Abstract: A nonreciprocal circuit device includes a first center electrode and a second center electrode intersecting each other, each having one end thereof grounded, a ferrimagnetic body provided in the vicinity of the first center electrode and the second center electrode, a magnet applying a magnetostatic field to the ferrimagnetic body, a series capacitor connected in series between the other end of the first center electrode and an input terminal and a series capacitor connected in series between the other end of the second center electrode and an output terminal, and a parallel capacitor connected in parallel between the other end of the first center electrode and a ground and a parallel capacitor connected in parallel between the other end of the second center electrode and the ground.

Abstract: The present invention provides a nonreciprocal circuit device which allows the inductance component of centeral conductors to be enlarged even when a magnetic body is reduced in the size, and which is thereby capable of achieving superior characteristics over a wide band while having a small size, and further provides a communication device using the same. In this nonreciprocal circuit device, a magnetic body is formed by winding two centeral conductors around a magnetic body having a rectangular-parallelepiped plate shape so as to intersect each other at an angle of substantially 90 degrees. As these centeral conductors, metallic wires constituted of a metallic material such as copper or silver are used, the metallic wires being coated with an insulative resin such as polyester or polyimide.

Abstract: A nonreciprocal circuit device includes a first center electrode and a second center electrode intersecting each other, each having one end thereof grounded, a ferrimagnetic body provided in the vicinity of the first center electrode and the second center electrode, a magnet applying a magnetostatic field to the ferrimagnetic body, a series capacitor connected in series between the other end of the first center electrode and an input terminal and a series capacitor connected in series between the other end of the second center electrode and an output terminal, and a parallel capacitor connected in parallel between the other end of the first center electrode and a ground and a parallel capacitor connected in parallel between the other end of the second center electrode and the ground.

Abstract: An S/N enhancer is provided which can be formed to be small in size and in which impedance matching can easily be achieved. The S/N enhancer includes two magnetostatic wave elements. First to fourth transducers each in the shape of a single line are disposed on YIG thin films of the magnetostatic wave elements in parallel and spaced from one another. An input terminal is connected to one end of the first transducer. An attenuator is connected between the other end of the first transducer and one end of the third transducer. A 180.degree. shifter and another attenuator are connected in series between one end of the second transducer and one end of the fourth transducer. An output terminal is connected to the other end of the fourth transducer. The other ends of the second and third transducers are respectively grounded.

Abstract: A compact, low-cost magnetostatic wave device which can serve as an S/N enhancer or a filter. The magnetostatic wave device includes a ferromagnetic base; at least one transducer having a portion arranged adjacent to one surface of the ferromagnetic base and another. portion arranged adjacent to the other surface of the ferromagnetic base; an input terminal with one side connected to one end of the transducer and the other side grounded; and an output terminal with one side connected to the other end of the transducer and the other side grounded. The ferromagnetic base is preferably disk-shaped.

Abstract: A magnetostatic wave device has an external magnetic field applied in a direction that is substantially parallel to a plane of a thin film of a magnetic single-crystal having a garnet structure. The thin film of the magnetic single-crystal has an axis of easy magnetization that is oriented in substantially the same direction as the direction of the externally applied magnetic field.

Abstract: A magnetostatic wave device includes a dielectric substrate. Micro strip lines as transducers are formed by forming a ground electrode and strip-line electrodes, on both surfaces of the dielectric substrate. A ferrimagnetic base material formed with a GGG substrate and a YIG thin film on the GGG substrate is arranged on the strip-line electrodes. The ferrimagnetic base material is formed so that the end portions slant from the strip-line electrodes outwardly. The length of the ferrimagnetic base material is established to provide a minimum value.

Abstract: A signal-to-noise enhancer 10 includes a first 90 degree hybrid set 20. A first output end of the first 90 degree hybrid set 20 is connected to an input end of a limiter used a magnetostatic wave element 62a utilized the magnetostatic surface wave mode. Also, a second output end of the first 90 degree hybrid set 20 is connected to an input end of a filter used a magnetostatic wave element 62b similar to the magnetostatic wave element 62a in structure, via a resistor 32 as a first attenuator. Furthermore, an output end of the limiter is connected to a first input end of a second 90 degree hybrid set 40 via a resistor 52 as a second attenuator. Also, an output end of the filter is connected to a second input end of the second 90 degree hybrid set 40.

Abstract: A magnetostatic wave resonator includes a YIG thin film. On one main surface of the YIG thin film, three circular conductors having different radii are disposed on concentric circles whose centers are the center of the YIG thin film. Furthermore, on the YIG thin film, two transducers are disposed so as to intersect with each other at right angles at the center of the YIG thin film and to connect magnetically to the YIG thin film.

Abstract: The magnetostatic wave device 10 includes a holder 12 made of synthetic resin. The holder 12 is provided with a number of recesses 14, 16, 22a, 22b, 24a and 24b. In the holder 12, a magnet 30 is housed in the recess 14, and a YIG element 32 as a ferromagnetic element is housed in the recess 16, and transducers 34a and 34b are housed in the recesses 22a, 22b, 24a and 24b.

Abstract: A magnetostatic wave filter comprises a waveguide having a cut-off frequency region. In this waveguide, a YIG thin film is installed as a ferrimagnetic base material. Also, the cut-off frequency region of this waveguide comprises an attenuation band of the magnetostatic wave filter. Electromagnetic wave in the attenuation band of the magnetostatic wave filter is attenuated by this waveguide.

Abstract: A magnetostatic wave device comprises a ferrimagnetic base material such as a thin film of YIG (yttrium iron garnet). The ferrimagnetic base material is formed on a supporting plate, for example, a GGG (gadolinium gallium garnet) substrate. On one principal surface of the thin ferrimagnetic base material, a first coupling antenna is formed. Furthermore, on one principal surface of the ferrimagnetic base material, second coupling antennas are formed on both sides of the first coupling antenna. In this magnetostatic wave device, the magnetostatic wave propagated from the first coupling antenna toward both sides of the first coupling antenna is received by the second coupling antennas on both sides of the first coupling antenna.