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:
A surface acoustic wave element includes: metal patterns that include interdigital transducers, each of the metal patterns being formed with a first alloy or multi-layer film of metals having different standard electrode potentials; and metal films each formed with a second alloy or multi-layer film containing metals having different standard electrode potentials from the standard electrode potentials of the metals forming the first alloy or multi-layer film, the metal films being formed at least on a part of the regions other than the regions corresponding to the electrode fingers of the interdigital transducers of all the metal patterns that are electrically independent of one another.
摘要:
A multi-mode surface acoustic wave filter device includes: a piezoelectric substrate; at least one input IDT (interdigital transducer) and at least one output IDT that are formed on the piezoelectric substrate; reflectors that are formed on the piezoelectric substrate and arranged on the external sides of the input IDT and the output IDT; an input terminal that supplies input signals to the input IDT; and an output terminal that receives output signals from the output IDT. In this multi-mode surface acoustic wave filter, the input terminal and the output terminal extend in the same direction.
摘要:
A surface acoustic wave filter includes a series-arm resonators and parallel-arm resonators that are connected in a ladder-like structure, each having an interdigital transducer formed on a piezoelectric substrate, and at least one of the series-arm resonators having a different static capacitance from the other series-arm resonators. In this surface acoustic wave filter, at least one of the series-arm resonators except the series-arm resonator located at the first stage in the ladder-like structure has a lower average resonant frequency than the other series-arm resonators.
摘要:
A method for manufacturing an acoustic wave device includes: bonding a piezoelectric substrate to a first surface of a first support substrate; thinning the piezoelectric substrate after the bonding to thus form a piezoelectric layer; forming a first electrode on a first surface of the piezoelectric layer; forming holes in the first support substrate located below the first electrode; and bonding a second support substrate to a second surface of the first support substrate opposite to the first surface after the forming of holes.
摘要:
An electronic circuit includes a plurality of duplexers that are coupled to an antenna terminal and have a pass band different from each other and a plurality of acoustic wave filters that are respectively coupled between the antenna terminal and the plurality of the duplexers, wherein filter characteristics of a first acoustic wave filter of the plurality of the acoustic wave filters are set so as to allow passage of a signal in both a pass band for transmitting and a pass band for receiving of a first duplexer of the plurality of the duplexers that is coupled to the first acoustic wave filter and suppress passage of a signal in both a pass band for transmitting and a pass band for receiving of a second duplexer of the plurality of the duplexers that is different from the first duplexer.
摘要:
A duplexer includes an unbalanced transmitting filter; a balanced receiving filter; a transmitting port connected to the transmitting filter; and a first receiving port and a second receiving port connected to the receiving filter. The duplexer also includes an electromagnetic coupling portion connected between the transmitting port and the first receiving port and between the transmitting port and the second receiving port. The electromagnetic coupling portion adjusts the phase between electric power that flows from the transmitting port to the first receiving port and electric power that flows from the transmitting port to the second receiving port.
摘要:
There is provided a piezoelectric thin film resonator that decreases only transverse mode waves selectively while maintaining resonance characteristics due to original thickness longitudinal vibration. The piezoelectric thin film resonator includes: a piezoelectric film (14); a first electrode (15a) formed on a first principal surface of the piezoelectric film (14); and a second electrode (13) formed on a second principal surface of the piezoelectric film (14) opposite to the first principal surface. The resonator has a resonance region (20) where the first electrode (15a) and the second electrode (13) are opposed to each other. An electrically discontinuous portion (18a) that is insulated from the first electrode (15a) is provided on the first principal surface of the piezoelectric film (14) in the resonance region (20), and the electrically discontinuous portion (18a) is surrounded by the first electrode (15a) on the first principal surface.
摘要:
A duplexer with a reduced filter loss is provided. The duplexer includes two or more filters F1 and F2 that are connected to a common terminal and that have different passbands. At least one of the filters F1 and F2 includes a plurality of series resonators S1 to Sn connected in series to a path between an input terminal and an output terminal of the filter, and parallel resonators P1 to Pm connected in parallel to the above-mentioned path. An inductance L1 is connected in parallel to at least one of the series resonators, and the series resonator S1 having the inductance L1 connected in parallel thereto is divided into a plurality of resonators S11 to S13 connected in series.
摘要:
A duplexer of the present invention includes a reception filter (3) for passing signals in a predetermined frequency band and attenuates signals in the other frequency bands among reception signals input to an antenna port, and a transmission filter (4) for passing signals in a predetermined frequency band and attenuates signals in the other frequency bands among transmission signals input from the outside and outputting them to the antenna port. The duplexer further includes a conversion circuit (22) provided with a single-ended input terminal connected to the antenna port and balanced output terminals. The reception filter (3) is provided with a balanced input terminal connected to the output terminal of the conversion circuit (22) and a balanced output terminal for outputting the filtered reception signal. Thus, a balance-output-type duplexer that is connectable to a balance-input-type LNA and is free from loss and degradation in power-handling capability, a communication module and a communication device can be realized.