An inductorless and capacitorless LNA with noise and distortion cancelation

In this paper, a broadband CMOS differential LNA for DC∼2 GHz software defined radio is proposed. The channel thermal noise and the flicker noise of input MOSFET is canceled by exploiting a noise-canceling technique. A lower noise figure and an excellent wide-band input matching can be achieved at the same time. Moreover, the distortions introduced by input MOSFET can be partly cancelled using the proposed technique. The input matching stage and the noise-canceling stage are coupled by a diode. The circuit is fabricated in a 0.18 µm CMOS process. The measurement results show that in DC∼2 GHz, S11 is lower than −11 dB, the gain is between 8∼12 dB, the minimum NF is 3.0 dB, and the OIP3 is >10.4 dBm. It consumes 10 mA under a 1.8V supply. This chip occupies 310 µm × 110 µm core area without any inductors and capacitors.