Epcos Ag

Snaptrack Incorporated

Andreas Detlefsen

Thomas Bauer

Dietmar Ritter

Markus Hauser

Ravi Kiran Challa

Franz Kubat

Ralph Durner

Peter Kirchhofer

Martin Bünner

Ralf Thomas

Miguel Angel Falagan Bobillo

Mohamed Nizar Mellouli

Stephan Bolze

An RF module with improved testing capabilities is provided. The module has a first switch with signal outputs and an additional auxiliary connection connected to an auxiliary terminal. The auxiliary terminal can be connected to an RF filter while a power amplifier is decoupled from the filter.

RF module and method for testing an RF module

A bandpass filter operates with electroacoustically active components. The bandpass filter includes a first transducer segment having a spike in the insertion loss at a first frequency fand a second transducer segment having a spike in the insertion loss at a second frequency f&#x2260;f. The frequencies fand fare chosen such that the insertion loss is smoothed.

Electroacoustic bandpass filter having smoothed insertion loss

A DMS filter has improved signal suppression in fly-back. At least two transformers of a first type are connected in parallel between a common node of the signal path and a ground connection/reference potential. A concentrated element is connected in the signal path of said transformers of the first type, so that the voltages present at the first transformers are different from each other.

DMS filter having improved signal suppression in the stop band

A SAW filter has two DMS tracks. Each DMS track includes six converters, with two converters each acting as input or output converters. The two DMS tracks are electrically connected in series by way of four pairs of coupling converters and the associated coupling lines. A common inner ground line is provided between the two DMS tracks, which extends over the entire length of the DMS tracks and crosses the coupling lines. The input converters of the first DMS track are connected to an asymmetrical port, while the output converters of the second DMS track are connected to a symmetrical port.

SAW filter operating in a balanced/unbalanced manner

A SAW filter circuit having improved ESD resistance is specified, in which a series interconnection composed of SAW resonators is interconnected between a first signal port and a dual-mode SAW filter port. The static capacitance of the series interconnection is at most four times the static capacitance of the dual-mode SAW filter transducers interconnected therewith.

SAW filter circuit having improved ESD resistance

A surface acoustic wave (SAW) filter includes at least one first electroacoustic transducer, and at least one second electroacoustic transducer. The at least one first electroacoustic transducer and the at least one second electroacoustic transducer are side-by-side inside an acoustic path having an aperture A. The at least one first electroacoustic transducer is connected to an electrical output of the SAW filter, and the at least one second electroacoustic transducer is connected to an electrical input of the SAW filter. At least one first electroacoustic transducer comprises a series circuit of a number of partial transducers, wherein each partial transducer has an individual aperture that is reduced in relation to the overall aperture A, and wherein the individual apertures add up to the overall aperture.

Saw filter featuring impedance transformation

An apparatus includes a piezoelectric substrate having a signal line with a first electrical port and a second electrical port, and a first partial filter connected in series with a second partial filter. The partial filters are arranged between the electrical ports. The first partial filter includes a first serial transducer and a second serial transducer located in an acoustic path and in series branches of the signal line. The serial transducers are acoustically coupled with one another. The second partial filter includes a coupler transducer and an end-positioned transducer that are located in a double mode surface acoustic wave (DMS) path. The end-positioned transducer is positioned at an end of the signal line.

Electronic component operated with surface acoustic waves

For improved conformance of a filter operating with acoustic waves, a transducer structure is provided in which the separations between respectively two adjacent electrode fingers of an inter-digital transducer (IDT) vary over the length of the transducer. The variation thereby preferably follows a continuous distribution function. Reactance filters that are provided with such filters in the serial branch show an improved electrical conformance in the transmission range.

Transducer structure that operates with acoustic waves

For improving the adjacent channel selectivity of a resonator filter, reflectors of resonators are differently designed so that the minimums of the reflection functions of different reflectors of a resonator are shifted relative to one another and preferably compensate with the corresponding maximum of the respectively other reflection function. This reduces noise spikes at the low-frequency side of the pass-band of corresponding resonator filters and, thus, improves the adjacent channel selectivity.

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Eichenau, Germany

Andreas Detlefsen