Low-power and high-linearity SiGe HBT low-noise amplifier using IM3 cancellation technique

In order to achieve high linearity and low noise figure (NF) simultaneously, a modified cascode structure with a series-shunt feedback capacitance achieving third-order intermodulation (IM3) cancellation is proposed. The proposed LNA is designed and simulated for 5.7 GHz wireless local area network (WLAN) band applications with a 0.35 μm silicon germanium (SiGe) bipolar-CMOS (BiCMOS) process. The LNA has the power gain of 16.25 dB, NF of 2.79 dB, IIP3 of 3.69 dBm with 4 mW DC power consumption from a supply voltage of 3 V. To our knowledge, by comparison with recently reported LNAs, the presented LNA achieves the highest figure of merit (FOM) by taking into account the power gain, IIP3, NF, power consumption, and operation frequency.

Figure optionsDownload as PowerPoint slideHighlights
► We propose a novel LNA topology with a series-shunt feedback capacitance.
► We examine the input impedance, noise, and linearity with respect to the capacitance.
► An optimal feedback capacitance can improve the linearity without noise degradation.
► This work demonstrates the highest figure of merit among recently published LNAs.