Abstract: Solder bumps are placed in direct contact with the silicon substrate of an amplifier integrated circuit having a flip chip configuration. A plurality of amplifier transistor arrays generate waste heat that promotes thermal run away of the amplifier if not directed out of the integrated circuit. The waste heat flows through the thermally conductive silicon substrate and out the solder bump to a heat-sinking plane of an interposer connected to the amplifier integrated circuit via the solder bumps.

Abstract: Remote compensators for mobile devices are provided. In certain embodiments, a mobile device includes a cable-side circulator, an antenna, receive amplifier circuitry that amplifies a receive signal from the antenna and provides an amplified receive signal to the cable-side circulator, transmit amplifier circuitry that amplifies a transmit signal from the cable-side circulator, and a first antenna-side circulator and a second antenna-side circulator each coupled between the transmit amplifier circuitry and the antenna. The first antenna-side circulator and the second antenna-side circulator operate to compensate the receive signal for transmit leakage arising from the transmit amplifier circuitry.

Abstract: Systems and methods for integrating injection-locked oscillators into transceiver arrays are disclosed. In one aspect, there is provided an injection-locked oscillator (ILO) distribution system including a master clock generator configured to generate a master clock signal. The ILO distribution system also includes an ILO distribution circuit including an ILO and configured to receive the master clock signal. The ILO is configured to generate a reference clock signal based on the master clock signal. The ILO distribution circuit is further configured to generate an output signal indicative of an operating frequency of the ILO. The ILO distribution system further includes an injection-locked detector (ILD) configured to receive the master clock signal and the output signal. The ILD is further configured to determine whether the ILO is in a locked state or in an unlocked state based on the master clock signal and the output signal.

Abstract: Systems and methods for integrating injection-locked oscillators into transceiver arrays are disclosed. In one aspect, there is provided an injection-locked oscillator (ILO) distribution system including a master clock generator configured to generate a master clock signal. The ILO distribution system also includes an ILO distribution circuit including an ILO and configured to receive the master clock signal. The ILO is configured to generate a reference clock signal based on the master clock signal. The ILO distribution circuit is further configured to generate an output signal indicative of an operating frequency of the ILO. The ILO distribution system further includes an injection-locked detector (ILD) configured to receive the master clock signal and the output signal. The ILD is further configured to determine whether the ILO is in a locked state or in an unlocked state based on the master clock signal and the output signal.

Abstract: A calibration operation determines a resistance of a sense resistor in a POE system. A voltage measurement is taken with a first current flowing through the sense resistor. A second voltage measurement is taken with a second current flowing through the resistor. A resistance value of the sense resistor is determined based on a voltage difference between the first and second voltage measurements and a current difference between the first current and the second currents.

Abstract: Apparatus and methods for power amplifier distortion networks are disclosed. In one aspect, there is provided a power amplifier system including a power amplifier configured to amplify a radio frequency input signal. The power amplifier including an input configured to receive the radio frequency input signal and an output configured to generate an amplified radio frequency signal. The power amplifier system further includes a distortion network electrically coupled to either the input or the output of the power amplifier. The distortion network including a plurality of channelized resistors. The channelized resistors connected in series to either an input or an output of the power amplifier.

Abstract: A method for driving an output node includes driving a control node of an output device coupled to the output node according to an input signal and using a fixed regulated voltage and a variable regulated voltage. The method includes generating the fixed regulated voltage based on a first power supply voltage, a second power supply voltage, and a first reference voltage. The method includes generating the variable regulated voltage based on the first power supply voltage, the second power supply voltage, and a second reference voltage. The method includes generating the second reference voltage based on the first power supply voltage, the second power supply voltage, a reference current, and a predetermined target voltage level of the control node of the output device. In an embodiment of the method, generating the second reference voltage includes periodically calibrating the second reference voltage.

Abstract: Apparatus and methods for quadrature combined Doherty amplifiers are provided herein. In certain embodiments, a separator is used to separate a radio frequency (RF) input signal into a plurality of input signal components that are amplified by a pair of Doherty amplifiers operating in quadrature. Additionally, a combiner is used to combine a plurality of output signal components generated by the pair of Doherty amplifiers, thereby generating an RF output signal exhibiting quadrature balancing.

Abstract: A power amplifier module can be formed that includes metamaterial matching circuits. This power amplifier module can be included as part of a front-end module of a wireless device. The front-end module can replace a passive duplexer with an active duplexer that uses the power amplifier module in combination with a low noise amplifier circuit that can include a metamaterial matching circuit. The combination of PA and LNA circuits that utilize metamaterials can provide the functionality of a duplexer without including a stand-alone or passive duplexer. Thus, in certain cases, the front-end module can provide duplexer functionality without including a separate duplexer. Advantageously, in certain cases, the size of the front-end module can be reduced by eliminating the passive duplexer. Further, the loss introduced into the signal path by the passive duplexer is eliminated improving the performance of the communication system that includes the active duplexer.

Abstract: Radio-frequency switch having improved linearity. In some embodiments, a radio-frequency switch circuit can include first and second switch arms, with each switch arm including a plurality of transistors arranged in series to form a stack between a first node and a second node. The first node of the first switch arm can be coupled to the first node of the second switch arm. The radio-frequency switch circuit can further include an amplitude-phase cancelling block implemented across one or more transistors of each switch arm, and configured such that a third harmonic resulting from an ON state of the first switch arm is substantially canceled by a third harmonic resulting from an OFF state of the second switch arm.

Abstract: A system includes a plurality of line cards and a timing card. A clock generation circuit on the timing card generates a clock signal which is pulse width modulated according to information to be transmitted. A clock line supplies the pulse width modulated clock signal to the line cards. The timing card sends a first control word to the plurality of line cards over the clock line after sending a beacon. The first control word includes a size field specifying a first length of first data following the first control word. The timing card sends time of day information over the clock line to the line cards following the first control word. The time of day information may be encrypted. A second control word follows the time of day information. One or more additional control words can follow the second control word before the next beacon.

Abstract: Multi-mode surface acoustic wave filters are disclosed. A multi-mode surface acoustic wave filter can include a plurality of interdigital transducer electrodes that are longitudinally coupled to each other and stepped acoustic reflectors on opposing sides of the plurality of interdigital transducer electrodes. The acoustic reflectors include acoustic reflector fingers with stepped lengths.

Abstract: A baseline difference is determined between a slave line card time stamp corresponding to a slave line card frame sync signal and a master line card time stamp corresponding to a master line card frame sync signal. The slave line card generates subsequent slave line card time stamps for subsequent slave line card frame sync signals and the master line card generates subsequent master line card time stamps for subsequent master line card frame sync signals. Current differences are determined between subsequent slave line card time stamps and the subsequent master line card time stamps and the current differences are compared to the baseline difference. When a mismatch difference occurs (current difference differs from the baseline difference), the mismatch difference causes a phase-locked loop in the master line card to be adjusted or an offset to be provided to the master line card time of day counter.

Abstract: Aspects of this disclosure relate to a hybrid acoustic LC filter cascaded with a non-acoustic LC filter. The hybrid acoustic filter can filter a radio frequency signal. The hybrid acoustic LC filter can include acoustic resonators, an inductor, and a capacitor. The inductor and capacitor can be external to an acoustic resonator die. The non-acoustic LC filter includes an LC circuit. Related multiplexers, wireless communication devices, and methods are disclosed.

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: Aspects of this disclosure relate to methods of manufacturing bulk acoustic wave components. Such methods include plasma dicing to singulate individual bulk acoustic wave components. A buffer layer can be formed over a substrate of bulk acoustic wave components such that streets are exposed.

Abstract: Systems and methods are provided herein that include an improved RF switch assembly. In at least one embodiment, the RF switch assembly may have an optimized topology including a common node shared by each signal path, reducing the size and cost of the RF switch assembly and providing improved performance.

Abstract: A control plane, available to all of the line cards in a system, is used to exchange time stamps to align the Time of Day counters in the master line cards. The master line cards are locked to a system clock distributed over the backplane by a timing card. The timing card is locked to timing of a slave line card that is synchronized with the grand master. Each master line card synchronizes updating its Time of Day counter based on a time stamp exchange and a local clock locked to the system clock and without the use of a 1 pulse per second signal.

Abstract: Multi-mode surface acoustic wave filters are disclosed. A multi-mode surface acoustic wave filter can include a plurality of interdigital transducer electrodes that are longitudinally coupled to each other and acoustic reflectors on opposing sides of the plurality of interdigital transducer electrodes. The acoustic reflectors include acoustic reflector fingers arranged to suppress a spurious response due to shear horizontal mode of the multi-mode surface acoustic wave filter. For example, the acoustic reflector fingers can include stepped lengths and/or slanted pitches to suppress the spurious response due to shear horizontal mode.

Abstract: Radio frequency (RF) communication systems with dynamic waveform control and power boost are provided herein. In certain embodiments, an RF communication system includes a power amplifier configured to amplify an RF signal to generate an RF transmit signal for transmission over a time-division duplex (TDD) communication link having a duty cycle, and a transmitter configured to provide the RF signal to the power amplifier. The transmitter is operable to change a type of waveform of the RF signal from a first waveform type to a second waveform type in response to a decrease in a signal-to-noise ratio (SNR) of the TDD communication link, and to boost a power of the RF transmit signal by an amount based on the duty cycle.