Epcos Ag

Qualcomm Incorporated

Snaptrack Incorporated

Siemens Matsushita Components Gmbh & Co Kg

Siemens Matsushita Comp. Gmbh & Co Kg

Andreas Bergmann

Markus Mayer

Pasi Tikka

Thomas Bauer

Jurgen Machui

Ulrich Knauer

Wolfgang Sauer

Thomas Ebner

Ralph Stömmer

Michael Jakob

Günter Kovacs

Gerhard Kloska

Karl-Christian Wagner

Karl Christian Wagner

Joachim Gerster

Jurgen Franz

Peter M&uuml;ller

Alexander Glas

A SAW resonator comprises two reflectors and a transducer arranged between the reflectors. A resonant space between the transducer and a respective reflector is set large enough to enable occurrence of main resonance and at least one further resonance of comparable admittance. Thus, a multiple resonant resonator is achieved that can be used as a parallel resonator in a filter circuit with a DMS track for example to improve attenuation in a stop band.

Saw resonator and filter comprising same

In a resonator, two interdigital transducers (W,W) are electrically series-connected and arranged next to each other in the longitudinal direction within an acoustic track delimited by reflectors. Between the two interdigital transducers, a transition area (UEB) is formed in that the finger period p, which is defined as the distance between the finger centers of adjacent transducer fingers, is higher in comparison to the remaining interdigital transducer.

Cascaded resonator

In an arrangement having a DMS filter, it is provided to symmetrically divide at least one of the transducers (W) of the DMS filter (DMS) into two sub-transducers (T,T') electrically connected in parallel and to shift them apart from each other by an amount of at least a half wavelength. This results in the signals of the two sub-transducers canceling each other out at a frequency in a stopband and thereby generating an attenuation pole in the upper blocking region.

Arrangement comprising a DMS filter and a steep right edge

A reactance filter can be use branching technology. A series circuit contains a first filter element, a second filter element and a third filter element. Each filter element includes a first impedance element that is connected in series with an impedance element of an adjacent element. Each filter element also includes a second element connected to the first impedance element of that filter. The first and/or second impedance element of each filter element comprises a includes a resonator. Each impedance element has a bandwidth that is expressed by its pole zero distance and each filter element comprises a means for setting the bandwidths of the impedance elements.

Broad-band filter in branching technology

A component is designed to work with acoustic waves. Embodiments have an improved temperature gradient of the frequency range and have increased performance strength. To this end, the component includes a stack of layers having a lower bonding layer, an electrode layer, an upper bonding layer, a compensation layer, and a trimming layer.

Component working with acoustic waves having reduced temperature coefficient of frequencies and method for producing same

A transducer includes an acoustic track in which an acoustic wave can be propagated, the acoustic track having a transversal fundamental mode, the acoustic track being subdivided in a transversal direction into an excitation area and two peripheral areas. The transducer also includes a first outside area and a second outside area bordering the acoustic track such that the acoustic track is arranged in the transversal direction between the first and second outside area. The transducer also includes peripheral areas configured such that the longitudinal phase velocity vof the acoustic wave in the respective peripheral area is greater than the longitudinal phase velocity vof the wave in the excitation area.

Acoustic wave transducer and filter comprising said transducer

A transducer operating with surface acoustic waves is specified, which is divided into cells, whose length essentially equals one wavelength, comprising cells of the second type, which are SPUDT cells and which have an excitation intensity of 100%, and at least one cell of the first cell type, which has at least four excitation centers, wherein an excitation center lies between two adjacent fingers with different polarities, and wherein the cell of the first cell type has an excitation intensity of a maximum of 30%.

Transducer operating with surface acoustic waves and having four excitation centers

A band pass filter includes partial filters, each of which has a pass band. Pass bands of different ones of the partial filters have center frequencies that are different. A partial filter with a lowest center frequency has a pass band with a first low-frequency edge and a first high-frequency edge. The first low-frequency edge is steeper than first high-frequency edge. A partial filter with a highest center frequency has a pass band with a second low-frequency edge and a second high-frequency edge. The second high-frequency edge is steeper than the second low-frequency edge.

Band pass filter

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

A surface acoustic wave arrangement has at least two interdigital transducers being provided on a piezoelectric substrate along an acoustic path, with at least one of the interdigital transducers being a fan transducer which is divided in a transverse direction into edge tracks and a center track. The acoustic wave excited in the edge tracks can be radiated either bidirectionally or unidirectionally in a predominant direction. On the other hand, the center track is formed so that the unidirectional radiation of the wave takes place in a direction opposite the predominant direction. In this manner, the signal transmission is suppressed in the frequency range corresponding to the finger period in the center track within the passband range of the transfer function. The obtained notch in the transfer function is used, for example, in receivers of terrestrial and satellite-based signals for suppressing the terrestrial signals in the satellite path of the receiver.

Surface acoustic wave arrangement for broadband signal transmission

A recursive surface-active wave filter with directed reflection is provided that such that the desired transmission behavior is modeled by superimposing the signals of three electrically interconnected individual tracks.

Recursive saw-filter with a low chip length

An interdigital transducer for a surface acoustic wave includes an acoustic track with a width of BSand subtransducers arranged adjacent to each other on the acoustic track and connected in series. The subtransducers include, in a transverse direction, n series subtransducers each having a track width of BS(i=1, 2, . . . n(x); n (x)&#x2267;2). In the subtranducersBSdoes not equal BS.

Interdigital transducer with distibuted excitation

A transducer includes base cells each having a length &lgr;, where &lgr; is a wavelength of a center frequency of the transducer. The base cells are arranged in a direction of propagation of a surface acoustic wave. The base cells include exciting base cells and reflecting base cells. The exciting base cells each have a same number of electrode fingers. Each base cell has a reflection portion. The reflection portion of each base cell has a same value mRo, where m is one of &minus;2, &minus;1, 0, 1, or 2 and Ro is a reference reflection. Each non-zero reflection portion in each base cell has a same phase position. Excitation and reflection in the transducer are equal in phase in one direction of propagation of the surface acoustic wave and opposite in phase in an opposite direction of propagation of the surface acoustic wave.

Surface wave converter with optimized reflection

A SAW duplexer having an impedance transformation network in a form of a series capacitance in at least one filter path.

Saw duplexer

A surface acoustic wave filter has one or more acoustic filter tracks. Each track has an input interdigital converter, an output interdigital converter, and a reflector. The reflector reflects surface waves between the input and output inter-digital converter by 180.degree.. The reflector is formed with a multiplicity of reflector electrode fingers which are combined into reflector finger groups. Mutually adjacent reflector finger groups are spaced apart by a defined spacing distance such that respective signals in adjacent reflector finger groups are superimposed in antiphase.

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Haiming, Germany

Andreas Bergmann