A 4.7-to-18-GHz Ultra-Wideband Variable-Gain Balun-LNA Using 3rd-Order-Band-Pass Input Matching in 40-nm CMOS

This article presents a novel ultra-wideband variable-gain balun-LNA with 3
^rd
-order-band-pass input matching network for C to Ku wideband communications. By employing a high order band-pass LC network for input matching, the matching bandwidth of the resistive feedback stage is further increased while only deteriorating an acceptable NF. Moreover, passive on-chip balun is integrated into the proposed LNA to provide single-to-differential conversion, cascaded by a variable gain amplifier (VGA). Fabricated in standard 40-nm CMOS technology, the proposed LNA achieves a measured 3-dB bandwidth of 4.7 to 18 GHz, NF of 5 – 6.4 dB in the 3-dB bandwidth, switchable gain of 19.3dB / 10.5dB and OP
1dB
of 3 dBm at 12 GHz. It consumes 60 mA current from a 1.1 V power supply and only occupies a die area of 0.31 mm
²
.