Plessey Overseas Limited

Tdk Corporation

Gec-marconi Limited

Infrared Integrated Systems Limited

Roger William Whatmore

Eiju Komuro

Paul B Kirby

Qingxin Su

Masaaki Imura

Anil Patel

Iain M Young

Paul C Osbond

Katsuhiko Gunji

Taku Takeishi

Ian Bennion

David John Pedder

William John Stewart

Nicholas Martin Shorrocks

Robert C Twiney

Joseph Edward Albert Southin

David W Lane

Andrew G Munns

Catherine S Oswald

John P Auton

Martin T Goosey

Laurence Considine

A ladder-type film bulk acoustic resonator (FBAR) filter comprises two series FBARs and two parallel FBARs. Each FBAR has a top electrode, a bottom electrode, and a piezoelectric layer sandwiched between the top and bottom electrodes. The top electrodes of the two series FBARs form part of a signal line of a coplanar waveguide transmission line. The top electrodes of the two series FBARs are connected to associated circuitry. The two series FBARs have a common bottom electrode.

Film bulk acoustic resonator filter

Multiple thin film bulk acoustic resonators () configured in series () and parallel () within a coplanar waveguide line structure provides a compact ladder filter. The resonators () are formed over an opening () in a substrate () and connected to associated circuitry by one or more transmission lines formed on the substrate (). The arrangement of the resonators () between the ground and signal lines of a coplanar line structure provides a means of minimising the area of the filter. Embedding a ladder filter within the coplanar transmission line structure eliminates the need for wire bonds, thus simplifying fabrication. Embodiments for 2&#xd7;2, and hither order filters are described.

Film bulk acoustic resonator filters with a coplanar waveguide

An electric filter comprises a plurality of thin film bulk acoustic resonants () arranged in series and in parallel which have electrodes () of different working area (L) and optionally a piezoelectric layer () of different thickness (T).

Electric filter comprising a plurality of thin film bulk acoustic resonators

A thin-film piezoelectric resonator including a piezoelectric thin film having piezoelectric characteristic, and an upper electrode and a lower electrode arranged on opposite surfaces of the piezoelectric thin film for applying an excitation voltage to the piezoelectric thin film, wherein: each of the upper electrode and the lower electrode includes a resonant portion, and a lead-out portion; and the electrode thickness of at least one part of the lead-out portion in at least one of the upper electrode and the lower electrode is larger than the electrode thickness of the resonant portion formed to be continued from the lead-out portion.

Thin-film piezoelectric resonator and method for fabricating the same

An electric filter comprises a plurality of thin film bulk acoustic resonators arranged in series and in parallel which have different thicknesses of one or more non-piezoelectric layers, for example top electrode.

Thin film bulk acoustic resonator filters with a piezoelectric layer of lead scandium tantalum oxide

Ferroelectric ceramics

A method of manufacturing a free standing perovskite lead scandium tantalate film. A film of lead scandium tantalate is formed on a layer of MgO deposited on a sapphire substrate. The MgO layer is etched by phosphoric acid thereby releasing the lead scandium tantalate film from the substrate.

Method of manufacturing free standing perovskite lead scandium tantalate

A hybrid structure comprising a lens 10, an antenna array 8 and a semiconductor microcircuit 2. The antenna array 8 is formed on a surface of the lens 10 or on a surface of a substrate 14 having substantially the same refractive index as the material of the lens 10. Metal bump bonds 6, 12 provide connections between the antenna array 8 and the semiconductor microcircuit 2.

Hybrid structures

Thermal IR detector electrode configuration

Method of manufacturing perovskite lead scandium tantalate

A device for measuring the liquid content of a gas, as for example measuring the liquid water content in the atmosphere. The device employs a probe fabricated in part from a material which is thermally self-stabilizing and which preferably has a positive temperature coefficient. In use the probe is electrically heated and disposed in a flowing gas or is adapted for movement through a static gas so that droplets of liquid are deposited on the surface of the probe. Means is provided for detecting a change in the electrical resistance of the probe in response to a change in the heat loss rate due to the integrated evaporation of droplets of liquid from the surface of the probe. The temperature of the gas, the degree of relative movement between the probe and the gas, and the gas pressure are also sensed so that when their measurements are processed with a measurement dependent on the change in the electrical resistance of the probe a measurement is obtained of the liquid droplet content in the gas. A particular application for the device is that of measuring the liquid water contents in the air flowing around helicopters and other aircraft, so that the crew can be given warning when they are flying into icing conditions.

Atmospheric sensor

A method of fabricating a piezoelectric composite comprising an array of piezoelectric elements and a reinforcement structure embedded in a material. The method includes the step of forming the reinforcement structure prior to assembly with the piezoelectric elements, the reinforcement structure defining an array of holes for receiving the piezoelectric elements.

Method of making piezoelectric composites

A pyroelectric ceramic having the composition: ##EQU1## where .phi. is U (uranium) or Mn (manganese) and in which .alpha. is a number substantially within the range 0.01 to 0.10; x is a number substantially within the range 0.10 to 0.25; y is a number substantially within the range 0 to 0.4; z is a number substantially within the range 0 to 0.05 and .delta. is a number substantially within the range 0 to 0.06. Methods of fabricating the pyroelectric ceramic are also described.

Pyroelectric ceramics

Spatial light modulator

An electronic device, such as a Surface Wave, Bulk Wave or pyroelectric device, exploiting the polar nature of an active material in which the active material is lithium tetraborate or a closely related compound for example one which is slightly deficient in Lithium or Boron e.g. (Li.sub.2.-+..delta.1)B.sub.4 O.sub.7 or Li.sub.2 (B.sub.4.-+..delta.2)O.sub.7 where .delta..sub.1 and .delta..sub.2 are small numbers.

Growing community of inventors

Milton Keynes, United Kingdom

Roger William Whatmore