Multi-core VCO with robust unwanted mode suppression and circular coil topology

A method comprising:

• forming a first voltage-controlled oscillator (VCO) core on a substrate including a first cross-coupled (CC) transistor pair having a first conductivity type and a second CC transistor pair having a second conductivity type;
• forming a second VCO core on the substrate including a third CC transistor pair having the first conductivity type and a fourth CC transistor pair having the second conductivity type;
• arranging the first and second VCO cores on a first circular path opposite with each other with respect to a center of the first circular path;
• disposing a first synchronization trace on the substrate to directly connect the first CC transistor pair to the third CC transistor pair;
• and
• disposing a second synchronization trace on the substrate to directly connect the second CC transistor pair to the fourth CC transistor pair,
• wherein at least one of the first synchronization trace or the second synchronization trace crosses the center.

A system comprising:

• a signal processing circuit to provide a signal;
• a mixer that mixes the signal with a mixing frequency to translate the signal to a converted signal;
• and
• a voltage-controlled oscillator (VCO) to generate the mixing frequency, the VCO comprising:
• a first VCO core disposed on a substrate and including a first cross-coupled (CC) transistor pair having a first conductivity type and a second CC transistor pair having a second conductivity type;
• a second VCO core disposed on the substrate and including a third CC transistor pair having the first conductivity type and a fourth CC transistor pair having the second conductivity type;
• a first synchronization trace disposed on the substrate to directly connect the first CC transistor pair to the third CC transistor pair;
• and
• a second synchronization trace disposed on the substrate to directly connect the second CC transistor pair to the fourth CC transistor pair,
• wherein the first and second VCO cores are arranged on a circular path and disposed opposite with each other with respect to a center of the circular path, and
• wherein at least one of the first synchronization trace or the second synchronization trace crosses the center.