An interferer filtering CMOS LNA for multiband wireless receiver

Abstract

In this paper, A CMOS low noise amplifier (LNA) with an integrated notch feedback for interferer cancellation is presented. The proposed LNA adopts the integrated tunable notch feedback stage to cancel interferer signals at the input of the LNA, which eliminates the need of an off-chip filter. To improve the quality factor of the LC resonators, Q-enhancement circuit is used in the notch feedback stage. The proposed LNA is designed in a 0.13 μm CMOS technology. The LNA with the integrated notch feedback achieves an interferer rejection of 21.6 dB with a interferer at 80 MHz offset. A noise figure is 6.1 dB at 1.9 GHz center frequency, an input-referred third-order intercept point is - 16.7 dBm and the LNA consumes a current of 37.8 mA from a 1.2 V supply voltage when the notch feedback stage is on.