摘要:
A bandpass filter includes input and output terminals, first and second acoustic resonators, and an acoustic coupling layer. The first acoustic resonator includes first and second electrodes, and a piezoelectric layer between the first and second electrodes. The first electrode of the first acoustic resonator is connected to the input terminal. The second acoustic resonator includes first and second electrodes, and a piezoelectric layer between the first and second electrodes. The acoustic coupling is provided between the second electrode of the first acoustic resonator and the first electrode of the second acoustic resonator. The output terminal is connected to the second electrode of the second acoustic resonator. A capacitor extends between the input terminal and the output terminal. The filter's frequency response includes at least two transmission zeros.
摘要:
A bulk acoustic wave device includes an acoustic decoupler between first and second film bulk acoustic resonators (FBARs). The first FBAR is resonant at a resonant frequency of the device and includes first and second planar electrodes abutting opposite sides of a first resonator volume free of any intervening electrodes and containing piezoelectric material disposed for acoustic vibrations parallel to a propagation axis normal to the first and second electrodes. The first FBAR has a first electrical impedance parallel to the propagation axis. The second FBAR is resonant at the resonant frequency and includes third and fourth planar electrodes abutting opposite sides of a second resonator volume free of any intervening electrodes and containing piezoelectric material disposed for acoustic vibrations parallel to the propagation axis. The second FBAR has a second electrical impedance parallel to the propagation axis and different from the first electrical impedance.
摘要:
A bulk acoustic wave device includes an acoustic decoupler between first and second film bulk acoustic resonators (FBARs). The first FBAR is resonant at a resonant frequency of the device and includes first and second planar electrodes abutting opposite sides of a first resonator volume free of any intervening electrodes and containing piezoelectric material disposed for acoustic vibrations parallel to a propagation axis normal to the first and second electrodes. The first FBAR has a first electrical impedance parallel to the propagation axis. The second FBAR is resonant at the resonant frequency and includes third and fourth planar electrodes abutting opposite sides of a second resonator volume free of any intervening electrodes and containing piezoelectric material disposed for acoustic vibrations parallel to the propagation axis. The second FBAR has a second electrical impedance parallel to the propagation axis and different from the first electrical impedance.
摘要:
A film acoustically-coupled transformer (FACT) has a first and a second stacked bulk acoustic resonator (SBAR 1, SBAR 2). Each SBAR has a stacked pair of film bulk acoustic resonators (FBARs) and an acoustic decoupler between the FBARs. Each FBAR has opposed planar electrodes and a layer of piezoelectric material between the electrodes. A first electrical circuit connecting one of the FBARs of SBAR1 to one of the FBARs of SBAR 2 and a second electrical circuit connecting the other of the FBARs of SBAR 1 to the other of the FBARs of SBAR 2. The first electrical circuit connects the respective FBARs in parallel and second electrical circuit connects the respective FBARs in series. A shunt inductor is included from the reception path to ground.
摘要:
A method and circuit matches a device to n filters, wherein each filter is a SAW filter, BAW filter, or FBAR filter. The method and system: (a) provide an inductor or transmission line connected between a common terminal and ground; (b) provide a plurality of capacitance values (C1m, C2m, . . . , Cnm) each corresponding to one of the n filters; and (c) for each of the n filters, directly connect a first terminal of the filter to either: (1) the common terminal, or (2) a first terminal of a corresponding capacitor having the correspondence capacitance value calculated in step (b), where a second terminal of the corresponding capacitor is directly connected to the common terminal.
摘要:
An electrical impedance transformer comprises a first film bulk acoustic resonator (FBAR), having a first electrical impedance and a first resonance frequency. The electrical impedance transformer also comprises: a second FBAR, having a second electrical impedance and a second resonance frequency, and being disposed over the first FBAR. The electrical impedance transformer also includes a decoupling layer disposed between the first and the second FBARs. The first electrical impedance differs from the second electrical impedance and the first and second resonance frequencies are substantially the same.
摘要:
In a filter having a half-ladder structure comprising an alternating series of series branches and shunt branches, including a signal input and a signal output related to a common ground. at least one series branch or one parallel branch of the filter is configured as a BAW device comprising a first BAW resonator and a second BAW resonator connected either antiparallel or antiseries. The second harmonic emission generated by the first BAW resonator substantially cancels the second harmonic emission of the second BAW resonator and the second harmonic emission of at least one other series branch or one other parallel branch of the filter. By this method, the filter's second harmonic emissions are reduced.