Abstract: A multi-mode envelope tracking (ET) amplifier circuit is provided. The multi-mode ET amplifier circuit can operate in a low-resource block (RB) mode, a mid-RB mode, and a high-RB mode. The multi-mode ET amplifier circuit includes fast switcher circuitry having a first switcher path and a second switcher path and configured to generate an alternating current (AC) current. A control circuit activates the fast switcher circuitry in the mid-RB mode and the high-RB mode, while deactivating the fast switcher circuitry in the low-RB mode. More specifically, the control circuit selectively activates one of the first switcher path and the second switcher path in the mid-RB mode and activates both the first switcher path and the second switcher path in the high-RB mode. As a result, it is possible to improve efficiency of ET tracker circuitry and the multi-mode ET amplifier circuit in all operation modes.

Abstract: According to an aspect, an auto-zero amplifier includes a main amplifier, a secondary amplifier connected to the main amplifier, a plurality of switching including a first switch and a second switch, and a leakage control circuit.

Abstract: A multi-stage transimpedance amplifier (TIA) with an adjustable input linear range is disclosed. The TIA includes a first stage, configured to convert a single-ended current signal from an optical sensor of a receiver signal chain to a single-ended voltage signal, and a second stage, configured to convert the single-ended voltage signal provided by the first stage to a differential signal. In such a TIA, the input linear range may be adjusted using a clamp that is programmable with an output offset current to keep the second stage of the TIA from overloading and to maintain a linear transfer function without compression.

Abstract: An example VGA includes a transistor arrangement having a plurality of transistors configured to realize one or more gain step circuits of the VGA, and a cross-couple switching arrangement having a plurality of switches configured to selectively change the coupling of the terminals of at least some of the transistors depending on whether a given gain step circuit is supposed to be in an ON state or in an OFF state. Using the cross-couple switching arrangement advantageously allows keeping all of the transistors ON at all times during operation and changing the coupling of some transistor terminals to either realize an in-phase addition of currents flowing through various transistors to apply the maximum gain or realize a subtraction of currents to apply the minimum gain. Such a VGA may be inherently wideband, enabling a highly linear, wideband operation without having to resort to significant trade-offs with other performance parameters.

Abstract: Bias arrangements for amplifiers are disclosed. An example bias arrangement for an amplifier includes a bias circuit, configured to produce a bias signal for the amplifier; a linearization circuit, configured to improve linearity of the amplifier by modifying the bias signal produced by the bias circuit to produce a modified bias signal to be provided to the amplifier; and a coupling circuit, configured to couple the bias circuit and the linearization circuit. Providing separate bias and linearization circuits coupled to one another by a coupling circuit allows separating a linearization operation from a biasing loop to overcome some drawbacks of prior art bias arrangements that utilize a single biasing loop.

Abstract: A fully differential amplifier includes: an input stage comprising a first amplification circuit and a second amplification circuit, one of which is configured to generate a push signal and the other of which is configured to generate a pull signal, each by amplifying a differential input signal; an output stage for generating a differential output signal based on the push signal and the pull signal; and a feedback circuit for providing common mode feedback to the first amplification circuit based on the differential output signal, wherein the second amplification circuit may include a passive network for setting a common mode voltage of the push signal or the pull signal.

Abstract: An envelope tracking (ET) amplifier apparatus is provided. The ET amplifier apparatus includes an ET integrated circuit (ETIC) and a distributed ETIC (DETIC) coupled to a single-wire bus that correspond to a first bus access priority and a second bus access priority, respectively. The ETIC and the DETIC can contend for access to the single-wire bus by asserting a bus contention indication(s) when the single-wire bus is in a defined bus state configured to permit bus contention. In a non-limiting example, a winner for the single-wire bus is a peer device having a highest bus access priority between the ETIC and the DETIC. In this regard, each of the ETIC and the DETIC can have a chance to initiate communications over the single-wire bus, thus making it possible for the single-wire bus to function based on bidirectional peer-to-peer (P2P) bus architecture capable of supporting more application and/or deployment scenarios.

Abstract: An amplification device includes an amplification circuit, an inductor, a regulator, and a impedance circuit. The amplification circuit has an input terminal for receiving a radio frequency signal, and an output terminal for outputting an amplified radio frequency signal. The inductor has a first terminal, and a second terminal coupled to the output terminal of the amplification circuit. The regulator is coupled to the first terminal of the inductor and generates a steady voltage and/or a steady current. The impedance circuit has a first terminal coupled to the output terminal of the amplification circuit, and a second terminal coupled to a first system voltage terminal. The impedance circuit provides a low frequency impedance path to suppress a beat frequency signal in the amplified radio frequency signal.

Abstract: A Class-D amplifier includes a plurality of power rails, a quantizer, and a driver stage. The quantizer and the driver stage have a combined gain. For each power rail of the plurality of power rails, the Class-D amplifier senses a voltage value for the power rail and determines a ramp amplitude based on the sensed voltage value. The Class-D amplifier concurrently switches from the driver stage using a first power rail to a second power rail of the plurality of power rails and switches from the quantizer using the ramp amplitude associated with the first power rail to using the ramp amplitude associated with the second power rail so that the combined gain is constant.

Abstract: A power amplifier circuit includes a first transistor, a capacitor, and a second transistor. The first transistor has an emitter electrically connected to a reference potential, a base, and a collector electrically connected to a first power supply potential. A first end of the capacitor is electrically connected to the collector of the first transistor. The second transistor has an emitter electrically connected to a second end of the capacitor and electrically connected to the reference potential, a base, and a collector electrically connected to the first power supply potential. An RF output signal obtained by amplifying the RF input signal is output from the collector of the second transistor. A second bias circuit includes a third transistor having a collector electrically connected to a second power supply potential, a base, and an emitter from which the second bias current or voltage is output.

Abstract: An apparatus includes a radio-frequency (RF) circuit, which includes a power amplifier coupled to receive an RF input signal and to provide an RF output signal in response to a modified bias signal. The RF circuit further includes a bias path circuit coupled to modify a bias signal as a function of a characteristic of an input signal to generate the modified bias signal. The bias path circuit provides the modified bias signal to the power amplifier.

Abstract: Gallium nitride based RF transistor amplifiers include a semiconductor structure having a gallium nitride based channel layer and a gallium nitride based barrier layer thereon, and are configured to operate at a specific direct current drain-to-source bias voltage. These amplifiers are configured to have a normalized drain-to-gate capacitance at the direct current drain-to-source bias voltage, and to have a second normalized drain-to-gate capacitance at two-thirds the direct current drain-to-source bias voltage, where the second normalized drain-to-gate capacitance is less than twice the first normalized drain-to-gate capacitance.

Abstract: A circuit includes a first operational amplifier having an inverting input and a non-inverting input, and a negative resistance circuit connected to the inverting input of the operational amplifier. The negative resistance circuit includes a second operational amplifier, a current source controlled by the second operational amplifier, and a cross-coupled transistor circuit having at least one transistor biased by a current produced by the current source.

Abstract: An amplifier includes an input transistor pair connected to amplifier input nodes, a complementary transistor pair connected to a common bias, amplifier output nodes connected to the input transistor pair and the complementary transistor pair, and variable capacitors connected between the complementary transistor pair and the amplifier output nodes.

Abstract: A filterless high-efficiency class D power amplifier (HEPA) exploits the phase relationships of even and odd harmonics at transistor drains of a push-pull topology to eliminate output filtering, enabling an ultra-high-efficiency, low harmonic signal. The filterless HEPA relieves the amplifier of a requirement for a power consuming filter by implementing a high-quality operational harmonic block on an output stage without output buffering. The operational harmonic block senses the voltage source radio frequency to the amplifier prior to waveform squaring and employs a harmonic canceling balun to block even harmonics (in-phase) but pass odd harmonics (180° out of phase). The sensed ideal voltage source shunts the odd-harmonic currents to ground, leaving only the fundamental current on its primary to pass to the load.

Abstract: The present invention relates to a Doherty combiner used in a Doherty power amplifier, the Doherty combiner comprising: a phase shift section connected to one end of a carrier amplifier so as to change a phase of an RF signal output from the carrier amplifier; a matching section connected to an output terminal of the Doherty power amplifier so as to impedance-match an output of the Doherty power amplifier; and a bandwidth improvement section connected to one end of a peaking amplifier so as to change at least one of a phase bandwidth and an amplitude bandwidth of the Doherty power amplifier.

Abstract: A power amplifier for a radio frequency transceiver including a driver, a disable circuit, and a bias circuit. The driver includes a source node for receiving a drive voltage when enabled and includes an output node that is susceptible to strong blocker signals when disabled. The bias circuit includes first and second bias nodes for driving the voltage level of the source and output nodes, respectively, to suitable bias voltage levels to minimize impact of blocker signals. The disable circuit includes switch circuits to couple the driver to the bias circuit in the disable mode. The bias circuit may include at least one voltage source. The bias circuit may be coupled to a supply voltage and may include a voltage divider coupled between the source and output nodes. The bias circuit may include a source-follower circuit to isolate the bias voltages from variations of the supply voltage.

Abstract: A power amplifier includes a semiconductor die, and an amplifier and bias circuit integrally formed with the semiconductor die. The die has opposed first and second sides, and a device bisection line extends between the first and second sides. The bias circuit includes a multi-point input terminal with first and second terminals that are electrically connected through a conductive path that extends across the device bisection line, and one or more bias circuit components connected between the multi-point input terminal and the amplifier. The amplifier may include a field effect transistor (FET) with gate and drain terminals, and the bias circuit component(s) are electrically connected between the multi-point input terminal and the gate terminal. In addition or alternatively, the bias circuit component(s) are electrically connected between a multi-point input terminal and the drain terminal. The one or more components may include a resistor-divider circuit.

Abstract: Systems and methods are provided for amplifying multiple input signals to generate multiple output signals. An example system includes a first channel, a second channel, and a third channel. The first channel is configured to receive one or more first input signals, process information associated with the one or more first input signals and a first ramp signal, and generate one or more first output signals. The second channel is configured to receive one or more second input signals, process information associated with the one or more second input signals and a second ramp signal, and generate one or more second output signals. The first ramp signal corresponds to a first phase. The second ramp signal corresponds to a second phase. The first phase and the second phase are different.

Abstract: A balun is disclosed and includes a dielectric substrate defining a first surface and a second surface. The balun includes a first output port including a first output ground portion and first output power portion; a second output port including a second output ground portion and a second output power portion; and an input port including an input ground portion and input power portion. The first output ground portion, the second output ground portion, and the input ground portion are coupled at a ground junction portion. The first output power portion, the second output power portion, and the input power portion are coupled at a power junction portion. The first output power portion, the second output power portion, and the input power portion are positioned on the first surface. The first output ground portion, the second output ground portion, and the input ground portion are positioned on the second surface.