Abstract: One example discloses a near-field wireless device, including: a stack of layers distributed along a first axis; a first near-field antenna having a conductive surface and embedded in a first layer within the stack of layers; wherein the conductive surface is configured to carry non-propagating quasi-static near-field electric-induction signals for on-body near-field communications; a second near-field antenna having an inductive loop and embedded in a second layer within the stack of layers; wherein the inductive loop is configured to carry non-propagating quasi-static near-field magnetic-induction signals for off-body near-field communications; wherein the first and second layers are different layers; and wherein the first and second antennas are not in galvanic contact.

Abstract: One example discloses a wireless device, including: a first near-field device, including a near-field transmitter or receiver and a controller, configured to be coupled to a near-field antenna having a first conductive surface and a set of feed-points; wherein the controller is configured to receive a transmitter output voltage from the set of feed-points; wherein the controller is configured to generate a correction signal based on a difference between the transmitter output voltage and a target transmitter output voltage; wherein the correction signal varies in response to a change in a distance between the first surface and a second conductive surface; and wherein the controller is configured to calculate the distance, between the first conductive surface and the second conductive surface, based on the correction signal.

Abstract: One example discloses a near-field wireless device, including: a coil, including a first feed-point and a second feed-point, and configured to carry non-propagating quasi-static near-field magnetic-induction wireless signals; a conductive surface, including a third feed-point, and configured to carry non-propagating quasi-static near-field electric-induction wireless signals; a tuning circuit including a first tuning element, a second tuning element, and a mid-point; wherein a first end of the first tuning element is coupled to the first feed-point; wherein a first end of the second tuning element is coupled to the second feed-point; wherein a second end of the first tuning element and a second end of the second tuning element are coupled to the mid-point; and wherein the third feed-point is coupled to the mid-point.

Abstract: One example discloses a near-field device, including: a conductive housing physically coupled to the near-field device; a near-field antenna, having a first feed point and a second feed point, and including, a first inductive coil having a first end coupled to the first feed point, a second end coupled to the second feed point, and a connection point; a conductive plate capacitively coupled to the conductive housing, and coupled to the first end of the first inductive coil; a tuning circuit; a reference potential; wherein another end of each of the capacitance banks and another end of each of the resistance banks are coupled to the reference potential; wherein the connection point is galvanically coupled to the reference potential; and wherein the conductive housing is galvanically coupled to the reference potential.

Abstract: One example discloses a device including a near-field electromagnetic induction (NFEMI) antenna, including: a first inductive coil having a first end coupled to a first feeding connection and a second end coupled to a second feeding connection; a second inductive coil, having a first end coupled to the second end of the first inductive coil and a second end; wherein the second inductive coil is formed into a first surface; a third inductive coil formed into a second surface; wherein the first surface including the second inductive coil and the second surface including the third inductive coil are configured to form a first capacitance (C); wherein the third inductive coil includes a first end galvanically coupled to the second end of the second inductive coil; wherein the first inductive coil is configured to receive or transmit non-propagating quasi-static near-field magnetic induction signals; and wherein the second and third inductive coil are configured to receive or transmit non-propagating quasi-static

Abstract: One example discloses a device including a near-field electromagnetic induction (NFEMI) antenna, including: a first inductive coil having a first end coupled to a first feed connection and a second end coupled to a second feed connection; a second inductive coil, having a first end coupled to either end of the first inductive coil or either one of the feed connections; wherein a second end of the second inductive coil is electrically open-ended; wherein the first inductive coil is configured to receive or transmit near-field magnetic signals; and wherein the second inductive coil is configured to receive or transmit near-field electric signals.

Abstract: One example discloses a wireless device, including: a first near-field device, including a near-field transmitter or receiver and a controller, configured to be coupled to a near-field antenna having a first conductive surface and a set of feed-points; wherein the controller is configured to receive a transmitter output voltage from the set of feed-points; wherein the controller is configured to generate a correction signal based on a difference between the transmitter output voltage and a target transmitter output voltage; wherein the correction signal varies in response to a change in a distance between the first surface and a second conductive surface; and wherein the controller is configured to calculate the distance, between the first conductive surface and the second conductive surface, based on the correction signal.

Abstract: An interference sensor device is disclosed. The interference sensor device includes a first conductive plate and a second conductive plate aligned parallel to the first conductive plate. A non-conductive matter is included between the first conductive plate and the second conductive plate. A band pass filter is coupled with the first conductive plate and the second conductive plate. The band pass filter includes a sensor coil. A current transformer having a primary side and a secondary side is included. The primary side is coupled with the band pass filter, and the secondary side is configured to be coupled with a cable. The current transformer having a high capacitive isolation.

Abstract: One example discloses a near-field device, including: a conductive housing physically coupled to the near-field antenna; a near-field antenna, having a first feed point and a second feed point, and including, a first inductive coil; a first conductive plate capacitively coupled to the conductive housing, and galvanically coupled to the first end of the first inductive coil; a second conductive plate capacitively coupled to the conductive housing, and galvanically coupled to the second end of the first inductive coil; a reference potential; and wherein the conductive housing 302 is galvanically coupled to the reference potential; wherein the first inductive coil is configured to receive or transmit near-field magnetic signals; and wherein the first and second conductive plates and the conductive housing are configured to receive or transmit near-field electric signals.

Abstract: One example discloses a near-field electromagnetic induction (NFEMI) device configured to be coupled to a non-planar conductive host surface, including: a coil antenna portion configured as a magnetic field antenna; and a conductive antenna surface configured as an electric field antenna; wherein the conductive antenna surface geometrically conforms to the non-planar host surface.

Abstract: Example of a near-field electromagnetic induction (NFEMI) device, including: an NFEMI antenna, having a first conductive plate, a coil, a first signal feed connection, and a second signal feed connection; wherein the coil is configured to generate or respond to a magnetic field and is coupled to the first and second signal feed connections; wherein the first conductive plate is coupled to the first signal feed connection; and an electrical apparatus, having a ground plane, a first capacitor and a second capacitor; wherein the electrical apparatus is coupled to the first and second signal feed connections; wherein the first capacitor is coupled between the first signal feed connection and the ground plane; wherein the second capacitor is coupled between the second signal feed connection and the ground plane; and wherein the first conductive plate in combination with the ground plane is configured to generate or respond to an electrical field.

Abstract: One example discloses a near-field device, including: a conductive housing physically coupled to the near-field antenna; a near-field antenna, having a first feed point and a second feed point, and including, a first inductive coil; a first conductive plate capacitively coupled to the conductive housing, and galvanically coupled to the first end of the first inductive coil; a second conductive plate capacitively coupled to the conductive housing, and galvanically coupled to the second end of the first inductive coil; a reference potential; and wherein the conductive housing 302 is galvanically coupled to the reference potential; wherein the first inductive coil is configured to receive or transmit near-field magnetic signals; and wherein the first and second conductive plates and the conductive housing are configured to receive or transmit near-field electric signals.

Abstract: One example discloses a first near-field electromagnetic induction (NFEMI) device, including: a controller configured to be coupled to an NFEMI antenna and to a structure; wherein the NFEMI antenna includes electric (E) near-field and magnetic (H) near-field generating and/or receiving portions; wherein the controller is configured to modulate a ratio of energy sent to and/or received from the electric and magnetic portions; wherein the controller is configured to receive a signal corresponding to whether the structure is between the first NFEMI device and a second NFEMI device; and wherein the controller is configured to decrease the ratio of energy sent to and/or received from the electric (E) portion as compared to energy sent to and/or received from the magnetic (H) portion if the structure is between the first and second NFEMI devices.

Abstract: One example discloses a combination antenna, including a near-field antenna, having a first portion and a second portion; and a far-field antenna, having a cavity; wherein the first portion of the near-field antenna structure is inside the cavity and the second portion is outside of the cavity.

Abstract: A near-field device, including: a near-field receiver coupled to a near-field receiver antenna and a decoder circuit; wherein the near-field receiver antenna is configured to be capacitively coupled at a first location on a conductive structure; wherein the near-field receiver antenna is configured to receive a near-field signal from the conductive structure through the receiver's capacitive coupling; and wherein the decoder circuit is configured to detect variations in the near-field signal.

Abstract: One example discloses a multi-channel near-field electromagnetic induction (NFEMI) device, including: a sub-channel controller configured to be coupled to a near-field magnetic antenna (H-field) and a near-field electric antenna (E-field) and configured to receive a message to be transmitted to a second near-field device in a near-field body-network through the near-field electric and magnetic antennas; wherein the sub-channel controller is configured to divide a narrow-band near-field channel into a set of sub-channels; and wherein the sub-channel controller is configured to calculate a signal-to-noise-ratio (SNR) for each sub-channel and select a sub-channel, from the set of sub-channels, for transmission of the message that has a higher SNR than another sub-channel in the set of sub-channels.

Abstract: One example discloses a wireless device, including: a first near-field device, including a near-field transmitter or receiver and a controller, configured to be coupled to a first conductive surface; wherein the near-field receiver includes a set of tuning values configured to either set a near-field resonance frequency or an operational bandwidth of the first near-field device; wherein the controller is configured to change at least one of the tuning values in response to a change in a distance between the first surface and a second conductive surface; and wherein the controller is configured to calculate the distance, between the first conductive surface and the second conductive surface, based on the at least one of the tuning values.

Abstract: One example discloses a near-field wireless device, including: a near-field antenna having a first conductive surface and a second conductive surface; wherein the conductive surfaces are configured to carry non-propagating quasi-static near-field electro-induction (NFEI) signals; a tuning circuit coupled to the near-field antenna and having a set of tuning parameters; a controller coupled to the tuning circuit; wherein the controller is configured to monitor a loading of the near-field antenna; wherein the controller is configured to adjust the tuning parameters if the loading is different from a preselected loading; and wherein the controller is configured to set a user present status in response to a predefined threshold change in the set of tuning parameters.

Abstract: One example discloses a near-field communications device, including: an energy harvesting circuit configured to be coupled to a near-field antenna that is responsive to non-propagating quasi-static near-field energy; wherein the harvesting circuit is configured to harvest energy from the non-propagating quasi-static near-field energy; and wherein the harvesting circuit includes a harvesting filter configured to input a first set of near-field energy and output a second set of near-field energy; and wherein the second set of near-field energy is a sub-set of the first set of near-field energy.

Abstract: One example discloses a near-field wireless device, configured to be coupled to a host conductive structure, including: an electric near-field antenna, having a first conductive antenna surface coupled to a first feed point, and a second conductive antenna surface coupled to a second feed point; wherein the first and second conductive surfaces are separated by an air-gap; wherein the first and second conductive surfaces are configured to be substantially equidistant from the host conductive structure; and wherein the first and second conductive surfaces geometrically conform to the host conductive structure.