Abstract: A frequency multiplier includes an input section having inputs to receive an input signal having an input frequency, a mixer section, and an output section magnetically coupled to the input section and generating an output signal in response to the input signal. The mixer section may be coupled to the input section by a common mode node forming a path for a common mode current to flow to the mixer section and be magnetically coupled to the common mode node. The input section may generate a signal current, and the mixer section may be magnetically coupled to the input section and be directly capacitively coupled to the input section through a capacitor in a signal current path. The mixer section may have differential inputs capacitively coupled to the input section and also be coupled to the input section through a current path. A current helper section may be coupled to the current path.

Abstract: A circuit includes a main amplifier having a first input and a first output. A main bias circuit is coupled to the main amplifier, and the main bias circuit configured to operate the main amplifier in a first frequency band. A feedforward cancellation amplifier has a second input and a second output, in which the second input is coupled to the first input, and the second output is coupled to the first output. A filter is coupled between the first input and the second input. A feedforward bias circuit is coupled to the feedforward cancellation amplifier. The feedforward bias circuit is configured to operate the feedforward cancellation amplifier in a second frequency band within and narrower than the first frequency band.

Abstract: An ultrasonic fluid flow measurement system includes an ultrasonic transducer having a semiconductor substrate and an interconnect region over the semiconductor substrate. The ultrasonic transducer has two arrays of ferroelectric resonators in the interconnect region. The arrays of ferroelectric resonators are parallel to a fluid boundary surface of a fluid flow channel attached to the ultrasonic transducer. The ultrasonic transducer includes a transmitter circuit and a detector circuit coupled to the arrays of ferroelectric resonators. The transmitter circuit and the detector circuit include active components in the semiconductor substrate. The ultrasonic fluid flow measurement system may be configured to measure speeds of particles in fluids in the fluid flow channel. The ultrasonic fluid flow measurement system may also be used to measure flow speeds of a fluid in the fluid flow channel.

Abstract: In one example, an apparatus comprises an integrated circuit, a first metal layer, and a second metal layer. The first metal layer includes a first antenna connected to the integrated circuit, the first antenna being in a first region, the first region being external to the integrated circuit. The second metal layer includes a second antenna in a second region external to the integrated circuit. The apparatus further comprises a substrate between the first and second metal layers, in which the substrate and the first and second metal layers form a laminate. The apparatus further comprises a through-via in the substrate that couples between the first and second antennas.

Abstract: In one example, an apparatus comprises: a first metal layer including a first segment and a second segment, in which the first segment is electrically coupled to a single-ended signal terminal, the second segment has a disconnected end; a second metal layer including a third segment and a fourth segment, in which the third segment is magnetically coupled to the first segment, the fourth segment is magnetically coupled to the second segment, a first end of the third segment and a first end of the fourth segment are electrically coupled at a center tap, and a second end of the third segment and a second end of the fourth segment are electrically coupled to respective first and second signal terminals of a pair of differential signal terminals; and a phase adjustment device proximate the center tap and electrically coupled to a second voltage reference terminal.

Abstract: In an example, a system includes a BAW resonator. The system also includes a first heater configured to heat the BAW resonator, where the first heater is controlled by a first control loop. The system includes a circuit coupled to the BAW resonator. The system also includes a second heater configured to heat the circuit, where the second heater is controlled by a second control loop.

Abstract: An example apparatus includes: a compensation circuit including: a current compensation output, a first transistor with a first current terminal and a first control terminal, the first current terminal coupled to the current compensation output, and a resistor ladder with a tap terminal coupled to the first control terminal, a current mirror circuit having a mirror input and a mirror output, the mirror input coupled to the current compensation output, and a rectification circuit having an input coupled to the mirror output.

Abstract: An oscillator circuit includes a first BAW oscillator, a first coupling stage, a second BAW oscillator, and a second coupling stage. The first BAW oscillator is configured to generate a first output signal at a frequency. The first coupling stage is coupled to the first BAW oscillator, and is configured to amplify the first output signal. The second BAW oscillator is coupled to the first coupling stage, and is configured to generate a second output signal at the frequency. The second output signal differs in phase from the first output signal. The second coupling stage is coupled to the first BAW oscillator and the second BAW oscillator, and is configured to amplify the second output signal and drive the first BAW oscillator.

Abstract: An electronic device has a substrate and first and second metallization levels with a resonant circuit. The first metallization level has a first dielectric layer on a side of the substrate, and a first metal layer on the first dielectric layer. The second metallization level has a second dielectric layer on the first dielectric layer and the first metal layer, and a second metal layer on the second dielectric layer. The electronic device includes a first plate in the first metal layer, and a second plate spaced apart from the first plate in the second metal layer to form a capacitor. The electronic device includes a winding in one of the first or second metal layers and coupled to one of the first or second plates in a resonant circuit.

Abstract: In described examples, an integrated circuit includes an on-off keying (OOK) digital isolator, which includes a first circuitry, a multiplexer, an OOK modulator, an isolation barrier, an OOK envelope detector, and a second circuitry. The first circuitry generates and outputs a calibration signal. The multiplexer has a data signal input, and an input coupled to a first circuitry output. An OOK modulator input is coupled to a multiplexer output. An isolation barrier input is coupled to an OOK modulator output. An OOK envelope detector input is coupled to an isolation barrier output. The second circuitry includes an input coupled to an OOK envelope detector output, and an output coupled to an OOK envelope detector control input. The second circuitry detects a duty cycle distortion (DCD) of the OOK envelope detector output, and outputs a control signal to change the OOK envelope detector output's duty cycle based on the detected DCD.

Abstract: An integrated circuit (IC) includes a semiconductor substrate having a first surface and a second surface opposite the first surface. A through wafer trench (TWT) extends from the first surface of the semiconductor substrate to the second surface of the semiconductor substrate. Dielectric material is in the TWT. An interconnect region has layers of dielectric on the first surface of the substrate. The interconnect region has a conductive transmit patch. An antenna is formed, at least in part, by the dielectric material in the TWT and the transmit patch in the interconnect region. The antenna is configured to transmit or receive electromagnetic radiation between the transmit patch and the second surface of the semiconductor substrate through the dielectric material within the trench.

Abstract: An integrated circuit (IC) includes a substrate having a first surface and a second surface opposite the first surface. The substrate has a first region containing a first circuit and a second region containing a second circuit. The first circuit operates at a first supply voltage. The second circuit operates at a second supply voltage. The second supply voltage is higher than the first supply voltage. The IC includes a through wafer trench (TWT) extending from the first surface of the substrate to the second surface of the semiconductor substrate. The TWT separates the first region from the second region. A dielectric material is in the TWT. An interconnect region has layers of dielectric on the first surface of the substrate. The interconnect region is continuous over the first region, the second region, and the TWT. A non-galvanic communication channel is between the first and second circuits.

Abstract: An on-chip directional coupler includes a first linear conductive trace, a second linear conductive trace, and a conductive loop. The first linear conductive trace including an end and a coupled port. The second linear conductive trace is spaced apart from and parallel to the first linear conductive trace. The second linear conductive trace includes an end and an isolated port. The conductive loop includes a first end conductively coupled to the end of the first linear conductive trace, and a second end conductively coupled to the end of the second linear conductive trace.

Abstract: A circuit includes a main amplifier having a first input and a first output. A main bias circuit is coupled to the main amplifier, and the main bias circuit configured to operate the main amplifier in a first frequency band. A feedforward cancellation amplifier has a second input and a second output, in which the second input is coupled to the first input, and the second output is coupled to the first output. A filter is coupled between the first input and the second input. A feedforward bias circuit is coupled to the feedforward cancellation amplifier. The feedforward bias circuit is configured to operate the feedforward cancellation amplifier in a second frequency band within and narrower than the first frequency band.

Abstract: An integrated circuit (IC) includes a semiconductor substrate and an interconnect region. The semiconductor substrate has a first surface and a second surface opposite the first surface. The semiconductor substrate has a first region with a passive component. The semiconductor substrate has a second region outside the first region. The resistance of the second region is smaller than the resistance of the first region. The interconnection region is on the second surface of the semiconductor substrate.

Abstract: A frequency multiplier includes an input section having inputs to receive an input signal having an input frequency, a mixer section, and an output section magnetically coupled to the input section and generating an output signal in response to the input signal. The mixer section may be coupled to the input section by a common mode node forming a path for a common mode current to flow to the mixer section and be magnetically coupled to the common mode node. The input section may generate a signal current, and the mixer section may be magnetically coupled to the input section and be directly capacitively coupled to the input section through a capacitor in a signal current path. The mixer section may have differential inputs capacitively coupled to the input section and also be coupled to the input section through a current path. A current helper section may be coupled to the current path.

Abstract: An electronic device has a substrate and first and second metallization levels with a resonant circuit. The first metallization level has a first dielectric layer on a side of the substrate, and a first metal layer on the first dielectric layer. The second metallization level has a second dielectric layer on the first dielectric layer and the first metal layer, and a second metal layer on the second dielectric layer. The electronic device includes a first plate in the first metal layer, and a second plate spaced apart from the first plate in the second metal layer to form a capacitor. The electronic device includes a winding in one of the first and second metal layers and coupled to one of the first and second plates in a resonant circuit.

Abstract: A reference frequency signal generator comprises a plurality of ovenized reference crystal oscillators (OCXOs) having different turn-over-temperatures, a selector logic circuit coupled to outputs of the OCXOs, a temperature sensor, and a controller coupled to an output of the temperature sensor. The selector logic circuit outputs one of the outputs of the OCXOs based on a control signal from the controller. The controller also generates control signals for the OCXOs. In some implementations, the reference frequency signal generator includes a phase-locked loop or a fractional output divider coupled to the output of the selector logic circuit and configured to receive a calibration signal from the controller.

Abstract: In described examples of a signal equalizer, a complex signal having a first signal component and a second signal component is received from a communication channel. Adaptive equalization of crosstalk between the first signal component and the second signal component is performed using a single complex tap of a feedforward equalizer. A feedforward filter with real only taps converts the channel into a minimum phase channel that has postcursor interference only so that a low complexity decision feedback filter with all complex taps can easily eliminate the postcursor interreference.

Abstract: In described examples, a method of operating a charge pump includes a first control signal deactivating a first transistor, and the first control signal's logical complement activating a second transistor to reset the first transistor's DC bias voltage. The first control signal's logical complement deactivates the second transistor, and the first control signal provides a bias voltage to the first transistor to activate it, causing current to be transmitted from an input voltage to an output terminal. A second control signal deactivates a third transistor, and the second control signal's logical complement activates a fourth transistor to reset the second transistor's DC bias voltage. The second control signal's logical complement deactivates the fourth transistor, and the second control signal provides a bias voltage to the third transistor to activate it, causing current to be transmitted from the output terminal to a ground.