Abstract: A system includes a tunable bulk acoustic wave (BAW) resonator device and a direct-current (DC) tuning controller coupled to the tunable BAW resonator device. The system also includes an oscillator circuit coupled to the tunable BAW resonator device. The DC tuning controller selectively adjusts a DC tuning signal applied to the tunable BAW resonator device to adjust a signal frequency generated by the oscillator circuit.

Abstract: A clock oscillator includes with a pullable BAW oscillator to generate an output signal with a target frequency. The BAW oscillator is based on a BAW resonator and voltage-controlled variable load capacitance, responsive to a capacitance control signal to provide a selectable load capacitance. An oscillator driver (such as a differential negative gm transconductance amplifier), is coupled to the BAW oscillator to provide an oscillation drive signal. The BAW oscillator is responsive to the oscillation drive signal to generate the output signal with a frequency based on the selectable load capacitance. The oscillator driver can include a bandpass filter network with a resonance frequency substantially at the target frequency.

Abstract: A high linearity phase interpolator (PI) is disclosed. A phase value parameter indicative of a desired phase difference between an output signal and an input clock signal edge may be provided by control logic. A first capacitor may be charged for a first period of time with a first current that is proportional to the phase value parameter to produce a first voltage on the capacitor that is proportional to the phase value parameter. The first capacitor may be further charged for a second period of time with a second current that has a constant value to form a voltage ramp offset by the first voltage. A reference voltage may be compared to the voltage ramp during the second period of time. The output signal may be asserted at a time when the voltage ramp equals the reference voltage.

Abstract: A sensor circuit includes a sensor array. The sensor array includes a sensor row that includes a first sensor cell, a second sensor cell, and an output stage of a distributed amplifier circuit. The first sensor cell includes a first photodetector, and a first preamplifier stage of the distributed amplifier circuit. The first preamplifier stage is coupled to the first photodetector, and is configured to amplify a signal received from the first photodetector. The second sensor cell includes a second photodetector, and a second preamplifier stage of the distributed amplifier circuit. The second preamplifier stage is coupled to the second photodetector, and is configured to amplify a signal received from the second photodetector. The output stage of the distributed amplifier circuit is coupled to the first and second sensor cells, and is configured to amplify a signal received from the first preamplifier stage and the second preamplifier stage.

Abstract: A high linearity phase interpolator (PI) is disclosed. A phase value parameter indicative of a desired phase difference between an output signal and an input clock signal edge may be provided by control logic. A first capacitor may be charged for a first period of time with a first current that is proportional to the phase value parameter to produce a first voltage on the capacitor that is proportional to the phase value parameter. The first capacitor may be further charged for a second period of time with a second current that has a constant value to form a voltage ramp offset by the first voltage. A reference voltage may be compared to the voltage ramp during the second period of time. The output signal may be asserted at a time when the voltage ramp equals the reference voltage.

Abstract: The present disclosure describes a low-power, low-phase-noise (LPLPN) oscillator. The LPLPN oscillator includes a resonator load, an amplifier stage, and a loop gain control circuit. The resonator load is structured to resonate at a primary resonant frequency. The amplifier stage is coupled with the resonator load to develop a loop gain that peaks at the primary resonant frequency. The loop gain control circuit is coupled with the amplifier stage, and it is structured to regulate the loop gain for facilitating the amplifier stage to generate an oscillation signal at the primary resonant frequency and suppress a noise signal at a parasitic parallel resonant frequency (PPRF).

Abstract: A clock oscillator includes with a pullable BAW oscillator to generate an output signal with a target frequency. The BAW oscillator is based on a BAW resonator and voltage-controlled variable load capacitance, responsive to a capacitance control signal to provide a selectable load capacitance. An oscillator driver (such as a differential negative gm transconductance amplifier), is coupled to the BAW oscillator to provide an oscillation drive signal. The BAW oscillator is responsive to the oscillation drive signal to generate the output signal with a frequency based on the selectable load capacitance. The oscillator driver can include a bandpass filter network with a resonance frequency substantially at the target frequency.

Abstract: A sensor circuit includes a sensor array. The sensor array includes a sensor row that includes a first sensor cell, a second sensor cell, and an output stage of a distributed amplifier circuit. The first sensor cell includes a first photodetector, and a first preamplifier stage of the distributed amplifier circuit. The first preamplifier stage is coupled to the first photodetector, and is configured to amplify a signal received from the first photodetector. The second sensor cell includes a second photodetector, and a second preamplifier stage of the distributed amplifier circuit. The second preamplifier stage is coupled to the second photodetector, and is configured to amplify a signal received from the second photodetector. The output stage of the distributed amplifier circuit is coupled to the first and second sensor cells, and is configured to amplify a signal received from the first preamplifier stage and the second preamplifier stage.

Abstract: A clock oscillator includes with a pullable BAW oscillator to generate an output signal with a target frequency. The BAW oscillator is based on a BAW resonator and voltage-controlled variable load capacitance, responsive to a capacitance control signal to provide a selectable load capacitance. An oscillator driver (such as a differential negative gm transconductance amplifier), is coupled to the BAW oscillator to provide an oscillation drive signal. The BAW oscillator is responsive to the oscillation drive signal to generate the output signal with a frequency based on the selectable load capacitance. The oscillator driver can include a bandpass filter network with a resonance frequency substantially at the target frequency.

Abstract: Broadband ultrasound transducers and related methods are disclosed herein. An example ultrasonic transducer disclosed herein includes a substrate and a first membrane supported by the substrate. The first membrane is to exhibit a first frequency response when oscillated. The example ultrasonic transducer includes a second membrane supported by the substrate. The second membrane is to exhibit a second frequency response different from the first frequency response when oscillated. The example ultrasonic transducer includes a third membrane supported by the substrate. The third membrane is to exhibit one of the second frequency response or a third frequency response different from the first frequency response and the second frequency response when oscillated. A shape of the first membrane is to differ from a shape of the second membrane and a shape of the third membrane.

Abstract: A system includes a tunable bulk acoustic wave (BAW) resonator device and a direct-current (DC) tuning controller coupled to the tunable BAW resonator device. The system also includes an oscillator circuit coupled to the tunable BAW resonator device. The DC tuning controller selectively adjusts a DC tuning signal applied to the tunable BAW resonator device to adjust a signal frequency generated by the oscillator circuit.

Abstract: For producing a low-power, low-phase noise oscillating signal using a self-injection locking oscillator, examples include: producing, using an oscillator, a signal having a base frequency component and an Nth harmonic component, in which N is a selected integer and N>1; filtering the signal through a bandpass filter with Q factor ?5, the filter configured to pass the Nth harmonic component as a filtered Nth harmonic component; and injecting the filtered Nth harmonic component into the oscillator to self-injection lock the base frequency of the signal.

Abstract: For producing a low-power, low-phase noise oscillating signal using a self-injection locking oscillator, examples include: producing, using an oscillator, a signal having a base frequency component, an Mth harmonic component and a Pth harmonic component, in which M and P are selected integers and M>P>1; filtering the signal through one or more bandpass filters including at least two resonators, the filters having Q factor ?5, the filters configured to pass the Mth and Pth harmonic components; multiplying the filtered Mth and Pth harmonic components together to produce a multiplied signal, and filtering the multiplied signal using a low pass filter to pass a difference between the filtered Mth and Pth harmonic components, the difference including a filtered beat frequency waveform; and injecting the filtered beat frequency waveform into the oscillator to injection lock the signal to the filtered beat frequency waveform.

Abstract: An oscillator is provided with an oscillator circuit having tank circuit terminals for coupling to a tank circuit. A microelectromechanical system (MEMS) resonator serves as a tank circuit. The MEMS resonator is coupled to the oscillator circuit using a transformer with a primary coil coupled to the oscillator tank circuit terminals and a secondary coil coupled to the MEMS resonator terminals, wherein the transformer has a turns ratio of N:1 and N is greater than 1.

Abstract: An integrated circuit package includes a first die that has a microelectromechanical system (MEMS) resonator coupled to a coil. A second die includes a coil fabricated on a top surface of the second die, and an electronic circuit with tank circuit terminals fabricated on the second die and coupled to the second coil. The second die is positioned adjacent the first die such that the first coil is operable to electromagnetically couple to the second coil.

Abstract: An integrated circuit package includes a first die that has a microelectromechanical system (MEMS) resonator coupled to a coil. A second die includes a coil fabricated on a top surface of the second die, and an electronic circuit with tank circuit terminals fabricated on the second die and coupled to the second coil. The second die is positioned adjacent the first die such that the first coil is operable to electromagnetically couple to the second coil.

Abstract: An oscillator is provided with an oscillator circuit having tank circuit terminals for coupling to a tank circuit. A microelectromechanical system (MEMS) resonator serves as a tank circuit. The MEMS resonator is coupled to the oscillator circuit using a transformer with a primary coil coupled to the oscillator tank circuit terminals and a secondary coil coupled to the MEMS resonator terminals, wherein the transformer has a turns ratio of N:1 and N is greater than 1.

Abstract: Methods and systems for producing a low-power, low-phase noise oscillating signal using a self-injection locking oscillator. Preferred embodiments include, for example, producing, using an oscillator, a signal having a base frequency component and an Nth harmonic component, wherein N is a selected integer and N>1; filtering said signal through a bandpass filter with Q factor ?5, said filter configured to pass said Nth harmonic component as a filtered Nth harmonic component; and injecting said filtered Nth harmonic component into said oscillator to thereby self-injection lock said base frequency of said signal.

Abstract: Methods and systems for producing a low-power, low-phase noise oscillating signal using a self-injection locking oscillator. Preferred embodiments include, for example, producing, using an oscillator, a signal having a base frequency component, an Mth harmonic component and a Pth harmonic component, wherein M and P are selected integers and M>P>1; filtering said signal through one or more bandpass filters comprising at least two resonators, said filters having Q factor ?5, said filters configured to pass said Mth and Pth harmonic components; multiplying said filtered Mth and Pth harmonic components together to produce a multiplied signal, and filtering said multiplied signal using a low pass filter to pass a difference between said filtered Mth and Pth harmonic components, said difference comprising a filtered beat frequency waveform; and injecting said filtered beat frequency waveform into said oscillator to thereby injection lock said signal to said filtered beat frequency waveform.

Abstract: Disclosed examples include fractional frequency divider circuits, including a counter to provide phase shifted pulse output signals in response to counting of an adjustable integer number NK cycles of an input clock signal, an output circuit to provide an output clock signal having a first edge between first edges of the pulse output signals, as well as a delta-sigma modulator (DSM), clocked by the second pulse output signal to receive a first predetermined value and to provide a DSM output value, and a phase accumulator to receive a step input value representing a sum of the DSM output value and a second predetermined value. The phase accumulator provides a divisor input signal to the counter, and provides a phase adjustment value to the output circuit to control the position of the first edge of the output clock signal between the first edges of the pulse output signals.