Abstract: A system and method are provided for reducing dynamic EVM of an integrated circuit power amplifier (PA) used for RF communication. In a multistage PA, the largest amplification stage is biased with a high amplitude current pulse upon receipt of a Tx enable, before receipt of the RF signal data burst. The high amplitude current pulse causes a large portion of the total ICQ budget of the multistage PA to pass through the largest amplification stage causing the entire integrated circuit to rapidly approach steady-state operating conditions. A smoothing bias current is applied to the largest amplification stage after the pulse decays to compensate for transient bias current levels while standard bias circuitry is still approaching steady-state temperature.

Abstract: Front-end systems for a transmitter included in a radio device are disclosed. An example front-end system may comprise a voltage-to-power mixer. The voltage-to-power mixer may be configured to up-convert a baseband signal to a high-frequency signal by multiplying the baseband signal with a local oscillator signal. Additionally, the voltage-to-power mixer may include a voltage feedback circuit. The example front-end system may further comprise a two-stage power amplifier. The two-stage power amplifier may be configured to amplify the high-frequency signal.

Abstract: In a power amplifier including an amplifier circuit unit for high power mode and an amplifier circuit unit for low power mode provided in parallel thereto between input and output of the amplifier and where, when one amplifier circuit unit is in an operating state, the other amplifier circuit unit is in a non-operating state, a cross-coupled capacitor is provided between a drain of one of two transistors in output side and a gate of the other transistor in the amplifier circuit unit for high power mode, and a series circuit where a switch and a capacitor are coupled in series is coupled between a drain of the transistor of output side in the amplifier circuit unit for low power mode and a ground, the switch being in a conducting state in high power mode operation and being in a non-conducting state in low power mode operation.

Abstract: Systems devices and/or methods that facilitate dynamic battery capacity allocation are presented. Extended use times or smaller form factors can be achieved for devices employing dynamic battery capacity allocation. By determining factors that can include the type of memory, the usage of the memory, and/or the user's preference to continue to use a device rather than retain data in a volatile memory for a period of time before supplying alternative power, the device can be available for use for longer periods of time on a battery or a smaller battery can be used to achieve similar use time.

Abstract: The transmission power is decreased in an appropriate manner, while suppressing the deterioration of the line quality to the minimum. A mobile communication terminal 1 controls the transmission power in response to a request given from a base transceiver station 2. When an average transmission power Wa that is an average value of the transmission power in a monitoring period Ta is smaller than a threshold value TH, mobile communication terminal 1 continuously controls the transmission power in response to the request given by the base transceiver station 2. When the average transmission power Wa in the monitoring period Ta is equal to or greater than the threshold value TH, the transmission power is controlled in a transmission power suppressing period Tb that follows the monitoring period Ta so that the average value of the transmission power becomes equal to or smaller than the threshold value in a control period Tc including the monitoring period Ta and the transmission power suppressing period Tb.

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: One embodiment of the present invention provides a transmitter for wireless communication. The transmitter includes a wideband tunable modulator, a number of power amplifiers with a particular power amplifier associated with a particular frequency range, and a wideband power amplifier (PA) driver. The PA driver is configured to receive an output signal from the wideband tunable modulator, amplify the output signal, and send the amplified output signal to at least one of the power amplifiers.

Abstract: A radio frequency (RF) transmission circuit includes an antenna connection terminal, a plurality of amplifiers connected to the antenna connection terminal in parallel, a plurality of drivers for driving the plurality of amplifiers, and a control circuit configured to control operation of the plurality of drivers based on information indicating a characteristic of a RF signal to be transmitted through the antenna connection terminal.

Abstract: There is provided a front end module, including an amplification circuit unit amplifying signal, a multistage matching circuit unit connected to an output terminal of the amplification circuit unit, and a switch circuit unit connected to the multistage matching circuit unit, wherein the switch circuit unit includes a series switch circuit and a parallel switch circuit, the parallel switch circuit being connected to a node between a plurality of matching circuits included in the multistage matching circuit unit.

Abstract: Exemplary embodiments are directed to a transmitter with a power amplifier and a switched output matching circuit implementing a plurality of output paths for a plurality of operating modes is described. The power amplifier receives an input RF signal and provides an amplified RF signal. An output matching network performs impedance transformation from low impedance at the power amplifier output to higher impedance at the matching network output. The plurality of output paths are coupled to the output matching network. Each output path provides a different target output impedance for the power amplifier and routes the amplified RF signal from the power amplifier to an antenna when that output path is selected. Each output path may include a matching network coupled in series with a switch. The matching network provides the target output impedance for the power amplifier when the output path is selected. The switch couples or decouples the output path to/from the power amplifier.

Abstract: An analog radio frequency input and an analog feedback from an output of a radio frequency amplifier are digitized and down-converted. Pre-distortion coefficients are calculated based on the down-converted input and down-converted feedback and the down-converted input is filtered using the pre-distortion coefficients. The filter output is then up-converted to a carrier frequency and converted to analog to be provided to the radio frequency amplifier.

Abstract: A software-defined tactical radio solution meets the original JTRS SWaP goals by providing four complete software-defined 125 W (peak) radio channels in four modules that replace the four UT modules of the current GMR design, while retaining the GVA and NIU of the GMR. Two dual transceiver modules each include two transceivers based on OMAP processors. Two dual-channel power amplifier modules each include two 125 W (peak) amplifiers, each amplifier combining two GaN transistors combined in parallel. In embodiments, the OMAP processors include TM320C64xx DSP cores. In some embodiments, the OMAP processors are DM3730 processors. In various embodiments, each dual transceiver module includes a five Watt power amplifier. In embodiments, SINCGAR, SRW, and/or WNW waveforms are supported by software configuration. In some embodiments transceivers can be transitioned by software between waveforms.

Abstract: Multi-mode power amplifiers that can support multiple radio technologies and/or multiple frequency bands are described. In one exemplary design, a first linear power amplifier supporting multiple radio technologies may be used to amplify a first RF input signal (e.g., for low band) and provide a first RF output signal. A second linear power amplifier also supporting the multiple radio technologies may be used to amplify a second RF input signal (e.g., for high band) and provide a second RF output signal. Each linear power amplifier may include multiple (e.g., three) chains coupled in parallel. Each chain may be selectable to amplify an RF input signal and provide an RF output signal for a respective range of output power levels. An RF input signal may be a phase modulated signal or a quadrature modulated signal and may be pre-distorted to account for non-linearity of the power amplifier.

Abstract: Systems and methods are provided for producing an amplified radio frequency (RF) signal representing a baseband input signal. A first amplifier amplifies a first intermediate signal to provide a first amplified signal. Second and third amplifiers amplify a second intermediate signal to provide second and third amplified signals. A signal combiner combines the first, second, and third amplified signals to produce the amplified RF signal. An RF modulator modulates an RF carrier signal with a baseband input signal to provide the first and second intermediate signals. The RF modulator provides the first and second intermediate signals such that the first amplified signal is out-of-phase with each of the second and third amplified signals at an output of an active device within the second amplifier when the amplitude of the baseband input signal exceeds a threshold voltage and in phase when the baseband input signal is below a threshold voltage.

Abstract: The invention relates to a method for configuring a set of multi-carrier power amplifiers, MCPAs, to provide power amplification for a set of base station transmitters. The method is characterized by switching at least a first MCPA in the set of multi-carrier power amplifiers such that the at least first MCPA stops providing power amplification to at least a first subset of the set of base station transmitters, and switching at least a second MCPA in the set of multi-carrier power amplifiers such that the at least second MCPA starts to provide power amplification to the at least first subset of the set of base station transmitters. The invention also relates to a distributing unit connectable to such a base station and a base station comprising a distributing unit.

Abstract: A radio frequency (RF) transmitter includes one or more power amplifiers and a controller that is configured to adjust amplitudes and phases of RF input signals of the one or more power amplifiers and supply voltages applied to the one or more power amplifiers. In embodiments where multiple power amplifiers are used, a combiner may be provided to combine outputs of the power amplifiers. In at least one implementation, amplitude adjustment of the RF input signals of the one or more power amplifiers may be used to provide transmit power control and/or power backoff for the RF transmitter.

Abstract: A transmitter is adapted to be programmed to select an amplifier operating class for the transmitter out of a plurality of amplifier operating classes. The transmitter is also adapted to operate according to the selected amplifier operating class to communicate a signal to an antenna.

Abstract: An RF power amplifier for a polar transmitter converts an amplitude component signal into a 1-bit digital amplitude signal, which is fed to a digital finite impulse response filter. Successive taps of the filter each have an RF amplification stage arranged to amplify successively delayed versions of the 1-bit digital amplitude signal, the amplifying being according to a respective tap coefficient, and according to the RF carrier modulated by the phase component. The filter is arranged to combine the outputs of the taps to provide the amplified RF signal. The power amplifier uses a one bit stream which therefore has only two states (2 values), thus achieving linearity in principle. Device mismatch between taps does not lead to non-linearity or distortion.

Abstract: Various embodiments may provide a circuit including a radio frequency (RF) power amplification module having an RF power amplifier. The RF power amplification module may further include a directional coupler coupled with the RF power amplifier and configured to produce a power signal at a coupling port of the directional coupler corresponding to an output power of the RF power amplifier. The RF power amplification module may further include a switch coupled between the coupling terminal and a sensing path to selectively couple the coupling port with a power detector via the sensing path. The RF power amplification module may further include a termination load coupled to an isolation port of the directional coupler. Some embodiments may include a plurality of RF power amplification modules coupled together by the sensing path.

Abstract: Systems and method for implementing a transmitter with hybrid closed loop power control in a communication device.

Abstract: One embodiment of the present invention provides a transmitter for wireless communication. The transmitter includes a wideband tunable modulator, a number of power amplifiers with a particular power amplifier associated with a particular frequency range, and a wideband power amplifier (PA) driver. The PA driver is configured to receive an output signal from the wideband tunable modulator, amplify the output signal, and send the amplified output signal to at least one of the power amplifiers.

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: One embodiment of the present invention provides an automatic gain control (AGC) module for a wireless communication system that includes a plurality of amplifiers. The AGC module includes a receiving mechanism configured to receive an input that indicates a total amount of gain adjustment; a collecting mechanism configured to collect a number of parameters associated with the amplifiers; a determining mechanism configured to determine a desired performance requirement; a gain-control engine configured to generate a gain profile for the amplifiers based on the collected parameters, the total amount of gain, and the desired performance requirement; and an output mechanism configured to output a plurality of control signals based on the generated gain profile, wherein a respective control signal independently controls gain of a corresponding amplifier, thereby enabling the wireless communication system to achieve the total amount of gain adjustment while meeting the desired performance requirement.

Abstract: A power efficient, small-packaged radio frequency (RF) transmitter for use in avionics applications. The RF transmitter utilizes Cartesian feedback to operate a power amplifier with Class AB biasing and efficiency, while delivering Class A biasing performance. The RF transmitter includes interstage pads and high pass filters specially configured to meet demanding requirements for both adjacent channel power (ACP) limits and wideband spurious energy limits. The RF transmitter is much smaller in size and dissipates less DC power and heat than previous RF transmitters used in avionics applications.

Abstract: Methods and systems for on-chip impedance control to impedance match a configurable front end are disclosed and may include selectively enabling one or more amplifiers coupled to taps on a multi-tap transformer in a chip including the amplifiers. The impedances of the amplifiers may be matched to impedances of the taps on the transformer. The amplifiers may include low noise amplifiers wherein the input impedance of each of the low noise amplifiers may be different. The amplifiers may include power amplifiers wherein an output impedance of each of the power amplifiers may be different. The transformer may be coupled to an on-chip antenna, or to an antenna integrated on a package coupled to the chip. The multi-tap transformer may be integrated on the package. RF signals may be communicated via the selectively enabled amplifiers and the multi-tap transformer. The multi-tap transformer may include ferromagnetic materials integrated in the chip.

Abstract: A signal separating unit separates an input signal into a first branch signal and a second branch signal in such a manner that, as the amplitude of the input signal decreases, the amplitude of the first branch signal and the second branch signal decreases and the difference between a phase of the first branch signal and a phase of the second branch signal increases and, as the amplitude of the input signal increases, the amplitude of the first branch signal and the second branch signal increases and the difference between the phase of the first branch signal and the phase of the second branch signal decreases. An amplifier amplifies the first branch signal. Another amplifier amplifies the second branch signal. A combining unit combines signals that are output from the amplifiers together, thereby generating an output signal.

Abstract: A monolithic integrated circuit (IC), and method of manufacturing same, that includes all RF front end or transceiver elements for a portable communication device, including a power amplifier (PA), a matching, coupling and filtering network, and an antenna switch to couple the conditioned PA signal to an antenna. An output signal sensor senses at least a voltage amplitude of the signal switched by the antenna switch, and signals a PA control circuit to limit PA output power in response to excessive values of sensed output. Stacks of multiple FETs in series to operate as a switching device may be used for implementation of the RF front end, and the method and apparatus of such stacks are claimed as subcombinations. An iClass PA architecture is described that dissipatively terminates unwanted harmonics of the PA output signal.

Abstract: According to the teachings presented herein, dynamic mapping is used to determine which multi-carrier power amplifiers (MC-PAs) provide the required transmit power for individual ones of the transmitters in a base station. With dynamic mapping, the required transmit power of any one or more of the transmitters can be distributed to more than one MCPA, providing for more efficient ‘packing’ of required transmit powers into the available transmit powers of the MCPAs, and/or providing for power mapping based on any one or more mapping criterion, As a non-limiting advantage, the dynamic mapping presented herein reduces the number of MCPAs needed to support a given number of transmitters.

Abstract: A tri-state control mechanism can be implemented for a line driver of a transmitter unit to switch the output impedance of the transmitter unit between a low impedance state in the transmit mode and a high impedance state in the receive mode while minimizing turn-off glitch. It may be determined whether a communication device comprising the transmitter unit is configured in a transmit operating mode or a receive operating mode. If the communication device is configured in the receive operating mode, a first bias voltage can be generated to bias output transistors of the line driver circuit in a sub-threshold state. If the communication device is configured in the transmit operating mode, a second bias voltage can be generated to bias output transistors of the line driver circuit in a saturation state.

Abstract: A portable communication terminal comprising: a first amplifier; a second amplifier; and a control unit configured to perform a first control, in which the first amplifier is amplified within a range of a first upper limit power value, and in which the second amplifier is amplified within a range of a first upper limit power value, wherein, when transmissions by both communication systems are performed in parallel, the control unit performs a second control of performing at least one of that the first amplifier performs amplification within a range equal to or less than a third upper limit power value that is less than the first upper limit power value and that the second amplifier performs amplification within a range equal to or less than a fourth upper limit power value that is less than the second upper limit power value.

Abstract: A method and system for optoelectronic receivers for uncoded data are disclosed and may include amplifying received electrical signals in a signal amplifier comprising differential gain stages with signal detectors coupled to the outputs. First and second output voltages may be tracked and held utilizing the signal detectors. A difference between the tracked and held value may be amplified in a feedback path of the gain stage, which enables the dynamic configuration of a decision level. The received electrical signals may be generated from an optical signal by a PIN detector, an avalanche photodiode, or a phototransistor. The electrical signal may be received from a read channel. The feedback path may comprise digital circuitry, including an A/D converter, a state machine, and a D/A converter. The detectors may comprise envelope detectors utilized to detect maximum or minimum voltages. The signal amplifier may be integrated in a photonically-enabled CMOS chip.

Abstract: Various embodiments described herein relate to a power management block and one or more amplification blocks used in the transmitter of a communication subsystem. The power management block provides improved control for the gain control signal provided to a pre-amplifier and the supply voltage provided to a power amplifier, both of which are included in a selected one of the amplification blocks. The power expended by the power amplifier is optimized by employing a continuous control method in which one or more feedback loops are employed to take into account various characteristics of the transmitter components and control values. Post power amplifier transmission power is detected for input into the one or more feedback loops executed in the power management block. A controller for the power amplifier is design to stabilize the system with respect to gain expansion in the power amplifier.

Abstract: Provided is a remote radio head receiver, including an antenna and an interference mitigation block. The antenna is configured to receive a signal. The interference mitigation block is configured to selectively pass and amplify the signal. The interference mitigation block does not include a liquefied gas cooling system.

Abstract: Methods and systems for a configurable front end are disclosed. Aspects of one method may include a transceiver on a single chip that may comprise a power amplifier (PA) and a low noise amplifier (LNA). The PA may amplify signals to be transmitted over a range of output transmit power. An upper limit for a power range may of substantially 12 dBm. The LNA may be tolerant to PA signals by, for example, being configured to follow signal voltages generated from an output of the power amplifier. For example, each input transistor of the LNA may be isolated from other transistors in the LNA. Accordingly, the input transistors may float since they may not be tied to a voltage level via other transistors. This may allow the input transistors to avoid damage. The transceiver may also be configured for differential RF input, differential RF output, single-ended RF input, and/or single-ended RF output.

Abstract: A communications device may include In-phase (I) power amplifiers configured to respectively generate I amplified signals, Quadrature (Q) power amplifiers configured to respectively generate Q amplified signals, I antennas respectively coupled to the I power amplifiers, and Q antennas respectively coupled to the Q power amplifiers. The communications device may also include an I controller coupled to the I power amplifiers and configured to selectively enable some of the I power amplifiers, and a Q controller coupled to the Q power amplifiers and configured to selectively enable some of the Q power amplifiers.

Abstract: A power management system for a radio frequency (RF) power amplifier (PA) load is disclosed. The power management system includes a first switching power supply that is adapted to output a relatively constant voltage, an electronic switch for selectively coupling the first switching power supply to the RF PA load, and a second switching power that is adapted to output a dynamic DC voltage to the RF PA load. The power management system further includes a control system that is adapted to close the electronic switch to supply the relatively constant DC voltage in addition to the dynamic DC voltage to the RF PA load in a first mode and to open the electronic switch wherein the relatively constant DC voltage is not supplied to the RF PA load in a second mode.

Abstract: This invention concerns a repeater for radio frequency signals having a channel filter and an active filter connected to the channel filter output. The active filter covers the channels adjacent to the channel filter and includes an amplifier and; two bandpass filters in parallel connected as a negative feedback loop around the amplifier. The first bandpass filter covers the lower adjacent channels and the second bandpass filter covers the higher adjacent channels. The invention notably applies to the development of domestic repeaters for mobile terminals meeting the DVB-H digital television standard.

Abstract: A power amplification apparatus that performs an inverse fast Fourier transformation on data allocated to a plurality of sub-carriers, converts time-domain data output in parallel from the inverse fast Fourier transformation into a time-domain analog signal, performs a power amplification on the time-domain analog signal, wherein a saturation output level of the power amplification is adjustable in accordance with a switching signal. The power amplification apparatus also compares an amplitude of a signal in each time slot of the time-domain analog signal with a predetermined threshold and switches the saturation output level of the power amplification based on an output of the comparing.

Abstract: A monolithic integrated circuit (IC), and method of manufacturing same, that includes all RF front end or transceiver elements for a portable communication device, including a power amplifier (PA), a matching, coupling and filtering network, and an antenna switch to couple the conditioned PA signal to an antenna. An output signal sensor senses at least a voltage amplitude of the signal switched by the antenna switch, and signals a PA control circuit to limit PA output power in response to excessive values of sensed output. Stacks of multiple FETs in series to operate as a switching device may be used for implementation of the RF front end, and the method and apparatus of such stacks are claimed as subcombinations. An iClass PA architecture is described that dissipatively terminates unwanted harmonics of the PA output signal.

Abstract: A radio frequency (RF) power amplifier (PA) amplifying transistor of an RF PA stage and an RF PA temperature compensating bias transistor of the RF PA stage are disclosed. The RF PA amplifying transistor includes a first array of amplifying transistor elements and a second array of amplifying transistor elements. The RF PA temperature compensating bias transistor provides temperature compensation of bias of the RF PA amplifying transistor. Further, the RF PA temperature compensating bias transistor is located between the first array and the second array. As such, the RF PA temperature compensating bias transistor is thermally coupled to the first array and the second array. The RF PA stage receives and amplifies an RF stage input signal to provide an RF stage output signal using the RF PA amplifying transistor.

Abstract: A communications device may include an In-phase (I) power amplifier configured to generate an I amplified signal, a Quadrature (Q) power amplifier configured to generate a Q amplified signal, an I digital-to-analog converter (DAC) configured to generate an I signal, and a Q DAC configured to generate a Q signal. The communications device may also include an I power supply circuit coupled to the I power amplifier and to the I DAC and configured to cause the I power amplifier to modulate an I carrier signal into the I amplified signal based upon the I signal, a Q power supply circuit coupled to the Q power amplifier and to the Q DAC and configured to cause the Q power amplifier to modulate a Q carrier signal into the Q amplified signal based upon the Q signal, and at least one antenna coupled to the I and Q power amplifiers.

Abstract: Embodiments provide a multi-stage radio frequency (RF) power amplifier (PA) having a low dynamic error vector magnitude (EVM). A first stage of the RF PA may include a first active device configured to receive an enable signal and to turn on in response to the enable signal, thereby activating the first stage. The RF PA may further include a second active device coupled in series with the first active device and configured to receive a main supply voltage. The second active device may provide a first supply voltage across the first active device that is less than and independent of the main supply voltage. One of the first active device or the second active device may be configured to receive an RF input signal and to pass an amplified RF output signal to a second stage of the RF PA circuit.

Abstract: The invention discloses a circuit and a method for reducing radio frequency power consumption of mobile phone, wherein a baseband processing chip (21) adjusts a base bias voltage and/or a collector bias voltage of a radio frequency power amplifier (23) according to radio frequency power output of the radio frequency power amplifier (23). Since the invention reduces the radio frequency output power of the radio frequency power amplifier (23) by moderately reducing the base bias voltage and/or the collector bias voltage at the same time when it is ensured that the mobile phone communicates with a base station normally and the linear index and the Adjacent Channel Power Ratio (ACPR) of the radio frequency power amplifier (23) meet the requirements of the specification, thus the efficiency of the radio frequency power amplifier can be improved, the battery energy is saved and the heating problem of the mobile phone is relieved.

Abstract: The present invention provides a CMOS-inverter-type frequency divider circuit that can further reduce power consumption. The CMOS-inverter-type frequency divider circuit includes: a plurality of CMOS inverters that contribute to realizing a frequency division function; a frequency division control section for performing control such that some or all of the plurality of CMOS inverters are intermittently driven at the respective different timings in accordance with an input signal; and a drive power supplying section for supplying powers for driving the plurality of CMOS inverters, and for, based on state information indicating whether VCO sub band selection or normal transmission is performed, switching some or all of the powers for the plurality of CMOS inverters between the VCO sub band selection and the normal transmission.

Abstract: Provided is a transmission circuit capable of compensating a variation in output power caused due to a temperature change or an individual variability when the operation mode is switched without an increase in the size of the transmission circuit which switches the operation mode between a linear operation mode and a nonlinear operation mode, and capable of suppressing the deterioration of the quality of a transmission signal. In the transmission circuit, a gain setting section (160) sets the gain (target gain) of a variable gain amplifier (140), to a value which enables the variable gain amplifier (140) to operate linearly and corresponds to a comparison result (output error level) obtained through comparison between the target level of the variable gain amplifier (140) corresponding to the set power level of the transmission signal and the power level of an output signal of the variable gain amplifier (140) detected by a power detection section (150).

Abstract: A closed loop power output calibration system for variable power output wireless devices. The wireless device includes a wireless transceiver having a transmit core coupled to a discrete power amplifier. Power detection circuitry formed in the wireless transceiver provides a detected power level of the power amplifier, and a reference power level, both of which are converted to digital signals using existing I and Q signal analog to digital converters in the receiver core. The digital signals are processed to cancel power distortion and temperature effects to provide a resulting power feedback signal. Corrective control signals are generated in response to the power feedback signal relative to a desired power output level. The gain in the transmit core is then adjusted in response to the corrective control signals such that the power amplifier outputs the target output power level.

Abstract: A circuit includes a passive element having an impedance. An active circuit can be configured to receive an impedance signal associated with the impedance. The impedance includes a real portion and an imaginary portion. The active circuit removes at least a portion of the real portion of the impedance signal. The circuit can be utilized in a wide array of applications including radio applications.

Abstract: Conventional spot beam satellites transmit downlink beams that each correspond to a separate and unique uplink signal. Power available for each downlink beam is typically set by an associated amplifier on the satellite, and total transmit power cannot be dynamically distributed across different spot beams. An embodiment of the present invention overcomes this distribution limitation by using multiple replicas of a single signal as input to a multi-port amplifier that allows transmit power to be dynamically distributed across the different spot beams. The replicas may be de-correlated through techniques such as selectively delaying some of the replicas. This power distribution effectively allows dynamic allocation of capacity between areas serviced by different beams. Offered load in different beams can be predicted and used to set the attenuation values appropriately and the attenuation values may also be controlled remotely.

Abstract: A radio apparatus capable of correcting a direct current offset with high accuracy in a short time is provided. A radio apparatus according to an embodiment includes a first amplifier amplifying a signal inputted to an input terminal with amplification gain determined by a variable resistor to generate a first amplified signal, and a second amplifier amplifying the first amplified signal to generate a second amplified signal. Further, the radio apparatus includes a first correcting unit correcting a direct current offset of the first amplifier, and a second correcting unit correcting a direct current offset of the second amplifier.

Abstract: An apparatus and a method for exponentially controlling a gain of a driver amplifier to drive a power amplifier are provided. The driver amplifier includes a plurality of cascode amplifier segments, wherein when a plurality of candidate gain values of the driver amplifier is arranged, the candidate gain values form a geometric sequence. A unit cost can be reduced by halving an area occupied by the driver amplifier.