A Submilliwatt K-Band Low-Noise Amplifier for Next Generation Radio Astronomical Receivers in 65-nm CMOS Process

An ultralow-power
$K$
-band low-noise amplifier (LNA) for next generation radio astronomical receivers fabricated in 65-nm CMOS technology is presented in this letter. A gate–source transformer feedback is utilized for the simultaneous noise and impedance matching. In order to achieve high gain with limited dc power consumption (
$P_{\mathrm {dc}}$
), a single-ended neutralization technique is applied to the circuit. According to measurement, the proposed
$K$
-band LNA achieves a 19.1-dB small signal gain with 2.8-GHz 3-dB bandwidth (21.2–24 GHz) and noise figure of 3.6 dB with only 0.99 mW
$P_{\mathrm {dc}}$
. To the best of author’s knowledge, this LNA shows the highest figure of merit (FoM), which is 7071 1/W, among published
$K$
-band low-power LNAs.