Concept of frequency-transconductance tuning of bipolar voltage-controlled oscillators

Due to technology limitations as well as stringent operating conditions that are imposed, the design of fully integrated analog RF front-end circuits is aimed at the edge of the required performances. Such an approach implies that each dB of power or noise is of high importance, as it directly determines the range of operation of a system. Accordingly, a design trajectory that offers certain power savings, while still keeping the system within the required range of operation, appears to be a promising candidate for nowadays highly stringent low-power RF front-end circuit design. The concept of frequency-transconductance tuning, introduced in this paper, offers the possibility for voltage-controlled oscillators to trade power consumption for loop-gain and phase-noise. Detailed analysis shows how this concept is employed to achieve full control over the operation of the oscillator that is being changed as a result of a frequency tuning.