Abstract: There has been a demand for a technique of expanding a communicable range as much as possible without increasing the time required for communication between an RF tag and a communication device. A communication device includes: a terminal electrically connected with an antenna; a transmitter electrically connected with the terminal and configured to generate a first radio signal superimposed with a predetermined command signal and transmit the first radio signal from the antenna; an amplifier electrically connected with the terminal and configured to receive from the antenna a second radio signal generated by an RF tag receiving the first radio signal; a detector configured to detect intensity of the signal having been amplified by the amplifier; and a suppressor configured to suppress the intensity of the amplified signal to be inputted into the detector such that the intensity does not exceed a predetermined upper limit.

Abstract: Selectable sizes for a local oscillator (LO) buffer and mixer are disclosed. In an exemplary embodiment, LO buffer and/or mixer size may be increased when a receiver or transmitter operates in a high gain mode, while LO buffer and/or mixer size may be decreased when the receiver or transmitter operates in a low gain mode. In an exemplary embodiment, LO buffer and mixer sizes are increased and decreased in lock step. Circuit topologies and control schemes for specific exemplary embodiments of LO buffers and mixers having adjustable size are disclosed.

Abstract: A torque measurement system that includes a rotor device and a stator device can perform automatic tuning to improve the initial tuning performed during design and assembly. The stator device can include a variable capacitive element and a micro-controller configured to adjust a capacitance value of the variable capacitive element. Additionally or alternatively, the rotor device can include a variable capacitive element and a micro-controller configured to adjust a capacitance value of the variable capacitive element. The adjustment of the capacitive elements can be based on the quality of signal detected at either the rotor device or stator device.

Abstract: Provided are a receiving apparatus and method for a wireless communication system using multiple antennas. A receiving method for a wireless communication system using multiple paths, the receiving method comprising: receiving signals through a predetermined number of multiple paths; sensing a carrier according to saturation state degrees of the signals, and providing saturation state information; calculating automatic gain components of the received signals by using the received signals and the saturation state information of the received signals; and performing a noise matching process to amplify noises on the predetermined multiple paths according to the automatic gain components during a predetermined period.

Abstract: A torque measurement system that includes a rotor device and a stator device can perform automatic tuning to improve the initial tuning performed during design and assembly. The stator device can include a variable capacitive element and a micro-controller configured to adjust a capacitance value of the variable capacitive element. Additionally or alternatively, the rotor device can include a variable capacitive element and a micro-controller configured to adjust a capacitance value of the variable capacitive element. The adjustment of the capacitive elements can be based on the quality of signal detected at either the rotor device or stator device.

Abstract: An apparatus and method for splitting a wide band input signal and overlaying multiple frequency bands on each path associated with one or more digitizers. All frequencies from the split signal on each path can be fed to a mixer. The local oscillator of each mixer receives a sum of signals, which can each be set to any arbitrary frequency, as long as an associated matrix determinant of coefficients is non-zero. Each oscillator signal is multiplied by a coefficient, which can represent phase and magnitude, prior to summing the oscillator signals together. Each mixer mixes a combined signal with the input, thereby generating a set of multiple overlaid frequency bands. The digitized signals are processed to substantially reconstruct the original input signal. Thus, the wide band input signal is digitized using multiple individual digitizers. In particular, a system can support two wide band signals using four digitizers of narrower bandwidth.

Abstract: A power amplifier controller circuit controls a power amplifier based upon an amplitude correction signal indicating the amplitude difference between the amplitude of the input signal and an attenuated amplitude of the output signal. The power amplifier controller circuit comprises an amplitude control loop and a phase control loop. The amplitude control loop adjusts the supply voltage to the power amplifier based upon the amplitude correction signal. The amplitude correction signal may also be split into two or more signals with different frequency ranges and provided respectively to different types of power supplies with different efficiencies to generate the adjusted supply voltage to the power amplifier. The phase control loop adjusts the phase of the input signal based upon a phase error signal indicating a phase difference between phases of the input signal and the output signal to reduce phase distortion generated by the power amplifier.

Abstract: Certain aspects of the method may comprise generating at least one control signal that may be utilized to control at least a first of a plurality of received spatially multiplexed communication signals. An amplitude and/or phase of the first received spatially multiplexed communication signal may be adjusted via the generated control signal so that the amplitude and/or phase of the first received spatially multiplexed communication signal may be equivalent to an amplitude and/or phase of a second received spatially multiplexed communication signal. The amplitude of the first received spatially multiplexed communication signal is adjusted within the processing path used to process the first received spatially multiplexed communication signal.

Abstract: A wireless communications device comprising duplexing means for directing signals from a transmit path towards an antenna and for providing signals from the antenna to a receive path, wherein the transmit path is arranged to send a first signal to the duplexing means, the receive path is arranged to recover a second signal and the device further comprises detecting means for detecting the presence in the receive path of a third signal that will interact with the first signal to produce intermodulation distortion tending to hamper recovery of the second signal and control means responsive to the detecting means for enhancing linearity in the receive path to reduce said intermodulation distortion.

Abstract: Methods and apparatus to perform radio frequency (RF) analog-to-digital conversion are described. According to one example, a receiver includes an amplifier to amplify received analog RF signals and a mixer-free circuit for converting the received analog RF signals to digital signals.

Abstract: An exemplary embodiment of the present invention described and shown in the specification and drawings is a transceiver with a receiver, a transmitter, a local oscillator (LO) generator, a controller, and a self-testing unit. All of these components can be packaged for integration into a single IC including components such as filters and inductors. The controller for adaptive programming and calibration of the receiver, transmitter and LO generator. The self-testing unit generates is used to determine the gain, frequency characteristics, selectivity, noise floor, and distortion behavior of the receiver, transmitter and LO generator. It is emphasized that this abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or the meaning of the claims.

Abstract: Methods and apparatus to perform radio frequency (RF) analog-to-digital conversion are described. According to one example, a receiver includes an amplifier to amplify received analog RF signals and a mixer-free circuit for converting the received analog RF signals to digital signals.

Abstract: A direct conversion satellite tuner is fully integrated on a common substrate. The integrated tuner receives an RF signal having a plurality of channels and down-converts a selected channel directly to baseband for further processing. The integrated tuner includes on-chip local oscillator generation, tunable baseband filters, and DC Offset cancellation. The integrated tuner can be implemented in a completely differential I/Q configuration for improved electrical performance. The entire direct conversion satellite tuner can be fabricated on a single semiconductor substrate using standard CMOS processing, with minimal off-chip components. The tuner configuration described herein is not limited to processing TV signals, and can be utilized to down-convert other RF signals to an IF frequency or baseband.

Abstract: A system and method for indicating signal strength of a multi-mode wireless communication device is disclosed. The wireless communications device simultaneously displays signal strength indicators of multiple radio access technologies on the multi-mode wireless communication device. In an exemplary method, the multi-mode wireless device determines a first signal strength of a first radio access technology and displays the signal strength in a designated annunciator area of a display of the device. The device then determines availability and signal strength for a second radio access technology and further displays a second signal strength indicator in the annunciator area corresponding to the second determined signal strength of the second radio access technology.

Abstract: A receiving apparatus includes a plurality of receivers, each including a variable gain section configured to amplify or attenuate an input signal input thereto with a gain corresponding to an AGC (Automatic Gain Control) signal, and a generator configured to generate an AGC signal in each case when an input signal input to the respective receivers is greater than a predetermined signal level, the AGC signal reducing the gain of the variable gain section in response to a signal level of the input signal. The variable gain section in each of the plurality of receivers amplifies or attenuates the input signal with a gain corresponding to the AGC signal generated by the generator, when the input signal input to the receiver is greater than the predetermined signal level.

Abstract: A multi-channel amplifier has inputs via which input signals can be fed to the multi-channel amplifier. The input signals are amplified into output signals by amplifier channels of an amplification stage of the multi-channel amplifier and then are emitted via outputs of the multi-channel amplifier. An adjustment device is associated with the amplification device that allows dynamic adjustment of a limit power, up to which the respective output signal can be amplified, for each output. The limit power can be set to a maximum value for each output. The multi-channel amplifier is fashioned such that the sum of the limit powers of all outputs can always be simultaneously emitted independent of the current setting of the limit powers, but such that the sum of the limit powers is always smaller than the sum of the maximum values of all outputs. Such a multi-channel amplifier is particularly suitable for use in a transmission arrangement for radio-frequency signals.

Abstract: A high frequency part, which amplifies a high frequency signal outputted from an intermediate frequency part and supplies to an antenna, is equipped with a gain controller with switch function. The gain controller with switch function comprises an attenuator with switch function has a function of switching a selected band between two bands outputted from the intermediate frequency part and controlling the gain of the high frequency signal in the selected band. The attenuator with switch function comprises a first variable resistor which connects a signal input part with a signal output part and a second variable resistor which is disposed parallel to said first variable resistor and connects a signal input part with a signal output part. The first and the second variable resistors are controlled by a common gain control voltage and set such that the gain control voltage ranges, which are for changing the resistor values, will not overlap with each other.

Abstract: A frequency conversion receiver comprises a passive mixer, a Low-Noise Amplifier (LNA) and a balun. The low-noise amplifier generates an amplified single-ended signal responsive to a single-ended receiver input signal. The passive mixer generates a mixer output signal responsive to a differential mixer input signal and a four-phase local oscillator signal. The balun transforms the amplified singled-ended signal into the differential mixer input signal, the balun having a first winding coupled to an output of the low-noise amplifier and a second winding coupled to an input of the passive mixer, the second winding having more turns than the first winding. The turn ratio of the second winding to the first winding provides gain compensation to the low-noise amplifier, and in conjunction with the low-noise amplifier and the passive mixer, provides a desired gain to the receiver and linearity over a dynamic range of the receiver input signal.

Abstract: A high frequency part, which amplifies a high frequency signal outputted from an intermediate frequency part and supplies to an antenna, is equipped with a gain controller with switch function. The gain controller with switch function comprises an attenuator with switch function has a function of switching a selected band between two bands outputted from the intermediate frequency part and controlling the gain of the high frequency signal in the selected band. The attenuator with switch function comprises a first variable resistor which connects a signal input part with a signal output part and a second variable resistor which is disposed parallel to said first variable resistor and connects a signal input part with a signal output part. The first and the second variable resistors are controlled by a common gain control voltage and set such that the gain control voltage ranges, which are for changing the resistor values, will not overlap with each other.

Abstract: A radio-frequency receiver circuitry includes a down-converter circuitry, an analog-to-digital converter circuitry, and a DC offset reduction circuitry. The down-converter circuitry accepts a received radio-frequency signal and processes the radio-frequency signal to provide an in-phase down-converted signal and a quadrature down-converted signal to the analog-to-digital converter circuitry. The analog-to-digital converter circuitry converts the in-phase and quadrature down-converted signals to an in-phase digital output signal and a quadrature digital output signal, respectively. The DC offset reduction circuitry couples to the analog-to-digital converter circuitry, and tends to reduce a DC offset transmitted to the in-phase and quadrature digital output signals.

Abstract: A base band circuit forms a part of an automatic gain controller incorporated in a direct conversion receiver, and includes a series of variable gain amplifiers controlled by a gain controller and a feedback loop connected between the output node and the input node of the series of variable gain amplifiers, wherein the feedback loop has an attenuation circuit connected between the output node of the series of variable gain amplifiers and an inverted integrating circuit which, in turn, is connected through an adder and a low pass filter to the input node of the series of variable gain amplifiers so that direct current offset voltage is eliminated from the output signal of the series of variable gain amplifiers without change of cut-off frequency.

Abstract: Systems and methods are described for a sideband suppression technique for quadrature modulation using magnitude measurements. Gain imbalance, phase imbalance, or both gain and phase imbalance are corrected in a quadrature modulator. Predetermined voltage levels are applied to one or both of the quadrature modulator input channels and resultant output magnitudes are measured. Then, a gain correction factor, a phase correction factor or both gain and a phase correction factors are determined as a function of the measured output magnitudes. Gain imbalance, phase imbalance or both gain and imbalance are then corrected using the gain and phase correction factors.

Abstract: A converter operative in a digital telecommunication system to receive signals coded at a first compression mode and convert them into a second compression mode. The conversion provided, leads to substantially less impairments in the decompressed form of the signals converted into the second compression mode, had the signals received been decompressed from the first compression mode into their decompressed form followed by compressing these decompressed signals into the second compression mode, and decompressing the signals thus obtained.

Abstract: Techniques are disclosed for compensating for second-order distortion in a wireless communication device. In a zero-intermediate frequency (IF) or low-IF architecture, IM2 distortion generated by the mixer (20) results in undesirable distortion levels in the baseband output signal. A compensation circuit (104) provides a measure of the IM2 distortion current independent of the radio frequency (RF) pathway to generate an IM2 calibration current. The IM2 calibration current is combined with the baseband output signal to thereby eliminate the IM2 currents generated within the RF pathway. In one embodiment, the calibration is provided at the factory during final testing. In alternative embodiment, additional circuitry (156, 158) may be added to the wireless communication device to provide a pathway between the transmitter (150) and the receiver (146). The transmitter signal is provided to the receiver to permit automatic calibration of the unit.

Abstract: The radio receiver includes a low noise amplifier that amplifies a received signal to one of three different gain settings. One gain setting is maximum amplification, a second gain setting is 6 dB below maximum amplification and a third gain setting is 32 dB below maximum amplification. In the case of the third setting, the low noise amplifier actually attenuates the received signal by 6 dB. The radio receiver includes a pair of received signal strength indicators that provide received signal strength indications to logic circuitry. Responsive to the received signal strength indications, the logic circuitry generates control commands to the low noise amplifier to prompt it to amplify at one of the three specified levels. Generally, if the received signal has a gain level that exceeds a specified threshold, the low noise amplifier actually attenuates the received signal; otherwise, the level of amplification that is actually provided is a function of the presence of intermodulation interference.

Abstract: A radio receiver of the is provided with a local oscillation circuit, a mixing circuit to perform a frequency conversion from a received signal into an intermediate frequency signal by using an oscillation signal generated by the oscillation circuit, an ALC circuit to detect a level of the oscillation signal and control the level of the oscillation signal at a specified value, and a switching circuit switch the operation of the ALC circuit from the operational state to the non-operational state and vice versa. The receiver thus constructed will not receive an influence from the image signal, and even when the receiver is used in an area where a strong interference wave is present, the receiver is able to operate the local oscillation circuit in a normal condition.