Millimeter wave transmission line structures

Apparatus, comprising:

• a stacked dielectric substrate having a first layer, a second layer, a third layer, and a fourth layer, wherein the second layer is interposed between the first and third layers and the third layer is interposed between the second and fourth layers;
• first metal traces on the first layer, wherein the first metal traces form a first antenna resonating element for a first millimeter wave antenna;
• second metal traces on the second layer;
• third metal traces on the third layer, wherein the third metal traces form a first coplanar waveguide that conveys millimeter wave signals for the first millimeter wave antenna;
• and
• fourth metal traces on the fourth layer, wherein the fourth metal traces form a second antenna resonating element for a second millimeter wave antenna and the second metal traces form a second coplanar waveguide that conveys millimeter wave signals for the second millimeter wave antenna.

An electronic device comprising:

• a stacked dielectric substrate having a first layer, a second layer over the first layer, and a third layer over the second layer;
• first metal traces on the first layer, wherein the first metal traces form an antenna ground for first and second antennas, a first coplanar waveguide transmission line for the first antenna, and a second coplanar waveguide transmission line for the second antenna;
• second metal traces on the third layer, wherein the second metal traces form a first patch antenna resonating element for the first antenna and a second patch antenna resonating element for the second antenna;
• and
• transceiver circuitry that is configured to transmit first signals to the first antenna over the first coplanar waveguide transmission line and second signals to the second antenna over the second coplanar waveguide transmission line, wherein the first and second signals are at frequencies between 10 GHz and 300 GHz.