A 0.0078mm2 3.4mW Wideband Positive-feedback-Based Noise-Cancelling LNA in 28nm CMOS Exploiting $\boldsymbol{G}_{\mathrm{m}}$ Boosting

The noise figure (NF) of the low-noise amplifier (LNA), located at the forefront of wideband receivers, directly influences the total NF of the receiver. A popular approach to suppress the noise of the input transistor to decrease the LNA NF is to utilize a noise-cancelling (NC) technique, where the main amplifier provides input matching, while the auxiliary amplifier removes the noise of the main amplifier [1]. In this scenario, the common-gate (CG) common-source (CS) NC LNA has been widely investigated because it features simultaneous noise and distortion cancellation. To achieve a NF of 3dB, the CG-CS LNA in [2] consumes 15.4mA. By employing the $g_{m}$ -boosting technique, a NF of 3.5dB is achieved in [3] while consuming 7.5mA. Benefiting from the current reuse technique, the current dissipation in [4] is reduced to 4.5mA with a NF of 2.09dB. For these reported works, the noise contribution of the auxiliary amplifier dominates the NF. However, the noise factor contributed by the auxiliary amplifier is inversely proportional to its transconductance $(g_{m})$; hence, the noise contribution of the auxiliary amplifier can only be reduced by increasing $g_{m}$ at the cost of current dissipation, rendering the NC LNA a power-hungry component of a wideband receiver.

The noise figure (NF) of the low-noise amplifier (LNA), located at the forefront of wideband receivers, directly influences the total NF of the receiver. A popular approach to suppress the noise of the input transistor to decrease the LNA NF is to utilize a noise-cancelling (NC) technique, where the main amplifier provides input matching, while the auxiliary amplifier removes the noise of the main amplifier [1]. In this scenario, the common-gate (CG) common-source (CS) NC LNA has been widely investigated because it features simultaneous noise and distortion cancellation. To achieve a NF of 3dB, the CG-CS LNA in [2] consumes 15.4mA. By employing the -boosting technique, a NF of 3.5dB is achieved in [3] while consuming 7.5mA. Benefiting from the current reuse technique, the current dissipation in [4] is reduced to 4.5mA with a NF of 2.09dB. For these reported works, the noise contribution of the auxiliary amplifier dominates the NF. However, the noise factor contributed by the auxiliary amplifier is inversely proportional to its transconductance ; hence, the noise contribution of the auxiliary amplifier can only be reduced by increasing at the cost of current dissipation, rendering the NC LNA a power-hungry component of a wideband receiver.