Bus signaling through electromagnetic couplers having different coupling strengths at different locations

A system comprising

• a circuit board bearing a bus, and
• at three or more coupling locations along the bus, coupling elements having respectively different coupling strengths for coupling with the bus, the coupling elements comprising one or more of the following:
• dielectric spacers of different heights and coupling elements of different material properties.

A method comprising

• manufacturing electromagnetic bus coupling elements having uncontrolled manufacturing variations associated with coupling strength, and
• sorting the coupling elements in accordance with the respective coupling strengths of the coupling elements within a tolerance range.

A method comprising

• providing electromagnetic coupling locations along a bus at which devices can be respectively coupled for communication on the bus,
• measuring electromagnetic coupling strengths of couplers to be used at the coupling locations, and
• causing electromagnetic coupling strengths associated with at least some coupling locations to have different, measured values, such that essentially equal amounts of energy are drained from the bus at the respective coupling locations.

A system comprising

• a circuit board bearing a bus, and
• at coupling locations along the bus, coupling elements associated with different measured coupling strengths for coupling with the bus, such that essentially equal amounts of energy are drained from the bus at the respective coupling locations, the coupling elements comprising one or more of the following:
• dielectric spacers of different heights and coupling elements of different material properties.

A motherboard comprising

• a bus, and
• at locations along the bus coupling elements having different strengths of coupling with communicating devices, such that essentially equal amounts of energy are drained from the bus at the respective coupling locations, the coupling elements comprising one or more of the following:
• coupling traces of different trace widths and coupling traces of different configuration patterns.

A method comprising:

• measuring electromagnetic coupling strength of couplers to be used at three or more coupling locations along a bus at which devices can be respectively coupled for communication on the bus;
• and
• making couplers having different measured electromagnetic coupling strengths for mounting in at least three of the coupling locations.