A wide band through-body communication system communicates data through the body ultrasonically. A MEMS device such as a CMUT transducer is configured to transmit and/or receive ultrasonic data signals within a broad band of operating frequencies. The transducer transmits the ultrasonic data signals through the body to a similarly configured ultrasonic receiver, and/or receives ultrasonic data signals which have been conveyed through the body from a similarly configured ultrasonic transmitter for decoding and processing. In a preferred implementation a CMUT transducer is operated in a collapsed mode.

RF filtering circuitry comprises a first node, a second node, and a series signal path between the first node and the second node. A number of acoustic resonators are coupled to one or more of the first node and the second node via the series signal path. A first one of the acoustic resonators is associated with a first quality factor and a first electromechanical coupling coefficient. A second one of the acoustic resonators is associated with a second quality factor and a second electromechanical coupling coefficient. The first quality factor is different from the second quality factor and the first electromechanical coupling coefficient is different from the second electromechanical coupling coefficient.

An RF diplexer circuit device using modified lattice, lattice, and ladder circuit topologies. The diplexer can include a pair of filter circuits, each with a plurality of series resonator devices and shunt resonator devices. In the ladder topology, the series resonator devices are connected in series while shunt resonator devices are coupled in parallel to the nodes between the resonator devices. In the lattice topology, a top and a bottom serial configurations each includes a plurality of series resonator devices, and a pair of shunt resonators is cross-coupled between each pair of a top serial configuration resonator and a bottom serial configuration resonator. The modified lattice topology adds baluns or inductor devices between top and bottom nodes of the top and bottom serial configurations of the lattice configuration. A multiplexing device or inductor device can be configured to select between the signals coming through the first and second filter circuits.

A RF transmitting device and method for transmitting digital information wherein the device is connected to or connectable with an antenna, the RF transmitting device having an RF source or transmitter, an electronic switch, a plurality electromechanical resonators each connected to the electronic switch. The electronic switch connects a selected one or selected ones of the electromechanical resonators between the RF source or transmitter and the antenna. Alternatively, the electronic switch connects a selected one or selected ones of the electromechanical resonators between different portions of the antenna. The electronic switch is controlled by a digital control unit for causing the electronic switch to couple RF energy produced by the RF source or transmitter to the antenna via the selected one or selected ones of the plurality of electromechanical resonators.

A high-frequency module includes an antenna terminal, a transmission signal terminal, a reception signal terminal, a plurality of earth terminals, a switch, a transmission filter, a reception filter, and a multilayer board. The multilayer board includes a ground electrode arranged between the transmission filter and the reception filter. The plurality of earth terminals include a first earth terminal and a second earth terminal. When the high-frequency module is viewed in a direction perpendicular to a principal surface of the multilayer board, the reception signal terminal is provided between the antenna terminal and the transmission signal terminal, the first earth terminal is provided between the antenna terminal and the reception signal terminal, and the second earth terminal is provided between the reception signal terminal and the transmission signal terminal.

A switch module includes a first terminal, first and second filters, and first and second switches. Impedance of the first filter for a signal in a stop band is capacitive. When the first switch is turned OFF, impedance of the first switch is capacitive, and impedance of the first filter seen from an end portion of the first switch connected to the first filter is not in a short state and impedance of the first filter seen from the first terminal is in an open state.

An ultrasonic device may include an electromechanical ultrasonic system defined by a predetermined resonant frequency, the electromechanical ultrasonic system including an ultrasonic transducer coupled to an ultrasonic blade. A method of controlling energy delivered to the ultrasonic device may include determining an impedance of the ultrasonic transducer during a transection process, analyzing the impedance of the ultrasonic transducer, profiling the ultrasonic blade based on the impedance, and adjusting a power delivered to the transducer during the transection process based on the profile of the blade. The method may further include pulsing, the power delivered to the ultrasonic transducer, determining changes in tissue characteristics of tissue located in an end effector, wherein the changes in tissue characteristics is determined between pulses, and adjusting power delivered to the ultrasonic transducer based on the tissue changes throughout the transection. An ultrasonic instrument may include components configured to effect the method.

A multiplexer (1) includes a plurality of filters connected to a common terminal (110). The multiplexer (1) includes: a low-frequency filter (11L) that is formed of at least one surface acoustic wave resonator arranged between the common terminal (110) and the input/output terminal (120) and has a first pass band; a high-frequency filter (12H) that is connected between the common terminal (110) and the input/output terminal (130) and has a second pass band located at a higher frequency than the first pass band; and a capacitor (C.sub.B1) that is serially arranged in a connection path between the common terminal (110) and the low-frequency filter (11L). The Q value of the capacitor (C.sub.B1) in the second pass band is higher than the Q value in the second pass band of a capacitance obtained by treating the at least one surface acoustic wave resonator of the low-frequency filter (11L) as a capacitance.

A radio frequency circuit includes a first acoustic wave filter that is connected to a common terminal and includes a first acoustic wave resonator, a first LC filter that is connected to the common terminal via the first acoustic wave filter and includes at least one of an inductor or a capacitor, a second acoustic wave filter that is connected to the common terminal and includes a second acoustic wave resonator, and a second LC filter that is connected to the common terminal via the second acoustic wave filter and includes at least one of an inductor or a capacitor.

A method of forming a film bulk acoustic wave resonator comprises depositing a bottom electrode on an upper surface of a layer of dielectric material disposed over a cavity defined between the layer of dielectric material and a substrate, depositing a seed layer of piezoelectric material on an upper surface of the bottom electrode, etching one or more openings through the seed layer of piezoelectric material, etching of the one or more openings including over-etching of the seed layer in an amount sufficient to damage portions of the upper surface of the bottom electrode exposed by etching of the one or more openings, and depositing a bulk film of the piezoelectric material on an upper surface of the seed layer, on a portion of the upper surface of bottom electrode including the damaged portions, and on a portion of the upper surface of the dielectric layer.