Abstract: A mass sensor has a common RF input, a set of mass sensor cells, and a common hold input. Each of the mass sensor cells has a local input node coupled to the common RF input, a local output node, a mass-dependent RF filter that includes an electroacoustic resonator having receptors immobilized on a surface thereof, an RF detector, and a hold circuit having a local hold input. The RF filter, the RF detector and the hold circuit are connected in series between the local input node and the local output node. The common hold input is coupled to the local hold inputs of the hold circuits of at least a subset of the mass sensor cells.

Abstract: An AC-DC converter, comprises: a first capacitor and a second capacitor; and a rectifier circuit connected to the first and second capacitor and operative to charge both the first and the second capacitor and to discharge the first capacitor independently of the second capacitor. The AC-DC converter circuit provides a rectified output voltage, and a duration of time that a current is drawn from the second capacitor is less than approximately 25% of a period of the rectified output voltage.

Abstract: A navigation device for navigating a user interface of a processor-controlled device includes an acoustic transmitter adapted to transmit an acoustic signal, an acoustic receiver adapted to receive the acoustic signal and located at a fixed position with respect to the acoustic transmitter, and a measurement circuit coupled to an output of the acoustic receiver and adapted to determine a distance traversed by the navigation device as a function of time.

Abstract: Systems and methods of detecting wireless channel status from acoustic discrimination of spectral content are described. In one aspect, a wireless system includes a spectrum analyzer, a detector, and a controller. The spectrum analyzer is operable to acoustically discriminate spectral content of an input electrical signal in multiple discrete frequency channels. The detector is operable to determine respective statuses of the frequency channels from the acoustically discriminated spectral content. The controller is operable to select one of the frequency channels based on the determined statuses of the frequency channels.

Abstract: A first and a second resonator are fabricated monolithically adjacent to one another. The first resonator is the reference resonator. The resonant frequency of the second resonator is offset by a difference frequency Fo from the first resonator. Each resonator is included within an oscillator. A mixer receives the output of both oscillators. A low pass filter receives the mixer output and generates a clock signal whose frequency is equal to the difference frequency Fo.

Abstract: A navigation device for navigating a user interface of a processor-controlled device includes an acoustic transmitter adapted to transmit an acoustic signal, an acoustic receiver adapted to receive the acoustic signal and located at a fixed position with respect to the acoustic transmitter, and a measurement circuit coupled to an output of the acoustic receiver and adapted to determine a distance traversed by the navigation device as a function of time.

Abstract: A navigation device for navigating a user interface of a processor-controlled device includes an acoustic transmitter adapted to transmit an acoustic signal, an acoustic receiver adapted to receive the acoustic signal and located at a fixed position with respect to the acoustic transmitter, and a measurement circuit coupled to an output of the acoustic receiver and adapted to determine a distance traversed by the navigation device as a function of time.

Abstract: A self-calibrating temperature compensated oscillator includes a monolithic structure having a first resonator, a second resonator, and a heating element to heat the first and second resonators. The temperature coefficient of the second resonator is substantially greater than the temperature coefficient of the first resonator. A first oscillator circuit operates with the first resonator and outputs a first oscillator output signal having a first oscillating frequency. A second oscillator circuit operates with the second resonator and outputs a second oscillator output signal having a second oscillating frequency. A temperature determining circuit determines the temperature of the first resonator using the second oscillating frequency. A temperature compensator provides a control signal to the first oscillator in response to the determined temperature to adjust the first oscillating frequency and maintain it at a desired operating frequency.

Abstract: An AC-DC converter and a power supply are described.

Abstract: A power supply comprises an AC-DC converter circuit, which comprises a first capacitor and a second capacitor. The converter also comprises a rectifier circuit connected to the first and second capacitor and operative to charge both the first and the second capacitor and to discharge the first capacitor independently of the second capacitor. The power supply also comprises an acoustic transformer.

Abstract: An acoustic power transformer includes: an input port adapted to receive an input signal; a transmitting acoustic transducer coupled to the input port and adapted to transmit an acoustic wave in response to the input signal received at the input port; a receiving acoustic transducer adapted to receive the acoustic wave and in response thereto to produce an output signal; an output port adapted to output the output signal; and an acoustic medium disposed in an acoustic wave propagation path between the transmitting acoustic transducer and the receiving acoustic transducer. In one case, at least one of the transmitting acoustic transducer and receiving acoustic transducer includes a Fresnel lens. In another case, the transformer includes an acoustic lens disposed in the acoustic wave propagation path between the transmitting acoustic transducer and the receiving acoustic transducer.

Abstract: A data coupler includes first and second acoustic isolation transformers that develop first and second isolated output signals in response to first and second modulated input signals. A first and a second transmitter is coupled to the first and second acoustic isolation transformers to receive a first and a second data input signal and generate the first and second modulated input signal in response to the first and second data input signals. A first and a second receiver is coupled to the first and second acoustic isolation transformers to receive the first and a second isolated output signals and generate first and second demodulated signals responsive to the first and second isolated output signals. An output decision circuit is coupled to the first and second receivers to receive the first and second data output signals and generates a data output signal responsive to the first and second demodulated signals.

Abstract: A self-calibrating temperature compensated oscillator includes a monolithic structure having a first resonator, a second resonator, and a heating element to heat the first and second resonators. The temperature coefficient of the second resonator is substantially greater than the temperature coefficient of the first resonator. A first oscillator circuit operates with the first resonator and outputs a first oscillator output signal having a first oscillating frequency. A second oscillator circuit operates with the second resonator and outputs a second oscillator output signal having a second oscillating frequency. A temperature determining circuit determines the temperature of the first resonator using the second oscillating frequency. A temperature compensator provides a control signal to the first oscillator in response to the determined temperature to adjust the first oscillating frequency and maintain it at a desired operating frequency.

Abstract: A data coupler includes an acoustic isolation transformer operable to develop an isolated output signal in response to an input signal. A transmitter is coupled to the acoustic isolation transformer and generates the input signal responsive to a data input signal. A receiver is coupled to the acoustic isolation transformer to receive the isolated output signal and generates a data output signal responsive to the isolated output signal.

Abstract: A navigation device for navigating a user interface of a processor-controlled device includes an acoustic transmitter adapted to transmit an acoustic signal, an acoustic receiver adapted to receive the acoustic signal and located at a fixed position with respect to the acoustic transmitter, and a measurement circuit coupled to an output of the acoustic receiver and adapted to determine a distance traversed by the navigation device as a function of time.

Abstract: An acoustic power transformer includes: an input port adapted to receive an input signal; a transmitting acoustic transducer coupled to the input port and adapted to transmit an acoustic wave in response to the input signal received at the input port; a receiving acoustic transducer adapted to receive the acoustic wave and in response thereto to produce an output signal; an output port adapted to output the output signal; and an acoustic medium disposed in an acoustic wave propagation path between the transmitting acoustic transducer and the receiving acoustic transducer. In one case, at least one of the transmitting acoustic transducer and receiving acoustic transducer includes a Fresnel lens. In another case, the transformer includes an acoustic lens disposed in the acoustic wave propagation path between the transmitting acoustic transducer and the receiving acoustic transducer.

Abstract: A spread-spectrum radio, such as a frequency-hopping spread-spectrum radio or a direct-sequence spread-spectrum radio, includes a transmitter that utilizes microelectromechanical systems (MEMS) based oscillation system to generate a spread-spectrum signal and/or a receiver that utilizes a MEMS-based frequency selection system to receive a spread-spectrum signal. In an embodiment, the MEMS-based oscillation system and the MEMS-based frequency selection system utilize MEMS resonators such as thin film bulk acoustic resonators (FBARs) that are fabricated in high density on a single substrate.

Abstract: An apparatus and method for measuring a target environmental variable (TEV) that employs a film-bulk acoustic resonator with motion plate. The film-bulk acoustic resonator (FBAR) includes an acoustic reflector formed in an FBAR wafer and a surface. A first electrode is formed on the surface of the acoustic reflector and has a surface. A piezoelectric layer is formed on the surface of the first electrode and has a surface. A second electrode is formed on the surface of the piezoelectric layer. A motion plate is suspended in space at a predetermined distance relative to the surface of the second electrode and is capacitively coupled to the FBAR.

Abstract: An apparatus and method for detecting a target environmental variable (TEV). A first film-bulk acoustic resonator (FBAR) oscillator that includes a first FBAR with a first response to the target environmental variable generates a first frequency. A second film-bulk acoustic resonator (FBAR) oscillator that includes a second FBAR with a second response to the target environmental variable generates a second frequency. A circuit that is coupled to the first FBAR oscillator and the second FBAR oscillator determines the target environmental variable (e.g., changes in the TEV) based on the first frequency and the second frequency.

Abstract: An AC-DC converter and a power supply are described.