Voltage-controlled oscillator devices

A device, comprising:

• a first planar coil including a first plurality of conductive loop segments that are concentric with one another and centered on a first axis, the first axis spaced laterally from a first side of a plane by a first distance, and the first axis extending in parallel with the plane;
• and
• a second planar coil coupled to the first planar coil, the second planar coil including a second plurality of conductive loop segments that are concentric with one another and centered on a second axis, the second axis extending in parallel with the first axis and spaced laterally from a second side of the plane by the first distance, the second side being opposite the first side,
• wherein the first planar coil is symmetric to the second planar coil about the plane.

A device comprising:

• an amplifier disposed in a substrate and having an input;
• a first oscillator disposed in the substrate and having an output coupled to the input of the amplifier;
• a second oscillator disposed in the substrate and having an output coupled to the input of the amplifier;
• a first loop disposed within the substrate, the first loop coupled to the first oscillator;
• and
• a second loop disposed within the substrate and coupled to the first loop, the second loop coupled to the second oscillator, and symmetric to the first loop about a plane,
• wherein the first oscillator and the second oscillator are arranged symmetrically distributed across the plane.

A system comprising:

• a digital circuit having an output terminal;
• a mixer having a first input terminal, a second input terminal, and an output terminal, the first input terminal of the mixer coupled to the output terminal of the digital circuit;
• an amplifier having an input terminal, a first output terminal, and a second output terminal, the input terminal of the amplifier coupled to the output terminal of the mixer;
• a transformer having a first input terminal, a second input terminal, and an output terminal, the first input terminal of the transformer coupled to the first output terminal of the amplifier, the second input terminal of the transformer coupled to the second output terminal of the amplifier, the output terminal of the transformer coupled to an antenna terminal;
• and
• a phase locked loop (PLL) having an output terminal coupled to the second input terminal of the mixer, and wherein the phase locked loop includes a first coil and a second coil,
• wherein a center of the first coil is spaced from a center of the transformer by a first distance, a center of the second coil is spaced from the center of the transformer by a second distance, and wherein an absolute difference between the first distance and the second distance is less than 10 micrometers.