Electrical connector having a circuit board with controlled impedance

A circuit board comprising:

• a top surface including a first region and a second region;
• circuit traces formed on the top surface and extending in the first region and the second region;
• a first ground plane in the circuit board, the first ground plane disposed below the circuit traces in the first region at a first depth;
• and
• a second ground plane in the circuit board, the second ground plane disposed below the circuit traces in the second region at a different second depth, wherein the first ground plane does not overlie at least a portion of the second around plane.

A circuit board comprising:

• a top surface having first and second regions;
• circuit traces formed on the top surface and extending in the first and second regions;
• a first ground plane disposed in the circuit board below the circuit traces in the first region at a first depth, the first ground plane controlling a characteristic impedance of the circuit traces in the first region based on at least one of surface area of the circuit traces within the first region and dielectric constant of material disposed between the top surface and the first ground plane;
• and
• a second ground plane disposed in the circuit board below the circuit traces in the second region at a different second depth, the first and second depths being different the second ground plane controlling a characteristic impedance of the circuit traces in the second region based on at least one of surface area of the circuit traces within the second region and dielectric constant of material disposed between the top surface and the second ground plane, wherein the first and second ground planes have at least one of different shapes, sizes and areas.