A CMOS Wideband Linear Low-Noise Amplifier Using Dual Capacitor-Cross-Coupled Configurations

A wideband differential common-gate (CG) low-noise amplifier is proposed with dual-capacitor-cross-coupling(CCC) feedforward structures. Besides the noise reduction benefit, the input CCC CG stage boosts the interstage gain to alleviate the trade-off between load headroom and gain. The other CCC structure is applied to an intermodulation distortion source and reduces auxiliary transistors' scaling by similar to 8x. The resulting significantly low parasitics are expected to reduce the sensitivity of the post-distortion technique to frequency variations. The configuration of all-nMOS and all-saturation-region bias is to ensure the robustness of linearization. The proposed circuit is fabricated in a 180 nm CMOS process. Experimental results have shown an average value of 14.5 dB gain and 3.1 dB NF across a passband range of 0.2-3.5 GHz. Moreover, the passband IIP3 is shown as 14-19.7 dBm while IIP2 linearity takes similar to 41.5 dBm. The circuit core consumes 7 mW with a 1.8 V supply and occupies an area of 598x265 mu m(2).