Design of Wideband LNAs Using Parallel-to-Series Resonant Matching Network Between Common-Gate and Common-Source Stages

A method is proposed to design wideband low-noise amplifiers (LNAs) made of cascaded common-gate (CG) and common-source (CS) stages with a parallel-to-series resonant interstage matching network. The first CG stage has a dual-band response, and the second CS stage has higher gain between these two bands. By applying the proposed interstage matching technique, conjugate matching is achieved at high and low bands, while the midband loss is compensated by the second stage. The output network of the first stage and the input network of the second stage resonate at the same frequency. Two wideband LNAs are designed based on this method and implemented in 0.18-mu m RF-mixed signal CMOS process. The first LNA operates at 3.1-10.3 GHz, having 9.6-12.71 dB of power gain and 2.5-3.9 dB of noise figure (NF) at the power consumption of 13.4 mW. The second LNA operates at 14.3-29.3 GHz, having 8.25 +/- 1.65 dB of power gain and 4.3-5.8 dB of NF at the power consumption of 13.9 mW.