摘要:
A reactance filter includes a series branch that connects a signal input to a signal output. At least one parallel branch branches off from the series branch with respect to ground. A parallel resonator is arranged in each parallel branch. Two or more series resonators are connected in series in the series branch. A capacitor is connected in parallel with one of the series resonators in the series branch.
摘要:
A BAW resonator includes a first piezoelectric layer made of a material oriented toward a first direction, and a second piezoelectric layer made of a material oriented toward a second direction which is opposed to the first direction. The first piezoelectric layer and the second piezoelectric layer are acoustically coupled with each other.
摘要:
A filter circuit comprises a balanced port, an unbalanced port and a substrate. A series circuit of a filter stage and a balun is disposed between the balanced port and the unbalanced port. The balun and the filter stage are formed on the substrate.
摘要:
A resonator device includes a piezoelectric resonator having a detuning layer sequence arranged on the piezoelectric resonator. The detuning layer sequence includes at least a first layer having a high acoustic impedance and a second layer having a low acoustic impedance.
摘要:
A characteristic curve of the impedance of a skin surface is measured as a function of the frequency of an electric AC voltage by applying the voltage to at least one electric conductor which is galvanically or capacitively coupled to the skin surface. The characteristic curve is compared with a reference characteristic curve, which has been generated previously. If the characteristic curve substantially corresponds to the reference characteristic curve, the skin surface is recognized as belonging to living tissue.
摘要:
An antenna matching circuit includes at least two signal paths are connected to one antenna connection. The signal paths are designed to transmit and/or receive RF signals. A matching circuit includes a discrete line for phase shifting integrated at the antenna end in at least one of the signal paths. In this case, at least one of the capacitances contained in the discrete line is in the form of a micro-acoustic resonator, whose resonance is shifted sufficiently far that it is outside the pass band of the respective signal paths.
摘要:
A mirror for a piezoelectric resonator consisting of alternately arranged layers of high and low acoustic impedance is manufactured by at first producing a first layer on which a second layer is produced, so that the second layer partially covers the first layer. Then, a planarization layer is applied on the first layer and on the second layer. Subsequently, a portion of the second layer is exposed by structuring the planarization layer, wherein the portion is associated with an active region of the piezoelectric resonator. Finally, the resulting structure is planarized by removing the portions of the planarization layer remaining outside the portion.
摘要:
A bulk acoustic wave (BAW) filter (40) is fabricated from thin film bulk acoustic wave resonators and a method eliminates unwanted side passbands. This BAW filter comprises a substrate (14) a resonator section (11) and an acoustic mirror section (12). Further it comprises a detuning component (31) positioned in the resonator section (11) to provide precise passband characteristics and an additional detuning component (41) in the acoustic mirror section (12) to suppress unwanted side-passband characteristics.
摘要:
A method for producing a piezoelectric component comprising at least two stacked crystal filters comprises the steps of depositing of the layer stack above the bottom electrode and the subsequent patterning of the upper electrically conductive layer and, if appropriate, second piezoelectric layers. Thus, it is possible, in a simple manner, with a minimum of process steps, to produce a piezoelectric component comprising two stacked crystal filters which are directly connected to one another via their bottom and central electrodes. The piezoelectric component furthermore has the advantage that applications in which a high stop band attenuation is important can be realized with a relatively small number of filter stages. In this case, through the use of at least two stacked crystal filters, it is possible to achieve an excellent out-of-band rejection also for “single-ended signals”.
摘要:
A BAW resonator includes a resonator region having a piezo-electric layer between two excitation electrodes, wherein an acoustic standing wave forms when operating the BAW resonator at a resonant frequency. Furthermore, the BAW resonator includes a leaky wave reflection structure formed to reflect leaky waves generated when operating the BAW resonator, wherein the leaky waves propagate in a direction differing from a propagation direction of the acoustic standing wave.