A Highly Linear SAW-Less Noise-Canceling Receiver With Shared TIAs Architecture

A modified noise/nonlinearity cancellation low-noise transconductance amplifier (LNTA) based on an inductively degenerated common-source stage is proposed to improve linearity. The linearity of the proposed LNTA is analyzed using the Volterra series yielding closed-form equations for the third-order input intercept point (IIP3) that shows excellent matching with the simulation results. The derived equations for noise figure (NF) and IIP3 are simple enough to be used for design optimization. Calculations and simulation results show that the proposed LNTA is more linear than a conventional one, while NF approximately remains unchanged. Another feature of the proposed noise-canceling LNTA is that no additional baseband recombination stage is needed, leading to reduced complexity in the receiver baseband stage. The NF and out-of-band (OOB) IIP3 of the receiver is about 3.3 dB and more than 20 dBm, respectively. The receiver consumes 10.5 mA from 1.8-V supply voltage. The current consumption of the LO divider is 6.5 mA from a dedicated 1-V supply voltage.