Abstract: Aspects of this disclosure relate to a multiplexer, such as a duplexer, a quadplexer, a hexaplexer, or the like. The multiplexer includes acoustic wave filters coupled to a common node. A first acoustic wave filter of the acoustic wave filters includes acoustic wave resonators of a first type and a series acoustic wave resonator of a second type coupled between the acoustic wave resonators of the first type and the common node.

Abstract: There are disclosed acoustic resonators and radio frequency filter devices. A back surface of a single-crystal piezoelectric plate is attached to a surface of a substrate except for portions of the piezoelectric plate forming a plurality of diaphragms, each of which spans a respective cavity in the substrate. A conductor pattern is formed on the front surface, the conductor pattern including interdigital transducers (IDTs) of one or more pairs of sub-resonators, each pair consisting of two sub-resonators. The IDT of each sub-resonator includes interleaved fingers disposed on a respective diaphragm. The piezoelectric plate and the IDTs are configured such that respective radio frequency signals applied to each IDT excite respective shear primary acoustic modes in the respective diaphragms. The two sub-resonators of each pair of sub-resonators are positioned symmetrically about a central axis.

Abstract: A system and method are disclosed for a superconducting traveling-wave parametric amplifier (TWPA) with improved control and performance. In a preferred embodiment, the amplifier comprises an integrated array of symmetric rf-SQUIDs in a transmission line structure. A device was fabricated using niobium superconducting integrated circuits, and confirmed predicted performance, with a maximum gain up to 17 dB and a bandwidth of 4 GHz. A similar device can be applied as a low-noise, low-dissipation microwave amplifier for output from a superconducting quantum computer, or as a preamplifier, switch, or frequency converter for a sensitive microwave receiver, or as an output amplifier for a frequency-multiplexed superconducting detector array.

Abstract: Resonator devices, filter devices, and methods of fabrication are disclosed. A resonator device includes a substrate and a single-crystal piezoelectric plate having front and back surfaces. An acoustic Bragg reflector is sandwiched between a surface of the substrate and the back surface of the piezoelectric plate. An interdigital transducer (IDT) is formed on the front surface of the piezoelectric plate. The IDT and the piezoelectric plate are configured such that a radio frequency signal applied to the IDT excites a primary acoustic mode within the piezoelectric plate. The acoustic Bragg reflector comprises alternating SiO2 and diamond layers and is configured to reflect the primary acoustic mode.

Abstract: Acoustic resonator devices and acoustic filter devices. An acoustic resonator includes a piezoelectric plate having front and back surfaces, a portion of the piezoelectric plate forming a diaphragm, and a conductor pattern on the front surface, the conductor pattern comprising an interdigital transducer (IDT), interleaved fingers of the IDT on the diaphragm. A ratio of a mark of the interleaved fingers to a pitch of the interleaved fingers is greater than or equal to 0.12 and less than or equal to 0.3. A thickness of the interleaved fingers is greater than or equal to 0.85 times a thickness of the piezoelectric plate and less than or equal to 2.5 times the thickness of the piezoelectric plate.

Abstract: This disclosure describes amplifiers that include impedance circuits that are configured to adapt to various contexts. For example, a variable-gain amplifier can include a gain circuit configured to amplify a signal and to operate in a plurality of gain modes, and an impedance circuit coupled to the gain circuit. The impedance circuit can include an inductor and a switching-capacitive arm coupled in parallel to the inductor. The impedance circuit can be configured to operate based at least in part on a gain mode from among the plurality of gain modes.

Abstract: A low noise amplifier for an RF sampling analog front end. The amplifier includes digital step attenuation for applying a selected attenuation to signals received at an input node, and a gain stage coupled to amplify the attenuated signal from the digital step attenuation circuit. In a differential amplifier implementation, a first input capacitor is coupled between a positive side input node and an output of the negative side digital attenuation circuit, and a second input capacitor is coupled between a negative side input node and an output of the positive side digital step attenuation circuit. In some embodiments, variable feedback circuits are coupled between each input node and an output of the corresponding gain stage, to selectively apply active termination at the input at high gain settings of the amplifier. Variable input and output resistors, and programmable noise filtering at the output, are provided in some embodiments.

Abstract: There is disclosed acoustic resonators and filter devices. An acoustic resonator device includes a piezoelectric plate, a portion of the piezoelectric plate forming a diaphragm, a thickness of the piezoelectric plate is greater than or equal to 300 nm and less than or equal to 500 nm, and an interdigital transducer (IDT) with interleaved fingers of the IDT on the diaphragm. The piezoelectric plate and the IDT are configured such that a radio frequency signal applied to the IDT excites a primary shear acoustic mode in the diaphragm.

Abstract: A power amplifier module includes a first amplifier, a power splitter, a second amplifier, a third amplifier, a phase shifter, a combining unit, and a controller. The first amplifier amplifies a first signal and outputs a second signal. The power splitter splits the second signal into a third signal and a fourth signal. The second amplifier amplifies the third signal and outputs a fifth signal. The third amplifier amplifies the fourth signal and outputs a sixth signal. The phase shifter receives the fifth signal and shifts a phase of the fifth signal. The combining unit combines the fifth signal having the phase shifted by the phase shifter and the sixth signal and outputs an amplified signal of the second signal. The controller outputs a first control signal for controlling a power level of the sixth signal output from the third amplifier.

Abstract: Acoustic filters, resonators and methods are disclosed. An acoustic resonator includes a substrate and a piezoelectric plate includes a diaphragm that spans a cavity in the substrate. A conductor pattern includes an interdigital transducer (IDT) with interleaved parallel fingers on the diaphragm. A center-to-center spacing between two adjacent parallel fingers is greater than or equal to 2.5 times a thickness of the diaphragm and less than or equal to 15 times the diaphragm thickness.

Abstract: Acoustic resonators and filter devices. An acoustic resonator includes a piezoelectric plate having front and back surfaces, a portion of the piezoelectric plate forming a diaphragm, and a conductor pattern on the front surface, the conductor pattern including an interdigital transducer (IDT), interleaved fingers of the IDT on the diaphragm. A ratio of a mark of the interleaved fingers to a pitch of the interleaved fingers is greater than or equal to 0.12 and less than or equal to 0.3. The pitch of the interleaved fingers is greater than or equal to 6 times a thickness of the piezoelectric plate and less than or equal to 12.5 times the thickness of the piezoelectric plate.

Abstract: Bulk acoustic wave resonators of two or more different filters can be on a common die. The two filters can be included in a multiplexer, such as a duplexer, or implemented as standalone filters. With bulk acoustic wave resonators of two or more filters on the same die, the filters can be implemented in less physical space compared to implementing the same filters of different die. Related methods, radio frequency systems, radio frequency modules, and wireless communication devices are also disclosed.

Abstract: Acoustic filters, resonators and methods are disclosed. An acoustic resonator includes a substrate and a piezoelectric plate including a diaphragm that spans a cavity in the substrate. A conductor pattern includes an interdigital transducer (IDT) with interleaved parallel fingers on the diaphragm. A ratio of a width of either of two adjacent parallel fingers and a center-to-center spacing between the two adjacent parallel fingers is greater than or equal to 0.2 and less than or equal to 0.3.

Abstract: There are disclosed acoustic resonators and method of fabricating acoustic resonators. An acoustic resonator includes a single-crystal piezoelectric plate having front and back surfaces, the back surface attached to a surface of a substrate except for portions of the piezoelectric plate forming a diaphragm spanning a cavity in the substrate. A conductor pattern on the front surface includes an interdigital transducer (IDT) with interleaved fingers of the IDT disposed on the diaphragm. A periodic array of holes is provided in the diaphragm.

Abstract: A high frequency amplifier includes an asymmetrical Doherty amplifier having a carrier amplifier, a peak amplifier, a branch circuit, and a phase adjusting circuit, a driver amplifier, and a base member mounting a first circuit board mounting the driver amplifier, the carrier amplifier, and the peak amplifier and a second circuit board mounting the circuits. The branch circuit divides a path of a RF signal into input paths of the peak and carrier amplifiers. The driver amplifier, the carrier amplifier, and the peak amplifier have rear surfaces in contact with the base member. The electrical length from the output terminal of the driver amplifier to the input terminal of the peak amplifier, when converted based on a phase of the signal, is from (2n+1)×???/4 to (2n+1)×?+?/4, where n is an integer greater than or equal to zero.

Abstract: An acoustic resonator device, filter devices, and methods of making the same. An acoustic resonator device includes a substrate having a surface and a single-crystal piezoelectric plate having front and back surfaces, where the back surface is attached to the surface of the substrate except for a portion of the piezoelectric plate forming a diaphragm that spans a cavity in the substrate. The device further includes an interdigital transducer formed on the front surface of the piezoelectric plate, where interleaved fingers of the IDT disposed on the diaphragm are configured such that a radio frequency signal applied to the IDT excites a primary shear acoustic mode in the diaphragm. The interleaved fingers include a first layer adjacent the diaphragm and a second layer over the first layer, the second layer having a narrower width than the first layer.

Abstract: Described is a system for modulating power to one or more radio frequency (RF) amplifiers to suppress undesired output signal components, improve linearity and reduce noise. The described systems and techniques enable shaping of spectral components introduced via an amplifier bias voltage owing to transitions among bias discrete states. The systems and techniques facilitate operation of multilevel, RF amplifiers under a wider range of operating conditions. In embodiments, the system includes modulators coupled to a supply terminal port of each of the one or more amplifiers to modulate the voltage levels supplied to the one or more amplifiers. The outputs of the modulators may be combined to provide a combined signal coupled to the amplifiers. A delay circuit delays switching of at least one of the power modulators relative to other modulator, by a variable time delay. This results in suppression of undesired output signal components of the amplifier output.

Abstract: There is disclosed acoustic resonators and filter devices. An acoustic resonator includes a substrate having a surface and a single-crystal piezoelectric plate having front and back surfaces, the back surface attached to the surface of the substrate except for a portion of the piezoelectric plate forming a diaphragm that spans a cavity in the substrate. An interdigital transducer (IDT) is formed on the front surface of the single-crystal piezoelectric plate such that interleaved fingers of the IDT are disposed on the diaphragm. The piezoelectric plate and the IDT are configured such that a radio frequency signal applied to the IDT excites a primary shear acoustic mode in the diaphragm. The interleaved fingers comprise a first layer adjacent the diaphragm and a second layer over the first layer opposite the diaphragm, the second layer having a greater width than the first layer.

Abstract: Low-load-modulation, broadband power amplifiers and method of use are described. The amplifiers can include multiple amplifiers connected in parallel to amplify a signal that has been divided into parallel circuit branches. One of the amplifiers can operate as a main amplifier in a first amplification class and the remaining amplifiers can operate as peaking amplifiers in a second amplification class. The main amplifier can see low modulation of its load between the fully-on and fully backed-off states of the amplifier. With lower load modulation, the power amplifiers described herein exhibit better power-handling capability and RF fractional bandwidth as compared to conventional amplifiers.

Abstract: Filter devices and methods are disclosed. A single-crystal piezoelectric plate is attached to substrate, portions of the piezoelectric plate forming a plurality of diaphragms spanning respective cavities in the substrate. A conductor pattern formed on the piezoelectric plate defines a low band filter including low band shunt resonators and low band series resonators and a high band filter including high band shunt resonators and high band series resonators. Interleaved fingers of interdigital transducers (IDTs) of the low band shunt resonators are disposed on respective diaphragms having a first thickness, interleaved fingers of IDTs of the high band series resonators are disposed on respective diaphragms having a second thickness less than the first thickness, and interleaved fingers of IDTs of the low band series resonators and the high band shunt resonators are disposed on respective diaphragms having thicknesses intermediate the first thickness and the second thickness.