Abstract: An apparatus includes a first power amplifier having a negative output terminal coupled to a first primary winding of a distributed transformer and a positive output terminal coupled to a second primary winding of the distributed transformer, a second power amplifier having a negative output terminal coupled to a third primary winding of the distributed transformer and a positive output terminal coupled to a fourth primary winding of the distributed transformer, a first conductive element connected between the negative output terminal of the first power amplifier and the negative output terminal of the second power amplifier, and a second conductive element connected between the positive output terminal of the first power amplifier and the positive output terminal of the second power amplifier.

Abstract: A transceiver front-end for a communication device is connectable at a signal transmission and reception arrangement node to a signal transmission and reception arrangement adapted to transmit a transmit signal having a transmit frequency and to receive a receive signal having a receive frequency. The transceiver front-end is also connectable at a transmitter node to a transmitter adapted to produce the transmit signal and at a receiver node to a receiver adapted to process the receive signal. The transceiver front-end comprises a transformer, wherein the transmitter node is connected to a first node of a first side of the transformer, the receiver node is connected to a first node of a second side of the transformer, and the signal transmission and reception arrangement node is connected to a second node of the first side of the transformer and to a second node of the second side of the transformer.

Abstract: There is provided a switching circuit for an active mixer. The switching circuit comprises a first pair of parallel switching devices and a second pair of parallel switching devices. The first and second pairs of parallel switching devices are arranged in a stacked configuration between an input node at which an input current comprising a first input frequency signal is received and a pair of differential output nodes. The first pair of switching devices are controlled by a second input frequency signal. The second pair of switching devices are controlled by a phase-shifted counterpart of the second input frequency signal. A common node between the first switching devices of the first and second pairs of switching devices is electrically coupled to a common node between the second switching devices of the first and second pairs of switching devices.

Abstract: There is provided a switching circuit for an active mixer. The switching circuit comprises a first pair of parallel switching devices and a second pair of parallel switching devices. The first and second pairs of parallel switching devices are arranged in a stacked configuration between an input node at which an input current comprising a first input frequency signal is received and a pair of differential output nodes. The first pair of switching devices are controlled by a second input frequency signal. The second pair of switching devices are controlled by a phase-shifted counterpart of the second input frequency signal. A common node between the first switching devices of the first and second pairs of switching devices is electrically coupled to a common node between the second switching devices of the first and second pairs of switching devices.

Abstract: A transceiver front-end for a communication device is connectable at a signal transmission and reception arrangement node to a signal transmission and reception arrangement adapted to transmit a transmit signal having a transmit frequency and to receive a receive signal having a receive frequency. The transceiver front-end is also connectable at a transmitter node to a transmitter adapted to produce the transmit signal and at a receiver node to a receiver adapted to process the receive signal. The transceiver front-end comprises a transformer, wherein the transmitter node is connected to a first node of a first side of the transformer, the receiver node is connected to a first node of a second side of the transformer, and the signal transmission and reception arrangement node is connected to a second node of the first side of the transformer and to a second node of the second side of the transformer.

Abstract: A power amplifier circuit utilizes a cross-coupled tapped cascade topology together with a technique of applying an RF injection current into a wideband node to provide a single-stage power amplifier with improved PAE, output power, and gain over a wide RF band. The amplifier circuit comprises a cross-coupled cascade transistor unit comprising a pair of cross-coupled cascode transistors, a cross-coupled switching transistor unit comprising a pair of cross-coupled switching transistors, and an RF current generator. RF current generator generates a differential RF injection current, while switching transistor unit amplifies the injection current to generate an amplified injection current at the wideband node of the amplifier circuit and the cascode transistor unit further amplifies the injection current to generate the desired amplified signal at the output of the amplifier circuit.

Abstract: A power amplifier circuit utilizes a cross-coupled tapped cascade topology together with a technique of applying an RF injection current into a wideband node to provide a single-stage power amplifier with improved PAE, output power, and gain over a wide RF band. The amplifier circuit comprises a cross-coupled cascade transistor unit comprising a pair of cross-coupled cascode transistors, a cross-coupled switching transistor unit comprising a pair of cross-coupled switching transistors, and an RF current generator. RF current generator generates a differential RF injection current, while switching transistor unit amplifies the injection current to generate an amplified injection current at the wideband node of the amplifier circuit and the cascode transistor unit further amplifies the injection current to generate the desired amplified signal at the output of the amplifier circuit.

Abstract: Switched-mode amplifiers and devices having such amplifiers include quadrature pulse-width modulation that is based on cartesian (as opposed to polar) coordinates. Two sets of pulses that represent respective in-phase and quadrature components of a conventional cartesian-coordinates input signal can be combined such that the combined set of pulses can be provided to a switched-mode amplifier without nonlinear cartesian-to-polar transformation and its associated wider internal bandwidth and other problems.

Abstract: Instead of reducing the pulse widths of all pulses simultaneously in order to reduce the output power of a switched-mode amplifier linearized by a pulse-width modulator, the width of every other (or every n-th) pulse is reduced. When the widths of the selected pulses have been reduced to zero, the amplifier's output power can be further reduced by selecting further pulses from the remaining non-zero-width pulses, and reducing the widths of those pulses. For example, after every other pulse of an original output signal has been removed, every other pulse of the remaining pulses can be reduced to obtain still lower amplifier output power. In this way, the number of pulses (and thus the number of switching transitions) is reduced for small signals, and therefore the amplifier's switching losses are reduced and efficiency is improved.

Abstract: Otherwise conventional pulse-width modulators (PWMs) generate signals that can be converted into other forms by reshapers, and thereby overcome many of the problems of conventional PWMs in applications that demand high performance, such as switched-mode amplifiers and radio-frequency transmitters in modern communication systems. With a suitable reshaper, a conventional PWM differential signal can be converted into a signal more typical of linear amplification with nonlinear components (LINC) and still retain low-frequency information, such as the information needed for linearization of a switched-mode amplifier. Apparatus and methods of transforming signals are disclosed.

Abstract: Instead of reducing the pulse widths of all pulses simultaneously in order to reduce the output power of a switched-mode amplifier linearized by a pulse-width modulator, the width of every other (or every n-th) pulse is reduced. When the widths of the selected pulses have been reduced to zero, the amplifier's output power can be further reduced by selecting further pulses from the remaining non-zero-width pulses, and reducing the widths of those pulses. For example, after every other pulse of an original output signal has been removed, every other pulse of the remaining pulses can be reduced to obtain still lower amplifier output power. In this way, the number of pulses (and thus the number of switching transitions) is reduced for small signals, and therefore the amplifier's switching losses are reduced and efficiency is improved.

Abstract: Otherwise conventional pulse-width modulators (PWMs) generate signals that can be converted into other forms by reshapers, and thereby overcome many of the problems of conventional PWMs in applications that demand high performance, such as switched-mode amplifiers and radio-frequency transmitters in modern communication systems. With a suitable reshaper, a conventional PWM differential signal can be converted into a signal more typical of linear amplification with nonlinear components (LINC) and still retain low-frequency information, such as the information needed for linearization of a switched-mode amplifier. Apparatus and methods of transforming signals are disclosed.

Abstract: Switched-mode amplifiers and devices having such amplifiers include quadrature pulse-width modulation that is based on Cartesian (as opposed to polar) coordinates. Two sets of pulses that represent respective in-phase and quadrature components of a conventional cartesian-coordinates input signal can be combined such that the combined set of pulses can be provided to a switched-mode amplifier without nonlinear cartesian-to-polar transformation and its associated wider internal bandwidth and other problems.