LC-oscillators above 100 GHz in silicon-based technology

In this paper, voltage-controlled LC-oscillators (VCO) are presented, reaching oscillation frequencies well above 100 GHz. The oscillators were fabricated in a 200 GHz SiGe:C BiCMOS technology with 0.25 μm minimum feature size. In the design of the VCOs, two approaches for the frequency tuning of the oscillators were investigated. In the first design, the current flowing through the oscillator core was varied to get control of the output frequency. In the second design, a MOS-type varicap was used to tune the frequency of the LC-oscillator. The fabricated oscillators have a tuning range from 105.8 GHz to 114.5 GHz and from 113.2 GHz to 117.2 GHz, respectively.