Abstract: A current canceling CMOS variable gain amplifier includes a first leg and a second leg. The first leg has a first input line, a first output line, a first ON transistor, a first control transistor and a first subtracting transistor. The second leg has a second input line, a second output line, a second ON transistor, a second control transistor and a second subtracting transistor. The second input line can provide a second input current. The second output line can provide a second output current. The first input line is arranged to provide a first input current to each of the first ON transistor, the first control transistor and the first subtracting transistor. The second input line is arranged to provide a second input current to each of the second ON transistor, the second control transistor and the second subtracting transistor. The first output line is in electrical connection with each of the first ON transistor, the first control transistor and the second subtracting transistor.

Abstract: A power amplifying device with linear corrector utilizing the polynomial format to realize pre-distortion is disclosed. Its effective order estimation technique for polynomial based pre-distorter includes the following steps. Firstly, it receives the polynomial of the described pre-distorter and then, the polynomial is transformed into the matrix expression, obtaining the pre-distorter consisted of K pre-distortion functions, where K denotes the maximum order of the described polynomials. Secondly, singular value decomposition is performed for the pre-distortion matrix, obtaining singular value matrix. Thirdly, on the basis of the singular value matrix, effective rank of the pre-distortion matrix is obtained. Such effective rank of the pre-distortion matrix is determined as the effective order of the polynomial.

Abstract: A cross-differential amplifier is provided. The cross-differential amplifier includes an inductor connected to a direct current power source at a first terminal. A first and second switch, such as transistors, are connected to the inductor at a second terminal. A first and second amplifier are connected at their supply terminals to the first and second switch. The first and second switches are operated to commutate the inductor between the amplifiers so as to provide an amplified signal while limiting the ripple voltage on the inductor and thus limiting the maximum voltage imposed across the amplifiers and switches.

Abstract: In a power amplification circuit an output signal is generated by combining the power of a first and second signal that have been amplified separately. An input signal is received that indicates a desired amplitude and phase of the output signal. A controllable phase shift circuit adapts the phase of first and second signals dependent on the desired amplitude, so that, when the signals with the adapted phases are combined, the resulting output signal will have an envelope with the desired amplitude. A time dependent common mode phase shift is applied to both the first and second signal. A control circuit selects the time dependent common mode phase shift as a function of the desired amplitude of the output signal, to compensate for envelope amplitude dependence of a common phase shift introduced by the amplification.

Abstract: This invention relates to a predistorter, a predistortion method, and a predistortion system. The predistorter comprises a modulus value determining section, for determining a modulus value of an input signal; a base searching section, for searching a predetermined base lookup table in accordance with the modulus value of the input signal, so as to obtain a base lookup table value; an offset searching section, for searching a predetermined offset lookup table in accordance with the modulus value of the input signal, so as to obtain an offset lookup table value; an interpolation factor generating section, for generating an interpolation factor in accordance with the modulus value of the input signal; a multiplying section, for multiplying the offset lookup table value with the interpolation factor; and a summating section, for adding a product obtained by the multiplying section to the base lookup table value, so as to obtain a predistortion value.

Abstract: Cross-coupled low noise amplifier for cellular applications. A circuitry implementation that includes two pairs of metal oxide semiconductor field-effect transistors (MOSFETs) (either N-type of P-type) operates as an LNA, which can be used within any of a wide variety of communication devices. In one embodiment, this design is particularly adaptable to cellular telephone applications. A majority of the elements are integrated within the design and need not be implemented off-chip, and this can provide for a reduction in area required by the circuitry. A very high output impedance is provided by using two transistors (implemented in a triple well configuration) with resistive source degeneration. A higher than typical power supply voltage can be employed (if desired) to accommodate the voltage drops of the resistors and transistors.

Abstract: An amplifier is provided with continuously-variable analog control that exhibits a highly linear gain control curve in db/volts, while preserving high dynamic range, low third order distortion, and low noise. This amplifier has a control mechanism that preserves a varied linear or log linear curve over a wide range and is inherently insensitive to process variations thereby allowing more accurate gain control and higher signal fidelity for amplifying high dynamic range signals.

Abstract: A variable gain amplifier includes an attenuator having a plurality of pairs of tap points, and a plurality of pairs of gm cells, wherein each pair of gm cells is coupled to a corresponding pair of the tap points, and each pair of gm cells is constructed and arranged to operate as a multi-tanh cell.

Abstract: A modulated amplifier output enable control eliminates audible pops when enabling and disabling an audio amplifier output stage. The output of the audio amplifier is transitioned between an enabled state and a disabled state using a modulated control signal that enables and disables the output of the audio amplifier. Durations of the enabled state vs. the disabled state of the amplifier are adjusted to cause a transition between a fully disabled state and a fully enabled state of the audio amplifier so that the transition between the disabled state and the enabled state of the amplifier output is inaudible.

Abstract: Provided are a detector circuit which has a simple circuit configuration, is capable of indicating an accurate power according to a load fluctuation of a radio frequency power amplifier or a difference in a modulation mode, and can be easily incorporated in the radio frequency power amplifier, and a wireless communication system using the detector circuit. The detector circuit 10 includes a detecting resistor 11 for detecting a part of a current flowing from a bias circuit 6, and a current-voltage conversion circuit 12 for converting a current obtained through the detecting resistor 11 into a voltage.

Abstract: A circuit includes a first resistive element coupled to a diode, a second resistive element, a first transistor having a first current electrode coupled the second resistive element, a second transistor having a first current electrode coupled to the first resistive element and a second current electrode coupled to the control electrode of the first transistor, a third resistive element coupled to a node, a third transistor having a first current electrode coupled to the node and having a control electrode and a second current electrode each coupled to the control electrode of the second transistor, a fourth transistor having a first current electrode coupled to the second resistive element and a control electrode coupled to the control electrode of the second transistor, and a fifth transistor having a first current electrode coupled to the node and a control electrode coupled to the second current electrode of the fourth transistor.

Abstract: A power amplifier includes a LDMOS transistor having a source, a drain, a control gate and a shielding electrode positioned between the control gate and the drain, and means for adaptively biasing the drain and shielding electrode power information for a RF signal.

Abstract: A variety of circuits, methods and devices are implemented for radiofrequency amplifiers. According to one such implementation, a radiofrequency amplifier circuit is implemented in a SMD package. The circuit amplifies a radiofrequency signal having a base-band portion and a plurality of carrier signals frequency-spaced larger than the base-band bandwidth. The circuit includes a radiofrequency transistor connected to a circuit output having a parasitic output capacitance. The source-drain terminal is electrically connected to the circuit output. An internal shunt inductor provides compensation for the parasitic output capacitance. A high-density capacitor is connected between the internal shunt inductor and a circuit ground. The high-density capacitor has a terminal with a surface area can be at least ten times that of a corresponding planar surface.

Abstract: The invention relates to a feedback network (60) for cascade amplifiers (200), which comprises an active stage (30) to feed signal back to a first internal node (65) at the output of the first amplifier stage (61) of the cascade. The invention further relates to a feedback network (60) which comprises said active feedback stage (30) with said first internal amplifier node (65) connection and a feedback resistor (10) connected from said cascade amplifier output port (out) to its input port (in).

Abstract: A supply voltage control device for an amplifier that controls a supply voltage for the amplifier has been improved.

Abstract: An apparatus for compensating a distortion characteristic of an amplifier includes an update unit configured to store a distortion compensation coefficient, configured to calculate the coefficient based on a signal before input to the amplifier and a feedback signal, and configured to update the stored coefficient to the calculated coefficient; a distortion compensation unit configured to perform distortion compensation processing of the signal before input to the amplifier by using the updated coefficient; a delay unit configured to delay the signal before input to the amplifier by a set delay time, to output the delayed signal to the distortion compensation coefficient update unit; and a delay controller configured to control the set delay time based on a phase of a complex number having a power component of the signal before input to the amplifier as a real part, and a power component of the feedback signal as an imaginary part.

Abstract: An apparatus and method for communications are disclosed. The apparatus may include an a quantizer having three levels, and a switching power amplifier configured to drive a load having first and second terminals, wherein the switching power amplifier is further configured to switch the first and second terminals between first and second power rails only if the output from the quantizer is at one of the three levels.

Abstract: Embodiments of a high-frequency millimeter-wave amplifier are generally described herein. The high-frequency millimeter-wave amplifier may be constructed on a substrate to operate at a frequency of at least 75 GHz. In some embodiments, the millimeter-wave amplifier may include at least first, second, third and fourth amplifier stages coupled in series. A single drain bias bond pad provided on the substrate to provide a drain bias voltage to the drains of the first, second, third and fourth amplifier stages. Drain bias lines may be electrically coupled to the single drain bias bond pad and extend at least partially alongside and between some of the amplifier stages. A signal path through the second amplifier stage extends in a direction opposite of signal paths through the first and third amplifier stages. In some embodiments, a 95 GHz amplifier is provided and configured occupy an area on the substrate of no greater than approximately four square millimeters.

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: The invention provides a method and apparatus for applying test signals to a multiport amplifier (MPA) and a method, apparatus and system for determining parameter adjustments for an MPA. Applying test signals to an MPA is performed so as to provide an output signal indicative of parameter adjustments for the MPA, the multiport amplifier arrangement comprising an input network, an amplifier unit and an output network, where the method includes providing a test signal directly to a point in the multiport amplifier arrangement between an output of the input network and an input of the amplifier unit.