Abstract: Systems, methods, and devices detect radio frequency identification devices. Methods include transmitting a signal from a transmitter of a wireless device compatible with a wireless communications protocol, receiving, using a receiver of the wireless device, an encoded signal from a radio frequency identification (RFID) device, and determining a plurality of data values based, at least in part, on the received encoded signal. Methods further include generating an estimated distance value based, at least in part, on the received encoded signal, the estimated distance value representing an estimate of a distance between the wireless device and the RFID device.

Abstract: Apparatuses and methods of high-distance directional proximity sensors are described. One apparatus includes at least three electrodes in a sensor layer, an electrode in a shield layer, and an insulator located between the layers. A processing device is configured to scan the at least three electrodes over a period of time to obtain a digital signal for each of the at least three electrodes while driving a shield signal on the electrode of the shield layer. The processing device detects a gesture by an object using the digital signals. The processing device measures an amplitude value of the digital signal for each of the at least three electrodes and outputs an indication of the gesture responsive to a ratio of a highest amplitude value and a lowest amplitude value satisfying a first threshold criterion that represents the object being within a proximity detection area above the sensor layer.

Abstract: Apparatus and methods of impedance sensing are described. One method includes performing a first digital conversion of an attribute of a sensor electrode and performing a second digital conversion of the attribute of the sensor electrode. The second digital conversion differs by at least one characteristic from the first digital conversion. The method further includes calculating a resistance of the sensor electrode from a first and second digital value of the first and second digital conversions, respectively; and calculating a capacitance of the sensor electrode from the first and second digital value of the first and second digital conversions, respectively.

Abstract: Apparatuses and methods of high-distance directional proximity sensors are described. One apparatus includes at least three electrodes in a sensor layer, an electrode in a shield layer, and an insulator located between the layers. A processing device is configured to scan the at least three electrodes over a period of time to obtain a digital signal for each of the at least three electrodes while driving a shield signal on the electrode of the shield layer. The processing device detects a gesture by an object using the digital signals. The processing device measures an amplitude value of the digital signal for each of the at least three electrodes and outputs an indication of the gesture responsive to a ratio of a highest amplitude value and a lowest amplitude value satisfying a first threshold criterion that represents the object being within a proximity detection area above the sensor layer.

Abstract: A system can include one or more electrodes; a sensor structure configured to position electrodes over a surface of a body that includes an artery. A capacitance sensing circuit can be coupled to the electrodes and configured to acquire capacitance values of the electrodes over a predetermined time period. The capacitance values can correspond to a distance between the body surface and the at least one electrode. Processor circuits can be configured to generate APW data from the capacitance values. Corresponding methods and devices are also disclosed.

Abstract: Apparatus and methods of impedance sensing are described. One method includes performing a first digital conversion of an attribute of a sensor electrode and performing a second digital conversion of the attribute of the sensor electrode. The second digital conversion differs by at least one characteristic from the first digital conversion. The method further includes calculating a resistance of the sensor electrode from a first and second digital value of the first and second digital conversions, respectively; and calculating a capacitance of the sensor electrode from the first and second digital value of the first and second digital conversions, respectively.

Abstract: A fingerprint sensor-compatible overlay material which uses anisotropic conductive material to enable accurate imaging of a fingerprint through an overlay is disclosed. The anisotropic conductive material has increased conductivity in a direction orthogonal to the fingerprint sensor, increasing the capacitive coupling of the fingerprint to the sensor surface, allowing the fingerprint sensor to accurately image the fingerprint through the overlay. Methods for forming a fingerprint sensor-compatible overlay are also disclosed.

Abstract: An example method of determining the position value reflecting an action applied to the capacitive sensor device comprises: receive a set of capacitance values of a plurality of capacitive cells of a capacitive sensor device; determining a local maximum of the set of capacitance values; identifying a set of neural network parameters corresponding to the local maximum of the set of capacitance values; and processing the set of capacitance values by a neural network using the identified set of neural network parameters to determine a position value reflecting an action applied to the capacitive sensor device.

Abstract: Apparatuses and methods of high-distance directional proximity sensors are described. One apparatus includes at least three electrodes in a sensor layer, an electrode in a shield layer, and an insulator located between the layers. A processing device is configured to scan the at least three electrodes over a period of time to obtain a digital signal for each of the at least three electrodes while driving a shield signal on the electrode of the shield layer. The processing device detects a gesture by an object using the digital signals. The processing device measures an amplitude value of the digital signal for each of the at least three electrodes and outputs an indication of the gesture responsive to a ratio of a highest amplitude value and a lowest amplitude value satisfying a first threshold criterion that represents the object being within a proximity detection area above the sensor layer.

Abstract: An example method of determining the position value reflecting an action applied to the capacitive sensor device comprises: receive a set of capacitance values of a plurality of capacitive cells of a capacitive sensor device; determining a local maximum of the set of capacitance values; identifying a set of neural network parameters corresponding to the local maximum of the set of capacitance values; and processing the set of capacitance values by a neural network using the identified set of neural network parameters to determine a position value reflecting an action applied to the capacitive sensor device.

Abstract: A device can include analog circuits formed with a substrate, including a comparator, analog switches, and a balance current circuit. A sensor current and balance current can be applied at an input of the comparator. The sensor current, balance current or both can be modulated with a switch control signal. Digital circuits can include switch control logic that generates the switch control signal in response to an output of the comparator and a modulation clock signal. Digital signal processing circuits can generate a multi-bit digital value from a bit stream output by the comparator circuit. The multi-bit digital value can be an analog-to-digital conversion of the sensor current. Corresponding methods and systems are also disclosed.

Abstract: Apparatus and methods of impedance sensing are described. One method includes performing a first digital conversion of an attribute of a sensor electrode and performing a second digital conversion of the attribute of the sensor electrode. The second digital conversion differs by at least one characteristic from the first digital conversion. The method further includes calculating a resistance of the sensor electrode from a first and second digital value of the first and second digital conversions, respectively; and calculating a capacitance of the sensor electrode from the first and second digital value of the first and second digital conversions, respectively.

Abstract: Technology directed to non-contact liquid sensing is described. One processing device includes a multi-port network, a capacitance measurement circuit, and a digital processing circuit. Processing device measures a first set and a second set of currents associated with a first electrode and a second electrode coupled to an exterior surface of a container holding liquid. Processing device determines independent impedances of the container, the liquid, and the liquid and container using the first set of currents and the second set of currents. Processing device determines an electrical property of the liquid using the independent impedances of the liquid.

Abstract: A capacitive fingerprint sensor includes a set of capacitive sensor electrodes in a sensing area. The set of capacitive sensor electrodes includes a set of transmit (Tx) sensor electrodes, a set of receive (Rx) sensor electrodes, and a set of compensation electrodes. The fingerprint sensor also includes a multiphase capacitance sensor that is configured to perform a sensing scan of the capacitive sensor electrodes by applying a first Tx signal to a first subset of the Tx sensor electrodes while simultaneously applying a second Tx signal to a second subset of the set of Tx sensor electrodes, and based on a compensation signal received at the set of compensation electrodes, reduce a component of the Rx signal originating from a source other than a contact at the sensing area.

Abstract: A fingerprint sensor-compatible overlay material which uses anisotropic conductive material to enable accurate imaging of a fingerprint through an overlay is disclosed. The anisotropic conductive material has increased conductivity in a direction orthogonal to the fingerprint sensor, increasing the capacitive coupling of the fingerprint to the sensor surface, allowing the fingerprint sensor to accurately image the fingerprint through the overlay. Methods for forming a fingerprint sensor-compatible overlay are also disclosed.

Abstract: An example system drives one or more transmit signals on first electrodes disposed in a first layer and propagating electrodes disposed in a second layer. The system measures a capacitance of sensors through a of second electrodes. Each second electrode crosses each first electrode to provide a plurality of discrete sensor areas, each discrete sensor area associated with a difference crossing and including a portion of at least one propagating electrode. Each second electrode is galvanically isolated from the first electrodes and the propagating electrodes.

Abstract: A processing device scans a capacitive sense array to determine a characteristic of a noise signal. A processing device further detects a location of a touch proximate to the capacitive sense array by a passive touch object using a first mode of capacitance touch detection. The first mode of capacitive touch detection uses a capacitive coupling of the noise signal to the capacitive sense array through the passive touch object to detect the touch.

Abstract: A fingerprint sensor-compatible overlay material which uses anisotropic conductive material to enable accurate imaging of a fingerprint through an overlay is disclosed. The anisotropic conductive material has increased conductivity in a direction orthogonal to the fingerprint sensor, increasing the capacitive coupling of the fingerprint to the sensor surface, allowing the fingerprint sensor to accurately image the fingerprint through the overlay. Methods for forming a fingerprint sensor-compatible overlay are also disclosed.

Abstract: A processing device scans a capacitive sense array to determine a characteristic of a noise signal. A processing device further detects a location of a touch proximate to the capacitive sense array by a passive touch object using a first mode of capacitance touch detection. The first mode of capacitive touch detection uses a capacitive coupling of the noise signal to the capacitive sense array through the passive touch object to detect the touch.

Abstract: The sensing circuit includes including first input of a first electrode, a first set of inputs of a first set of two or more electrodes forming a first intersection and a second intersection, and a second set of inputs of a second set of two or more electrodes forming the second intersection and a third intersection. The sensing circuit includes a scan control circuit, coupled to the touch panel of electrodes, to concurrently select the sets of electrodes via a multiplexer. The touch sensing circuit includes an analog front end configured to generate digital values representative of mutual capacitances of a first and second unit cell, wherein the first unit cell comprises the first and second intersections and the second unit cell comprises the second and third intersections, and a channel engine configured to generate capacitance values corresponding to the unit cells.