Siemens Aktiengesellschaft

Siemens Matsushita Comp. Gmbh & Co Kg

Peter Zibis

Wolf-Eckhart Bulst

Richard Veith

Wolfgang Pahl

Werner Ruile

Leonhard Michael Reindl

Jurgen Machui

Gerd Riha

Bernd Fleischmann

Hans P Grassl

Ekkeh Ehrmann-Falkenau

Karlheinz Rott

Wilfried Schott

Stefan Kurp

Christoph Hartel

Gertrud Lindemann

Mira Erthel

An interdigital converter of a surface acoustic wave filter is internally protected against electrostatic discharges. The protection is provided by a resistor which is connected in parallel to the interdigital converter.

Component working with surface acoustic waves

A surface-wave-type reflective delay line includes an input/output interdigital converter, and a plurality of surface wave reflectors. The surface wave reflectors are disposed at positions corresponding to an order of magnitude of half of a particular desired transit time of a surface wave between the input/output interdigital converter and an applicable surface wave reflector and back. At least some of the surface wave reflectors are each shifted by a mathematically random value out of the positions corresponding to half the particular desired transit time.

Surface-wave-type reflective delay line

A surface-wave filter that has a variable transmission band is formed of at least two parallel tracks having input and output transducers whereby the bus-bars of one transducer of one track lie at two different potentials and one bus-bar of one transducer of a further track lies at one of the two potentials. The other bus-bar is selectively connectable to the other of these potentials so that the transducer of the further track is selectively enabled or disabled. Since the tracks have different transmissions bands, the transmission band of the filter is thus, selectable by connecting and disconnecting the further track.

Surface-wave filter with selectively connectable tracks to provide a

A cantilever mount for a substrate lamina of a surface wave device wherein the substrate lamina 42 of the component is attached only at its one end 45 and is a wedge-shaped structure. The tapered end 46 of the substrate lamina 42 which is remote from the atachment location is mounted above the surface 41 of the base plate 41 which causes minimization of disturbing influences.

Cantilever mount of a substrate lamina of a surface wave device

A surface-wave resonator filter having at least two reflector structures and at least one interdigital transducer. At least a portion of one of the reflector structures has interruptions in the metallization strips thereof to define subsections of the metallization strip. Connecting metallizations are provided parallel to the wave propagation direction x between neighboring sub-sections of neighboring sub-divided metallization strips to electrically connect the neighboring sub-sections such that no two sub-sections of the same sub-divided metallization strip are electrically connected.

Surface-wave resonator structure having metallization strips interrupted

An acoustic wave filter comprising a piezoelectric substrate body upon which at least two digital structures are formed and which comprise input and output transducers and at least one further digital structure and wherein the filter digital structure has a center frequency of f.sub.2 and wherein the pass band of said two digital structures is at least twice as broad banded as said further digital structure and where the center frequencies f.sub.1 and f.sub.2 of the two digital structures are shifted relative to each other and relative to the center frequency f.sub.2 of the further digital structure.

Acoustic wave filter

A surface wave filter with an input transducer and an output transducer. The input and output transducers have finger weightings such that a finger-overlap profile of the input/output transducer repeats in multiple fashion in the output/input transducer.

Electrical filter with acoustic waves

Digital structures of a surface wave filter are manufactured in a photolithographic method with a lift-off or with an etching technique. The surface wave filter comprises at least one resonator structure, this resonator structure having auxiliary coatings of the substrate surface allocated to it. These auxiliary coatings are continuations of existing, neighboring pads which compensate during an exposure step associated with manufacture of the digital structures.

Filter functioning with acoustic waves

A surface wave filter is provided with digital structures formed of strip-shaped coatings which are photolithographically produced. The digital structures have groups allocated to them which are also formed of strip-shaped coatings and which follow a respective digital structure. By use of such groups, which do not produce interfering reflections, a level exposure during formation of the digital structures is achieved.

A surface wave filter (1, 11, 21, 31, 41) having a shielding structure (13, 23, 33, 43, 53) arranged between the inter-digital, asymmetrically operating structures (2, 3), which encompasses two such sub-structures (14, 24, 34, 44, 44a) and/or (15, 25, 35, 45, 35a), which are individually connected with the finger structures of the adjacent transducer structure (2 and/or 3) that are at reference ground potential.

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Munich, Germany

Peter Zibis