Abstract: In a radio frequency circuit for multi-mode operation on which multiple transceivers complying with multiple communication systems are disposed, signal interference between circuits is reduced. The PA 222, and the output matching networks 223a and 223b of GSM system, which are circuits independent of the circuit operation of W-CDMA, are disposed in a section of the shortest distance between the PA 121 that handles RF transmission signals of W-CDMA being a first communication system, a third output matching network and an isolator, and a receiver that handles RF received signal of W-CDMA, and in a section of the shortest distance between the PA 121 and the transmitter 130 of W-CDMA. The PA 222, which is a circuit independent of the circuit operation of W-CDMA, is disposed in a section of the shortest distance between the PA 121 and the inter stage filter 125 of W-CDMA.

Abstract: One or more beamsteering matrices are applied to one or more signals to be transmitted via multiple antennas. After the one or more beamsteering matrices are applied to the one or more signals, the plurality of signals is provided to a plurality of power amplifiers coupled to the multiple antennas. Signal energies are determined for the plurality of signals provided to the plurality of power amplifiers, and relative signal energies are determined based on the determined signal energies. Output power levels of the plurality of power amplifiers are adjusted based on the determined relative signal energies.

Abstract: A multi-rank beamforming (MRBF) scheme in which the downlink channel is estimated and an optimal precoding matrix to be used by the MRBF transmitter is determined accordingly. The optimal precoding matrix is selected from a codebook of matrices having a recursive structure which allows for efficient computation of the optimal precoding matrix and corresponding Signal to Interference and Noise Ratio (SINR). The codebook also enjoys a small storage footprint. Due to the computational efficiency and modest memory requirements, the optimal precoding determination can be made at user equipment (UE) and communicated to a transmitting base station over a limited uplink channel for implementation over the downlink channel.

Abstract: A non-Foster impedance power amplifier has a current amplifying device coupled in either an emitter-follower or source-follower configuration with a reactive load such as an antenna load. A negative impedance circuit is provided upstream of a gate or base or other control element of said current amplifying device.

Abstract: An internal operation of RF IC is adjusted so that the level of an RF transmitter signal is substantially stopped from rising, or made to descend in course of ramp-up of the RF transmitter signal. This adjustment is enabled by ramp-up adjustment data Last 4 symbols contained in preamble data precedent to real transmission data transmitted after completion of ramp-up. The ramp-up adjustment data and real transmission data are supplied from a baseband LSI. The RF transmitter signal contains phase and amplitude modulation components according to the EDGE system. RF IC includes phase and amplitude modulation control loops PM LP and AM LP. Ramp-up of RF power amplifiers PA1 and PA2 is performed by controlling the gain of the first variable amplifier MVGA included in the AM LP according to ramp information. Thus, unwanted radiation's level is reduced during ramp-up of the RF transmitter signal of the RF power amplifiers.

Abstract: A device for generating a crest factor reduced signal is disclosed. The device comprises an interface for receiving an input signal; a peak identifier for identifying one or more peak regions of the input signal; a squelch level determiner for determining a reduction of the input signal near the one or more peak regions; a squelcher for reducing the one or more peak regions of the input signal as indicated by the squelch level determiner; and an interface for outputting a crest factor reduced signal. The crest factor reduced signal has a reduced dynamic range due to the reduction of the one or more peak regions of the input signal. The crest factor reduced signal also has been filtered to reduce undesired frequency components by: calculating a difference between a squelched signal from the squelcher and the input signal, band-pass filtering the difference to generate a result, and summing the result with the input signal that has been delayed.

Abstract: The present invention relates to a method, apparatus, and computer program product, wherein a level of a first signal received via first channel is determined. Additionally, a moving average of a plurality of determined levels of the first signal is obtained, and the moving average is subtracted from the determined level. The subtraction result is then used for estimating a noise variance of a second signal received via a second channel.

Abstract: A radio data communication apparatus includes a circuit unit and at least one antenna unit. The circuit unit performs data read and write operations relative to an IC tag. Each antenna unit has an antenna and conducts a predetermined signal modulation to a first signal to be transmitted through the antenna by radio to a specific IC tag in the data write operation. Also, each antenna unit conducts a predetermined signal demodulation to a second signal received through the antenna from the specific IC tag in accordance with the data read operation. The antenna unit is arranged at a position separated from the circuit unit.

Abstract: A power correction module for use with an amplifier driving a load impedance is configured to sample the supply current and to cause a change in a control voltage, which corrects the supply voltage in response to a change in the load impedance. The supply voltage is corrected to cause the power amplifier to have a substantially constant output power. The power correction module is further configured to output a corrected peak voltage determined by an average value of the supply current.

Abstract: In one embodiment a universal front end module for network communications is disclosed. The module can include a mode controller coupled to components of a transmission path. A first tunable filter on a transmit path can receive a mode control signal from the mode controller and receive a signal to be transmitted and provide a filtered output signal responsive to the mode control signal and the signal to be transmitted. The mode control signal can be associated with a predetermined network protocol such as WiMax, a WiFi, a 3G LTE and a cellular standard where each standard has a predetermined operating frequency and protocol. The module can also include a tunable power amplifier to provide an amplified transmittable signal over a single transmit path can be utilized to transmit the transmittable signal in at least two different modes responsive to the mode controller.

Abstract: A radio frequency power amplifier (RF PA) apparatus includes an RF PA and a waveform converter. The waveform converter is configured to receive a sinusoidal RF signal and generate a nonsinusoidal RF signal, which is used to drive an active device (e.g., a field effect transistor (FET) or bipolar junction transistor (BJT)) of the RF PA. The nonsinusoidal RF signal, which may comprise a square wave or a substantially-square wave signal, has signal characteristics that result in less leakage through the active device's input-output parasitic capacitance, compared to the leakage that would result if the sinusoidal RF signal was used to drive the active device. The leakage control methods and apparatus of the present invention may be advantageously employed in a variety of applications including, for example, RF polar transmitters.

Abstract: A system and a method are disclosed for initiating a voice communication, such as a telephone call, or modifying an output device used to present audio data. After receiving a destination identifier, such as a telephone number, data from one or more sensors included in the mobile computing device is analyzed. Responsive to the sensor data describing movement in a first direction of a first axis, such as upward motion along a vertical axis, a voice communication is established using the destination identifier. While audio data from the voice communication, or from another source, is presented, data from the sensors is also analyzed. Responsive to the sensor data indicating one or more types of movement or interactions with a surrounding environment, the output device used to present the audio data is modified.

Abstract: Described herein are mechanisms and methods that facilitate preparation of inter-radio access technology (inter-RAT) and/or inter-frequency handover with respect to a mobile device (user equipment). User equipment can indicate to a network servicing the user equipment that the user equipment desires to perform measurements with respect to a different frequency and/or different technology. Data on the downlink channel can then be scheduled to ensure that data intended for the user equipment is not lost while the user equipment is performing the measurements.

Abstract: In some embodiments, a mobile media device enclosure can include: (a) an enclosure having an interior, an exterior, a top side, a bottom side, a right side, and a left side, the interior configured to form a cavity, the cavity is sized to retain a mobile media device therein; (b) a vertical boundary, the vertical boundary having a substantially vertical orientation and configured to substantially bisect the mobile media device enclosure from the top side to the bottom side; and (c) a horizontal boundary, the horizontal boundary having a substantially horizontal orientation and configured to substantially bisect the mobile media device enclosure from the left side to the right side. The vertical boundary and the horizontal boundary are further configured to substantially divide the mobile media device enclosure into four sections. Each of the four sections is elastically coupled to two other sections of the four sections. Other embodiments and related methods are also disclosed herein.

Abstract: Image rejection calibration includes initializing the calibration mode by applying to quadrature mixers, in place of the wanted RF input, an RF source in the frequency range of the wanted RF input, sensing the power output from the poly-phase filter, developing gain adjust and phase adjust correction values in response to the power output and adjusting in accordance with the correction values the gain of the quadrature signals from the quadrature mixers to the poly-phase filter and the phase of local oscillator quadrature signals from the local oscillator to the quadrature mixers to reduce the power output.

Abstract: A matching circuit, connected to a receiving antenna and to the input of a receiving circuit, incorporates a variable capacitor that is adjustable for tuning the resonance frequency of the antenna to a desired reception frequency. In an automatic tuning mode of operation, an oscillator signal of different frequency from the reception frequency is applied to induce resonance of the antenna and matching circuit, and the variable capacitor is adjusted until an output signal level from the receiving circuit attains a predetermined value which has been stored beforehand in a memory and which corresponds to a condition whereby the antenna resonance frequency corresponds to the reception frequency and impedance matching exists between the antenna and receiving circuit.

Abstract: In one embodiment, the present invention includes an amplifier having a transistor stage coupled between a supply voltage and a bias current. The transistor stage has an input to receive a radio frequency (RF) input signal obtained from an antenna. The amplifier has an input impedance that is unmatched to a source impedance of the antenna. In some embodiments, this unmatched input impedance may be substantially greater than the source impedance, and may further be controlled based on a strength of the RF input signal.

Abstract: A mobile wireless communications device includes a housing and circuit board in the housing and having radio frequency (RF) circuitry and a power amplifier and microphone mounted thereon. An antenna is carried within the housing and operative with the RF circuitry. An RF shield surrounds and isolates the microphone from the RF circuitry, power amplifier and antenna and shields the microphone from radiated energy generated from the RF circuitry, antenna or power amplifier.

Abstract: A multi-rank beamforming (MRBF) scheme in which the downlink channel is estimated and an optimal precoding matrix to be used by the MRBF transmitter is determined accordingly. The optimal precoding matrix is selected from a codebook of matrices having a recursive structure which allows for efficient computation of the optimal precoding matrix and corresponding Signal to Interference and Noise Ratio (SINR). The codebook also enjoys a small storage footprint. Due to the computational efficiency and modest memory requirements, the optimal precoding determination can be made at user equipment (UE) and communicated to a transmitting base station over a limited uplink channel for implementation over the downlink channel.

Abstract: Implementations and examples of power amplifier devices, systems and techniques for amplifying RF signals, including power amplifier systems based on Composite Right and Left Handed (CRLH) metamaterial (MTM) structures.