A 1.2-V Highly Linear Balanced Noise-Cancelling LNA in 0.13-$\mu{\hbox{m}}$ CMOS

In this paper, a current-to-voltage combiner is proposed to realize a highly linear, balanced noise-cancelling low-noise amplifier (LNA) capable of low-voltage operation. The current-to-voltage combiner, implemented in the load of the amplifier, converts the output currents of the parallel common-gate (CG) and common-source (CS) stages of the LNA to voltages, equalizes the amplitudes of the voltages, and combines the voltages to a single output voltage. Since only a CS stage and passive components are employed to cancel the noise and distortion due to the CG input impedance matching circuit, high linearity is achieved in spite of the low supply voltage of 1.2 V. The LNA achieves a noise figure (NF) of 3.0 dB at 2.1 GHz with an input-referred third-order intercept point (IIP3) of $+$10.5 dBm while consuming 10.5 mA from a 1.2-V supply. The amplifier is fabricated in 0.13-$\mu{\hbox{m}}$ CMOS process.