A 450 mV supply self-biased wideband inductorless balun LNA for sub-GHz applications

This paper presents a CMOS wideband LNA topology operating under a 450 mV voltage supply in the analog TV white spaces frequency band from 54 MHz to 862 MHz. It could be used in a wideband RFID or energy harvesting communication network applications. The proposed circuit is self-biased, uses no inductors and it has a cascaded amplifier in the noise canceling branch for a better trade-off of noise figure (NF), S11 and IP3. The 450 mV operation is achieved by a proper choice of the basic amplifiers that compose the noise canceling topology. This paper demonstrates the use of low-VT PMOS transistors and zero-VT NMOS transistors in a RF circuit, in order to be self-biased in a 130 nm CMOS technology PDK from Global Foundries. The post-layout simulations included bondwire inductances and pad capacitances parasitics for more realistic results. Under such a low supply, the LNA circuit is capable of Voltage Gain > 17 dB, NF < 6.2 dB and S11 < -10.3 dB, in the 54 MHz -- 862 MHz range. The overall LNA power consumption is only 2 mW.