Epcos Ag

Infineon Technologies Ag

Ralph Stömmer

Pasi Tikka

Edgar Schmidhammer

Habbo Heinze

Matthias Goldbach

Thomas Metzger

Andreas Bergmann

Markus Mayer

Günter Kovacs

Michael Unterberger

The invention relates to a resonator operating with bulk acoustic waves (BAW resonator, BAW=Bulk Acoustic Wave) and band-pass filters constructed of such resonators. To increase the edge steepness of the transmission band of a BAW band-pass filter, the invention proposes reducing the effective coupling of a BAW resonator by using the connection in parallel of a BAW resonator and a capacitor instead of only one resonator. In addition, to increase the edge steepness of the transmission band, the use of a connection of coupled BAW resonators in the serial branch of a filter circuit with another resonator or resonator stack in the parallel branch of the filter circuit is proposed, the additional resonator or resonator stack being connected to the center electrode of the resonator stack specified initially.

Bulk acoustic wave resonator and circuit comprising same

An acoustic wave transducer includes an acoustic track having electrode fingers for different electrodes. The electrode fingers engage to form exciting finger pairs. The acoustic track also includes marginal areas and an excitation area. The electrode fingers engage in the excitation area. The marginal areas and the excitation area are located along a transverse direction of the acoustic wave transducer. A longitudinal phase speed of an acoustic wave in the acoustic track is less in a marginal area than in the excitation area, and the acoustic wave is excitable and has a transversal basic mode. The following applies in the transversal basic mode for a wave number ky: (ky)2&#x3e;0 in a marginal area, and (ky)2&#x3c;0 in an exterior area outside the acoustic track. ky is smaller in the excitation area than in the marginal areas and in the exterior area.

Acoustic wave transducer with transverse mode suppression

Spacer structures of field effect transistor structures are enhanced at least in sections with immobile charge carriers. The charge accumulated in the spacer structures induces an enhancement zone of mobile charge carriers in the underlying semiconductor substrate. The enhancement zone reduces the resistance of a channel coupling between the respective source/drain region and a channel region of the respective field effect transistor structure, wherein the channel region being controlled by a potential of a gate electrode. Source/drain regions drawn back from the gate electrode of the field effect transistor structure reduce an overlap capacitance between the gate electrode and the respective source/drain regions. A method for fabricating transistor arrangements having n-FETs and p-FETs with enhanced spacer structures.

Field effect transistor with gate spacer structure and low-resistance channel coupling

Overlapped electrodes of an electrical component are dimensioned in such a way that when there is translational displacement of one electrode in relation to the electrode situated opposite, their area of overlap remains within a manufacturing tolerance &#x3b2;/2, and also remains constant within the tolerance limits when there is a simultaneous rotation of the electrodes with respect to one another. This is achieved in that the intersecting edge pairs of the overlapping electrodes are designed parallel to one another, whereby the length, measured in the direction parallel to the respective edge pair, of the corresponding electrode everywhere exceeds by &#x3b2; the corresponding length of the area of overlap.

Electrical component having overlapping electrodes, and method for the manufacture of same

A frequency-tunable resonator comprises a basic element having at least one piezoelectric layer and at least one semiconducting layer. The electrodes, formed on main surface situated opposite one another of the basic element, are loaded with an external voltage, whereby the resonant frequency of the basic element or of the resonator can be in dependence on the voltage.

Frequency-tunable resonator

A component working with acoustic bulk waves is provided that has a multi-layer substrate, where the multi-layer substrate comprises an integrated matching network and further circuit elements for adapting the electrical filter properties and can serve as carrier substrate for thin-film resonators.

Growing community of inventors

Neubiberg, Germany

Ralph Stömmer