$K$ -Band CMOS-Based MESFET Cascode Amplifiers

Cascode amplifiers consisting of a common-source MOSFET integrated with a common-gate metal-semiconductor field-effect transistor (MESFET) have been manufactured using a commercial 45-nm silicon-on-insulator RF CMOS process. The enhanced breakdown voltage of the MESFETs combined with the high speed of the RF MOSFETs, results in a maximum cutoff frequency of up to 70 GHz, with a maximum available gain of 18 dB at K-band frequencies (18-27 GHz) using a 6-V supply. This high-frequency operation makes the proposed amplifier a prospective candidate for 5G and millimeter wave applications.