Differential input/output surface acoustic wave device with proximity coupling
AssigneeThomson-CSF
InventorsMarc Solal, Pierre Dufilie
Life of this patent
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Abstract
The disclosure relates to differential input/output surface acoustic wave devices with proximity coupling. The disclosed device comprises a whole number N of acoustic channels, where N is at least equal to two. The acoustic channels are coupled together by proximity. A first acoustic channel comprises at least one transducer separated into several parts electrically connected in parallel with one another to form a first differential port (E+) and a second differential port (E-). The polarities of the different parts of the transducer are chosen so that the first differential port (E+) and the second differential port (E-) are electrically symmetrical. Application in particular to surface acoustic wave filters for portable telephones.
Claims13
A surface acoustic wave device using a proximity coupling of a whole number N of acoustic channels, where N is at least equal to two, with a given transduction length, these acoustic channels being positioned in parallel on a substrate and numbered successively 1 to N, wherein said device comprises a first particular acoustic channel comprising at least one transducer, comprising two connection buses extended by electrodes, separated into several parts electrically connected in parallel with one another to form a first differential port (E+) and a second differential port (E-), the polarities of the different parts of the transducer being chosen so that the first differential port (E+) and the second differential port (E-) are electrically symmetrical.
Dependencies are inferred from the claim text.