A1-11 GHz Balun CMOS LNA Achieving 1.9-dB NF Gain-Error <0.15 dB and Phase-Error < 0.9°

In this paper, we propose a broadband balun low-noise amplifier (LNA), employing a two-stage capacitor cross-coupled common gate (CCCG) and complementary n/pMOS configuration. Based on the traditional common-source(CS) active feedback topology, the two-stage CCCG structure employed reduces the gain and phase errors of the differential output. Additionally, the complementary
$\mathrm{n}/\text{pMOS}$
configuration is utilized to achieve doubled current efficiency while alleviating the voltage headroom at the output. By using the series peaking technique, the gate-inductor extends the bandwidth of
$\mathrm{s}_{11}$
. After applying these techniques, we design a prototype of the LNA in a standard 65 nm CMOS technology. Simulation results show that within the bandwidth of 1–11 GHz, we achieve a gain of 19.5 dB, a noise figure (NF) of 1.9-2.7 dB. Gain and phase errors are within 0.15 dB and 0.9° while the IIP3 reaches −1.4 dBm. The proposed circuit consumes only 9.7 mW and occupies a core area of only 0.104
$\text{mm}^{2}$
.