Vectron International Gmbh

Vectron International Gmbh & Co. Kg

Tele Filter Zweigniederlassung Der Dover Germany, Gmbh

Leibniz-institut Fuer Festkoerper-und Werkstoffforschung Dresden E.v.

Ctr Carinthian Tech Research Ag

Bert Wall

Guenter Martin

Sergey Biryukov

Manfred Weihnacht

Richard Gruenwald

G&uuml;nter Martin

Gudrun Bruckner

Bernd Steiner

Jochen Bardong

Alexander Darinski

Rene Fachberger

Richard Grünwald

Electrically conductive thin film metallizations having continuous operating temperatures of 300&#xb0; C. and more are of considerable practical interest for a number of technical applications, such as surface wave elements. Technical reasons and high production costs are a bar to the use of standard films. In order to remedy this, films including a mixture of a high-melting conductive metal and aluminum oxides, wherein in particular aluminum-rich non-stoichiometric aluminum oxides are used. The aluminum oxides act as components thermally stabilizing the conductive metal film; an optional proportion of chemically available aluminum can additionally alloy with the conductive metal and thereby enables essential film properties, such as the electrical conductivity to be specifically influenced. It is thus possible, using standard materials and methods of thin film deposition, in a cost-effective manner to produce highly electrically conductive, thermally resistant films having good structurability and comparatively low density for a wide range of different applications.

High temperature-resistant, electrically conductive thin films

The invention relates to a measurement system for the wireless and position-independent measurement of the temperature of the load of an oven with high accuracy using passive temperature probes. The measurement system for the wireless measurement of the temperature of food or workpieces in ovens has an interrogation unit located outside the oven chamber, one or more interrogation antennas located in the oven chamber and at least one passively operated temperature probe with a probe antenna and at least one temperature sensor designed as a resonator, said temperature probe being freely movable within the oven, characterized in that the temperature sensor has at least two resonances with different temperature coefficients of frequency, wherein the electrical equivalent circuit diagrams of the resonance elements differ only slightly from each other.

Measurement system for the wireless position-independent measurement of the temperature

A surface wave component contains at least two interdigital transducers having natural unidirectionality, disposed on a piezoelectric crystal substrate, which form a transducer pair consisting of transmission transducer and reception transducer. The transducers consist of an interdigital electrode structure having prongs and bus bars, and have opposite forward directions. At least two of the prongs form a transducer cell that has at least one excitation center for exciting an electrical potential wave and at least one reflection center for reflection of electrical potential waves, The transducer cells consist of two prongs having the same width, having a distance between the prong centers equal to half the length of a transducer period, whereby the electrode structures of the two transducers consist of the same material, but have different layer thicknesses.

Surface acoustic wave component

A transducer has natural unidirectionality for surface acoustic waves. An interdigital electrode structure is arranged on a piezoelectric crystal substrate and is constructed with interdigital transducers including collecting electrodes and fingers. At least two of the fingers form a transducer cell, which includes at least one excitation center for exciting an electrical potential wave and at least one reflection center for reflecting electrical potential waves. The fingers are oriented perpendicularly to a direction R parallel to a 1- or 3-fold rotational axis of the substrate crystal and the derivative dv/d&#x3b8;=0 applies to R, wherein v is the phase velocity of the surface wave and &#x3b8; is an angular deviation of the perpendicular to the finger direction from the direction R.

Transducer having natural unidirectionality for surface acoustic waves

A transducer for surface acoustic waves, and a resonator and a filter for surface acoustic waves having the transducer are provided. The transducer for surface acoustic waves has cells containing two electrode fingers per cell, wherein the transducer exhibits unidirectional behavior for propagation directions of the surface acoustic waves parallel to highly symmetrical directions of the crystal substrate. Each of two electrodes have a plurality of electrode fingers, the electrode fingers having center axes extending parallel to their longitudinal axes and being spaced apart from center axes of adjacent electrode fingers of the same electrode by a distance which equals the ratio of the velocity of the surface acoustic wave and the cut-off frequency of the transducer. The electrode fingers of both electrodes define a plurality of cells each consisting of two fingers.

Transducer for surface acoustic waves and a resonator and a filter having said transducer

An oscillator circuit includes a combination of two frequency-determining elements, designed as single-port surface wave resonators with interdigital converters, and one active electronic circuit. The two single-port surface wave resonators are connected to each other, avoiding inductive components. In the case of a combination in a parallel circuit, the connection is designed as a combination oscillating at high-frequency anti-resonance, and in the case of a combination in a series circuit, the combination is designed as a combination oscillating at high-frequency resonance. A ratio of apertures of the interdigital converters to one another, a ratio of their number of prongs to one another, and the thickness of the electrode layer of the single-port surface wave resonators as well as the propagation direction for acoustic surface waves of the single-port surface wave resonators are selected so that the temperature-dependent change of the phase of the combination and the temperature-dependent change of the total phase of the rest of the elements of the oscillator circuit have signs opposite to one another and that the sum of these phase changes in a thermal operating range of the oscillator circuit is smaller than a value of the phase change of the combination and smaller than a value of the phase change of the rest of the elements of the oscillator circuit.

Oscillator circuit with acoustic single-port surface wave resonators

A resonator filter cascade has resonator structures disposed adjacent to one another and form a waveguide for acoustic surface waves, and coupling transducers. The present invention changes resonator filter cascades so that the insertion attenuation is reduced by decreasing the attenuation of cascading, without using a coupling coil. A resonator filter cascade has resonator structures having coupling transducers which transversely couple resonator filters and the coupling transducers, belonging the same transversely coupled resonator filter, are not connected with one another. Coupling transducers of different transversely coupled resonator filters are each connected with one another over a pair of electrically conducting connections.

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Potsdam, Germany

Bert Wall