摘要:
A filter includes a parallel resonator having first comb electrodes provided on a piezoelectric substrate and a first dielectric film that covers the first comb electrodes, and a series resonator having second comb electrodes provided on the piezoelectric substrate and a second dielectric film covers the second comb electrodes and is made of a material identical to that of the first dielectric film. The first dielectric film has a different thickness from that of the second dielectric film.
摘要:
An acoustic wave device includes a piezoelectric substrate, a first dielectric film formed on the piezoelectric substrate, and electrodes that are provided on the first dielectric film and excite an acoustic wave, the electrodes including electrode fingers. At least a part of the first dielectric film is cut out between adjacent electrode fingers among the electrode fingers.
摘要:
A duplexer includes an antenna terminal, a first filter connected to the antenna terminal, and a second filter connected to the antenna terminal. At least one of the first filter and the second filter is a ladder type filter in which a parallel resonator and multiple series resonators are included, one or more first inductors are respectively connected in parallel with one or more series resonators out of the multiple series resonators, and one of the one or more first inductors is connected in parallel with one of the multiple series resonators that is arranged closest to the antenna terminal.
摘要:
A duplexer that includes: a transmission filter and a reception filter that are connected to a common terminal; and a reactance circuit that is connected to at least one of the transmission filter and the reception filter. The reactance circuit includes an insulating substrate, lumped-constant inductors, and at least one capacitor. The lumped-constant inductors and the capacitor are formed directly on the surface of the insulating substrate.
摘要:
An acoustic wave device includes a piezoelectric substrate, a first dielectric film provided on the piezoelectric substrate, electrodes that are provided on the first dielectric film and excite an acoustic wave, and a second dielectric film that is provided so as to cover the electrodes and is thicker than the electrodes.
摘要:
A demultiplexer has a common terminal, a transmission terminal, and a reception terminal, and furthermore includes a transmission filter connected between the common terminal and the transmission terminal, a reception filter connected between the common terminal and the reception terminal, and a phase shift circuit connected in series to the reception filter connected between the common terminal and the reception terminal. A node on the line from the phase shift circuit to the common terminal or the transmission terminal, and a node on the line from the phase shift circuit to the reception terminal are coupled via a reactance. Accordingly, it is possible to fundamentally reduce or eliminate the situation in which transmission signals from the transmission filter arrive at the reception circuit, and improve isolation.
摘要:
There is provided a filter including a first resonator, a second resonator in which an excitation efficiency is reduced more than the first resonator, and an inductor connected in parallel with the second resonator.
摘要:
An acoustic wave device includes a piezoelectric substrate, a resonator having comb electrodes that are provided above the piezoelectric substrate and excite an acoustic wave, and a capacitor that is provided above the piezoelectric substrate and is connected in series or parallel with the resonator, the capacitor including electrodes that horizontally face each other above the piezoelectric substrate. The electrodes of the capacitor are further from the piezoelectric substrate than the comb electrodes of the resonator.
摘要:
There is provided a filter including a first resonator, a second resonator in which an excitation efficiency is reduced more than the first resonator, and an inductor connected in parallel with the second resonator.
摘要:
Efficient transverse energy confinement, and provision of a surface acoustic wave filter having preferable characteristics of both insertion loss and shape factor are obtained. In the surface acoustic wave filter, electrode fingers of one comb electrode are laid in a state of being inserted to the electrode fingers of the other comb electrode, and a thick film thicker than each plurality of electrode fingers is produced in a partial area of the bus bar, and a tip gap is provided between the top of each plurality of electrode fingers and the end face of the opposed bus bar, with a distance therebetween set not greater than 0.2λ (where, λ is one period of the comb electrode).