Abstract: A millimeter-wave communication system includes a transmitter and a receiver. The transmitter is configured to be connected to a waveguide that is transmissive at millimeter-wave frequencies, the waveguide having a propagation parameter that varies with frequency at the millimeter-wave frequencies. The transmitter is configured to generate a millimeter-wave signal comprising multiple sub-carriers that are modulated with data, wherein each sub-carrier is modulated with a respective portion of the data and is subjected to only a respective fraction of a variation in the propagation parameter, and to transmit the millimeter-wave signal into a first end of the waveguide. The receiver is configured to receive the millimeter-wave signal from a second end of the waveguide, and to extract the data from the multiple sub-carriers.

Abstract: A power amplification system includes a Power Amplifier (PA) for amplifying an input RF signal. An adaptive bias circuit is configured to adaptively set a bias of the PA. The adaptive biasing circuit includes a gain expansion circuit, a gain compression circuit and a biasing circuit. The gain expansion circuit derives a gain-expansion control signal from the input RF signal. For a first sub-range of the input RF signal, the gain-expansion control signal has a larger dynamic range than the input RF signal. The gain compression circuit derives a gain-compression control signal from the input RF signal. For a second sub-range of the input RF signal having higher power levels than the first sub-range, the gain-compression control signal has a smaller dynamic range than the input RF signal. The biasing circuit sets the bias of the PA responsively to the gain-expansion control signal and the gain-compression control signal.

Abstract: A millimeter-wave communication device includes a coupler, Radio-Frequency (RF) circuitry and a composite right/left-handed metamaterial assembly. The coupler is configured to connect to a waveguide, the waveguide being transmissive at millimeter-wave frequencies and having a given dispersion characteristic over a predefined band of the millimeter-wave frequencies. The RF circuitry is configured to transmit a millimeter-wave signal into the waveguide via the coupler, or to receive a millimeter-wave signal from the waveguide via the coupler, and to process the millimeter-wave signal. The composite right/left-handed metamaterial assembly is formed to apply to the millimeter-wave signal, or to an Intermediate-Frequency (IF) signal corresponding to the millimeter-wave signal, a dispersion compensation that compensates for at least part of the dispersion characteristic of the waveguide over the predefined band.

Abstract: A steering wheel assembly for a vehicle includes a steering wheel, a first conductive coil coupled to the steering wheel, a second conductive coil that magnetically interacts with the first conductive coil, and a detection circuit coupled to the second conductive coil. The detection circuit includes a first circuit to generate a first signal based on a change in inductance and a second circuit to generate a second signal based on the first signal, the second signal to allow detection of a hand on the steering wheel.

Abstract: A millimeter-wave communication system includes a transmitter and a receiver. The transmitter is configured to be connected to a waveguide that is transmissive at millimeter-wave frequencies, the waveguide having a propagation parameter that varies with frequency at the millimeter-wave frequencies. The transmitter is configured to generate a millimeter-wave signal comprising multiple sub-carriers that are modulated with data, wherein each sub-carrier is modulated with a respective portion of the data and is subjected to only a respective fraction of a variation in the propagation parameter, and to transmit the millimeter-wave signal into a first end of the waveguide. The receiver is configured to receive the millimeter-wave signal from a second end of the waveguide, and to extract the data from the multiple sub-carriers.

Abstract: A millimeter-wave communication device includes a coupler, Radio-Frequency (RF) circuitry and a composite right/left-handed metamaterial assembly. The coupler is configured to connect to a waveguide, the waveguide being transmissive at millimeter-wave frequencies and having a given dispersion characteristic over a predefined band of the millimeter-wave frequencies. The RF circuitry is configured to transmit a millimeter-wave signal into the waveguide via the coupler, or to receive a millimeter-wave signal from the waveguide via the coupler, and to process the millimeter-wave signal. The composite right/left-handed metamaterial assembly is formed to apply to the millimeter-wave signal, or to an Intermediate-Frequency (IF) signal corresponding to the millimeter-wave signal, a dispersion compensation that compensates for at least part of the dispersion characteristic of the waveguide over the predefined band.

Abstract: Radio-frequency front-end circuitry includes an output terminal, a receive amplifier controllably coupled to the output terminal, at least one transmit amplifier controllably inductively coupled to the output terminal, and at least one impedance element controllably coupled between ground and one of the at least one transmit amplifier to reduce degradation of output of the radio-frequency front-end circuitry when the at least one transmit amplifier is not in use. In differential signaling, there is an impedance element between ground and each pole of the differential signal. A second transmit amplifier may generate second transmit signals and harmonics of the second transmit signals, and the second transmit amplifier may be switchably connected to the output of a first transmit amplifier so that output of the second transmit amplifier is filtered by the one of the first transmit amplifier. The transmit amplifiers may include a WiFi power amplifier and a BLUETOOTH® power amplifier.

Abstract: In some implementations, a filter circuit includes a first signal path that includes a first amplifier and a second signal path that includes a second amplifier. The first signal path is configured to receive a first component of a complex signal and provide a filtered version of the first component of the complex signal. The second signal path is configured to receive a second component of the complex signal and provide a filtered version of the second component of the complex signal. The first signal path before the first amplifier is coupled to the second signal path before the second amplifier. The first signal path after the first amplifier is coupled to the second signal path before the second amplifier. The second signal path after the second amplifier is coupled to the first signal path before the first amplifier.

Abstract: A wireless communication device including a transceiver, a medium access control device, a first module and a second module. The transceiver is configured to receive a signal on a channel. The medium access control device is configured to determine a parameter, wherein the parameter is a rank of a matrix of the channel, an angle of array of the signal, a packet error rate of the signal, a frame error rate of the signal, or a signal-to-noise ratio of the signal. The first module is configured to, based on the parameter, determine whether an operating environment of the wireless communication device is a rich-scattering environment or a line of sight environment. The second module is configured to adjust a bandwidth of the wireless communication device based on the operating environment as determined by the first module.

Abstract: Aspects of the disclosure provide a phase-locked loop (PLL). The PLL includes a voltage-controlled oscillator (VCO), a detector module, and a ramp module. The VCO has a first capacitor unit and a second capacitor unit. The VCO is configured to generate an oscillating signal having a frequency based on a first capacitance of the first capacitor unit and a second capacitance of the second capacitor unit. The detector module is configured to generate a voltage signal as a function of the oscillating signal and a reference signal. The voltage signal is used to control the first capacitor unit to stabilize the frequency of the oscillating signal. The ramp module is configured to generate a ramp signal based on the voltage signal. The ramp signal is used to control the second capacitor unit to ramp the second capacitance from a first value to a second value.

Abstract: An authenticated RFID system is provided that uses elliptic curve cryptography (ECC) to reduce the signature size and read/write times when compared to traditional public key implementations such as RSA. Either ECDSA or ECPVS can be used to reduce the signature size and ECPVS can be used to hide a portion of the RFID tag that contains sensitive product identifying information. As a result, smaller tags can be used or multiple signatures can be written at different stages in a manufacturing or supply chain. A key management system is used to distribute the verification keys and aggregate signature schemes are also provided for adding multiple signatures to the RFID tags, for example in a supply chain.

Abstract: A system and method for frequency hopping precalibrates a subset of a plurality of channels, storing the channels' associated curves in a computer readable medium. Before hopping to a new channel, decision making circuitry can access the precalibrated curves. If the destination channel has an associated curve, then the system can use the values from that curve when hopping to a new channel. If the destination channel does not have an associated precalibrated curve, then the system can identify a closely situated channel with a precalibrated curve and use an offset value to settle at the destination channel. According to another aspect of the present invention, the offsets can be updated. According to a further aspect of the invention, the updated can be done dynamically.

Abstract: A wireless communication device includes a medium access control device, a first module and a second module. The medium access control device is configured to determine a first parameter based on a condition of a channel. The wireless communication device communicates, via the channel, with a device separate from the wireless communication device. The first module is configured to, based on the first parameter, determine whether an operating environment of the wireless communication device is a rich-scattering environment or a line of sight environment. The second module is configured to adjust a second parameter of the wireless communication device based on the operating environment as determined by the first module. The second parameter is different than the first parameter.

Abstract: A system and method for voltage controlled oscillator (VCO) biasing in low voltage circuits including low resistance elements that are especially susceptible to noise. In one embodiment, a poly resistor and triode resistor is used to cancel or offset the effects that temperature variations have on the circuit. The triode resistor is powered by a voltage source that uses a pair of diodes coupled to a constant transconductance (gm) circuit to generate a reduced noise voltage that is independent of the power supply noise. The size of the triode resistor and poly resistors can be varied.

Abstract: Aspects of the disclosure provide a phase-locked loop (PLL). The PLL includes a voltage-controlled oscillator (VCO), a detector module, and a ramp module. The VCO has a first capacitor unit and a second capacitor unit. The VCO is configured to generate an oscillating signal having a frequency based on a first capacitance of the first capacitor unit and a second capacitance of the second capacitor unit. The detector module is configured to generate a voltage signal as a function of the oscillating signal and a reference signal. The voltage signal is used to control the first capacitor unit to stabilize the frequency of the oscillating signal. The ramp module is configured to generate a ramp signal based on the voltage signal. The ramp signal is used to control the second capacitor unit to ramp the second capacitance from a first value to a second value.

Abstract: A system and method for frequency hopping precalibrates a subset of a plurality of channels, storing the channels' associated curves in a computer readable medium. Before hopping to a new channel, decision making circuitry can access the precalibrated curves. If the destination channel has an associated curve, then the system can use the values from that curve when hopping to a new channel. If the destination channel does not have an associated precalibrated curve, then the system can identify a closely situated channel with a precalibrated curve and use an offset value to settle at the destination channel. According to another aspect of the present invention, the offsets can be updated. According to a further aspect of the invention, the updated can be done dynamically.

Abstract: Circuits, methods, and apparatus that provide isolation between receive and transmit circuits in a wireless transceiver. One example provides switches that can be included on an integrated circuit with at least portions of a wireless transceiver. These switches vary the impedance of transmitter and receiver circuits between a termination impedance and a high impedance by inserting or removing components in parallel with matching networks. Signal losses are minimized since these switches are shunt connected to input and output paths on the wireless circuit and are not connected directly in either signal path.

Abstract: Aspects of the disclosure provide a phase-locked loop (PLL). The PLL includes a voltage-controlled oscillator (VCO), a detector module, and a ramp module. The VCO has a first capacitor unit and a second capacitor unit. The VCO is configured to generate an oscillating signal having a frequency based on a first capacitance of the first capacitor unit and a second capacitance of the second capacitor unit. The detector module is configured to generate a voltage signal as a function of the oscillating signal and a reference signal. The voltage signal is used to control the first capacitor unit to stabilize the frequency of the oscillating signal. The ramp module is configured to generate a ramp signal based on the voltage signal. The ramp signal is used to control the second capacitor unit to ramp the second capacitance from a first value to a second value.

Abstract: A system and method for voltage controlled oscillator (VCO) biasing in low voltage circuits including low resistance elements that are especially susceptible to noise. In one embodiment, a poly resistor and triode resistor is used to cancel or offset the effects that temperature variations have on the circuit. The triode resistor is powered by a voltage source that uses a pair of diodes coupled to a constant transconductance (gm) circuit to generate a reduced noise voltage that is independent of the power supply noise. The size of the triode resistor and poly resistors can be varied.

Abstract: A wireless communications device for a multiple input multiple output (MIMO) wireless communications system. The wireless communication device includes a radio frequency (RF) transceiver including at least two antennae. A medium access control (MAC) device to dynamically adjust a bandwidth of the wireless communications device by adjusting a number of channels associated with at least two antennae. The adjusting of the number of channels associated with at least two antennae is based at least on a transmission error rate or a correlation measurement.