Analysis and design of a compact ultrawideband LNA with 2.3 ± 0.1 dB NF and ±14.6 ps group‐delay‐variation in 0.18‐µm CMOS

Abstract

ABSTRACTA low‐noise figure (NF) and high power gain (S21) 3–10 GHz ultrawideband low‐noise amplifier (UWB LNA) with excellent phase linearity using standard 0.18‐µm CMOS technology is reported. An enhanced π‐match input network is used to achieve wideband input impedance matching. Both high and flat S21 and low and flat NF frequency responses are achieved by tuning the pole frequencies and pole quality factors of the second‐order gain and NF frequency responses to approximate the maximally flat condition simultaneously. The LNA consumes 18 mW, achieving S11 better than −10 dB for frequency lower than 12.2 GHz and group‐delay‐variation smaller than ±14.6 ps for frequencies 3–10 GHz. Additionally, high and flat S21 of 13.7 ± 1.5 dB is achieved for frequencies 1–12.5 GHz, which means the corresponding 3‐dB bandwidth is 11.5 GHz. Furthermore, the LNA achieves minimum NF of 2.2 dB at 4 GHz and NF of 2.3 ± 0.1 dB for frequencies 3–10 GHz, one of the best NF results ever reported for a 3–10 GHz CMOS UWB LNA. The measured input third‐order intermodulation point (IIP3) is −0.2 dBm at 6 GHz. The chip area is only 0.601 × 0.662 mm2 (i.e., 0.4 mm2) excluding the test pads. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:2047–2053, 2014