A 300-GHz Fundamental Oscillator in 65-nm CMOS Technology

Fundamental oscillators prove the existence of gain at high frequencies, revealing the speed limitations of other circuits in a given technology. This paper presents an oscillator topology that employs feedback from an output stage to the core, thus achieving a high speed. The behavior of the proposed oscillator is formulated and simulations are used to compare it with the conventional cross-coupled pair circuit. Three prototypes realized in 65-nm CMOS technology operate at 205 GHz, 240 GHz, and 300 GHz, each drawing 3.7 mW from a 0.8-V supply.