Abstract: A method and apparatus provides an input structure for a power amplifier. In one example, the input structure has an input network and a predriver circuit to provide an input signal to the power amplifier. The input network includes a transformer for helping to maintain a constant input impedance. The predriver includes a limiting amplifier that provides isolation between the power amplifier and the RF input. A DC feedback circuit is used by the predriver that maintains the DC level of the inverters to a desired level.

Abstract: A BALUN circuit (20) for low voltage operation for receiving single ended input signal at an input terminal (24) and providing a differential output signal across a pair of output terminals (OUT+, OUT?) is disclosed. The BALUN circuit (20) comprises a first branch including an input terminal (24) for receiving a single ended input voltage signal (RFin), a transistor (Q1), a resistance (R1) (28), a resistance (RL), and an output terminal (OUT+). A second branch includes a transistor (Q3), a resistance (RL) and an output terminal (OUT?). An operational amplifier (26) maintains current flowing through the resistances RL in the first and second branches substantially equal to each other, in dependence upon the output voltage signal across the output terminals (OUT+, OUT?).

Abstract: The present invention suppresses a harmonic component without impairing the phase orthogonality of a pair of complex signals. A polyphase filter is configured so that K pieces of filter circuits, each of which comprises a resistor and a capacitor, are connected and +360/K degrees out of phase with a preceding one. Since counterclockwise rotation occurs when expression is given in terms of the complex plane, a notch occurs in a negative frequency region. A RC value is set so that a notch occurs in a specified frequency band to suppress a (4N+1)-order harmonic component. Since the polyphase filter has a symmetrical structure, an unbalanced component contained in an input signal is eliminated at a frequency that agrees with a pole determined by the RC value. This action improves the orthogonality.

Abstract: A method and apparatus for single-to-differential conversion includes a single-to-differential stage (22), a phase balancing stage (24), and a buffer stage (26). The single-to-differential stage (22) converts a single input signal (Vclk) to a first and second output signal (Vn,Vp), where the first and second output signals (Vn,Vp) correspond to one another. The phase balancing stage (24) is electrically connected to the single-to-differential stage (22), balances and receives the first and second output signals (Vn,Vp), and outputs first and second balanced output signals (V+,V?). The buffer stage (26) is electrically connected to the phase balancing stage (24) for shaping the first and second balanced output signals (V+,V?). The single-to-differential converter (20) is operable over a substantially large bandwidth and achieves low-power consumption and good phase noise performance.

Abstract: An active balun device is provided. The active balun device includes: a differential input portion for receiving an external single input signal to output two complementary differential signals; and a differential amplifier connected to the differential input portion in cascade to amplify the two differential signals received from the differential input portion. Thus, the active balun device has a sufficient gain and a desired bandwidth in a semiconductor circuit.

Abstract: An input stage for an integrated circuit device provides constant gain in selectable modes of either differential or single-ended operation. In one embodiment, transconductance devices are arranged so that the input impedance of the input stage matches the signal source impedance, regardless whether the input stage is selected to operate in a differential mode or in a single-ended mode. In accordance with an alternative embodiment, constant-gain and constant-impedance conditions are maintained in a configuration that comprises and input signal attenuator. In one application, the input stage may serve as a low-noise amplifier (LNA) for an integrated transceiver.

Abstract: A signal converter includes a signal converting unit and a compensation unit. The signal converting unit generates intermediate differential signals at intermediate nodes in response to a single-ended signal. The compensation unit generates compensated differential signals at output nodes by minimizing phase and amplitude mismatch errors between the intermediate differential signals. The compensation unit includes a pair of transistors and a pair of capacitors configured in symmetry between the intermediate and output nodes. The signal converter of the present invention may be used to particular advantage in an RF receiver.

Abstract: An RF amplifier can include a differential inductor for single-ended-to-differential signal conversion. With a center tap of the differential inductor coupled to signal ground and the RF input signal coupled to one of the end taps of the inductor, the negative of the RF input signal is obtained at the other end tap of the inductor. The differential RF signal produced can be coupled to a differential transistor amplifier that has cross-coupling capacitances, improving the signal balance of the differential output signal.

Abstract: A low noise amplifier has the properties of low noise figure and high gain under a high-frequency operation. The low noise amplifier includes a first transistor, a first inductive impedance, a first gate voltage source, a matching circuit, an input, a second inductive impedance, a second transistor, a first capacitive impedance, a second gate voltage source, a third transistor, a third gate voltage source, a second capacitive impedance, a first impedance, a second impedance, a direct current source, a first output, a second output, a first resistor, a second resistor, a third resistor, a first bulk voltage source, a second bulk voltage source, and a third bulk voltage source.

Abstract: In a balanced output circuit, an input signal inputted thereto is provided as a first output signal thereof on one hand, and on the other hand the input signal is inputted to an inverting amplification circuit and is compared with a comparison voltage before the signal is outputted as a second output signal. Based on the comparison of the first and second output signals, the comparison voltage is controlled by a charging voltage of a capacitor such that the DC voltage of the second output signal is equalized to that of the first output signal. Thus, the DC offset voltage between the first output signal (non-inverted output signal) and the second output signal (inverted output signal) can be properly annihilated by a simple circuit.

Abstract: Disclosed is a differential amplifier which includes first and second input terminals, an output terminal, first and second differential pairs, and first and second current sources for supplying currents to the first and second differential pairs. The first differential pair has first and second inputs of an input pair connected to the first input terminal and the output terminal, respectively. The second differential pair has first and second inputs of an input pair connected to the second input terminal the output terminal, respectively.

Abstract: Disclosed is a power amplifier having highly stable and excellent controllability, and having low noise in comparison with conventional power amplifiers. With the power amplifier, a differential amplifier made up of transistors Q1, Q2 is provided in the initial stage thereof, and baluns doubling as inter-stage matching circuits, comprised of Cp1, Cp2, Lp1, and Ct1, Ct2, Lt1, respectively, are provided between the initial stage, and a second stage while an unbalanced single-ended circuit is provided in the second stage. The differential amplifier has an emitter-coupled type configuration for coupling both emitters with each other, and output control of the amplifier in the initial stage is executed by varying current of a current source coupled to both the emitters.

Abstract: A method and system to use voltage isolated and floating differential output amplifiers wired in series and parallel to achieve arbitrary output drive voltage and current for the applications load. A second embodiment uses multiple matched voltage-isolated and floating differential output amplifiers in a single chassis to enable selection between a multi-channel amplifier and a high current and/or high voltage mono amplifier. A third embodiment uses a step-up transformer and paralleled unity-gain buffer amplifiers, on input and/or output stages, to produce a zero feedback, high performance, high drive amplifier. A fourth embodiment uses a high voltage unity-gain driver amplifier to bias a unity-gain buffer amplifier and its power supply to achieve an ultra low distortion high voltage buffer amplifier. A fifth embodiment uses multiple voltage-isolated and linearized devices to enable dynamically modifiable, Class A, Class B, and Class AB topologies of predetermined voltage and current performance.

Abstract: A radio frequency power amplifier including control electronics for providing control signals for timing of the power amplifier. A first group of the drivers are coupled to the control electronics and a second group of drivers are coupled to the control electronics. The first group of drivers operate in response to the control signals to generate first drive signals and the second group of drivers operate in response to the control signals to generate second drive signals with a phase difference of 180° relative to the first drive signals. A first group of switches energize a first group of primary windings in response to the first drive signals and a second group of switches energize a second group of primary windings in response to the second drive signals. An output summing transformer has a plurality of ferrite cores, the first group of primary windings and the second group of primary windings passing through the ferrite cores.

Abstract: Monolithic transformer based amplifier for integrated circuits. The amplifier includes an input transformer with a first impedance transforming ratio. The input transformer includes a coupled line structure. An amplification circuit is coupled to the input transformer. The amplifier also includes an output transformer with a second impedance transforming ratio that is coupled to the amplification circuit.

Abstract: An apparatus and method for eliminating unwanted signal power dissipation in balanced amplifier circuits and for prohibiting unwanted signal power from appearing at the balanced amplifier load is presented. Load impedances to the amplifier power output transistors are maintained very low at unwanted frequencies, and are at an operational impedance level at the fundamental frequency. An impedance network control concept is presented, which may be either manually or automatically implemented.

Abstract: The present invention discloses a single-ended input/differential output amplifier includes a first bonding wire, a transduction gain circuit coupled to the first bonding wire for receiving an input voltage, a gain control circuit coupled to the transduction gain, a load unit with an end coupled to the gain control circuit to form a first output end, and a second bonding wire coupled to another end of the load unit to form a second output end.

Abstract: The present invention discloses an apparatus for generating an output signal according to an input signal, including a signal generating circuit for generating a first and a second control signal according to the input signal; a first output stage has a first amplifying configuration for receiving the first control signal; and a second output stage has a second amplifying configuration for receiving the second control signal, wherein the first amplifying configuration is different from the second amplifying configuration.

Abstract: A converter is for a differential input signal into a single-ended output signal and may include a differential pair of identical first and second transistors driven by the differential input signal, and a circuit for filtering DC components, connected between the current terminal of the second transistor not in common with the first transistor of the differential pair and an output node of the converter on which the single-ended output signal is generated. The converter generates a single-ended signal without employing a transformer, in lieu thereof the converter may include a current generator biasing the differential pair by of third and fourth output transistors, in a current mirror configuration, connected in series with the first and second transistors, respectively. The converter may also include degeneration resistors of the transistors of the current mirror, dimensioned such that the gains of the converter for each of the two input nodes of the differential signal are equal and of opposite sign.

Abstract: Low current differential signal/swing I/O interfaces and techniques can be implemented. An output interface converts input data signals to differential current signals for transmission over transmission lines. When the differential current signals are received by an input interface, they are converted to differential voltage signals and appropriately amplified.

Abstract: A single-ended input to differential-ended output amplifier circuit comprises an amplifier for amplifying an input signal into an amplified signal comprises an input for receiving the input signal; and a first input and a single-ended input to differential-ended output conversion circuit to convert the amplified signal to a differential signal pair, comprising a first transistor for receiving the amplified signal having a first gate coupled to the first output, a first first terminal coupled to a second output, and a first second terminal coupled to a first node; a second transistor having a second gate, a second first terminal coupled to a third input, and a second second terminal coupled to the first node; a second capacitor coupled between the second output and the second gate; a first and a second resistors and the voltage source; and a current source coupled between the first node and a ground.

Abstract: An integrated preamplifier circuit for detecting a signal current from a photodiode and converting the signal current into an output voltage is provided. The circuit includes a signal amplifier and a dummy amplifier, the dummy amplifier being matched to the signal amplifier. Each of these amplifiers includes an input transistor and an output transistor, the input transistor of the signal amplifier receiving an input signal derived from the signal current and the input transistor of the dummy amplifier receiving no input signal. The signal and dummy amplifiers provide the desired differential output signal. The input transistors of the signal and dummy amplifiers each have a biasing current source forced to follow a reference current source implemented within the integrated circuit.

Abstract: A differential pair of transistors includes a first transistor and a second transistor having their sources coupled together. Their sources are further coupled to ground via a pull-down network. A single-ended output is coupled to the drain of the second of the pair of differential transistors. A differential current adjust circuit is coupled to a drain of the first of the pair of differential transistors, and the current adjust circuit is configured so that the second side of the differential output driver circuit conducts approximately the same current as the first side of the differential output driver circuit.

Abstract: A method for transforming single-ended signals outputted from a low-noise amplifier of a wireless transceiver into differential signals. The method includes: providing a transformer according to a default requirement of the wireless transceiver; transferring the single-ended signals provided by the low-noise amplifier to a first end of a primary end of the transformer, and coupling a second end of the primary end of the transformer to a power source; grounding a center tap of a secondary end of the transformer; and outputting the differential signals from two ends of the secondary end of the transformer.

Abstract: high-gain and low-noise low noise amplifier (LNA) includes a differential amplifier, a pre-amplifier and an impedance matching network. The differential amplifier includes a first input end and a second input end coupled to a grounded impedance. The pre-amplifier includes an input end and an output end. The impedance matching network is coupled between the first input end of the differential amplifier and the output end of the pre-amplifier for matching an input impedance of the differential amplifier with an output impedance of the pre-amplifier. The present invention provides a LNA structure with low noise, high gain and easy design.

Abstract: A multiple-stage operational amplifier including a gain stage for amplifying an input signal and implementing a dominant pole producing a frequency response having a gain roll-off with frequency and a unity gain frequency. An intermediate stage is coupled to an output of the gain stage and has a high input impedance and a low output impedance. A high gain amplifier configured as a low gain output stage using resistive feedback and coupled to an output of the intermediate stage drives an output of the operational amplifier and implements a dominant pole at a frequency substantially higher than the unity gain frequency implemented by the dominant pole implemented the gain stage.

Abstract: A converter includes an input circuit to receive a single-ended input signal to generate a number of control signals. The control signals have a delay different from one another relative to the single-ended input signal. The converter also includes a first output circuit and a second output circuit. The first output circuit responds to the control signals to generate a first output signal. The second output circuit responds to the control signals to generate a second output signal. The first and second output signals are non-overlapping and form a complimentary signal pair.

Abstract: A single-ended input to differential output LNA with a cascode topology of the present invention overcomes a much greater consumption of current and area for the single-ended input to differential output LNA of the prior art. The LNA needs to supply an operating bias for each transistor. The LNA has a few transistors, a few capacitive impedances, and a few inductive impedances. The main objective of the present invention not only reduces costs and conserves area and current consumption, but also has a much higher linearity and gain under the same current consumption when compare to the prior art.

Abstract: Between an output terminal (drain terminal) of a semiconductor device in a first unit amplifier and an output port, a ?90 degrees phase-shift circuit is connected, while between an output terminal (drain terminal) of a semiconductor device in a second unit amplifier and the output port, a +90 degrees phase-shift circuit is connected. Between the first and second ports, there is inserted a series circuit made up of first and second inductance components with an almost identical size. Then, to a middle point between the first and second inductance components, a bias feed terminal is connected, and between the middle point and a ground, a series circuit made up of a resistance component and a capacitance component is connected. The small-size balanced amplifier circuit can perform accurate balance operation in wide bands.

Abstract: A power amplifier comprises an amplification stage comprises a plurality of amplifiers, wherein each amplifier provides an amplified output, and an inductive summing device configured to receive the plurality of amplified outputs and provide a combined output signal. A method of amplifying a signal comprises applying the signal to an amplifier stage comprising a plurality of amplifiers, wherein each amplifier is configured to provide an amplified output, and providing a combined output signal via an inductive summing device configured to receive the plurality of amplified outputs.

Abstract: Techniques and circuits for generating a pair of differential signals with balanced switching between logical states from a single ended input signal are provided. The differential signals may be generated by controlling the switching of substantially identical driver stages with a set of control signals generated based on the single ended input signal.

Abstract: A method and apparatus provides an input structure for a power amplifier. In one example, the input structure has an input network and a predriver circuit to provide an input signal to the power amplifier. The input network includes a transformer for helping to maintain a constant input impedance. The predriver includes a limiting amplifier that provides isolation between the power amplifier and the RF input. A DC feedback circuit is used by the predriver that maintains the DC level of the inverters to a desired level.

Abstract: A differential to single-ended signal transfer circuit that allows increased gain and improved AC performance while reducing power supply voltage requirements. The transfer circuit includes a first operational transconductance amplifier (OTA), a second operational amplifier (OPA), first and second controlled current sources, a third current source, and first and second bipolar junction transistors. The inverting and non-inverting inputs of the transfer circuit are provided at the inverting input and the non-inverting input, respectively, of the OTA, which is coupled to the first and second controlled current sources to form a current mirror with tracking feedback. The output voltage of the transfer circuit is provided at the emitter of the first transistor, the base of which is connected to the non-inverting input INp. The first transistor is coupled to the third current source in an emitter follower configuration to provide both current gain and impedance matching.

Abstract: A circuit for amplifying an input voltage (VIN) into an output voltage (VOUT) with an overall gain factor, which is a product of a first gain factor (S) and a second gain factor (R1), comprises means for generating an intermediate signal (I2) from the input voltage (VIN) and the first gain factor (S) and means for generating the output voltage (VOUT) from the intermediate signal (I2) and the second gain factor (R1). The first gain factor (S) and the second gain factor (R1) have opposite temperature dependencies.

Abstract: An input stage for an integrated circuit device provides constant gain in selectable modes of either differential or single-ended operation. In one embodiment, transconductance devices are arranged so that the input impedance of the input stage matches the signal source impedance, regardless whether the input stage is selected to operate in a differential mode or in a single-ended mode. In accordance with an alternative embodiment, constant-gain and constant-impedance conditions are maintained in a configuration that comprises and input signal attenuator. In one application, the input stage may serve as a low-noise amplifier (LNA) for an integrated transceiver.

Abstract: The use of the magnetic coupling between bonding wires can be advantageously used to transform a differential signal to a single-ended signal. Because bonding wires are very good conductors, this differential to single-ended signal transformation can be performed with minimal signal loss. Moreover, because bonding wires are already part of an integrated circuit package, both system cost and board resources are minimized. The magnetic coupling between bonding wires can also be used to combine the power of a plurality of amplifiers. This magnetic coupling can also be used to provide a single-ended to differential signal transformation.

Abstract: A radio frequency integrated circuit includes a power amplifier, a low noise amplifier, a first transformer balun, and a second transformer balun. The power amplifier includes a first power amplifier section and a second power amplifier section. When enabled, the first and second power amplifier sections amplify an outbound radio frequency (RF) signal to produce a first amplified outbound RF signal and a second amplified outbound RF signal, respectively. The power amplifier provides the first amplified outbound RF signal to the first transformer balun and the second outbound RF signal to the second transformer balun, where the first transformer balun is coupled to a first antenna and the second transformer balun is coupled to a second antenna. The low noise amplifier includes a first low noise amplifier section and a second low noise amplifier section.

Abstract: The invention concerns an integrated circuit amplifier designed to supply an amplified signal at a power of a few hundreds of milliwatts at frequencies from one to several Gigahertz.

Abstract: A semiconductor chip for amplification is connected between input-side and output-side matching circuits, and each of matching circuits includes balanced circuits which receive signals different in phase by 180 degrees, divided from an input signal. The balanced circuits are connected at a virtual grounding point, which is used as a grounding point sensitive to RF characteristics in an IPD. Thus, a semiconductor device can be free from influence of variations of grounding wires and can be reduced in size, weight, and cost.

Abstract: A balanced power amplifier includes grounded-emitter first and second bipolar transistors that are disposed in parallel, first and second variable impedance elements with each one end being electrically connected to each base of the first and second bipolar transistors, a regulator circuit disposed between the other end of the first variable impedance element and the other end of the second variable impedance element, a first resistance for electrically connecting the line between the first variable impedance element and the regulator circuit and a voltage source, and a second resistance for electrically connecting the line between the second variable impedance element and the regulator circuit and the voltage source. The balanced power amplifier is small in the number of component parts and in size.

Abstract: A demodulator which includes an active balun circuit and at least one mixer driven by the active balun circuit. The active balun circuit includes a negative shunt feedback arrangement.

Abstract: A method and circuits of a high isolation and high-speed buffer amplifier capable to handle frequencies in the GHz range have been achieved. The output to input isolation is primary dependent on the gate-source capacitance of the active buffer transistor. Having two or more in series and by reducing the impedance between them a high isolation can be achieved. The input signals are split in several signal paths and are amplified in the push-pull mode using source follower amplifiers. Then the amplified signals are being combined again. The amplified output current is mirrored applying a multiplication factor. Said method and technology can be used for buffer amplifiers having differential input and differential output or having single input and single output or having differential input and single output. A high reversed biased (output to input) isolation and a reduced quiescent current have been achieved.

Abstract: A circuit to provide a differential signal output in response to a single-ended signal input, the circuit allowing for a wide common-mode input signal by providing complementary amplifier structures.

Abstract: A high voltage differential amplifier including an input differential pair of low voltage transistors, a sense differential pair of low voltage transistors, first and second high voltage transistors, a low voltage bias transistor, a cascaded pair of low voltage transistors, and an output pair of high voltage transistors. The sense differential pair has a pair of control terminals that detect a common mode voltage of the differential input signal, and establishes a sense node which follows the common mode voltage. The first high voltage device is coupled to the sense node to establish bias node voltage levels which track the common mode voltage, including an output bias node biasing the output pair and a cascade bias node biasing the cascaded pair. In this manner, the terminals of the low voltage devices slide up or down with the common mode voltage and are protected from high voltage levels.

Abstract: In a translinear amplifier, where the output voltage difference is kept at the same relative difference as the input voltage difference and which is normally formed by two current balancing circuits and some form of an amplifier stage, said amplifier stage is drastically simplified and even replaced by a simple diode. Two additional functions sharply limit the analog operating region: an added current limiting transistor on one side and the purpose use of the voltage limited by the power supply on the other side. One key objective is linearly switching on or off a transistor, and getting sharp maxima and minima of its RDSon at the extreme ends.

Abstract: An active balun circuit is provided for single-ended to differential RF signal conversion with enhanced common-mode rejection which suppresses common mode signal and which achieves phase and amplitude balance without sophisticated tuning or compensation methods. The circuit has a single-ended input and balanced output with phase and amplitude balance error less than 2° and 1.2 dB, respectively, measured from 1.5 GHz to 1.8 GHz at 5V supply. When supply voltage drops down to 1.5V, its phase and amplitude balance error remains within 5° and 2 dB, respectively. The circuit achieves a balanced output via an output network which behaves as an impedance matching network for differential mode signal and is grounded for common mode signal. As a result, common mode signal is suppressed and 180-degree phase balance at output is achieved. The circuit has high-linearity (P1 dBin=5 dBm, IIP3=16.

Abstract: A device converts a differential signal (Vin1, Vin2) to a single signal (Vout). The device includes at least one pair of transistors (Q1, Q2) having equal transconductance gain (gm) and arranged according a differential stage configuration. The transistors (Q1, Q2) have the differential signal (Vin1, Vin2) in input at the drivable terminals, have first non drivable terminals coupled respectively to first terminals of a first (R1) and a second (Rout) passive elements having second terminals connected with a first supply voltage (VDD), second non drivable terminals coupled to a second supply voltage (VEE) lower than the first supply voltage (VDD). The first terminal of the second passive element (Rout) is the output terminal (OUT) of the device.

Abstract: A balanced high-frequency device is constituted by a balanced device and a phase circuit. The input side of the balanced device is connected to an input terminal IN serving as an unbalanced input/output terminal and the output side of it is connected to output terminals OUT1 and OUT2 serving as balanced input/output terminals. Moreover, the phase circuit is connected between the output terminals.

Abstract: In a transmission output stage for a multifrequency mobile telephone, the transmit signal of operation at the low frequency is generated by a push-pull output stage which is operated in single-ended mode for generating the transmit signal at the higher frequency.

Abstract: The present invention relates to circuits having differential structure which uses complementary devices for processing single-ended signal. The single-ended differential circuit in accordance with the present invention, comprises first and second complementary devices having first, second, and third terminals, respectively, wherein current flowing from the second terminal to the third terminal has its quantity and direction being varying in dependant on the voltage driven to the first terminal, wherein the currents flowing through the first and second complementary devices vary in opposite relationship.