Abstract: A wireless device configured for optimizing a delivered power is described. The wireless device includes a filter duplexer or switch coupled to a transmitter and a receiver. The wireless device also includes a power/impedance detector coupled to the filter duplexer or switch. The power/impedance detector includes a directional coupler. An antenna is coupled to the power/impedance detector. Other aspects, embodiments and features are also claimed and described.

Abstract: A system for linearization signal processing with context switching comprises a plurality of signal processing units, a storage unit, a feedback channel, and a correlator. The plurality of signal processing units is associated with corresponding input data signals. The storage unit is to store context states associated with input data signals and corresponding feedback signals. The feedback channel is to convey feedback signals from outputs associated with the plurality of signal processing units. The correlator is coupled to the feedback channel and generates respective correcting information to be used by respective signal processing units, wherein a respective correcting information is based upon a context state and a feedback state associated with an input data signal.

Abstract: A method of operating an electronic device includes providing a plurality of antenna elements, determining that a change is to be made to at least one of the plurality of antenna elements, and scheduling the change to the at least one of the plurality of antenna elements during a time interval that a transmission power amplifier has a power level below a threshold. The change to the at least one of the plurality of antenna elements may also be made responsive to a reduction to the power level of the transmission power amplifier below the threshold.

Abstract: Stacked CMOS power amplifier (PA) and radio frequency (RF) coupler devices and related methods are disclosed. The stacked device includes a CMOS PA die configured to receive a transmit input signal and to output an amplified transmit signal, and a RF coupler device configured to receive the amplified transmit signal, to output an antenna transmit signal, and to output an RF signal proportional to the antenna transmit signal. The CMOS PA die and the RF coupler device are stacked on top of and electrically coupled to each other, and the CMOS PA die and the RF coupler device are combined within a single semiconductor package. In some embodiments, the RF coupler device is positioned on top of the CMOS PA die, and in other embodiments the CMOS PA die is positioned on top of the RF coupler device.

Abstract: A system that incorporates teachings of the present disclosure may include, for example, a tuning system for a communication device having an antenna, where the tuning system includes at least one first tunable element connected with at least one radiating element of the antenna for tuning the antenna where the adjusting of the at least one first tunable element is based on at least one of a use case associated with the communication device and location information associated with the communication device, and a matching network having at least one second tunable element coupled at a feed point of the antenna, wherein the matching network receives control signals for adjusting the at least one second tunable element to tune the matching network. Additional embodiments are disclosed.

Abstract: Systems and methods for calibrating antenna tuner device parameters can involve measuring a first signal level of an antenna tuner device, adjusting a tuning setting of the antenna tuner device, measuring one or more adjusted signal levels of the antenna tuner device, determining a level change between the first signal level and the one or more adjusted signal levels, comparing the level change to a predefined reference level change, and adjusting a device setting of the antenna tuner device to compensate for a difference between the level change and the predefined reference level change.

Abstract: A novel digitally controlled antenna tuning circuit that enables the implementation of low cost, wideband tuning circuits for antennas in receive applications. The invention is operative to switch a plurality of tuning elements into and out of a main receive signal path. Each individual tuning element is switched into or out of the receive signal path using a single PIN diode. For series connected tuning elements, the diode is connected in parallel to the tuning element. For tuning elements connected in parallel, the diode is connected in series with the tuning element. The diodes are switched in accordance with control voltages which forward bias the diodes to effectively create a low resistance path thus either inserting or removing a tuning element from the receive signal path depending on its configuration in the circuit.

Abstract: A wireless transceiver includes an antenna array that transmits an outbound RF signal containing outbound data to remote transceivers and that receives an inbound RF signal containing inbound data from the remote RF transceivers, wherein the antenna array is configurable based on a control signal. An antenna configuration controller generates the control signal to configure the antenna array to hop among a plurality of radiation patterns based on a hopping sequence. An RF transceiver section generates the outbound RF signal based on the outbound data and that generates the inbound data based on the inbound RF signal. In one configuration, a switching section selectively couples a selected one of the antennas in the array to the RF transceiver section, based on the control signal. In another configuration, the RF transceiver section includes an RF section for each antenna in the array.

Abstract: Example embodiments disclosed herein relate to a connector assembly that includes a plurality of antennas including a first antenna operating at a first frequency and a second antenna operating at a second frequency different from the first antenna. The SMA connector assembly also includes an SMA socket to mount the plurality of antennas on an SMA aperture of the computing device and a controller to select at least one antenna of the plurality of antennas corresponding to at least one operating frequency. Example methods and machine-readable storage media are also disclosed.

Abstract: A self-calibration circuit and associated method for testing an RF device includes the RF device to be tested having transmit and receive sections, and a built-in self test (BIST) circuit coupled to the transmit and receive sections of the RF device on the same chip. The self-calibration circuit is configured to calibrate the receive section of the RF device in a receive test mode, and calibrate the transmit section of the RF device in a subsequent transmit test mode using the calibrated receive section to measure a transmit output signal from the transmit section and to provide calibration data therefrom used in the transmit section calibration. The self-calibration circuit may include a duplex filter coupled between the transmit and receive sections and the BIST circuit, and a multiplexor coupled between the RF device, and the BIST circuit, configured to select one or more of a plurality of RF devices to be tested.

Abstract: A radio front end includes a power amplifier, a tone injection module, a duplexer, a balancing network, and a processing module. The tone injection module is operable, in a first mode, to produce a tone having a carrier frequency that is substantially similar to a carrier frequency of an inbound wireless signal. The duplexer is operable, in the first mode, to provide electrical isolation between the outbound wireless signal and a combination signal of the tone and inbound wireless signal and is operable, in a second mode, to provide electrical isolation between the outbound wireless signal and the inbound wireless signal. The processing module is operable to determine an amplitude of a tone component of the combination signal; correlate the amplitude of the tone component to an inbound frequency band isolation; and adjust baseband processing of a down converted representation of the combination signal based on the inbound frequency band isolation.

Abstract: A system for coupling a communication unit to an antenna. The system includes a tunable bandpass filter and a second tunable filter, such as a tunable low-pass filter, in parallel with the tunable bandpass filter. The system also includes a measurement and control unit configured to measure a frequency of a signal generated by the communication unit and to tune the tunable bandpass filter to pass the signal generated by the control unit.

Abstract: A system that incorporates teachings of the present disclosure may include, for example, a computer-readable storage medium having computer instructions to perform actual measurements of one or more performance parameters of a communication device according to a subset of tuning states of a tunable matching network operable in a communication device, determine estimated measurements of the one or more performance parameters of the communication device for a portion of the tuning states not included in the subset of tuning states according to the actual measurements, identify a data set for each of the one or more performance parameters from at least portions of the tuning states and the actual and estimated measurements, and determine from at least a portion of the date sets one or more tuning states that achieve at least one desirable performance characteristic of the communication device. Additional embodiments are disclosed.

Abstract: A method and system configures operating parameters associated with an operation of a connected accessory or second device in order to mitigate harmonic interference within an operating frequency band of a wireless communication device (WCD). In response to a connection between the WCD and the second device via a physical communications interface, Accessory Authentication and Configuration (AAC) logic of the WCD receives device identifying information about the second device. The AAC logic determines candidate values for each operating parameter, based on the device identifying information. The AAC logic dynamically selects a particular candidate value for each operating parameter, based on a current operating frequency band of the WCD, and an expected level of harmonic interference.

Abstract: An embodiment of the present invention provides an apparatus, comprising a transceiver, an antenna tuner connecting said transceiver to an antenna, a power sensor adapted to acquire measurements about transmit power, a receive signal strength indicator (RSSI) adapted to acquire measurements about receive power and wherein said tuner tunes said antenna based upon said transmit and receive measurements to optimize said antenna in both the receive and transmit bands.

Abstract: An electronic device includes a radio frequency module having a communication port, and an antenna module having a number of antennas electrically coupled to the communication port. A method of reducing specific absorption rate (SAR) for the electronic device includes: a) measuring the SAR for the electronic device to obtain a measurement result; b) increasing the number of antennas of the antenna module when the measurement result is not lower than a standard value; and c) repeating steps a) and b) until the measurement result is equal to or smaller than the standard value.

Abstract: This disclosure is directed to a wireless device with a suppressor that couples to the aggressor signal of a frequency source to generate a cancelling signal for suppressing spurs resulting from operation of the frequency source. The amplitude and phase delay of the cancelling signal are adjusted to optimize the cancellation of the spur. Preferably, a calibration routine is performed to establish appropriate delay and amplitude values to cancel the spurs occurring at each device gain setting.

Abstract: Radio frequency (RF) architectures for spectrum access networks are provided. Embodiments of the invention generally provide a radio frequency (RF) architecture for customer premise equipment (CPE) for use in, for example, IEEE 802.22 wireless regional area networks (WRANs). In some embodiments, the CPE RF architecture includes two receive chains with a directional antenna and an omni-directional antenna, respectively. The CPE RF architecture facilitates opportunistic out-of-band spectrum sensing and WRAN signal receiving that are performed in parallel with data transmission.

Abstract: A wireless device is described. The wireless device includes a tunable front end module. The tunable front end module includes a Tx microelectromechanical system bandpass filter. The tunable front end module also includes a first Rx microelectromechanical system bandpass filter. The wireless device also includes a power amplifier. The wireless device further includes a low noise amplifier.

Abstract: Methods and apparatus for mitigating data server time-outs in e.g., a hybrid wireless network. In one exemplary embodiment, a client device operating in a hybrid network environment utilizes its knowledge about tune-away periods so as to minimally affect data network operation. For example, during periods of data downlink activity, the client device induces some delay in the acknowledgement packets sent back towards the network prior to entering into a tune away period. These delayed acknowledgement packets result in an increased retransmission time out period value thereby reducing the probability of encountering a data server time-out. Alternative embodiments are also discussed which preoccupy the network apparatus during these tune away periods so as to also mitigate time-outs during these periods. These mitigation algorithms are useful in both downlink and uplink data transmissions. Apparatus for implementing these methodologies are also disclosed.

Abstract: A mobile communication device includes an antenna unit to operate in multiple frequency bands by shifting the resonance frequency of the antenna using capacitors. A first capacitor unit may be formed by the disposal of a first electrode in a hole in a first antenna pattern and the formation of a second electrode in the portion of the first antenna pattern opposing the first electrode. The first capacitor unit may be formed in various ways to be activated by a switch. The connection of the first capacitor unit to a voltage supply and ground may trigger a shift in the resonant frequency of the first antenna pattern.

Abstract: Methods and systems for a smart antenna utilizing leaky wave antennas (LWAs) are disclosed and may include a programmable polarization antenna including one or more pairs of LWAs configured along different axes. One or more pairs of leaky wave antennas may be configured to adjust polarization and/or polarity of one or more RF signals communicated by the programmable polarization antenna. RF signals may be communicated via the configured programmable polarization antenna utilizing the configured one or more pairs of the leaky wave antennas. A resonant frequency of the LWAs may be configured utilizing micro-electro-mechanical systems (MEMS) deflection. The polarization and/or polarity may be configured utilizing switched phase modules. The LWAs may include microstrip or coplanar waveguides, wherein a cavity height of the LWAs is dependent on spacing between conductive lines in the waveguides. The LWAs may be integrated in one or more integrated circuits, packages, and/or printed circuit boards.

Abstract: Provided is a frequency selective noise canceller including: a frequency selective single to differential converter having a band pass filter function, converting a received single input signal into a differential signal in a wanted signal pass frequency band and into a common mode signal in an unwanted signal frequency band; and a common mode rejector functioning as a load having an arbitrary impedance with respect to the differential signal outputted from the frequency selective single to differential converter and functioning as a filter with respect to the common mode signal.

Abstract: A radio-frequency (RF) apparatus, which may reside in a receiver or transceiver, includes receive-path circuitry. The receive-path circuitry includes a poly-phase filter and a harmonic filter. The poly-phase filter accepts an input signal and generates two output signals. One output signal of the poly-phase filter constitutes an in-phase (I) signal. The other output signal of the poly-phase filter constitutes a quadrature (Q) signal. The a harmonic filter couples to the poly-phase filter. The harmonic filter accepts as input signals the in-phase and quadrature output signals of the poly-phase filter.

Abstract: A portable electronic device and method for tuning an antenna is provided. The portable electronic device includes an antenna, a tunable element, a first input unit, at least one additional input unit, and a processor. The method involves receiving a first set of data, determining a plurality of possible physical states, activating a second input unit, receiving a second set of data from the second input unit, selecting a physical state of the portable electronic device from the plurality of possible physical states, and tuning the antenna based on the physical state of the portable electronic device.

Abstract: A communication terminal apparatus and method for performing wireless communication, including a first channel including a first antenna to transmit a first signal at a first frequency, a second channel including a second antenna to receive or transmit one or more second signals at a frequency other than the first frequency of the first signal, and a feedback circuit unit to selectively generate a feedback signal to the second channel to reduce a noise signal from the first signal among the one or more second signals received or transmitted through the second channel. The feedback circuit unit may include a coupler to segment and transfer at least a portion of the first signal, a filter unit to transmit a frequency signal, a phase converter to modulate a phase of the signal transmitted through the filter, and a gain control amplifier to amplify the phase-modulated signal.

Abstract: In a wireless communication device (10), adjustment means (matching controlling means (152)) changes a reactance of a matching section (17), determination means (calculation means (151), matching controlling means (152)) determines whether a resonance frequency of an antenna (11) exists on a side higher than or lower than the operation frequency of the antenna (11) on the basis of a change in an intensity of a signal, which change is caused by a change in the reactance and is detected by a signal intensity detection section (14), and the adjustment means adjusts the reactance so that the resonance frequency is closer to the operation frequency on the basis of a result of determination of the determination means.

Abstract: An example wireless device includes a radio receiver to measure a signal quality of a data signal independent of a direct frequency measurement, the signal quality correlated to an offset between a transmitter reference frequency and a receiver reference frequency but not indicative of a direction of the offset. The example wireless device further includes a reference frequency generator to determine from the measured signal quality that a previous adjustment to the receiver reference frequency in a first direction has worsened the signal quality, and responsive to that determination adjust the receiver reference frequency in a second direction that is opposite to the first direction.

Abstract: A wireless communication unit is described that includes a transceiver; at least one antenna port operably coupled to the transceiver via at least one antenna switch; a radio frequency part of the transceiver that includes at least one tuneable radio frequency (RF) component; and a test signal generator for generating an RF test signal for receiver calibration. The radio frequency part includes a coupler located between the at least one tuneable RF component and the at least one antenna switch for coupling the RF test signal to or from the radio frequency part for calibration.

Abstract: A method and communications device for providing antenna tuning to compensate for antenna de-tuning caused by a presence of an object detected using an antenna element within a capacitive touch and proximity sensor (CTPS). The CTPS propagates object detection signals associated with a detected object to a detection IC. An object detection and antenna tuning (ODAT) logic uses object detection signal information to generate tuning control signals to trigger compensatory antenna tuning, based on pre-established mappings of object detection signal data and antenna tuning states. The tuning control signals indicate at least one of (a) a level of compensatory antenna impedance tuning and (b) an amount of compensatory antenna length adjustment. In response to generating the tuning control signals, the ODAT logic triggers the propagation of the tuning control signals to the antenna matching and control circuit to provide the corresponding antenna tuning.

Abstract: In an ADPLL circuit, on the basis of a gain of a digitally controlled oscillator estimated when a loop gain of a certain value is set in the loop filter and on the basis of a device parameter of the digitally controlled oscillator, the DCO gain estimation unit estimates a gain of the digitally controlled oscillator when a loop gain of another value is set in the loop filter.

Abstract: The disclosed invention relates to a transceiver system configured to cancel RF second-order intermodulation distortion (IMD2) within a differential reception path. In some embodiments, the transceiver system has one or more common-mode attenuation elements that attenuate common-mode interferer signals within the differential reception path. The common-mode attenuation elements detect a common-mode interferer from one or more nodes within a transceiver system front-end. One or more properties of the detected common-mode interferer are adjusted and then fed into the differential reception path, where the adjusted common-mode signal attenuates the common-mode interferers. In other embodiments, the differential reception path has a tunable amplifying stage. The tunable amplifying stage has first and second amplifier elements that are independently operated to intentionally introduce an operating parameter mismatch between the elements.

Abstract: Systems and methods for tuning an antenna for a frequency modulation (FM) transceiver are provided. A representative system includes: a network of electrical adjustable passive components that receives and sends radio frequency (RF) signals to a receiver circuitry via the network of electrical adjustable passive components. The receiver circuitry determines the received signal strength indication (RSSI) of the RF signal. The system further includes a transmitter circuitry that transmits RF signals via the network of electrical adjustable passive components, and a peak detector circuitry that receives and determines a voltage output of the RF signals from the variable capacitors. An auto-tune circuitry receives the RSSI and output value from the receiver circuitry and the peak detector circuitry, respectively.

Abstract: Systems and devices for controlling frequency drift in satellite broadcast systems. A receiver antenna system for a direct broadcast satellite signal communications system in accordance with one or more embodiments of the present invention comprises an oscillator, a mixer, coupled to the oscillator, for converting satellite signals at a first frequency to signals at an intermediate frequency, an analog-to-digital (A/D) converter, coupled to the mixer, for receiving the signals at the intermediate frequency and for converting the signals at the intermediate frequency at near-real-time to a digital data stream, a Digital Signal Processor (DSP), coupled to the A/D converter, for processing the digital data stream, and a drift estimator, coupled to the DSP, the drift estimator determining a frequency drift of the oscillator, wherein the receiver antenna system corrects the frequency drift of the oscillator using the determined frequency drift.

Abstract: Electronic devices may be provided that contain wireless communications circuitry. The wireless communications circuitry may include radio-frequency transceiver circuitry and antenna structures. The antenna structures may form an antenna having first and second feeds at different locations. The transceiver circuit may have a first circuit that handles communications using the first feed and may have a second circuit that handles communications using the second feed. A first filter may be interposed between the first feed and the first circuit and a second filter may be interposed between the second feed and the second circuit. The first and second filters and the antenna may be configured so that the first circuit can use the first feed without being adversely affected by the presence of the second feed and so that the second circuit can use the second feed without being adversely affected by the presence of the first feed.

Abstract: Techniques for enhanced co-existence for co-located radios are described. A mobile computing device may comprise a first radio module operative to communicate wirelessly across a first link using a first set of communications channels, a second radio module operative to communicate wirelessly across a second link using a second set of communications channels, and a coordination module operative to receive information regarding operation of the first and second radio modules, and modify a communications parameter for the first or second radio module based on the received information. Other embodiments are disclosed and claimed.

Abstract: A mobile wireless communications device may include a processor configured to generate a baseband signal, a modulator coupled downstream from the processor, a power amplifier coupled downstream from the modulator, an antenna, and a tunable antenna matching network coupled between the power amplifier and the antenna and configured to match an impedance of the antenna and thereby causing a phase change in an output from the antenna. The processor may be configured to provide upstream phase change compensation in the baseband signal for the phase change in the output from the antenna.

Abstract: Aspects of a method and system for 60 GHz wireless clock distribution may include configuring a microwave communication link established between a first chip and a second chip via a wireline communication bus. The configuration may comprise adjusting beamforming parameters of a first antenna array communicatively coupled to the first chip, and of a second antenna array communicatively coupled to the second chip. The first chip and the second chip may communicate a clock signal via the microwave communication link. The microwave communication link may be routed via one or more relay chips, when the first chip and the second chip cannot directly communicate. Control data may be transferred between the first chip, the second chip, and/or the one or more relay chips, which may comprise one or more antennas. The relay chips may be dedicated relay ICs or multi-purpose transmitter/receivers.

Abstract: Methods of transmitting a plurality of communications signals over a plurality of discontiguous bandwidth segments in a frequency band include defining a plurality (NFFT) of orthogonal subcarriers across the frequency band, defining a plurality (N) of available physical subcarriers from among the orthogonal subcarriers. The available physical subcarriers are distributed among the plurality of discontiguous bandwidth segments. The methods further include multiplexing the plurality of communications signals onto the plurality of available physical subcarriers. Multiplexing the plurality of communications signals onto the plurality of available physical subcarriers may include assigning the communications signals to respective ones of a plurality (N) of logical subcarriers, and mapping the plurality of logical subcarriers to corresponding ones of the plurality of available physical subcarriers. Related transmitters, receivers and communications systems are also disclosed.

Abstract: In accordance with the present disclosure, method may include receiving one or more environment parameter signals indicative of an environment of a wireless communication element. The method may also include communicating one or more control signals to an antenna tuner of the wireless communication element for controlling an impedance of the antenna tuner based on the one or more environment parameter signals.

Abstract: Systems, methods and products directed toward tuning a wireless antenna of an information handling device are disclosed herein. One aspect includes tuning one or more wireless antennas connected to an information handling device via one or more antenna tuning pins arranged within a system bus slot; wherein the one or more antenna tuning pins are configured to tune the one or more wireless antennas to operate within a frequency band based on one or more connections with one or more wireless communication pins of a device interface module arranged to interface with the system bus slot. Other embodiments are described herein.

Abstract: A device and method of duplex audio communication over a broadcast channel are disclosed. The device and method disclosed in the present invention use the clear channel technique to automatically select an un-occupied channel for the transmit side and utilizes an identification embedded in a sub-channel to allow the receiver to automatically tune to the channel used by the transmitter. The clear channels may be determined by respective transceivers or determined by a master transceiver.

Abstract: A method for automatically tuning a frequency modulator in a mobile device is described. The geographical location of the mobile device is obtained. A database of one or more frequencies associated with the geographical location of the mobile device is searched. Quality associated with channels of the one or more frequencies is analyzed to identify at least one available channel at a first frequency. The first frequency is assigned to an FM modulator. The FM modulator is integrated as a part of the mobile device. A determination is made as to whether a command to search for a second frequency is received. If the command to search for the second frequency is not received, a signal is transmitted on the first frequency by the FM modulator.

Abstract: In one embodiment, an apparatus includes a first block configured to decompose an input signal into a positive component and a negative component. The apparatus further includes a second block configured to generate a mixer positive driver component from the positive component and a mixer negative driver component from the negative component and input the mixer positive driver component and the negative driver component into a mixer for a wireless transmitter.

Abstract: A mobile wireless communications device includes a portable housing, a transmitter carried by the portable housing and configured to modulate an input signal, and an adjustable impedance matching network coupled downstream from the transmitter. An antenna is coupled downstream from the adjustable impedance matching network, and a non-directional coupler is coupled between the adjustable impedance matching network and the antenna. A feedback receiver is coupled to the non-directional coupler to generate a feedback signal. A controller is configured to control the adjustable impedance matching network based upon the input signal and the feedback signal.

Abstract: A system that incorporates the present disclosure may include, for example, a computer-readable storage medium having computer instructions to perform actual measurements of one or more performance parameters of a communication device according to a subset of tuning states of a tunable matching network operable in a communication device, determine estimated measurements of the one or more performance parameters of the communication device for a portion of the tuning states not included in the subset of tuning states according to the actual measurements, identify a data set for each of the one or more performance parameters from at least portions of the tuning states and the actual and estimated measurements, and determine from at least a portion of the data sets one or more tuning states that achieve at least one desirable performance characteristic of the communication device. Additional embodiments are disclosed.

Abstract: One embodiment of the present invention provides a transceiver for a wireless mobile device. The transceiver includes a transmitter, a receiver, and a bandwidth-determination mechanism configured to determine a transmission bandwidth for the transmitter and a receiving bandwidth for the receiver.

Abstract: According to one embodiment, a register outputs a first control code in first and second operation modes, saves the first control code as a third control code at an end of the first operation mode, and outputs the third control code at a beginning of a third operation mode. In the first operation mode, a digital-to-analog converter supplies a control signal with a control voltage to a voltage controlled oscillator. In the second operation mode, the control signal is supplied to a buffer amplifier, the amplifier drives a bandlimiting filter, and the filter generates the control voltage. In the third operation mode, the control signal is supplied to the filter, and the filter generates the control voltage.

Abstract: A technique for tuning the receiver (RX) synthesizer independently from the transmitter (TX) synthesizer helps a mobile communication device with multiple SIMs to concurrently monitor the paging channel of a first network associated with one SIM while transmitting on a second network associated with a second SIM. By independently tuning the RX and the TX synthesizers, each SIM card can maintain synchronization with the network without disruption of service in either network. As a result, the mobile communication device exhibits an increased ability to maintain communication sessions for two different networks, without the need for a second set of TX/RX synthesizer hardware.

Abstract: A system that incorporates teachings of the present disclosure can include, for example, an apparatus having a matching network adapted to reduce a magnitude of a signal reflection at a port of the matching network. The matching network can have one or more controllable variable reactive elements. A controller can be adapted to determine reflection coefficient information from incident and reflected waves sampled at the port of the matching network, and follow at least one cycle of a coarse tune process for generating one or more control signals to tune one or more reactances of the one or more controllable variable reactive elements. Additional embodiments are disclosed.