Voltage-controlled oscillators and related systems

A voltage-controlled oscillator, comprising:

• a first node adapted to receive a first voltage;
• a second node adapted to receive a second voltage;
• a third node adapted to receive a third voltage;
• a fourth node adapted for receiving a first oscillating signal;
• a fifth node adapted for receiving a second oscillating signal;
• an active-circuit arrangement adapted to facilitate the first oscillating signal at the fourth node and the second oscillating signal at the fifth node, the active-circuit arrangement being coupled to the first node;
• a resonator arrangement coupled to the second node and the third node, the resonator arrangement adapted to substantially determine an oscillation frequency for the first oscillating signal at a first resonator node and adapted to substantially determine an oscillating frequency for the second oscillating signal at a second oscillator node, wherein the oscillating signals at the first and second resonator nodes are based on a difference between the voltages at the second and third nodes;
• a first capacitive element coupled between the fourth node and the first resonator node;
• a second capacitive element coupled between the fifth node and the second resonator node;
• and
• wherein the active-circuit arrangement comprises a first amplifying element having a first main terminal thereof coupled to the fourth node and a second amplifying element having a first main terminal thereof coupled to the fifth node, and wherein control terminals of the first and second amplifying elements are cross-coupled, respectively, to the second and first resonator nodes.