Active-inductor-based low-power broadband harmonic VCO in SiGe technology for wideband and multi-standard applications

This paper presents the first reported description, analysis, and measured performance of a wideband harmonic generation technique that utilizes the non-linearity of a tunable active inductor (TAI) in SiGe technology. The technique demonstrates the highest reported measured fundamental tuning range of 3.5 GHz, for a TAI-VCO, from 1.7-5.2 GHz (100% tuning) while consuming only 3.7 mW from a 1.8 V supply. Higher frequencies, as high as the 4th harmonics, between 3.4-8.4 GHz, are generated with output power close to or higher than that of the fundamental frequency. Detailed analysis has been performed to optimize the noise performance of the TAI, as well as to study the principle of harmonic generation.