A 2.76‐mW, 3‐ to 10‐GHz ultrawideband LNA using 0.18‐μm CMOS technology

A low‐power (2.76 mW) common‐gate (CG) low‐noise amplifier (LNA) for ultrawideband (UWB) systems using standard 0.18 μm CMOS technology is demonstrated.Instead of the traditional single parallel inductor ( L S1 only), we propose a new matching network consisting of a series L S1 – R S1 in series with a parallel L S2 – R S2 to enhance the input matching bandwidth. Flat and high S 21 was achieved by using the connecting inductor L C and the peaking inductor L D2 to compensate the gain loss at medium frequency and high frequency, respectively. In addition, for suitable values of L C and L D2 , flat and low noise figure (NF; i.e., a nearly critically damped Q‐factor for the second‐order NF frequency response) can also be achieved. Over the 3–10 GHz band of interest, the LNA achieved S 21 of 10.1 ± 1.7 dB, minimum NF of 3.9 dB (at 4 GHz) and an average NF of 4.6 dB. The power dissipation was 2.76 mW, and the corresponding figure of merit was 4.3. Both are of the best results ever reported for a CMOS UWB LNA. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:94–97, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25667