Abstract: A filter structure (1090, 1100, 1200) comprises a first piezoelectric resonator (1021a), whose resonance frequency is a first resonance frequency and which is connected to an input conductor (1030a, 1030b). In order to increase the power handling capacity of the filter structure, it comprises other piezoelectric resonators connected in series with the first piezoelectric resonator. In this plurality (1020, 1110, 1220) of piezoelectric resonators, each resonator has a resonance frequency substantially equal to the first resonance frequency. The plurality (1020, 1110, 1220) of piezoelectric resonators is connected to the rest of the filter structure only through the first piezoelectric resonator (1021a) at one end of said plurality and through a second piezoelectric resonator (1021b), which is at the other end said plurality. The impedance of said plurality is arranged to match the impedance level of the filter structure.

Abstract: A component has a piezoelectric layer, which is arranged between a first lower electrode and a first upper electrode and also a second lower electrode and a second upper electrode. The first lower electrode, the first upper electrode, the second lower electrode and the second upper electrode are in each case structured, the structures of the first upper electrode and the structures of the second upper electrode, and the structures of the first lower electrode and the structures of the second lower electrode respectively engaging in one another. The component is suitable as a filter, transformer, and impedance matcher in high-frequency applications.

Abstract: A bulk acoustic wave device having two resonators in a stacked-up configuration separated by a dielectric layer. The device can be coupled to a lattice filter or a ladder filter to form a passband filter with an unbalanced input port and two balanced output ports. One or more such passband filters can be used, together with another lattice or ladder filter, to form a duplexer having an unbalanced antenna port, two balanced ports for one transceiver part and two balanced ports for another transceiver part.

Abstract: A bulk acoustic wave device having two resonators in a stacked-up configuration separated by a dielectric layer. The device can be coupled to a lattice filter or a ladder filter to form a passband filter with an unbalanced input port and two balanced output ports. One or more such passband filters can be used, together with another lattice or ladder filter, to form a duplexer having an unbalanced antenna port, two balanced ports for one transceiver part and two balanced ports for another transceiver part.

Abstract: A method of producing a BAW device with reduced spurious resonance, wherein the device comprises a top electrode, a bottom electrode and a piezoelectric layer therebetween. A frame-like structure is formed on top of the top electrode for suppressing the spurious resonances. The frame-like structure is produced in a self-aligning fashion in that the frame-like structure is used to define the top electrode area. Furthermore, it is preferred that the frame-like structure is made of a different material from the top electrode. The frame-like structure is caused to fuse with the contacting part of the top electrode to form an alloy. An etching mask is then used to cover at least part of the frame-like structure and the entire top electrode surrounded by the frame-like structure for etching. An etching medium is used to remove the unreacted portion of the top electrode outside the frame-like structure.

Abstract: A dual-channel passband filtering system having a first, second and third balanced ports for connecting, respectively, to a first transceiver, an antenna and a second transceiver. A first lattice-type passband filter is connected between the first and the second port, and a second lattice-type passband filter is connected between the second and the third port. A phase shifter is used to match the first and second transceiver and the second port. A balun can be used for each port to convert the balanced port to a single-ended port. In each passband filter, two series resonators are use to provide two balanced ends, and two shunt resonators are connected to the series resonators in a crisscross fashion to form a differential or balanced topology. The first and second passband filters have different frequencies.

Abstract: A filter structure (900, 1300, 1400, 1610) comprises a filter section (900) having at least two branches (901, 902) connected in parallel. A first branch (901) of said at least two branches comprises a first plurality (921, 701) of piezoelectric resonators connected in series, and a second branch (902) of said at least two branches comprises a second plurality (922, 702) of piezoelectric resonators and phase shifting means (910) connected in series. The phase shifting means are arranged to provide a phase shift of substantially 180 degrees.

Abstract: A method of fabricating a plurality of bulk acoustic wave (BAW) resonators on a single substrate, and the corresponding product, the BAW resonators having substantially different resonant frequencies, the method including the steps of: providing a substrate having an upper facing surface; depositing an isolation structure on the upper facing surface of the substrate; depositing a first metallic layer on the isolation structure, the first metallic layer serving as a bottom electrode; and depositing piezolayer material on the bottom electrode so as to have thicknesses corresponding to each of the different resonant frequencies, each different thickness located in a location where a resonator having a resonant frequency corresponding to the thickness is to be located.

Abstract: A method of fabricating a bulk acoustic wave (BAW) resonator and a BAW resonator so fabricated, the method including the steps of: providing a substrate; providing a first isolation structure; and providing a resonator section including a piezolayer; wherein the first isolation structure includes an acoustic mirror made from only electrically conductive layers of alternating high and low acoustic impedance. In some applications, the first isolation structure is situated between the resonator section and the substrate, while in other applications, the first isolation structure is situated above the resonator section (on the side of the resonator section facing away from the substrate), so that the resonator section lies between the first isolation structure and the substrate, and the resonator then further comprises a second isolation structure situated between the resonator section and the substrate.

Abstract: A method of fabricating a multi-resonator bulk acoustic wave (BAW) filter and a filter provided by such a method, the filter having a plurality of layers of materials serving as an acoustic mirror for a plurality of resonator sections, each resonator section including at least a top electrode and a bottom electrode sandwiching a piezolayer, the method including the steps of: choosing dielectric materials for some of the layers of materials serving as the acoustic mirror and metallic materials for the others of the layers; and providing at least one of the metallic layers via a fabrication procedure in which the metallic layer is patterned into distinct portions by an etching process that removes enough of the metallic layer between where different resonator sections are to be placed as to provide electrical isolation between the portions of the layer beneath the different resonator sections; thereby providing a multi-resonator BAW filter with reduced capacitive coupling between resonators, compared to the cap

Abstract: A method and system for tuning a bulk acoustic wave device at wafer level by reducing the thickness non-uniformity of the topmost surface of the device using a chemical vapor deposition process. A light beam is used to enhance the deposition of material on the topmost surface at one local location at a time. Alternatively, an electrode is used to produce plasma for locally enhancing the vapor deposition process. A moving mechanism is used to move the light beam or the electrode to different locations for reducing the thickness non-uniformity until the resonance frequency of the device falls within specification.

Abstract: A method and system for tuning a bulk acoustic wave device at wafer level, wherein the thickness of topmost layer of the device is non-umiform. The thickness non-unifornity causes the resonant frequency of the device to vary from one location to another location of the topmost layer. A laser beam, operatively connected to a beam moving mechanism, is used to locally trim the topmost layer, one location at a time.

Abstract: A method and system for tuning a bulk acoustic wave device at wafer level by reducing the thickness non-uniformity of the topmost surface of the device using a chemical vapor deposition process. A light beam is used to enhance the deposition of material on the topmost surface at one local location at a time. Alternatively, an electrode is used to produce plasma for locally enhancing the vapor deposition process. A moving mechanism is used to move the light beam or the electrode to different locations for reducing the thickness non-uniformity until the resonance frequency of the device falls within specification.

Abstract: A method of producing a bulk acoustic wave device with reduced spurious resonance, wherein the device comprises a top electrode, a bottom electrode and a piezoelectric layer therebetween. A frame-like structure is formed on top of the top electrode for tuning the device by suppressing the spurious resonances. The frame-like structure is produced in a self-aligning fashion in that the frame-like structure is used to define the top electrode area. Furthermore, it is preferred that the frame-like structure is made of a different material from the top electrode. The frame-like structure is caused to fuse with the contacting part of the top electrode to form an alloy. An etching mask is then used to cover at least part of the frame-like structure and the entire top electrode surrounded by the frame-like structure for etching. An etching medium is used to remove the unreacted portion of the top electrode outside the frame-like structure.

Abstract: A method and system for tuning a bulk acoustic wave device at wafer level, wherein the thickness of topmost layer of the device is non-uniform. The thickness non-uniformity causes the resonant frequency of the device to vary from one location to another location of the topmost layer. A laser beam, operatively connected to a beam moving mechanism, is used to locally trim the topmost layer, one location at a time.

Abstract: A method and system for tuning a bulk acoustic wave device at the wafer level by adjusting the device thickness. In particular, the device thickness has a non-uniformity profile across the device surface. A mask with an aperture is placed over the device surface and a particle beam is applied over the mask to allow part of the particle beam to make contact with the device surface at a localized area beneath the aperture. The particles that pass through the aperture are deposited on the device surface to add material on the device surface, thereby increasing the surface thickness to correct for thickness non-uniformity. Alternatively, the particles that pass through the aperture remove part of the device surface in an etching process, thereby reducing the surface thickness. Prior to thickness adjustment, a frequency measurement device or thickness measurement device is used to map the device surface for obtaining the non-uniformity profile.

Abstract: A method and system for tuning a bulk acoustic wave device at the wafer level by adjusting the thickness of the device. In particular, the thickness of the device has a non-uniformity profile across the device surface. A mask having a thickness non-uniformity profile based partly on the thickness non-uniformity profile of the device surface is provided on the device surface for etching. A dry etching method is used to remove part of the mask to expose the underlying device surface and further removed the exposed device surface until the thickness non-uniformity of the device surface falls within tolerance of the device.

Abstract: A method and system for tuning a bulk acoustic wave device at the wafer level by adjusting the thickness of the device. In particular, the thickness of the device has a non-uniformity profile across the device surface. A mask with an aperture is placed over the device surface and a particle beam is applied over the mask so as to allow part of the particle beam to make contact with the device surface at a localized area beneath the aperture. The particles that pass through the aperture are deposited on the device surface to add material on the device surface, thereby increasing the surface thickness to correct for the thickness non-uniformity. Alternatively, the particles that pass through the aperture remove part of the device surface in an etching process, thereby reducing the surface thickness. Prior to thickness adjustment, a frequency measurement device or thickness measurement device is used to map the device surface for obtaining the non-uniformity profile.

Abstract: A method of fabricating a bulk acoustic wave (BAW) resonator and a BAW resonator so fabricated, the method including the steps of: providing a substrate; providing a first isolation structure; and providing a resonator section including a piezolayer; wherein the first isolation structure includes an acoustic mirror made from only electrically conductive layers of alternating high and low acoustic impedance. In some applications, the first isolation structure is situated between the resonator section and the substrate, while in other applications, the first isolation structure is situated above the resonator section (on the side of the resonator section facing away from the substrate), so that the resonator section lies between the first isolation structure and the substrate, and the resonator then further comprises a second isolation structure situated between the resonator section and the substrate.

Abstract: A filter structure (1090, 1100, 1200) comprises a first piezoelectric resonator (1021a), whose resonance frequency is a first resonance frequency and which is connected to an input conductor (1030a, 1030b). In order to increase the power handling capacity of the filter structure, it comprises other piezoelectric resonators connected in series with the first piezoelectric resonator. In this plurality (1020, 1110, 1220) of piezoelectric resonators, each resonator has a resonance frequency substantially equal to the first resonance frequency. The plurality (1020, 1110, 1220) of piezoelectric resonators is connected to the rest of the filter structure only through the first piezoelectric resonator (1021a) at one end of said plurality and through a second piezoelectric resonator (1021b), which is at the other end said plurality. The impedance of said plurality is arranged to match the impedance level of the filter structure.