Abstract: A zero insertion loss directional coupler includes an input port, an antenna port, an isolation port, and a detect port. The coupler has a first signal trace, a second signal trace, and an inductive winding. The first signal trace is on one of two layers and is connected to the input port and the antenna port, while the inductive winding is on another one of the two layers. A first terminal of the inductive winding is connected to the isolation port. A first terminal of the second signal trace is connected to the detect port and a second terminal of the second signal trace is connected to a second terminal of the inductive winding.

Abstract: Devices and methods are disclosed, related to shielding and packaging of radio-frequency (RF) devices on substrates. In some embodiments, A radio-frequency (RF) module comprises a lead-frame package with a plurality of pins and at least one pin exposed from overmold compound. The module further includes a metal-based covering over a portion of the lead-frame package. Additionally, the metal-based covering can be in contact with the at least one pin.

Abstract: In an embodiment, an apparatus includes a first transmit path, a second transmit path, and a switch element. The first transmit path can provide a first radio frequency (RF) signal in accordance with a nominal specification. The second transmit path can provide a second RF signal in accordance with an intermittent specification, in which the first and second RF signals are within the same transmit band. The switch element can provide the first RF signal as a transmit mode output in a first state and provide the second RF signal as the transmit mode output in a second state.

Abstract: Aspects of this disclosure relate tuning an impedance presented to a common port of a multi-throw switch and a tunable notch filter coupled to the common port. The impedance presented to the common port can be tuned based on an impedance associated with a throw of the multi-throw switch that is activated. According to embodiments of this disclosure, a shunt inductor in parallel with a tunable capacitance circuit can tune the impedance presented to the common port of the multi-throw switch. In certain embodiments, the tunable notch filter includes a series LC circuit in parallel with a tunable impedance circuit.

Abstract: Apparatus and methods for low noise amplifiers (LNAs) are provided herein. In certain configurations, an LNA includes a gain stage and a bypass stage electrically connected in parallel with one another between an input and an output. The bypass stage and the gain stage are selectively activated based on a mode of the LNA. For example, the gain stage provides inverting amplification to an input signal received at the input in a gain mode. Additionally, the bypass stage provides a low gain path from the input to the output in a bypass mode. Additionally, the bypass stage includes a balun that provides inversion to the bypass stage such that a phase delay through the bypass stage is similar to a phase delay of the gain stage.

Abstract: Circuits, devices, and method for selecting voltage sources. A voltage selection module may include an analog voltage input. The voltage selection module may also include a digital based voltage input. The voltage selection module further include a control component coupled to the analog voltage input and the digital based voltage input, the control component configured to determine whether to use a first voltage received from the analog voltage input or a second voltage received from the digital based voltage input to generate an output voltage.

Abstract: Apparatus and methods for envelope tracking systems are provided. In certain configurations, an envelope tracking system includes a digital filter that generates a filtered envelope signal based on a digital envelope signal representing an envelope of a radio frequency signal, a buck converter controllable by the filtered envelope signal and including an output electrically connected to a power amplifier supply voltage, a digital-to-analog converter module including an output electrically connected to the output of the buck converter and that provides an output current, and a digital shaping and delay circuit configured to generate a shaped envelope signal based on shaping the filtered envelope signal. The shaped envelope signal controls a magnitude of the output current, and the digital shaping and delay circuit controls a delay of the shaped envelope signal to align the output of the digital-to-analog converter module and the output of the buck converter.

Abstract: A power amplifier system front end measures both forward and reverse power associated with an RF transmit signal. A processor is configured to use measurements derived from the measured forward and reverse power output to adjust the RF transmit signal in order to compensate for one or more memory effects of the power amplifier system.

Abstract: Circuits and devices related to voltage conversion. In some embodiments, a voltage converter can include a voltage conversion circuit configured to convert an input voltage to an output voltage based on a drive signal, and a feedback circuit configured to generate an error signal based on the output voltage and a reference voltage. The voltage converter can further include a feedforward circuit configured to generate a feedforward signal indicative of a change opposite to that of a change in the input voltage. The voltage converter can further include a drive control circuit configured to generate the drive signal based on the feedforward signal and the error signal.

Abstract: A power amplifier module includes a transistor and transistor control circuitry configured to receive an internal regulator voltage and provide the internal regulator voltage to control the transistor in a stand-by mode of operation.

Abstract: Aspects of this disclosure relate to methods of selectively shielded radio frequency modules. A radio frequency module can be provided with a radio frequency component and an antenna. A shielding layer can be formed over a portion of the radio frequency module such that the radio frequency component is shielded by the shielding layer and the antenna is unshielded by the shielding layer.

Abstract: A radio frequency (RF) power combining amplifier circuit has a circuit input and a circuit output. A first amplifier is connected to the circuit input and to a first bias input. A first output matching network is connected to an output of the first amplifier and to the circuit output. A second amplifier is connected to the circuit input and to a second bias input. A second output matching network is connected to an output of the second amplifier, and to the circuit output. A voltage level of an input signal applied to the circuit input, together with the respective first bias input and the second bias input, selectively activates the first amplifier and the second amplifier.

Abstract: An RF power amplifier biasing circuit has a start ramp signal input, a main current source input, an auxiliary current source input, and a circuit output. A ramp-up capacitor is connected to the auxiliary current source input. A ramp-up switch transistor is connected to the start ramp signal input and is selectively thereby to connect the auxiliary current source input to the ramp-up capacitor. A buffer stage has an input connected to the ramp-up capacitor and an output connected to the main current source input at a sum node. A mirror transistor has a gate terminal corresponding to the circuit output and a source terminal connected to the sum node and to the gate terminal.

Abstract: Embodiments disclosed herein relate to a bias circuit that uses Schottky diodes. Typically, a bias circuit will include a number of transistors used to generate a bias voltage or a bias current for a power amplifier. Many wireless devices include power amplifiers to facilitate processing signals for transmission and/or received signals. By substituting the bias circuit design with a design that utilizes Schottky diodes, the required battery voltage of the bias circuit may be reduced enabling the use of lower voltage power supplies.

Abstract: Apparatus and methods for programmable low dropout (LDO) regulators for radio frequency (RF) electronics are provided herein. In certain configurations, an LDO regulator for generating a programmable output voltage includes a regulation field-effect transistor (FET) having a drain electrically connected to the LDO regulator's output, an error amplifier that controls a gate of the regulation FET, a feedback circuit that provides a feedback signal to an inverting input of the error amplifier, an output capacitor electrically connected to the LDO regulator's output, and an alternative discharge circuit. When the output voltage of the LDO regulator is programmed from a high voltage level to a low voltage level, the alternative discharge circuit activates to discharge the output capacitor to improve the LDO regulator's transient response.

Abstract: The present disclosure relates to methods, modules and devices for detecting and preventing occurrence of a saturation state in a power amplifier. A method is disclosed for detecting a saturation condition of a power amplifier, including monitoring a first base current of a first transistor of a cascade transistor pair of the power amplifier and a second base current of a second transistor of the cascade transistor pair. The method can also include generating a current ratio based on comparing the first base current and the second base current. The method can further include determining if the current ratio exceeds or satisfies a threshold value and modifying one or more operating characteristics of the power amplifier in accordance with a determination that the current ratio exceeds or satisfies the threshold value.

Abstract: Power amplifier having selective signal paths. In some embodiments, a power amplifier circuit can include a plurality of signal paths sharing a common amplification stage configured to partially amplify a signal. Each signal path can further include a dedicated amplification stage coupled to the common amplification stage and configured to be capable of further amplifying the partially amplified signal. The power amplifier circuit can further include a bias selector having a switch configured to provide a bias signal to a selected dedicated amplification stage among the plurality of signal paths to thereby allow the selected dedicated amplification stage to further amplify the partially amplified signal.

Abstract: A multistage linear power amplifier receiving an input signal. The multistage linear power amplifier comprises a plurality of Class-AB amplifiers connected in a cascade configuration. The plurality of Class-AB amplifiers amplifies the input signal to generate an amplified input signal. At least one of the plurality of Class-AB amplifiers is biased such that the multistage linear power amplifier emulates a Class-C amplifier.

Abstract: Aspects of this disclosure relate to a shielded radio frequency component with an integrated antenna. An antenna can be on a first side of a multi-layer substrate and a radio frequency component can be disposed on a second side of the multi-layer substrate such that a ground plane of the multi-layer substrate is positioned between the antenna and the radio frequency component. Conductive features can be disposed around the radio frequency component and electrically connected to the ground plane. The conductive features and the ground plane can provide shielding for the radio frequency component. In certain embodiments, the conductive features can include bumps, such as solder bumps and/or copper pillars.

Abstract: A packaged module for a radio frequency wireless device has a substrate supporting a first wireless device component and a second wireless device component where the first wireless device component is between the second wireless device component and a first surface of the substrate. At least a first overhanging portion of the second wireless device component extends beyond at least a portion of the periphery of the first wireless device component.