband Gm-Boosted Balun LNA With nMOS-pMOS Configuration and Capacitively Coupled Loads for Sub-GHz IoT Applications

This brief presents an inductorless <inline-formula> <tex-math notation="LaTeX">$g_{m}$ </tex-math></inline-formula>-boosted wideband balun low noise amplifier (LNA) for low power sub-GHz IoT applications. The proposed common source (CS) - common gate (CG) based <inline-formula> <tex-math notation="LaTeX">$g_{m}$ </tex-math></inline-formula>-boosted balun LNA uses nMOS-pMOS configuration for doubling the transconductance and gain efficiency. Loads of CS and CG stages are capacitively coupled to remove the tradeoff between voltage gain and voltage headroom. In addition to this, the circuit employs noise cancelation using the CS-CG pair. The LNA is implemented in 0.18 <inline-formula> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula> RFCMOS process, which achieves a maximum voltage gain of 19.6 dB with a minimum noise figure (NF) of 3.6 dB. The 3-dB bandwidth ranges from 0.13 GHz to 0.93 GHz. The minimum IIP3 and IIP2 measured are −8.5 dBm and 12 dBm, respectively. The LNA core area is 0.18 <inline-formula> <tex-math notation="LaTeX">$mm^{2}$ </tex-math></inline-formula> and dissipates a total power of 3 mW from 1.8 V power supply.