Abstract: A power tuning method determines values of a magnitude control signal that controls the magnitude of an amplitude-modulated power supply signal applied to a power supply port of a power amplifier of a polar transmitter and an amplitude control signal that controls the amplitude of a constant-envelope phase-modulated signal applied to a radio frequency input port of the power amplifier necessary to set the output power of the polar transmitter to a target output power. The method is repeated and performed for a plurality of different target output powers. Output-power-level dependent power control parameters calculated from the applied method are used to set the values of the magnitude control and amplitude control signals during normal operation.

Abstract: The invention concerns controlling automatic gain control for a digital signal receiver. The method includes receiving a digital feedback signal for controlling an amplifier and processing the digital feedback signal to deliver a driving signal to an analog amplifier. Processing the digital feedback signal comprises regulating the evolution of the driving signal so that it is maintained constant during a predetermined period of time after every change.

Abstract: A power amplifier system is provided that includes a power amplifier configured to receive an RF input. A DC-DC converter is coupled to the power amplifier. Clocking circuits drive the DC-DC converter. The clocking circuits use the RF input to generate a clock. The clock acts with the DC-DC converter to provide an output voltage used in the power amplifier.

Abstract: A power amplification circuit includes a power amplifier, an RF detector, an error amplifier, a saturation detector, and an offset circuit. The power amplifier provides an amplified signal based on an input signal and a gain control signal. The RF detector provides a detection signal indicative of a logarithm of the power of the amplified signal. The error amplifier provides the gain control signal based on an amplification control signal and the detection signal. The saturation detector provides a saturation signal in response to the gain control signal differing from a reference signal by less than a first predetermined voltage. The offset circuit decreases a voltage level of the amplification control signal by up to a second predetermined voltage in response to the saturation signal and the amplification control signal differing from the detection signal by less than the second predetermined voltage.

Abstract: Plural variable gain amplifiers amplify audio signals of plural channels for each channel. An interface receives, from outside, plural gain control data individually designating gain of each channel. Plural gain controllers respectively switch the gain of the plural variable gain amplifiers, based on the plural gain control data. The plural gain controllers arrange timing to change gain of a variable gain amplifier corresponding to gain control data received in a predetermined data entry period, among the plural gain control data that are inputted at different timing.

Abstract: An amplifier includes a voltage detector that detects current flowing to a drain terminal of a transistor which amplifies a signal using GaN as a voltage difference by means of voltage conversion, a compensation decision unit that decides whether or not to perform gain compensation based on the voltage difference detected by the voltage detector, and a gain compensation unit that performs the gain compensation according to the voltage difference when the compensation decision unit decides to perform the gain compensation.

Abstract: A Power Amplifier (PA) apparatus includes a first stage PA tube, configured to amplify gain of input signals. A first stage bias circuit is connected to the first stage PA tube and is configured to provide bias voltage for the first stage PA tube. A second stage PA tube is configured to amplify gain of output signals of the first stage PA tube. A second stage bias circuit is configured to provide bias voltage for the second stage PA tube. A reference voltage unit is connected to the first stage bias circuit and the second stage bias circuit. A voltage control unit is connected to the first stage bias circuit and the second stage bias circuit and is configured to connect and disconnect the first stage PA tube through the first stage bias circuit, and connect and disconnect the second stage PA tube through the second stage bias circuit.

Abstract: A modulated gain audio control and zipper noise suppression techniques provide reduction in audible artifacts caused by discrete-valued gain changes. The gain of a signal is controlled by modulating between multiple gain values for corresponding time durations, so that a resulting average gain is controlled according to the average of the multiple gain values as weighted by their corresponding time durations. The modulation frequency is above the bandwidth of the signal. Transitions between gain levels are performed by changing the relative proportion of the durations to slowly change the gain according to a transition profile, which may be linear or non-linear. The modulation employed may be pulse-width modulation, or another modulation pattern such as a delta-sigma modulation pattern.

Abstract: The invention relates to a variable gain amplifier comprising a first attenuator (1) for receiving an input signal (rf_in) and for transmitting a first attenuated input signal to a first amplifier (2) for amplifying the first attenuated input signal and for generating a first amplified signal to a second attenuator (3) for attenuating the first amplified signal and for transmitting a second attenuated signal to a second amplifier (4) for amplifying the second attenuated signal and for generating an output signal (rf_out). The first attenuator (1) is supplied from a first supply voltage source (10). The second attenuator (3) is supplied from a second supply voltage source (30). The first amplifier (2) is supplied from a third supply voltage source (20), and the second amplifier (4) is supplied from a fourth supply voltage source (40).

Abstract: A dynamic voltage scaling system for a packet-based data communication transceiver includes a constant voltage supply, a variable voltage supply, and a voltage control unit. The constant voltage supply is configured to supply a constant voltage to at least one parameter-independent function of the transceiver, and the variable voltage supply is configured to supply a variable voltage in accordance with a control signal to at least one parameter-dependent function of the transceiver. Parameter-independent transceiver functions perform operations independent of a predetermined parameter and parameter-dependent transceiver functions perform operations dependent on the predetermined parameter The voltage control unit is configured to generate the control signal based on information provided by at least one parameter-independent transceiver function about the predetermined parameter.

Abstract: A measurement system includes a detector to generate a measurement signal responsive to an input signal, and a nulling circuit coupled to the detector to generate a control signal responsive to the difference between the measurement signal and a set-point signal. The nulling circuit may include a bandwidth compensation stage to maintain the overall control loop bandwidth at a substantially constant value.

Abstract: A communication device having an RF power amplifier stage with a Cartesian feedback loop is provided. The loop has forward paths whose outputs are combined to form an output signal that is fed back to a single feedback path. Each forward path has a common path with a filter that filters the overall loop response and a unique split path. The main and auxiliary split paths have a power amplifier and carry signals respectively of lower and higher frequencies. The auxiliary amplifier is faster than the main amplifier. Different phases of the carrier signal are used during upconversion such that the overall phase response through the split paths is equal. Instability recovery problems introduced by higher-order loop filters are mitigated by baseband loop filters with switchable order. Upon detecting instability, the loop filter order is reduced and is subsequently increased after eliminating the unstable operation.

Abstract: A switched current resistor (SCR) PGA for constant-bandwidth gain control includes an inverting amplifier, a feedback resistor forming a feedback loop between an output side and an input side of the inverting amplifier, and a switched current resistor (SCR) array connected in parallel to the feedback resistor, and configured to tune a gain range between a maximum and a minimum. The SCR array includes a plurality of switched resistors, each comprising a switch in series with a resistor. When the plurality of switched resistors are switched by a gain-control logic, a plurality of switched current sources and a plurality of grounded resistors are switched correspondingly to deliver a transient current, an equivalent of which flows through the plurality of grounded resistors out from the input side of the inverting amplifier, leading to a feedback factor of the PGA being constant.

Abstract: A radio receiver adapted to alternatively receive data over a communication channel in a first mode and a second mode. The second mode facilitates reception of data at higher data rates than the first mode. The radio receiver comprises a signal-processing unit and a control unit. The signal processing unit is adapted to determine a quality condition of the communication channel. The control unit is adapted to determine, based on the quality condition, whether the communication channel facilitates operation in the second mode and assess at least one configuration condition, one of the at least one configuration condition being that the communication channel is determined to facilitate operation in the second mode. The control unit is further adapted to configure the radio receiver to operate in the second mode when all of at least one configuration condition are fulfilled or to operate in the first mode otherwise. A method for controlling the radio receiver is also disclosed.

Abstract: A voltage control apparatus used for an electron tube or a power supply apparatus includes a detecting circuit for detecting current flowing through a helix electrode, a voltage-limiting circuit for controlling a potential difference between the helix electrode and the anode electrode based on a predetermined voltage level; and a switch for switching based on an output from the detecting circuit. The switch connects the helix electrode and the anode electrode through the voltage-limiting circuit, or causes a short circuit between the helix electrode and the anode electrode.

Abstract: The audio amplifier includes a variable gain amplifier receiving the input audio signal and providing the output signal, whereby the output signal corresponds to the input signal amplified by a limiter gain. The audio amplifier further includes a limiter gain calculation unit, thus the input signal is amplified by the limiter gain. A control unit receives a signal representative of the input signal and is configured to estimate, based on a mathematical model, the input current or the total output current of the audio amplifier thus providing an estimated current signal corresponding to (and resulting from) the output signal, whereby the limiter gain calculation unit is configured to calculate, dependent on the estimation, the limiter gain such that the actual input current or the total output current of the audio amplifier does not exceed a threshold current value.

Abstract: Embodiments of the present invention provide systems and methods for automatic amplifier gain profile control, including a method for automatically configuring a variable gain profile amplifier according to received input and a variable gain profile amplification system. Further, embodiments of the present invention provide systems and methods for increased gain profile accuracy, including methods and systems to reduce the effects of temperature and/or process variations on the gain profile of an amplifier.

Abstract: Apparatus and method for reducing the current consumption and increasing the efficiency of an RF power amplifier (PA), according to which the load, connected to the output stage of the PA, tuned dynamically or statically for each level of the desired output power. By doing so, the output impedance of the output stage is essentially matched, such that the dynamic RF load line has a slope that corresponds to the impedance required to provide this level. Whenever a smaller output power is desired in response to reduction in the input signal to the amplifier, the load is further tuned, such that the dynamic or static RF load line has a slope that causes the power amplifier to essentially remain in saturation at the smaller output power.

Abstract: A radio frequency (RF) power amplifier system adjusts the supply voltage provided to a power amplifier (PA) adaptively, responsive to the measured or estimated power of the RF output signal of the PA. The RF PA system includes a power amplifier (PA) which receives and amplifies an RF input signal to generate an RF output signal at a level suitable for transmission to an antenna. A PA supply voltage controller generates a supply voltage control signal, which is used to control the supply voltage to the final stage of the PA. The supply voltage control signal is generated responsive to the measured or estimated power of the PA RF output signal, and also may be responsive to a parameter indicative of impedance mismatch experienced at the PA output. By controlling this supply voltage to the RF PA, the efficiency of the PA is improved.

Abstract: An amplifier circuit performs a characteristic correction process and a smooth curvilinear process on an input signal before being subjected to amplification. The characteristic correction process is a frequency characteristic process, which is performed on the input signal so as to produce a processed signal (Vp). Either the input signal or the processed signal, or the mixture of these signals is subjected to the smooth curvilinear process whose start point is designated by a state variation of amplification (VxTyp). Alternatively it is subjected to a gain decrement process instead of the smooth curvilinear process when the state variation of amplification is less than a default value (VxTHD). Thus, it is possible to prevent clipping from occurring in the amplified output signal while maintaining an adequate power.

Abstract: An packet detection controller accepts an input from an AGC controller which indicates the presence of an increased signal energy and also completion of an AGC process and generates an output to suspend the AGC process. The packet detection controller also receives a plurality of IQ receiver streams and forms a single stream for use by a packet detector, which is controllable by an SNR_MODE indicating whether the signal to noise ratio is above or below a particular threshold, and a PD_RESET signal indicating that no packet detection should occur. The controller also receives a PACKET_DET signal indicating that packet detection is completed. The packet detection controller examines the incoming receiver streams and suspends AGC process if a packet detect is generated, or suspends the packet detector if an AGC process is required.

Abstract: An automatic power tuning system and method, and a transmitter employing either the system or the method. In one embodiment, the system includes: (1) a power detector circuit coupled to an output of a transmitter, the transmitter having an integrator with a first, reference integrator current power control input, a second, integrator capacitor power control input and a plurality of driver fingers selectably employable by a third, driver finger power control input, the power detector configured to generate signals indicating an output voltage of the transmitter and (2) a digital processing circuit coupled to the power detector circuit and configured to employ the signals to determine at least near-optimum reference integrator current and integrator capacitor settings and select a number of driver fingers to employ to drive the output voltage.

Abstract: A signal amplifier controls an output amplitude of a differential transmitted from an amplifier circuit to two output terminals via each of 2N number of MOS transistors that operate as a switch by switching a control value n, and includes an amplitude-control-word switching unit that multiplies the control value n by a value 1 or a value ?1 and switches between an amplitude control word of a value (N+n) and an amplitude control word of a value (N?n) of a complementary 2N-bit amplitude control word.

Abstract: There is provided a power amplifier with a variable supply of bias power according to a look-up table having a voltage value determined based on a level of an RF signal being input to the power amplifier to thereby increase power efficiency. A power amplifier according to an aspect of the invention may include an amplification section amplifying an input signal according to a bias voltage being supplied; and a bias supply section comparing a level of the input signal with a look-up table set in advance and supplying a bias voltage to the amplification section according to a result of the comparison.

Abstract: A radio frequency amplifier system is disclosed in which the amplifier bias supply and power supply voltages are instantaneously modulated with signals derived from the envelope voltage of the input signal. Separate non-linear mapping functions are used to derive the supply and bias voltages. The two mapping functions are optimised jointly to achieve particular system performance goals, such as optimum efficiency, constant gain, constant phase, or minimum spectral spreading. An optimisation of particular interest is that which achieves best RF amplifier power added efficiency subject to achieving constant amplifier gain. In this way the need for pre-distortion linearization may be reduced or eliminated.

Abstract: There is disclosed a technique for controlling at least one amplification stage, comprising: selecting a linearity objective for the amplification stage; in dependence on an input signal to said amplification stage, determining a combination of supply input and bias input for the amplification stage in order to meet said linearity objective; and in dependence on there being more than one combination of supply input and bias input for meeting the linearity objective, selecting the combination that optimizes a further system performance objective for the amplification stage. The further system performance objective may be one or more of: an efficiency objective; an envelope signal bandwidth objective; or a robustness to production tolerance objective.

Abstract: There is provided a power amplifier that can maintain a constant gain by detecting a level of a signal being input and a level of a signal being output. A power amplifier according to an aspect of the invention may include: an amplification section having at least one amplification unit amplifying an input signal according to an adjustable gain to thereby output the amplified input signal; a detection section detecting signal levels of an input signal and an output signal of the amplification section; and a gain maintaining section controlling a bias power according to a detection result of the detection section so that a gain of the amplification section is maintained within a predetermined gain range.

Abstract: Aspects of a method and system for polar modulation with discontinuous phase for RF transmitters with integrated amplitude shaping may include amplifying a signal via a plurality of amplifiers such that a combined gain of the plurality of amplifiers comprises a coarse amplitude gain, an amplitude offset gain and a pulse-shaping gain. A gain of one or more of the plurality of amplifiers may be adjusted to set the coarse amplitude gain. A gain of one or more of the plurality of amplifiers may be adjusted to set the amplitude offset gain and the pulse-shaping gain, wherein the one or more of the plurality of amplifiers used to set said amplitude offset gain and said pulse-shaping gain are distinct from the one or more of said plurality of amplifiers used to set the coarse amplitude gain.

Abstract: A radio frequency (RF) power amplifier system adjusts the supply voltage provided to a power amplifier (PA) adaptively, responsive to the measured or estimated power of the RF output signal of the PA. The RF PA system includes a power amplifier (PA) which receives and amplifies an RF input signal to generate an RF output signal at a level suitable for transmission to an antenna. A PA supply voltage controller generates a supply voltage control signal, which is used to control the supply voltage to the final stage of the PA. The supply voltage control signal is generated responsive to the measured or estimated power of the PA RF output signal, and also may be responsive to a parameter indicative of impedance mismatch experienced at the PA output. By controlling this supply voltage to the RF PA, the efficiency of the PA is improved.

Abstract: Aspects of a method and system for polar modulation with discontinuous phase for RF transmitters with integrated amplitude shaping may include amplifying a signal via a plurality of amplifiers such that a combined gain of the plurality of amplifiers comprises a coarse amplitude gain, an amplitude offset gain and a pulse-shaping gain. A gain of one or more of the plurality of amplifiers may be adjusted to set the coarse amplitude gain. A gain of one or more of the plurality of amplifiers may be adjusted to set the amplitude offset gain and the pulse-shaping gain, wherein the one or more of the plurality of amplifiers used to set said amplitude offset gain and said pulse-shaping gain are distinct from the one or more of said plurality of amplifiers used to set the coarse amplitude gain.

Abstract: According to one general aspect, a distributed threshold adjuster (DTA) may be interspersed between stages of a multistage amplifier to adjust the DC voltage of an input signal. The DTA may include an input signal terminal configured to receive the input signal. The DTA may also include a plurality of current sources configured to produce an adjustment current signal whose amperage is configured to be increased or decreased by fixed steps in order to adjust the DC voltage of the input signal. The DTA may include a control unit configured to selectively turn on or off the individual current sources of the plurality of current sources to select the amperage of the adjustment current signal. The DTA may further include an output terminal configured to produce an output signal, comprising a combination of the input signal and the adjustment current signal, to a stage of a multistage amplifier.

Abstract: An output circuit including a fine-adjustment VGA and a rough-adjustment VGA, where the maximum gain of the fine-adjustment VGA, as attained when the minimum gain of the rough-adjustment VGA is attained, is lower than the maximum gain of the fine-adjustment VGA as attained when the maximum gain of the rough-adjustment VGA is attained, so that the power consumption of the rough-adjustment VGA is reduced.

Abstract: N drivers convert n digital values into n voltages. N amplifiers amplify the n voltages, thereby generate n drive voltages. An amplifier voltage supply supplies an amplifier voltage for driving the n amplifiers. An amplifier voltage controller detects a maximum digital value among a plurality of digital values, and sets the amplifier voltage to a voltage value dependent on the maximum digital value.

Abstract: DC-DC converters adapted to provide two or more DC output voltages. More particularly, a multi-state or mode DC-DC converter circuit comprising first and second controllable switches configured for unidirectional conduction of charging current.

Abstract: A method and a device for tuning power amplifier (PA, 203) properties such as back-off. A peak-to-average value (PAR) of the amplifier input signal is first obtained by control means (206) and then used for adjusting the power amplifier (203) with tuning means (204, 208, 210) functionally connected to the amplifier (203). The suggested solution is advantageously exploited in a wireless communications device like a mobile terminal to optimize the performance thereof by, for example, reducing the power dissipation in the transmitter.

Abstract: An apparatus for controlling power of a mobile terminal is provided. The apparatus includes a power conversion for providing a ground connection during a time interval if a power value is input for testing the mobile terminal and a power control unit having one terminal for controlling the power of the mobile terminal wherein, if the given power value is grounded during the time interval and a voltage level required to control power of the mobile terminal changes, the power control unit turns on power to the mobile terminal.

Abstract: An audio control method and audio processing system utilize an ADC to sample an analog audio input signal and convert it to a digital audio signal. A control module determines input signal level from the digital audio signal. Based on different input signal levels, output gain range of the amplifier can be set. In this way, the present invention can prevent speakers being burned out or volume being too low.

Abstract: A method of controlling operating parameters of a radio frequency power amplifier amplifying an input signal applied in bursts with controlled input power to an input of the power amplifier, comprising responding to gain variation parameters relating to variations in the scalar gain of said amplifier starting during an initial ramp-up period of a first burst to control supply voltage and quiescent current parameters for said amplifier during a subsequent burst.

Abstract: A power amplifier controller circuit controls an adjustable impedance matching network at the output of a power amplifier to vary its load line to improve the efficiency of the RF PA. The PA controller circuit comprises an amplitude control loop that determines an amplitude correction signal. The amplitude loop is configured to control or correct for distortion from the adjustable matching network based upon the amplitude correction signal.

Abstract: An RF power amplifier system adjusts the supply voltage to the power amplifier based upon an amplitude correction signal indicating the amplitude difference between the amplitude of the RF input signal and an attenuated amplitude of the RF output signal of the power amplifier. A variable gain amplifier (VGA) adjusts the amplitude of the RF input signal, thus providing a second means of adjusting the amplitude of the output of the power amplifier. The gain of the VGA or the supply voltage to the power amplifier is controlled based on the AC components of the amplitude correction signal, while the DC components of the amplitude correction signal are blocked from controlling the VGA or the supply voltage to the power amplifier. The DC level of the gain control of the VGA, the average supply voltage to the power amplifier, or the closed loop gain of the overall amplitude correction loop is controlled separately by a compression control signal.

Abstract: An apparatus and method for controlling a high power amplifier in a communication system are provided. The apparatus includes a Radio Frequency (RF) power detection unit for detecting an intensity of an RF input signal, a high power amplifier controller for determining a control signal, which indicates a voltage value of a drain bias to be provided to at least one drain node from among drain nodes of a drive amplifier and a main amplifier included in the high power amplifier, according to the detected intensity, a Direct Current (DC) voltage supplying unit for generating a DC voltage corresponding to the determined control signal, a drain bias connection unit for providing the generated DC voltage to said at least one drain node from among the drain nodes of the drive amplifier and the main amplifier, and the drive amplifier and the main amplifier for amplifying the RF input signal according to the provided DC voltage.

Abstract: A system and method for carrier recovery includes a plurality of carrier recovery modules, each processing the same input symbols, and each having a gain input and an error output. A loop gain control receives errors from the carrier recovery modules and provides gains to the carrier recovery modules. Based upon the errors during a current period, the loop gain control determines which module produced lowest errors, and selects the gain associated with that module as a best gain which is applied to a module which outputs symbols for decoding during a next period.

Abstract: A reception device according to the present invention includes: a step-variable gain amplifier; and a controller operable to control the gain of the step-variable gain amplifier based on the signal quality value of a demodulator. The gain of the step-variable gain amplifier varies within N gains from a first gain to an N-th gain, and the controller changes a number of the gain one by one when changing the gain of the step-variable gain amplifier. Thus, it is possible to realize a reception device using the step-variable gain amplifier requiring a low control voltage as compared to a continuously-variable gain amplifier.

Abstract: A gain circuit includes an analog section with variable gain and a digital section with variable gain. The gain steps for the digital section have a higher resolution than the gain steps for the analog section. In some implementations, gain steps can be achieved much finer than 0.1 db or less without sensitivity to device tolerances.

Abstract: A count control signal generating section for generating a count control signal on the basis of an output signal of a variable gain amplifier; an up/down counter for performing an up-count operation or a down-count operation on the basis of the count control signal; a gain control signal generating section for generating a gain control signal to be supplied to the variable gain amplifier on the basis of a count value of the up/down counter; and a state detector section for outputting a state detection signal indicating whether a state of a circuit operation is a steady state or another state are provided. When the state detection signal indicates that the state of the circuit operation is the steady state, the operation of at least one of the up/down counter and the gain control signal generating section is controlled so as to fix the gain control signal.

Abstract: An amplification control device for controlling a variable-gain amplifier the amplification factor of which is controlled based on an analog control signal, and which amplifies an analog input signal and outputs an analog output signal, includes component acquisition means that transforms, by the discrete Fourier transform, a digital output signal converted from the analog output signal into digital form by an A/D converter, thereby acquiring a desired frequency component of the digital output signal, differentiating means that acquires a difference between the electric power of the frequency component acquired by the component acquisition means and a target value of the electric power of the frequency component, and digital control signal output means that outputs a digital control signal, based on the difference acquired by the differentiating means, for controlling the amplification factor of the variable-gain amplifier, in which the analog control signal is obtained by converting the digital control signa

Abstract: A Variable Gain Amplifier (VGA) amplifies an input signal according to a gain, to produce an amplified signal. A detector module detects a power indicative of a power of the amplified signal. A comparator module compares the detected power to a high threshold, a low threshold and a target threshold intermediate the high and low thresholds. A controller module changes the gain of the VGA so as to drive the detected power in a direction toward the middle threshold when the comparator module indicates the detected power is not between the high and low thresholds.

Abstract: A power amplifier power controller in the power amplifier system monitors various operating conditions of the power amplifier, and controls the output transmit power of the power amplifier by coordinated control of both the input drive level to the power amplifier and the gain of the power amplifier. The power amplifier power controller controls the input drive level to the power amplifier so that the input drive level does not change substantially while adjusting the gain of the power amplifier to maximize the transmit power. The power amplifier power controller may also adjust the input drive level by some portion of the overall change required to the power of the power amplifier, while adjusting the gain of the power amplifier by the remaining portion of such overall change.

Abstract: An automatic gain control method of a receiving apparatus is provided. The automatic gain control method includes low-noise amplifying a signal using a first gain value, amplifying the low-noise amplified signal to a second gain value, determining the first gain value using a strength of the low-noise amplified signal, and determining the second gain value using the signal amplified to the second gain value. Accordingly, the reliability of the automatic gain control may be guaranteed.

Abstract: A hybrid structure circuit for the cancellation of both Type-I and Type-II DC offsets. It comprises a static compensator in conjunction with a servo-loop feedback amplifier to suppress the undesired DC components present along the path of the base band after the direct conversion mixer. Two mixers are used to down convert a received RF signal directly to a base band signal with two components: in-phase and quadrature-phase. Both in-phase and quadrature-phase branches employ the same circuitry for DC offset cancellation. Miller effect is also utilized in the structure in order to implement the circuit on-chip.