Out-band interference rejection in UWB LNA receiver using coupled inductors in 3.1–10.6 GHz

In this paper, a UWB LNA circuit with a new input stage is proposed. In this scheme, a combination of coupled inductors in the input stage is utilized. The input stage is able to easily reject out-band interference with 29.6 dB. This input stage is applied in an LNA with 0.18 μm technology. The LNA has a peak gain of 24 dB in 3.1-10.6 GHz frequency band while showing a minimum noise figure of 1.44 dB in the mentioned frequency band. Power consumption of the UWB LNA core is 14.1 mW DC which is supplied from a 1.8 V power supply. S₁₁ is less than -10.3 dB over the entire bandwidth since the best value of IIP3 over the entire bandwidth is -13 dBm which occurs at the frequency of 6GHz.