A K To Ka Band Single-ended To Balanced Ultra-wideband LNA In 45nm CMOS SOI

In this paper, a K to Ka band single-ended to balanced ultra-wideband low noise amplifier (LNA) is presented. By employing shunt feedback network, the LNA circuit can achieve a better wideband performance. On the other hand, adding another transistor in the first-stage circuit to invert the signal, the LNA circuit can operate at a differential mode while maintaining a single-ended signal input. In addition, a capacitance cross coupling network is introduced to solve the problem of signal amplitude inconsistency. Using a standard 45nm SOI CMOS process, the proposed LNA exhibits 23 dB gain and a noise figure of 2.7 dB to 3.2 dB from 18 to 40 GHz, while the input and output return loss are less than 10 dB, respectively.