Disclosed is a filter bank die that includes a first acoustic wave (AW) filter having a first antenna terminal coupled to the antenna port terminal and a first filter terminal, wherein the first AW filter is configured to have a filter skirt with a slope that spans at least a 100 MHz gap between adjacent passbands, and a second AW filter having a second filter terminal, and a second antenna terminal coupled to the first antenna terminal to effectively diplex signals that pass through the first AW filter and the second AW filter.

Disclosed is a filter bank module having a substrate, an antenna port terminal, and a filter bank die. The filter bank die is fixed to the substrate and includes a first acoustic wave (AW) filter having a first antenna terminal coupled to the antenna port terminal and a first filter terminal, wherein the first AW filter is configured to pass a first passband and attenuate frequencies outside the first passband, and a second AW filter having a second filter terminal, and a second antenna terminal coupled to the first antenna terminal to effectively diplex signals that pass through the first AW filter and the second AW filter, wherein the second AW filter is configured to pass a second passband that is spaced from the first passband to minimize interference between first bandpass and the second bandpass while attenuating frequencies outside the second passband.

Disclosed is a filter bank die having a first acoustic wave (AW) filter having a first antenna terminal and a first filter terminal, and a second AW filter having a second filter terminal, and a second antenna terminal coupled to the first antenna terminal to effectively diplex signals that pass through the first AW filter and the second AW filter.

A bulk acoustic wave resonator comprises a piezoelectric material layer, a first metal layer disposed on the upper surface of the piezoelectric material layer, a second metal layer disposed on the lower surface of the piezoelectric material layer, and a laterally distributed raised frame including a first raised frame disposed on the upper surface of the first metal layer and having an inner raised frame section with a tapered portion and a non-tapered portion and an outer raised frame section, and a second raised frame disposed beneath the first metal layer and the outer raised frame section, but not beneath the inner raised frame section, the inner raised frame section being laterally disposed from a central active region of the bulk acoustic wave resonator by a first distance, the outer raised frame section being laterally disposed from the central active region by a second distance greater than the first distance.

A transmission filter is arranged in a first filter region and has one or more acoustic wave resonators, a plurality of terminal electrodes, and a plurality of wires. A reception filter is arranged in a second filter region and has one or more acoustic wave resonators, a plurality of terminal electrodes, and a plurality of wires. The first filter region and the second filter region are arranged adjacently to each other and have at least sides constituting a pair and opposing to each other. At least either one of the first filter region and the second filter region has no wire extending along one side in a forbidden region that is defined by a width including a terminal electrode nearest to the one side, along the one side and over the one side opposing to the other filter region.

A transmit filter circuit includes an input terminal, an output terminal, plural series arm resonators, and a parallel arm resonator. The input terminal receives a transmit signal. The output terminal is electrically connected to an antenna. The plural series arm resonators are electrically connected in series with each other on a line between the input and output terminals. The plural series arm resonators include first and second series arm resonators. The first series arm resonator is closest to the output terminal. The second series arm resonator is second closest to the output terminal. A first end of the parallel arm resonator is electrically connected to a node between the first and second series arm resonators. A reference potential is provided to a second end of the parallel arm resonator. The resonant frequency of the first series arm resonator is higher than that of the second series arm resonator.

Aspects of this disclosure relate to a multiplexer that includes a switchable acoustic wave filter. The switchable acoustic wave filter can include one or more acoustic wave resonators, switchable acoustic wave resonators, and a switch configurable into at least a first state and a second state. The switch can select a different subset of the switchable acoustic wave resonators to filter a radio frequency signal together with at least the one or more acoustic wave resonators in the first state than in the second state. Related filters, radio frequency systems, wireless communication devices, and methods are also disclosed.

A film bulk acoustic wave resonator (FBAR) comprises a recessed frame region including an undulating perimeter.

A filter includes a series arm resonator that defines at least a portion of a signal path connected between first and second terminals, a parallel arm resonator including one end that is grounded, a first inductor including one end that is connected to one end of the series arm resonator and another end that is connected to another end of the parallel arm resonator, and a second inductor including one end that is connected to another end of the series arm resonator and another end that is connected to the other end of the parallel arm resonator. A relative band width of the parallel arm resonator is smaller than a relative band width of the series arm resonator.

Aspects of this disclosure relate to methods of manufacturing bulk acoustic wave components. Such methods include plasma dicing to singulate individual bulk acoustic wave components. A buffer layer can be formed over a substrate of bulk acoustic wave components such that streets are exposed. The bulk acoustic wave components can be plasma diced along the exposed streets to thereby singulate the bulk acoustic wave components