A Transformer Noise-Canceling Ultra-Wideband CMOS Low-Noise Amplifier

Previously reported wideband CMOS low-noise amplifiers (LNAs) have difficulty in achieving both wideband input impedance matching and low noise performance at low power consumption and low supply voltage. We present a transformer noise-canceling wideband CMOS LNA based on a common-gate topology. The transformer, composed of the input and shunt-peaking inductors, partly cancels the noise originating from the common-gate transistor and load resistor. The combination of the transformer with an output series inductor provides wideband input impedance matching. The LNA designed for ultra-wideband (UWB) applications is implemented in a 90 nm digital CMOS process. It occupies 0.12 mm2 and achieves |S 11 | < −10 dB, NF < 4.4 dB, and |S 21 | > 9.3 dB across 3.1–10.6 GHz with a power consumption of 2.5 mW from a 1.0 V supply. These results show that the proposed topology is the most suitable for low-power and low-voltage UWB CMOS LNAs. key words: CMOS, low-noise amplifier (LNA), noise cancellation, ultrawideband (UWB), transformer