The use of any micro-mechanical component in an ultrasound system is disclosed. In particular, the use of micro-relays, micro-switches and inductors in the transducer probe head, in the transducer connector, coupled with the system transducer connector(s) or anywhere else in the system. In an ultrasound system, micro-mechanical components such as micro-fabricated switches, relays and inductors permit impressive size reduction, cost reduction, signal-integrity enhancement and improved operational flexibility.

Diagnostic medical ultrasound systems and transducers utilizing micro-mechanical components

A method of fabricating micro-electromechanical switches (MEMS) integrated with conventional semiconductor interconnect levels, using compatible processes and materials is described. The method is based upon fabricating a capacitive switch that is easily modified to produce various configurations for contact switching and any number of metal-dielectric-metal switches. The process starts with a copper damascene interconnect layer, made of metal conductors inlaid in a dielectric. All or portions of the copper interconnects are recessed to a degree sufficient to provide a capacitive air gap when the switch is in the closed state, as well as provide space for a protective layer of, e.g., Ta/TaN. The metal structures defined within the area specified for the switch act as actuator electrodes to pull down the movable beam and provide one or more paths for the switched signal to traverse. The advantage of an air gap is that air is not subject to charge storage or trapping that can cause reliability and voltage drift problems. Instead of recessing the electrodes to provide a gap, one may just add dielectric on or around the electrode. The next layer is another dielectric layer which is deposited to the desired thickness of the gap formed between the lower electrodes and the moveable beam that forms the switching device. Vias are fabricated through this dielectric to provide connections between the metal interconnect layer and the next metal layer which will also contain the switchable beam. The via layer is then patterned and etched to provide a cavity area which contains the lower activation electrodes as well as the signal paths. The cavity is then back-filled with a sacrificial release material. This release material is then planarized with the top of the dielectric, thereby providing a planar surface upon which the beam layer is constructed.

Method of fabricating micro-electromechanical switches on cmos compatible substrates

The present invention is directed to enable mode conversion between a TEM mode and another mode to be performed among a plurality of waveguides. An RF module comprises: a microstrip line as a first waveguide for propagating electromagnetic waves in a TEM mode; and a waveguide having a multilayer structure as a second waveguide connected to the first waveguide, for propagating electromagnetic waves in another mode different from the TEM mode. An end of the first waveguide is directly or indirectly connected so as to be conductive to one of ground electrodes of the second waveguide from the direction orthogonal to the stacking direction of the ground electrodes. Since magnetic fields are coupled so that the direction of the magnetic field of the first waveguide and that of the magnetic field of the second waveguide match with each other in the E plane, mode conversion between the TEM mode and another mode to be excellently performed between the waveguides.

RF module and mode converting structure and method

The tunable filters of the present invention incorporate tunable dielectric materials (e.g., bulk and thin film ferroelectric and paraelectric materials) in contact with segments of resonators that are at an RF voltage maximum to alter the pass band or stop band characteristic of an RF signal outputted by the filter. The biasing circuitry in contact with the tunable dielectric material can include components for inhibiting or retarding the coupling of RF energy to the biasing circuit.

Electrically tunable microwave filters

The present invention provides an electronically tunable resonating apparatus which uses a tunable dielectric material which is biased by an electric field to alter the resonant frequency in a resonating cavity. The electrodes which apply the electric field are connected to a variable voltage source. The electrodes can therefore apply a plurality of electric field strengths and provide a range of resonant frequencies in the resonating apparatus. The resonating apparatus is particularly useful for microwave and millimeterwave electromagnetic energy.

Method and apparatus for electrically tuning a resonating device

An RF switch formed as a micro electro-mechanical switch (MEMS) which can be configured in an array forming a micro electro-mechanical switch array (MEMSA). The MEMS is formed on a substrate. A pin, pivotally carried by the substrate defines a pivot point. A rigid beam or transmission line is generally centrally disposed on the pin forming a teeter-totter configuration. The use of a rigid beam and the configuration eliminates the torsional and bending forces of the beam which can reduce reliability. The switch is adapted to be monolithically integrated with other monolithic microwave integrated circuits (MMIC) for example from HBTs and HEMTs, by separating such MMICs from the switch by way of a suitable polymer layer, such as polyimide, enabling the switch to be monolithically integrated with other circuitry. In order to reduce insertion losses, the beam is formed from all metal, which improves the sensitivity of the switch and also allows the switch to be used in RF switching applications. By forming the beam from all metal, the switch will have lower insertion loss than other switches which use SiO2 or mix metal contacts.

Micro-electro system (MEMS) switch

Monolithic 3D radial power combiner and splitter

A high frequency coaxial interconnection solder ball grid array produces a low loss, reproducible electrical interconnection at the circuit board level for mounting one or more high frequency components, such as high frequency IMA modules. Since the coaxial interconnection ball grid array can be and is generally implemented as part of a larger ball grid array, high frequency signal generation, signal reception and digital processing can be combined in a single electronic component, such as a circuit board. A coaxial-like interconnection is formed from a plurality of solder balls configured in a three-by-three square array. The coaxial interconnection solder ball grid array includes a single centrally disposed solder ball for interconnecting with a centrally disposed conductor of a coaxial line and a plurality of solder balls surrounding the single centrally disposed solder ball, some balls of which interconnect with a coaxial ground shield of the coaxial line. When soldered together, the centrally disposed solder ball and the central conductor of the coaxial line have the appearance of a rod with a diameter having a standard 50 ohm impedance. The outer conductive shield or ground signal path of the coaxial line is connected with multiple solder balls, to achieve a lower inductance ground-to-ground connection.

Solder ball grid array for connecting multiple millimeter wave assemblies

A lanthanum aluminate (LaAlO₃) substrate on which thin films of layered perovskite copper oxide superconductors are formed Lanthanum aluminate, with a pseudo-cubic perovskite crystal structure, has a crys­tal structure and lattice constant that closely match the crystal structures and lattice constants of the layered perovskite superconductors Therefore, it pro­motes epitaxial film growth of the superconductors, with the crystals being oriented in the proper direc­tion for good superconductive electrical properties, such as a high critical current density In addition, LaAlO₃ has good high frequency properties, such as a low loss tangent and low dielectric constant at super­conductive temperatures Finally, lanthanum aluminate does not significantly interact with the superconduc­tors Lanthanum aluminate can also used to form thin insulating films between the superconductor layers, which allows for the fabrication of a wide variety of superconductor circuit elements

High-frequency substrate material for thin-film layered perovskite superconductors

A waveguide structure (10) that provides a transition from a polymeric waveguide (26) to a coaxial connection (48). The coaxial connection (48) includes an outer conductor (50) electrically connected to a top ground plate (36) of the waveguide (26) and an inner conductor (52) that extends into the polymeric material within the waveguide (26). The inner conductor (52) is electrically connected to a capacitive plate (56), and the capacitive plate (56) is electrically connected to an elongated conductive probe (58). The conductive probe (58) is electrically connected to a conductive post (60), which is electrically connected to a bottom ground plate (38) opposite to the top ground plate (36). The conductive probe (58) extends in a direction transverse to the propagation direction of electromagnetic waves, and acts to pick up the energy in the electromagnetic radiation. The capacitive plate (56) provides a shunt capacitance that resonates out the inductance caused by the conductive probe (58) and the inner conductor (52). The conductive probe (58) is positioned relative to a backshort surface (44) of the waveguide (26) a distance that is less than a quarter wavelength of the electromagnetic radiation of interest.

Alfred E. Lee

Papers

Micro-electro system (MEMS) switch

Monolithic 3D radial power combiner and splitter

Solder ball grid array for connecting multiple millimeter wave assemblies

High-frequency substrate material for thin-film layered perovskite superconductors

Millimeter wave polymeric waveguide-to-coax transition