Design of Wideband LNA Employing Cascaded Complimentary Common Gate and Common Source Stages

A wideband low noise amplifier (LNA) is presented, which composes of cascaded complimentary common gate (CCG) stage and common source (CS) stages. Based on the current reusing technique, the CCG stage saves dc power and reduces chip area by replacing two inductors with one transformer. The source-degenerated CS stage helps form a frequency-dependent load for the CCG stage. With a load reusing technique, this load can be transformed to the input and helps achieve simultaneous wideband gain, wideband input matching, and flat noise figure (NF) over the desired band. The proposed LNA shows the measured 3-dB bandwidth from 7.6 to 29 GHz, the maximum power gain of 10.7 dB, and the NF from 4.5 to 5.6 dB. The power consumption is 12.1 mW with 1-V supply voltage and the chip occupies an area of 0.3 mm(2) in Taiwan Semiconductor Manufacturing Company (TSMC) 65-nm CMOS process.