Multi-channel cooling for extended distance wireless power transmitter

A power transmitter for wireless power transfer to a mobile device having a power receiver couplable with the power transmitter, the mobile device defining, at least, a mobile device front surface and a mobile device rear surface, the power transmitter comprising:

• a control and communications unit;
• an inverter circuit configured to receive input power and convert the input power to a power signal;
• a transmitter antenna including:
• at least one coil structure configured to transmit the power signal to the power receiver, the at least one coil structure comprising at least one layer of Litz wire, wherein the at least one coil structure has a top surface, a bottom surface, and a side surface, and
• a shielding structure comprising a ferrite material and having a cavity, the cavity configured such that the ferrite material substantially surrounds at least a portion of the bottom surface of the at least one coil structure and at least a portion of the side surface of the at least one coil structure;
• and
• a housing configured for housing, at least, the transmitter antenna, the housing defining:
• a top surface, upon which the mobile device is placed for wireless power transfer,
• a bottom surface, wherein a housing thickness is, at least in part, defined between the top surface and the bottom surface,
• an airflow opening,
• a first airflow channel configured to provide airflow, via the airflow opening, proximate to one or more of the top surface of the housing, the mobile device rear surface, or combinations thereof,
• a protrusion extending outward, at least in part, from the top surface, the protrusion having a protrusion side face the protrusion side face forming an angle with the top surface of the housing, the angle being less than about 180 degrees and greater than about 0 degrees, and
• a second airflow channel configured to provide the airflow, via the airflow opening, proximate to one or more of the protrusion side face, the mobile device top surface, or any combinations thereof,
• wherein the top surface of the housing defines a first plane and the first airflow channel defines a second plane, the first and second planes staggered such that the first and second planes are offset from one another, the first plane having a first height relative to the top surface of the at least one coil structure and the second plane having a second height relative to the top surface of the at least one coil structure, wherein the first height is greater than the second height by a gap distance in a range of 8 millimeters (mm) to 10 mm,
• wherein the at least one coil structure is positioned below the first and second planes, and
• wherein the housing is configured such that, when the mobile device is placed on the top surface of the housing, the mobile device sits above the second plane such that the power receiver is separated from the at least one coil structure by a separation distance that is no less than the gap distance between the first height and the second height and the power transmitter is capable of delivering wireless power signals to the power receiver.

A power transmitter for wireless power transfer to a mobile device having a power receiver couplable with the power transmitter, the mobile device defining, at least, a mobile device front surface and a mobile device rear surface, the power transmitter comprising:

• a control and communications unit;
• an inverter circuit configured to receive input power and convert the input power to a power signal;
• a transmitter antenna including
• a transmitter coil array structure including a top surface and two or more transmitter coils, the transmitter coil array structure configured to transmit the power signal to the power receiver, each of the two or more transmitter coils comprising at least one layer of Litz wire, wherein the transmitter coil array structure has the top surface, a bottom surface, and a side surface, and
• a shielding structure comprising a ferrite material and having a cavity, the cavity configured such that the ferrite material substantially surrounds at least a portion of the bottom surface of the transmitter coil array structure and at least a portion of the side surface of the transmitter coil array structure;
• and
• a housing configured for housing, at least, the transmitter antenna, the housing defining
• a top surface, upon which the mobile device is placed for wireless power transfer,
• a bottom surface, wherein a housing thickness is, at least in part, defined between the top surface and the bottom surface,
• an airflow opening,
• a first airflow channel configured to provide airflow, via the airflow opening, proximate to one or more of the top surface of the housing, the mobile device rear surface, or combinations thereof,
• a protrusion extending outward, at least in part, from the top surface, the protrusion having a protrusion side face the protrusion side face forming an angle with the top surface of the housing, the angle being less than about 180 degrees and greater than about 0 degrees, and
• a second airflow channel configured to provide the airflow, via the airflow opening, proximate to one or more of the protrusion side face, the mobile device top surface, or any combinations thereof,
• wherein the top surface of the housing defines a first plane and the first airflow channel defines a second plane, the first and second planes staggered such that the first and second planes are offset from one another, the first plane having a first height relative to the top surface of the transmitter coil array structure and the second plane having a second height relative to the top surface of the transmitter coil array structure, wherein the first height is greater than the second height by a gap distance in a range of 8 millimeters (mm) to 10 mm,
• wherein the transmitter coil array structure is positioned below the first and second planes, and
• wherein the housing is configured such that, when the mobile device is placed on the top surface of the housing, the mobile device sits above the second plane such that the power receiver is separated from the transmitter coil array structure by a separation distance that is no less than the gap distance between the first height and the second height and the power transmitter is capable of delivering wireless power signals to the power receiver.