Class / Patent application number | Description | Number of patent applications / Date published |
455108000 | Amplitude modulation | 28 |
20080207144 | Method and System for Improving Efficiency Over Power Control for Linear and Class AB Power Amplifiers - Aspects of a system for improving efficiency over power control for linear and class AB power amplifiers may include a current source circuit that enables determination of a bias current level for a PA circuit within an IC die based on an amplitude of an input modulation signal. The PA circuit may enable generation of an output signal based on a differential input signal and the input modulation signal to the current source circuit. A generated bias voltage may be applied to a transformer external to the IC die, but internal to an IC package containing the IC die and/or a circuit board containing the IC package. One or more amplifier bias voltage levels may be applied to the PA circuit wherein the amplifier bias voltage levels may be derived from the generated bias voltage level and/or the determined bias current level. | 08-28-2008 |
20080207145 | TRANSMITTER - Briefly, a transmitter that includes first and second fractional N synthesizers that may generate outphased modulated signals. First and second sigma-delta modulators may control the modulation of the first and second fractional N synthesizers. | 08-28-2008 |
20080233899 | High-frequency circuit device - A high-frequency circuit device is provided that achieves cost reduction and reduction in power consumption and does not require an additional high-frequency amplifier even when a transmission frequency band is newly added. The high-frequency circuit device has a configuration including a transmission amplifier circuit for transmitting high-frequency power from an antenna, which includes at least one high-frequency amplifier for a wide frequency band that amplifies signals in a plurality of transmission frequency bands differing by not less than 200 MHz from each other, a duplexer that is provided for performing simultaneous transmission/reception, upstream and downstream switch circuits in the direction of transmission that are provided so as to sandwich the duplexer between the high-frequency amplifier for a wide frequency band and the antenna and are switched on when the simultaneous transmission/reception is performed, and a power supply amplitude modulator that supplies an amplitude modulation voltage to a power supply terminal of the transmission amplifier circuit. | 09-25-2008 |
20080248766 | Reuse of digital-to-analog converters in a multi-mode transmitter - A transmitter for generating modulated signals is shown, wherein in a first-type operating mode, a first digital signal is input into a digital-to-analog converter to obtain a first analog signal that is input into a first-type unit, in which a first-type modulated signal is generated in dependence on at least the first analog signal; and wherein in a second-type operating mode, a second digital signal is input into the digital-to-analog converter to obtain a second analog signal that is input into a second-type unit, in which a second-type modulated signal is generated in dependence on at least the second analog signal. Correspondingly, a wireless communication device is shown, as well as a base station, a module in a wireless communication device, a module in a base station, an integrated circuit, a method, a computer program and a computer program product. | 10-09-2008 |
20080299919 | SIGNAL ENHANCEMENT IN RF TRANSMITTERS EMPLOYING NON-LINEAR FILTERING - A communications transmitter having a main transmit chain for main signal features and one or more auxiliary transmit chains for auxiliary signal enhancements. In one embodiment, a communications signal is produced by digitally processing a representation of a desired signal so as to limit a trajectory of a signal represented by a resulting processed signal. A digital representation of a difference signal approximating a difference between the processed signal and the desired signal is produced. A first modulated, amplified signal is produced in dependence on the processed signal, and a second modulated, amplified signal is produced in response to the difference signal. The first modulated, amplified signal and the second modulated, amplified signal are combined to produce the desired signal. In this manner, a main transmit chain may be optimized with respect to other properties than signal quality (e.g., power efficiency), while one or more auxiliary transmit chains may be used to enhance the signal quality of the final signal. | 12-04-2008 |
20090042520 | Envelope tracking RF amplifier - Apparatus is presented for broadcasting an RF signal. This includes an amplifier having a first input and a second input for a vacuum tube amplifier embodiment. A sampler receives a composite RF signal and provides therefrom a sample signal and a driver signal each signal having digital and analog components. An envelope extractor receives the sample signal and provides therefrom an amplitude modulated baseband signal for application to the second input bias power supply on a vacuum tube or the first input bias supply on an MOS-FET device. The RF sampler circuit supplies the drive signal including both amplitude and phase modulation to the first input (grid or gate) of the RF amplifier. | 02-12-2009 |
20090111396 | AM TRANSMITTER AND MODULATION METHOD USING SAME - An AM (Amplitude-Modulated) transmitter capable of improving modulation distortion is provided. An adder adds a modulation signal to a pre-set power reference signal. An APC (Automatic Power Control) amplifier compares a level of a detecting signal outputted by the LPF (Low Pass Filter) with a level of an adder signal. The APC amplifier, based on the comparison result, generates a gain controlling signal that makes a difference between a level of the detecting signal and level of the signal approach zero and feeds the gain controlling signal to a power amplifier. The power amplifier modulates the signal outputted from the amplifier by the gain controlling signal and power-amplifies the modulated signal according to a level of the gain controlling signal. Since the APC amplifier feeds the gain controlling signal to the power amplifier, a modulation degree does not depend on a nonlinear distortion characteristic of the power amplifier. | 04-30-2009 |
20090111397 | POLAR MODULATION TRANSMITTER WITH ENVELOPE MODULATOR PATH SWITCHING - Methods and apparatus for controlling power in a polar modulation transmitter. An exemplary polar modulation transmitter includes a radio frequency power amplifier (RF PA), a phase path having circuitry operable to generate a constant amplitude phase modulated signal, and an amplitude path including an envelope modulator circuit having first and second envelope modulation paths. The RF phase modulated signal is applied to an RF input of the RF PA, while an envelope modulated power supply signal generated by a selected one of the first and second envelope modulation paths is coupled to a power supply input of the RF PA. The second envelope modulation path is selected during times when the power required by the RF PA is below some predetermined power level. During times when the RF PA requires power above the predetermined power level, the first envelope modulation path is selected. | 04-30-2009 |
20090117863 | High efficiency rf transmitter system using non-linear amplifiers - An RF transmitter with improved efficiency and good linearity decomposes an input AM signal into two signal envelopes with phased modulation at a phase angle θ. The transmitter has three principal embodiments. A first solution uses at least one added RF amplifier for each decomposed signal envelope with one or more amplifiers having a low gain compared to that of a high gain amplifier in another branch for the same signal envelope. A phase angle θ | 05-07-2009 |
20090181626 | TRANSMITTER - An apparatus comprising a first circuit configured to receive a signal and output a first output signal, a second circuit configured to receive the same signal and output a second output signal with a phase delay compared to the first signal, and a combiner configured to combine said first and second output signals to provide a combined signal, wherein said phase delay is controlled such that an amplitude of said combined signal is controlled. | 07-16-2009 |
20090258611 | POLAR MODULATION TRANSMISSION APPARATUS AND POLAR MODULATION TRANSMISSION METHOD - The polar modulation apparatus of the present invention can control the output power of a transmission signal over a wide range and compensate characteristic degradation reliably upon temperature change. Polar modulation transmission apparatus | 10-15-2009 |
20100003933 | SIGNAL TRANSMISSION APPARATUS AND SIGNAL TRANSMISSION METHOD - A signal transmission apparatus of the invention comprises: a correlator | 01-07-2010 |
20100056080 | TRANSMISSION CIRCUIT AND COMMUNICATION DEVICE - Provided is a transmission circuit that can broaden a controlled bandwidth of a voltage controller while ensuring voltage withstanding ability of the voltage controller. The transmission circuit includes: a phase modulator that outputs a phase modulation signal; a power amplifier that includes a transistor; a collector controller that controls a collector voltage; a base controller that controls a base bias voltage; and a switching controller, which switches, when a level indicated by the power level signal is lower than a predefined value, only a control of the collector controller into a control that is in accordance with an amplitude signal and a power level signal, and which switches, when the level indicated by the power level signal is equal to or more than the predefined value, only a control of the base controller into a control that is in accordance with the amplitude signal and the power level signal. | 03-04-2010 |
20100081397 | TIME ALIGNMENT METHODS AND APPARATUS FOR POLAR MODULATION TRANSMITTERS - A polar modulation transmitter includes an amplitude modulation (AM) path with an amplitude modulation to amplitude modulation (AM/AM′) correction circuit and a phase modulation (PM) path with a delay element and an amplitude modulation to phase modulation (AM′/PM) correction circuit. The AM/AM′ correction circuit receives and predistorts a digital amplitude component signal depending on amplitudes of samples in the digital amplitude component signal, thereby generating a predistorted digital amplitude component signal. The delay element receives and delays a digital phase component signal, to generate a delayed digital phase component signal having a delay corresponding to the latency introduced by the AM/AM′ correction circuit. The AM′/PM correction circuit predistorts the delayed digital phase component signal depending on amplitudes of samples in the predistorted amplitude component signal, thereby generating a predistorted digital phase component signal. | 04-01-2010 |
20100124889 | ADAPTIVE DELAY ALIGNMENT IN POLAR TRANSMITTERS - A polar transmitter includes a power amplifier (PA), an amplitude modulation (AM) path including an AM path adjustable delay, an AM path delay measurement circuit, a phase modulation (PM) path including a PM path adjustable delay, and a PM path delay measurement circuit. The AM path delay measurement circuit is configured to measure an AM path delay using waveform correlation, e.g., using peak magnitude events (PMEs) in signals transmitted along the AM path to a power supply port of the PA. The PM path delay measurement circuit is configured to measure a PM path delay using waveform correlation, e.g., using PMEs in signals transmitted along the PM path to a phase-modulated input of the PA. The measured AM and PM path delays are used to adjust the AM and PM path adjustable delays, to reduce the delay mismatch between signals appearing at the power supply and phase-modulated input ports of the polar transmitter's PA. | 05-20-2010 |
20100136931 | METHOD FOR TRANSMITTING AND RECEIVING ADDITIONAL CONTROL SIGNALS - A method for transmitting/receiving an additional control signal without any loss of bandwidth and power in an original Tx signal is disclosed. If the additional control signal is transmitted via the Tx signal composed of at least one of data and control signals, at least one of the amplitude and phase of the Tx signal of the time- and frequency-resource domain is modulated according to the additional control signal to be transmitted. The modulated Tx signal is transmitted to the receiver, so that the additional control signal can be transmitted irrespective of the original Tx signal. According to a modulation status of at least one of an amplitude and a phase of the Rx signal contained in the time- and frequency-resource domain, the additional control signal can be acquired. | 06-03-2010 |
20100151802 | AMPLITUDE MODULATION CIRCUIT IN POLAR TRANSMITTER AND METHOD FOR CALIBRATING AMPLITUDE OFFSET IN POLAR TRANSMITTER - An amplitude modulation circuit in a polar transmitter and a method for calibrating amplitude offset in the polar transmitter are provided. The amplitude modulation circuit includes a digital-to-analog converter (DAC), a low pass filter (LPF), a gm stage, and a calibration module. The DAC is coupled to an amplitude modulation signal input. The LPF is coupled to the DAC, and the gm stage is coupled to the LPF. The calibration module has an input coupled to the gm stage, and an output coupled to a node on a path between the DAC and the gm stage. The method includes: generating an amplitude offset calibration signal according to an amplitude modulation signal generated from the gm stage; and transmitting the amplitude offset calibration signal via the output of the calibration module to a node on a path between the DAC and the gm stage so as to calibrate the amplitude offset. | 06-17-2010 |
20100184389 | WIRELESS COMMUNICATION UNIT, INTEGRATED CIRCUIT AND METHOD FOR BIASING A POWER AMPLIFIER - A wireless communication unit ( | 07-22-2010 |
20100184390 | METHOD AND SYSTEM FOR EXTENDING DYNAMIC RANGE OF AN RF SIGNAL - Aspects of a method and system for extending dynamic range of an RF signal are provided. In this regard, an amplitude signal that is representative of an amplitude of a pair of baseband signals may be generated, an amplitude of the generated amplitude signal may be modified according to a function; and an amplitude of the baseband signals may be modified according to an inverse of the function. The modifications may adjust the peak-amplitude-to-average-amplitude ratio of one or more signals. An intermediate signal may be generated from the modified baseband signals and the amplitude of the intermediate signal may be amplitude modulated by the intermediate signal. The intermediate signal may be amplitude modulated by controlling a gain of a power amplifier. The intermediate signal may be amplitude modulated by controlling a current source and/or voltage source supplying power to a power amplifier. | 07-22-2010 |
20100248657 | POWER CORRECTION MODULE FOR POWER AMPLIFIERS - 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. | 09-30-2010 |
20100297965 | AMPLITUDE MODULATION CONTROLLER FOR POLAR TRANSMITTER - Apparatus for generating a modulation signal for use in modulating the power supply of a power amplifier uses coarse and fine control for controlling the amplitude of the modulation signal, and thereby controlling the output power of the power amplifier. The modulation signal may be generated in the digital domain and converted to the analog domain by a digital-to-analog converter, with the digital-to-analog converter providing the fine control and a variable gain amplifier providing the coarse control of the analog signal. | 11-25-2010 |
20110092173 | TRANSMITTING UNIT THAT REDUCES PAPR USING OUT-OF-BAND DISTORTION AND METHOD THEREFOR - A transmitting unit ( | 04-21-2011 |
20110244817 | FORWARD LINK SIGNALING - Exemplary embodiments are directed to forward link signaling via transmitter detuning A method may include selectively detuning a circuit to adjust an amplitude of an associated transmit signal based on data to be transmitted. The method may also include selectively retuning the circuit to differently adjust the amplitude of the transmit signal based on the data to be transmitted. | 10-06-2011 |
20120040630 | AMPLITUDE MODULATION CIRCUIT IN POLAR TRANSMITTER AND METHOD FOR CALIBRATING AMPLITUDE OFFSET IN POLAR TRANSMITTER - An amplitude modulation circuit in a polar transmitter includes a digital-to-analog converter (DAC), a filter, a gm stage, and a calibration module. The DAC is arranged to be coupled to an amplitude modulation signal input in a normal mode. The filter is coupled to the DAC, and the gm stage is coupled to the filter. The calibration module has an input coupled to the gm stage, and an output coupled to a node on a path between the DAC and the gm stage. A method for calibrating an amplitude offset in the polar transmitter includes: generating an amplitude offset calibration signal according to an amplitude modulation signal generated from the gm stage; and transmitting the amplitude offset calibration signal via the output of the calibration module to a node on a path between the DAC and the gm stage so as to calibrate the amplitude offset. | 02-16-2012 |
20120071115 | Method of Controlling RF Transmissions to Mitigate Interference with Critical Care Medical Equipment - Various methods of mitigating RF inference with one or more critical care medical devices is provided, wherein a predetermined threshold energy acceleration value is associated with the one or more critical care medical devices that, if exceeded, will cause RF inference with the one or more critical care medical devices. The methods includes generating and transmitting RF energy, wherein at least a portion of said RF energy follows an RF power profile of power versus time having a particular format designed to mitigate interference. | 03-22-2012 |
20130252564 | POWER CONTROL TECHNIQUES FOR WIRELESS TRANSMITTERS - Various embodiments are disclosed relating to power control techniques for wireless transmitters. In an example embodiment, an apparatus is provided that may include a digital-to-analog converter (DAC) adapted to convert a digital amplitude signal to an analog amplitude signal during a first transmission mode and adapted to convert a digital power level signal to an analog power level signal during a second transmission mode. | 09-26-2013 |
20140038534 | HARMONIC SUPPRESSION IN SWITCHING AMPLIFIERS - Configurable suppression of harmonics in a radio frequency (RF) transmitter circuit having two class-D switching amplifiers that produce a differential output signal having introduced harmonics is contemplated. A selected harmonic is used to determine a time duration. A harmonic suppression circuit modifies a radio frequency polar modulated data signal that is encoded using an amplitude component and a phase component. The modification is responsive to the determined time duration. The switching power amplifiers amplify the modified polar modulated data signal to produce an amplified signal. The amplified signal includes three signal levels, a high signal level, a middle signal level and a low signal level. The timing of transitions between the high and low signal levels represents the phase component, and the transitions include the middle signal level for the time duration, thereby suppressing the selected harmonic. | 02-06-2014 |
20150318943 | TRANSMITTER AND MONITORING SYSTEM USING THE SAME - The present disclosure discloses a transmitter and a monitoring system using this transmitter, the transmitter includes: a multi-to-one multiplexing switch configured to receive a plurality of sensor signals of a plurality of channels through a plurality of input terminals, select one sensor signal from the plurality of sensor signals, and output the selected sensor signal through a output terminal; a first variable gain amplifier configured to receive the selected sensor signal, amplify the selected sensor signal with a gain within a first gain range, and output the amplified sensor signal; a control parameter input terminal configured to receive an input control parameter from outside of the transmitter; and an operating and switching selector configured to perform operations according to the input control parameter, so as to control the multi-to-one multiplexing switch to select the one sensor signal and control the gain of the first variable gain amplifier. | 11-05-2015 |