Abstract: A valve includes a valve body, a diaphragm dividing the inside of the valve body into first and second valve chambers and being displaced under a pressure of fluid, first and second openings in communication with the first valve chamber, and a third opening in communication with the second valve chamber. When a pump is not driven, the force applied to a side of the diaphragm facing the second valve chamber is greater than the force applied to a side of the diaphragm facing the first valve chamber, and the second opening is sealed by the diaphragm. When the pump is driven and the force applied to the side of the diaphragm facing the first valve chamber becomes greater than the force applied to the side of the diaphragm facing the second valve chamber, the diaphragm allows the first and second openings and to communicate with each other.

Abstract: A valve includes a valve body, a diaphragm dividing the inside of the valve body into first and second valve chambers and being displaced under a pressure of fluid, first and second openings in communication with the first valve chamber, and a third opening in communication with the second valve chamber. When a pump is not driven, the force applied to a side of the diaphragm facing the second valve chamber is greater than the force applied to a side of the diaphragm facing the first valve chamber, and the second opening is sealed by the diaphragm. When the pump is driven and the force applied to the side of the diaphragm facing the first valve chamber becomes greater than the force applied to the side of the diaphragm facing the second valve chamber, the diaphragm allows the first and second openings and to communicate with each other.

Abstract: A valve includes a valve body, a diaphragm dividing the inside of the valve body into first and second valve chambers and being displaced under a pressure of fluid, first and second openings in communication with the first valve chamber, and a third opening in communication with the second valve chamber. When a pump is not driven, the force applied to a side of the diaphragm facing the second valve chamber is greater than the force applied to a side of the diaphragm facing the first valve chamber, and the second opening is sealed by the diaphragm. When the pump is driven and the force applied to the side of the diaphragm facing the first valve chamber becomes greater than the force applied to the side of the diaphragm facing the second valve chamber, the diaphragm allows the first and second openings and to communicate with each other.

Abstract: A valve includes a valve body, a diaphragm dividing the inside of the valve body into first and second valve chambers and being displaced under a pressure of fluid, first and second openings in communication with the first valve chamber, and a third opening in communication with the second valve chamber. When a pump is not driven, the force applied to a side of the diaphragm facing the second valve chamber is greater than the force applied to a side of the diaphragm facing the first valve chamber, and the second opening is sealed by the diaphragm. When the pump is driven and the force applied to the side of the diaphragm facing the first valve chamber becomes greater than the force applied to the side of the diaphragm facing the second valve chamber, the diaphragm allows the first and second openings and to communicate with each other.

Abstract: A check valve is housed in a valve chamber and includes a support portion and a flexible portion. The support portion extends along a principal axis thereof. The flexible portion is supported by the support portion in a manner extending from the principal axis. A diaphragm defines a lower wall of the valve chamber, and includes an inflow port for fluid at a position that is closed with the flexible portion when the flexible portion is displaced. A bottom plate defines an upper wall of the valve chamber, and faces the diaphragm with the flexible portion arranged therebetween. An uneven portion is provided in at least one of mutually facing areas of an upper principal surface, which is one of two principal surfaces of the flexible portion and faces the bottom plate, and a lower principal surface of the bottom plate, the uneven portion being partially uneven.

Abstract: A check valve is housed in a valve chamber and includes a support portion and a flexible portion. The support portion extends along a principal axis thereof. The flexible portion is supported by the support portion in a manner extending from the principal axis. A diaphragm defines a lower wall of the valve chamber, and includes an inflow port for fluid at a position that is closed with the flexible portion when the flexible portion is displaced. A bottom plate defines an upper wall of the valve chamber, and faces the diaphragm with the flexible portion arranged therebetween. An uneven portion is provided in at least one of mutually facing areas of an upper principal surface, which is one of two principal surfaces of the flexible portion and faces the bottom plate, and a lower principal surface of the bottom plate, the uneven portion being partially uneven.

Abstract: A dielectric filter, a composite dielectric filter, a dielectric duplexer, a dielectric diplexer, and a communication apparatus, in which isolation between adjacent dielectric filters can be obtained, and deterioration of filter characteristics can thereby be prevented. A plurality of dielectric resonators formed by disposing dielectric cores in cavities, and coupling loops for coupling to predetermined resonance modes of the dielectric resonators, are combined to form a dielectric filter. The dielectric resonators and the coupling loops are arranged in such a manner that when the dielectric resonators of the dielectric filters are close to each other, the directions of the coupling portions of the adjacent coupling loops are substantially vertical to each other.

Abstract: A resonator includes a conductive casing provided with a threaded screw hole, a screw at least partially inserted into the casing, and a fixing member fixing the screw and having a threaded screw hole. In the resonator, the linear expansivity of the casing and the linear expansivity of the fixing member, and preferably also that of the screw, are substantially equal.

Abstract: A resonator includes a conductive casing provided with a threaded screw hole, a screw at least partially inserted into the casing, and a fixing member fixing the screw and having a threaded screw hole. In the resonator, the linear expansivity of the casing and the linear expansivity of the fixing member, and preferably also that of the screw, are substantially equal.