摘要:
In a high frequency device, resonators (IDT capacitors) that function as capacitors are included in a lumped constant balun included in a filter or duplexer, and furthermore, the resonance frequency of the IDT capacitors is set higher than the passband frequency of the filter. This improves the capacitor Q value, thus enabling the realization of a low-loss balance filter.
摘要:
A filter includes at least one series resonator and parallel resonators, the at least one series resonator and the parallel resonators including excitation electrodes and reflectors, the parallel resonators having different resonance frequencies, and at least one of the parallel resonators other than the parallel resonator having the highest resonance frequency being configured to have a pitch of reflectors that is smaller than that of excitation electrodes.
摘要:
A ladder filter includes at least one series resonator connected in series between an input terminal and an output terminal, at least one parallel resonator connected in parallel with the at least one series resonator, and an inductor connected in parallel with the at least one series resonator. The at least one series resonator and the inductor generate a first attenuation pole at a frequency equal to or lower than a frequency band defined by the at least one series resonator and the at least one parallel resonator. The first attenuation pole is located at a frequency that is equal to or higher than a resonance frequency of a parallel resonator that is included in the at least one parallel resonator and has a highest resonance frequency and that is equal to or lower than a high-frequency end of the pass band.
摘要:
A ladder filter includes at least one series resonator connected in series between an input terminal and an output terminal, at least one parallel resonator connected in parallel with the at least one series resonator, an additional resonator connected in series between the at least one series resonator and one of the input terminal and the output terminal, and an inductor connected in series to the additional resonator, the additional resonator having a resonance frequency higher than an anti-resonance frequency of the at least one series resonator.
摘要:
A filter has a filter section that is provided with a balanced input terminal including a terminal 1 and a terminal 2 and a balanced output terminal including a terminal 3 and a terminal 4, and that passes a signal in a passband out of input balanced signals, and a balanced-to-unbalanced converter that is connected between the filter section and a single terminal. In the filter section, the frequency transfer characteristics between the terminals 1 and 3 differ from the frequency transfer characteristics between the terminals 2 and 4.
摘要:
A ladder type filter includes series resonators connected in series between an input terminal and an output terminal, parallel resonators connected in parallel between the input terminal and the output terminal, a resonator connected in series with the series resonators between the input terminal and the output terminal, the resonator having a resonance frequency lower than resonance frequencies of the series resonators, and an inductor connected in parallel with the resonator. According to the present ladder filter, signals having frequencies away from the pass band can be suppressed by an attenuation pole formed by the inductor. it is further possible to suppress the insertion loss in the pass band by the resonator.
摘要:
A duplexer includes a reception filter that is connected between a reception terminal and an antenna terminal and includes one or a plurality of series resonators that are acoustic wave resonators, and a transmission filter that is connected between a transmission terminal and the antenna terminal and includes one or a plurality of acoustic wave resonators, a resonance frequency of a first series resonator that is one of the one or the plurality of series resonators and is closest to the antenna terminal in the reception filter being higher than an upper limit frequency of a reception band of the reception filter.
摘要:
A controller and a display device are connected to each other by a network. The controller comprises a network control program which controls a network control section to communicate with the display device for each of a plurality of operation modes, including an initialization mode, a normal action mode, and an alarm mode. Various data, such as operation mode information for the controller, are transmitted to the display device connected by the network through the network control section and display data is displayed on the display device.