Channel tracking in an orthogonal frequency-division multiplexing system
Granted: March 18, 2014
Patent Number:
8675744
A receiver determines phase and frequency information from data signals that carry information from a transmitter to a receiver, instead of or in addition to, information from control signals. In a specific embodiment, the information is obtained from data signals modulated as a binary phase-shift keying (“BPSK”) waveform by demodulation. Other phase-shift keyings might be used instead. Encoded information might be recovered in received OFDM packets by receiving OFDM subcarriers…
Touch finding method and apparatus
Granted: February 25, 2014
Patent Number:
8659557
A method of determining touches from a data set output from a touch screen comprising an array of sensing nodes. The method comprises analyzing the dataset and identifies a node with a maximum signal value among all unassigned nodes, and, if present, assigns that node to a touch. A logical test is applied to each node that is a neighbor to the assigned node to determine if that node should also be assigned to the touch and the logical test is repeatedly applied to the unassigned…
Counter circuit
Granted: February 18, 2014
Patent Number:
8653871
A counter circuit includes two pairs of registers configured to swap contents based on a timer overflow or underflow condition. The counter circuit also includes a waveform generator that generates a composite pulse width modulated signal with a period and duty cycle specified by values stored in the registers. A demultiplexing circuit generates first and second signals from the composite signal.
Touch screen element
Granted: February 11, 2014
Patent Number:
8648819
A capacitive two-dimensional (2D) touch panel has three sets of interleaved electrodes. A first set of electrodes is spaced apart along the y-direction and these are galvanically connected to each other by a resistive strip connected at either end to a connection line. A second set of electrodes is also arrayed along the y-direction and these are galvanically connected to each other via a notionally non-resistive first connection. A third set of electrodes is also arrayed along the…
System, method, and circuit for distance measurement between two nodes of a radio network
Granted: February 4, 2014
Patent Number:
8644768
A system and method for distance measurement between two nodes of a radio network is provided. A first unmodulated carrier signal is transmitted by the first node and received by the second node. A second unmodulated carrier signal is transmitted by the second node and received by the first node. A first value and a second value of a first phase are measured by the first node, whereby the first value of the first phase is assigned to a first frequency of the received second carrier…
Closed path capacitive position sensor
Granted: February 4, 2014
Patent Number:
8643626
A capacitive position sensor for detecting the position of an object relative to a resistive sensing element. The sensing element comprises a sensing path that has terminals connected along it that subdivide the sensing path into multiple sections. Each terminal is coupled to its own sensing channel, each of which generates a signal that is sensitive to the capacitance between its terminal and a system ground. The signals are fed to a processor for analysis. The processor determines over…
Touch-sensitive user interface
Granted: February 4, 2014
Patent Number:
8643621
A touch-sensitive user interface includes a sensor element providing a plurality of sensing areas, a measurement circuit coupled to the sensor element and operable to iteratively acquire measurement signal values indicative of the proximity of an object to the respective sensing areas, and a processor operable to receive the measurement signal values from the measurement circuit and to classify a sensing area as an activated sensing area for a current iteration according to predefined…
Locating a backscatter-based transponder
Granted: February 4, 2014
Patent Number:
8643472
A method and apparatus for locating a transponder is provided. A carrier signal is transmitted by a base station and a transponder transmits a locating signal that is generated through phase modulation and backscattering of the carrier signal sent by the base station when the transponder is within a transmission range of the base station, whereby the transponder is located on the basis of the locating signal.
Calibration of temperature sensitive circuits with heater elements
Granted: February 4, 2014
Patent Number:
8643174
One or more heating elements are disposed on a semiconductor substrate proximate a temperature sensitive circuit disposed on the substrate (e.g., bandgap circuit, oscillator). The heater element(s) can be controlled to heat the substrate and elevate the temperature of the circuit to one or more temperature points. One or more temperature measurements can be made at each of the one or more temperature points for calibrating one or more reference values of the circuit (e.g., bandgap…
Serial bit processor
Granted: January 28, 2014
Patent Number:
8639851
A serial bit processor is disclosed that configures a timer/counter module to determine a number of data bits to be decoded from a serial bit stream. In some implementations, a serial peripheral is coupled to a timer/counter module. The serial peripheral sends a restart command to reload an internal count register of the timer/counter module with a pre-defined value. The serial peripheral then sends count commands that cause the timer/counter to decrement (or increment) by one each time…
Capacitive touch buttons combined with electroluminescent lighting
Granted: January 28, 2014
Patent Number:
8638314
A capacitive touch sensor includes a layer of electro-luminescent (EL) material arranged between a first electrode and a second electrode, A controller includes a capacitance sensing circuit coupled to first and/or second electrode and arranged to measure a capacitive coupling associated with the first and/or second electrode. The controller is further operable to apply an EL drive signal across the first and second electrodes to cause the layer of EL material between the electrodes to…
Method, transponder, and circuit for selecting one or more transponders
Granted: January 28, 2014
Patent Number:
8638195
A method and device for selecting one or more transponders, in particular backscatter-based transponders, from a plurality of transponders by a base station, which method is based on a slotted ALOHA method, in which the base station defines numbered time slots and a random number generated in a given transponder determines a time slot when the transponder transmits its transponder-specific identification to the base station. The random number is generated in a given transponder with the…
Method for data communication between a base station and a transponder
Granted: January 21, 2014
Patent Number:
8634401
A method for data communication between a base station and at least one transponder by a high-frequency electromagnetic carrier signal is disclosed, onto which information packets are modulated, whereby each information packet has a header section, a middle section, and an end section and whereby the middle section has a data field for the transmission of data and/or address information and a protection field placed thereafter for the correction of errors in the transmission of the data…
Method and apparatus for iterative synchronization of two or more electronic devices
Granted: January 21, 2014
Patent Number:
8634341
Dynamic adjustment of offset between timebases of separated electronic circuits is provided based on an amount of time between synchronization events, wherein a synchronization event is an event involving communication across a separation between the separated electronic circuits in order to synchronize the timebases. The dynamic adjustment can be dynamically or adaptively adjusting a margin of error to account for drift that may have occurred since a prior synchronization event.…
Circuit and method for image frequency rejection
Granted: January 14, 2014
Patent Number:
8630603
A circuit and method for image frequency rejection is provided that includes an analog dual-quadrature mixer device whose signal inputs for an in-phase-signal and a quadrature-phase signal are connected to an input circuit in the signal path and whose oscillator inputs for an in-phase oscillator signal and a quadrature-phase oscillator signal are connected to a local oscillator device, having an analog adder-amplifier device, which has a number of transistor pairs, in which in each case…
Preventing interference between microcontroller components
Granted: January 14, 2014
Patent Number:
8629796
A microcontroller includes first and second modules. The first module can operate in a mode that causes interference with operation of the second module. A control circuit on the first module and a control circuit on the second module coordinate operation of the first and second modules to prevent the interference from causing the second module to function incorrectly.
Noise measurement in capacitive touch sensors
Granted: January 14, 2014
Patent Number:
8629686
In particular embodiments, an apparatus includes a charge-measurement capacitor having a first plate coupled to a second plate of a coupling capacitor and a non-transitory computer-readable storage medium embodying logic that is operable when executed to ground a first plate of the coupling capacitor; inject a pre-determined amount of charge onto the charge-measurement capacitor; and transfer an amount of charge accumulated on the second plate of the coupling capacitor to the first plate…
Force sensor with compressible electrode
Granted: January 7, 2014
Patent Number:
8621942
A sensor includes a first electrode and a second, compressible electrode. A dielectric layer separates the first electrode from the second electrode. At least one of the first and second electrodes compress responsive to force, increasing capacitance between the first and second electrodes.
Two-dimensional position sensor
Granted: January 7, 2014
Patent Number:
8624609
A two-dimensional position sensor is formed by drive electrodes (52) and sense electrodes (62, 64, 66) both extending in the x-direction and interleaved in the y-direction. The sense electrodes comprise several groups, two of which co-extend in the x-direction over each different portions of extent in the x-direction. The drive and sense electrodes are additionally arranged to capacitively couple with each other. In use, drive signals are applied to the drive electrodes and then the…
Measuring voltage
Granted: January 7, 2014
Patent Number:
8624607
In one embodiment, a method includes, at a first input of a comparator, receiving from an analog multiplexer one of multiple first voltages. Each of the first voltages results at least in part from an interaction between an object and an electrode of each of one or more nodes of a capacitive touch sensor. The method includes, at a second input of the comparator, receiving a second voltage across a measurement capacitor that has a first terminal coupled to the second input of the…
