90results about How to "Improve attenuation characteristics" patented technology

A duplexer includes a transmit filter of a ladder type filter, connected between a common terminal and a transmitting terminal, and a receive filter of the ladder type filter, connected between the common terminal and a receiving terminal. One or more parallel resonators in the transmit filter are grounded through a transmitting inductance, and a portion of multiple parallel resonators are grounded through a first receiving inductance and a remaining portion of the multiple parallel resonators are grounded through a second receiving inductance.

A duplexer includes a piezoelectric substrate, a transmitting filter, and a receiving filter. The transmitting filter includes a ladder filter having a first resonator group which has one or more resonators in one or more series arms and one or more resonators in one or more parallel arms. The receiving filter has a passband higher than that of the transmitting filter, and includes a second resonator group which has one or more resonators in one or more series arms and one or more resonators in one or more parallel arms. A node connects both the transmitting filter and the receiving filter. The receive-side closest resonator closest to the node in the parallel arm is closer to the node than a resonator which is closest to the node in the series arm, and a resonance frequency of the receive-side closest resonator is lower than the passband of the transmission filter.

The invention relates to an optical fiber large in effective area. The optical fiber large in the effective area comprises a fiber core layer and a covering layer. The optical fiber large in the effective area is characterized in that the fiber core layer comprises an inner core layer and an outer core layer, the radius r1 of the inner core layer is 1 to 4 microns, a relative refractive index difference delta 12 of the inner core layer to the outer core layer meets the condition that -0.2% <= delta 12 < 0%, the relative refractive index difference of the inner core layer to the outer core layer is invariant or gradually increased along with increasing of the radius, the radius r2 of the outer layer is 4 to 7 microns, and the relative refractive index difference delta 2 of the outer core layer is -0.15 % to 0.05 %; the covering layer comprises an inner covering layer, a sunk concave covering layer and an outer covering layer, the inner covering layer covers the fiber core layer, the radius r3 of the inner covering layer is 7 to 20 microns, the relative refractive index difference delta 3 is within the range of -0.5 % to -0.1 %, the radius r4 of the sunk concave covering layer is 12 to 40 microns, the relative refractive index difference delta 4 is within the range of -1.0 % to -0.3 %, and the relative refractive index difference delta 5 is within the range of -0.2% to -0.4%. The optical fiber large in the effective area has a large effective area, quite low transmission loss and good curve characteristics, and is particularly suitable for application of a long-distance high-speed large-volume communication system.

An actual vehicle actuator operation control input and a model operation control input are determined by an FB distribution law such that the difference between a reference state amount determined in a vehicle model and an actual state amount of an actual vehicle approximates zero, and then an actuator device of the actual vehicle and the vehicle model are operated on the basis of the control inputs. The value of a parameter of the vehicle model set according to an actual vehicle motional state such that the attenuation property of a reference state amount when a drive manipulated variable is changed is higher than the attenuation property of an actual state amount. Accordingly, the actual vehicle actuator device is properly controlled independently of an actual vehicle motional state such that a state amount related to an actual vehicle motion approximates a vehicle state amount on a dynamic characteristic model.

The invention discloses a fiber drawing and annealing device, comprising an annealing tube. An axial cavity for a fiber to pass through is arranged in the annealing tube; an electric heater is arranged in a tube body of the annealing tube and is arranged around the axial cavity; by adjusting the working temperature of the electric heater, the temperature in the axial cavity decreases gradually from the direction of the fiber passing in the axial cavity to the direction of the fiber passing out of the axial cavity. The fiber drawing and annealing device also includes an annealing assistor hermetically connected to the fiber outgoing end of the annealing tube; a lining is arranged in the annealing assist and is coaxial to the axial cavity. The fiber drawing and annealing device of optical structural design is abutted to a drawing furnace; after the fiber is drawn and fed out of the furnace, the fiber enters the annealing device having the temperature slowly decreasing; attenuation features, warping characteristics and fiber internal stress can be improved for the fiber, and fiber quality is improved in a whole.

The present invention is intended to provide a line filter having an outstanding attenuation characteristic over a wide frequency band from low frequency band to high frequency band, with an improved elimination characteristic for common mode noises. To achieve this object, the invention incorporates a structure wherein a first coil unit (14) for second band and a second coil unit (16) for second band are disposed vertically to a closed-loop magnetic core (11).

The invention relates to a damper device for inhibiting torsional vibration of an engine in a broad range. A damper device (11) is provided between the engine (12) and a transmission (13) and has a torque distribution mechanism (20) that is provided with a bracket C connected to the engine (12), a first gear ring (R1) connected to the engine (12) via a first elastic member (22), a sun gear S connected to the transmission (13), and a second gear ring (R2) connected to the transmission (13) via a second elastic member (24). The damper device (11) further has a first clutch (CL1) that is provided between the sun gear (S) and the transmission (13) that is switched between an engaged state of connecting the sun gear (S) and the transmission (13) and a released state of disconnecting the sun gear (S) from the transmission (13) and a second clutch (CL2) that is provided between the second gear ring (R2) and the transmission (13) and that is switched between an engaged state of connecting the second gear ring (R2) to the transmission (13) and a released state of disconnecting the second gear ring (R2) from the transmission.

A friction material includes base fibers, a friction conditioner, a binder and enlarged dust. The enlarged dust is a combination of grinding dust and an elastic material such as rubber.

A surface acoustic wave filter includes a piezoelectric substrate (110) and a plurality of one-terminal-pair surface acoustic wave resonators (111,112), which are disposed on the piezoelectric substrate in a ladder pattern and each of which includes an IDT electrode having a pair of comb electrodes. The one-terminal-pair surface acoustic wave resonators disposed in a ladder pattern include series resonators (111a-c), all of which are thinned-out. The electrode pitch of the IDT electrode of at least one (111b) of the series resonators is different from that of the IDT electrodes of the other series resonators (111a,c).

A band rejection filter with attenuation poles includes a plurality of series resonant circuits having end terminals connected in common and other end terminals connected in series via a plurality of transmission lines each having a length that is an odd multiple of about the one-quarter wavelength at the resonance frequency of the plurality of series resonant circuits, and a jump-coupling circuit for roughly coupling two of the plurality of series resonant circuits, which are not adjacent to each other, to each other.

The invention discloses a novel 3D printed protective material in a high-negative-Poisson-ratio interwoven structure. The novel 3D printed protective material in the high-negative-Poisson-ratio interwoven structure is printed and formed from shape memory materials and common rubber through droplet injection additive manufacturing. The structure of the novel 3D printed protective material in the high-negative-Poisson-ratio interwoven structure is internally provided with triangular structures (1), of which nodes are connected through linear structures (3); the neighboring linear structures (3)define unclosed hexagonal structures. By means of the 3D printing technology, improved photosensitive materials can be 3D-printed by temperature stimulus into objects with excellent memory, response,resilience, anti-seismic and adaptive properties and the like.

The invention discloses an improved control strategy for shaft system concussion inhibition of doubly-fed wind generators. The strategy comprises the following steps of: firstly calculating a theoretical expression of an electromagnetic torque under the sudden rise of power grid voltage on the basis of a doubly-fed wind generator mathematic model with a mechanical transmission system, and analyzing a mechanism of causing torsional vibration of a shaft system by high-voltage faults by combining mathematic models of two quality blocks of the shaft system; and proposing a control strategy for compensating a compensation torque which is directly proportional with a torque differential in the electromagnetic torque so as to increase model damping of the two quality blocks. According to the strategy, feature values of speed ring small-signal models are solved, stability and a free attenuation characteristic of systems after increasing compensation torques are analyzed, and a torque observeris imported to extract to-be-overlapped compensation torques.