Abstract: A voltage-controlled oscillator includes two first inductors having a common node, two varactors respectively coupled to the first inductors, a cross-connected pair coupled to the first inductors, and a reversely tunable source degeneration module coupled to the cross-connected pair. The reversely tunable source degeneration module cooperates with the cross-connected pair to form a negative equivalent capacitance seen into the cross-connected pair from the common node of cross-connected pair and each first inductor. An oscillatory signal pair is provided at the first terminals of the first and second transistors.

Abstract: A voltage-controlled oscillator includes two first inductors having a common node, two varactors respectively coupled to the first inductors, a cross-connected pair coupled to the first inductors, and a reversely tunable source degeneration module coupled to the cross-connected pair. The reversely tunable source degeneration module cooperates with the cross-connected pair to form a negative equivalent capacitance seen into the cross-connected pair from the common node of cross-connected pair and each first inductor. An oscillatory signal pair is provided at the first terminals of the first and second transistors.

Abstract: A voltage-controlled oscillator includes two first inductors having a common node, two varactors receiving a first bias voltage and respectively coupled to the first inductors, first and second transistors each having a first terminal coupled to a respective one of the varactors, and two second inductors. One of the second inductors is coupled between the control terminal of the first transistor and the first terminal of the second transistor. The other second inductor is coupled between the control terminal of the second transistor and the first terminal of the first transistor. An oscillatory signal pair is provided at the first terminals of the first and second transistors.