Abstract: Acoustic wave devices and methods of coating a protective film of alumina (Al2O3) on the acoustic wave devices are disclosed herein. The protective film is applied through an atomic layer deposition (ALD) process. The ALD process can deposit very thin layers of alumina on the surface of the acoustic wave devices in a precisely controlled manner. Thus, the uniform film does not significantly distort the operation of the acoustic wave device.

Abstract: Antenna switching circuitry comprises a plurality of communication ports, an antenna port, a plurality of switches, and an ESD protection device. The plurality of switches are adapted to selectively couple one or more of the communication ports to the antenna port in order to transmit or receive a signal. The ESD protection device is coupled between one of the plurality of communication ports and ground, and is adapted to form a substantially low impedance path to ground during an ESD event. Upon the occurrence of an ESD event, a received electrostatic charge passes through one or more of the plurality of switches to the ESD protection device, where it is safely diverted to ground. By using only one ESD protection device, desensitization of the antenna switching circuitry due to the parasitic loading of the ESD protection device is avoided. Further, the area of the antenna switching circuitry is minimized.

Abstract: A first transmit path, a second transmit path, and a third transmit path are disclosed. The first transmit path includes a first radio frequency (RF) power amplifier (PA) and alpha switching circuitry, which is coupled to an output from the first RF PA. The second transmit path includes a second RF PA and beta switching circuitry, which is coupled to an output from the second RF PA. The third transmit path includes a third RF PA.

Abstract: Pilot switch circuitry grounds a hot node (an injection node) of a microelectromechanical system (MEMS) switch to reduce or eliminate arcing between a cantilever contact and a terminal contact when the MEMS switch is opened or closed. The pilot switch circuitry grounds the hot node prior to, during, and after the cantilever contact and terminal contact of the MEMS come into contact with one another (when the MEMS switch is closed). Additionally, the pilot switch circuitry grounds the hot node prior to, during, and after the cantilever contact and terminal contact of the MEMS disengage from one another (when the MEMS switch is opened).

Abstract: This disclosure includes embodiments of a tunable hybrid coupler. The tunable hybrid coupler includes a first inductive element having a first inductance, a second inductive element having a second inductance and mutually coupled to the first inductive element, a first variable capacitive element having a first variable capacitance, and a second variable capacitance having a second variable capacitance. The first variable capacitive element is coupled between a first port and a second port. The second variable capacitive element is coupled between a third port and a fourth port. The first inductive element is coupled from the first port to the third port, while the second inductive element is coupled from the second port to the fourth port. Accordingly, the tunable hybrid coupler may form an impedance matching network that is tunable to different RF communication bands. The tunable hybrid coupler may thus be included in a tunable RF duplexer.

Abstract: A tunable radio frequency (RF) duplexer is disclosed. The tunable RF duplexer includes a first hybrid coupler, a second hybrid coupler, and an RF filter circuit. The first hybrid coupler is operable to split an RF receive input signal into first and second RF quadrature hybrid receive signals (QHRSs). The first hybrid coupler is also operable to split an RF transmission input signal into first and second RF quadrature hybrid transmission signals (QHTSs). The RF filter circuit is operable to pass the first and second RF QHRSs to the second hybrid coupler and to reflect the first and second RF QHTSs back to the first hybrid coupler. Additionally, the second hybrid coupler is configured to combine the first and second RF QHRSs into an RF receive output signal, while the first hybrid coupler is configured to combine the first and second RF QHTSs into an RF transmission output signal.

Abstract: This disclosure includes embodiments of a radio frequency (RF) transceiver having a distributed duplex filtering topology. The RF transceiver includes a power amplifier and a tunable RF duplexer. The tunable RF duplexer is configured to input an RF transmission input signal from the power amplifier, generate an RF transmission output signal that operates within an RF transmission band in response to the RF transmission input signal from the power amplifier, and simultaneously output the RF transmission output signal to an antenna and input an RF receive input signal that operates within an RF receive band from the antenna. The power amplifier includes a plurality of RF amplifier stages coupled in cascode and an RF filter coupled between a first one of the RF amplifier stages and a second one of the RF amplifier stages. Accordingly, the RF filter is configured to provide tuning within the RF receive band.

Abstract: A radio frequency (RF) communications system, which includes an RF power amplifier (PA) and an envelope tracking power supply, is disclosed. The RF communications system processes RF signals associated with at least a first RF communications band, which has a first bandwidth. The RF PA receives and amplifies an RF input signal to provide an RF transmit signal using an envelope power supply signal. The envelope tracking power supply provides the envelope power supply signal, which has switching ripple based on a programmable switching frequency. The programmable switching frequency is selected to be greater that the first bandwidth.

Abstract: Analog-to-digital pulse width modulation circuitry includes thermometer code generator circuitry, clock generator circuitry, delay selection circuitry, and an output stage. The thermometer code generator circuitry is adapted to generate a digital thermometer code based upon a received analog input voltage. The clock generator circuitry is adapted to generate a reference clock and a plurality of delayed clock signals. The delay selection circuitry is connected between the thermometer code generator circuitry and the clock generator circuitry, and is adapted to select one of the delayed clock signals to present to the output stage based upon the generated thermometer code. The selected delayed clock signal is delayed by an amount of time that is proportional to the generated thermometer code. The reference clock signal and the selected delayed clock signal are delivered to the output stage where they are used to generate a pulse width modulated output signal.

Abstract: Radio frequency (RF) duplexing devices and methods of operating the same are disclosed. In one embodiment, an RF duplexing device includes a transmission port, a receive port, a first duplexer, and a second duplexer. The first duplexer is coupled to the transmission port and the receive port, and is configured to provide a first phase shift from the transmission port to the receive port. The second duplexer is also coupled to the transmission port and the receive port. However, the second duplexer is configured to provide a second phase shift that is differential to the first phase shift from the transmission port to the receive port. By providing the second phase shift so that the second phase shift is differential to the first phase shift, the RF duplexing device can provide isolation through cancellation without needing to introduce significant insertion losses.

Abstract: A multiple functional equivalence digital communications interface and a group of functional circuits are disclosed. The multiple functional equivalence digital communications interface presents a functional equivalence of each of a group of digital communications interfaces to a digital communications bus. Each functional equivalence of the group of digital communications interfaces is associated with a corresponding one of the group of functional circuits.

Abstract: Radio frequency (RF) duplexing devices and methods of operating the same are disclosed. In one embodiment, an RF duplexing device includes a transmission port, a receive port, a first duplexer, and a second duplexer. The first duplexer is coupled to the transmission port and the receive port, and is configured to provide a first phase shift from the transmission port to the receive port. The second duplexer is also coupled to the transmission port and the receive port. However, the second duplexer is configured to provide a second phase shift that is differential to the first phase shift from the transmission port to the receive port. By providing the second phase shift so that the second phase shift is differential to the first phase shift, the RF duplexing device can provide isolation through cancellation without needing to introduce significant insertion losses.

Abstract: A direct current (DC)-DC converter, which includes switching circuitry, a first parallel amplifier, and a second parallel amplifier, is disclosed. The switching circuitry has a switching circuitry output. The first parallel amplifier has a first feedback input and a first parallel amplifier output. The second parallel amplifier has a second feedback input and a second parallel amplifier output. A first inductive element is coupled between the switching circuitry output and the first feedback input. A second inductive element is coupled between the first feedback input and the second feedback input.

Abstract: A direct current (DC)-DC converter, which includes a parallel amplifier, a radio frequency (RF) trap, and a switching supply, is disclosed. The switching supply includes switching circuitry and a first inductive element. The parallel amplifier has a feedback input and a parallel amplifier output. The switching circuitry has a switching circuitry output. The first inductive element is coupled between the switching circuitry output and the feedback input. The RF trap is coupled between the parallel amplifier output and a ground.

Abstract: Radio frequency (RF) amplification devices and methods of amplifying RF signals are disclosed. In one embodiment, an RF amplification device includes a control circuit and a Doherty amplifier configured to amplify an RF signal. The Doherty amplifier includes a main RF amplification circuit and a peaking RF amplification circuit. The control circuit is configured to activate the peaking RF amplification circuit in response to the RF signal reaching a threshold level. In this manner, the activation of the peaking RF amplification circuit can be precisely controlled.

Abstract: DC to DC converter circuitry includes a dual phase charge pump and at least one pair of multiplier phase circuits. The dual phase charge pump is coupled to each one of the at least one pair of multiplier circuits and adapted to receive a DC input voltage and only four control signals, and produce a stepped-up output voltage. Each one of the at least one pair of multiplier phase circuits are adapted to receive the stepped-up output voltage, a cross-coupled control signal from the other multiplier phase circuit in the pair of multiplier phase circuits, and a different one of the control signals and further multiply the stepped-up output voltage to produce a multiplied stepped-up output voltage with a magnitude that is approximately three times that of the DC input voltage or greater.

Abstract: This disclosure relates to radio frequency (RF) power converters and methods of operating the same. In one embodiment, an RF power converter includes an RF switching converter, a low-drop out (LDO) regulation circuit, and an RF filter. The RF filter is coupled to receive a pulsed output voltage from the RF switching converter and a supply voltage from the LDO regulation circuit. The RF filter is operable to alternate between a first RF filter topology and a second RF filter topology. In the first RF filter topology, the RF filter is configured to convert the pulsed output voltage from a switching circuit into the supply voltage. The RF filter in the second RF filter topology is configured to filter the supply voltage from the LDO regulation circuit to reduce a ripple variation in a supply voltage level of the supply voltage. As such, the RF filter provides greater versatility.

Abstract: Circuitry, which includes a linear amplifier and a linear amplifier power supply, is disclosed. The linear amplifier at least partially provides an envelope power supply signal to a radio frequency (RF) power amplifier (PA) using a selected one of a group of linear amplifier supply voltages. The linear amplifier power supply provides at least one of the group of linear amplifier supply voltages. Selection of the selected one of the group of linear amplifier supply voltages is based on a desired voltage of the envelope power supply signal.

Abstract: This disclosure relates to radio frequency (RF) power converters and methods of operating the same. In one embodiment, an RF power converter includes an RF switching converter, a low-drop out (LDO) regulation circuit, and an RF filter. The RF filter is coupled to receive a pulsed output voltage from the RF switching converter and a supply voltage from the LDO regulation circuit. The RF filter is operable to alternate between a first RF filter topology and a second RF filter topology. In the first RF filter topology, the RF filter is configured to convert the pulsed output voltage from a switching circuit into the supply voltage. The RF filter in the second RF filter topology is configured to filter the supply voltage from the LDO regulation circuit to reduce a ripple variation in a supply voltage level of the supply voltage. As such, the RF filter provides greater versatility.

Abstract: Embodiments of circuitry, which includes power supply switching circuitry and a first inductive element, are disclosed. The power supply switching circuitry has a first switching output and a second switching output. The first inductive element is coupled between the first switching output and a power supply output. The power supply switching circuitry operates in one of a first operating mode and a second operating mode. During the first operating mode, the first switching output is voltage compatible with the second switching output. During the second operating mode, the first switching output is allowed to be voltage incompatible with the second switching output.