Abstract: A high-frequency package comprising a dielectric substrate, a high-frequency element that operates in a high-frequency region and is mounted in a cavity formed on said dielectric substrate, and a microstrip line formed on the surface or in an inner portion of said dielectric substrate and electrically connected to said high-frequency element, wherein a signal transmission passage of a waveguide is connected to a linear conducting passage or to a ground layer constituting the microstrip line. In the junction portion of the waveguide, for example, an end of the linear conducting passage is electromagnetically opened, so that the end portion works as a monopole antenna inside the waveguide that is connected. The high-frequency package makes it possible to connect the waveguide without adversely affecting the sealing of the high-frequency element and to transmit high-frequency signals with a low loss.

Abstract: A slot antenna comprising a dielectric substrate, a high-frequency signal transmission line formed on one surface of said dielectric substrate and having an open end, and a ground layer formed on the other surface of said dielectric substrate, said ground layer having a slot at a position opposed to the open end of said transmission line, wherein a dielectric plate for impedance matching is laminated on the surface of said ground layer on the side where said slot is formed so as to cover said slot. The slot antenna not only features a high antenna efficiency but also can be easily and cheaply produced by a layer-laminating method which is a generally employed technology for producing multi-layer wiring substrates. Besides, the slot antenna has a very simple structure which is small in size and is light in weight, and can be very well adapted to the systems that require these characteristics.

Abstract: A structure for mounting a high-frequency device on an insulating board having a circuit on a top surface and transmitting signals to the high-frequency device. The high-frequency device is sealed within a cavity on a top surface of a dielectric board. The dielectric board has a first signal transmission line on its top surface and a second signal transmission line on its bottom surface, the first and second signal transmission lines overlapping each other over a portion where the signal is transmitted through coupling of the first and second signal transmission lines. A recess is formed at the top surface of the insulating board below the overlapping portion of the first and second signal transmission lines to suppress transmission loss of the high-frequency signal between the first and second signal transmission lines. The recess may be filled with air or a material having a dielectric constant low than that of the insulating board.

Abstract: A high-frequency semiconductor device contains a semiconductor element in a cavity formed by a dielectric board and a cap. A first high-frequency transmission line connected to the semiconductor element is formed on the surface of said dielectric board in said cavity and a second high-frequency transmission line is formed on the bottom surface of said dielectric board, so that said first high-frequency transmission line and said second high-frequency transmission line are electromagnetically coupled together. In this semiconductor devise in which the first transmission line and the second transmission line are electromagnetically coupled together, the transmission lines need not be passed over the side wall of the cap, and neigther reflection loss or radiation loss takes place on the side wall. Besides, transmission loss of high-frequency signals is caused by neigther through-holes or via-holes, and is effectively suppressed.

Abstract: In the production of a 124-type or 123-type superconductor by a sol-gel method using alkoxides of respective metals, the use of a compound wherein a sec-butoxy group and a hydroxy group are coordinated with a copper atom gives a superconductor composed of flat particles having a broad C plane. The dimensional ratio defined by l/d is at least 6.7 in the case of the 124-type or is at least 8.4 in the case of the 123-type. It shows a superconducting property at a liquid nitrogen temperature. This superconductor shows a higher critical current density than one obtained by a sintering method.

Abstract: In the production of a 124-type or 123-type superconductor by a sol-gel method using alkoxides of respective metals, the use of a compound wherein a secbutoxy group and a hydroxy group are coordinated with a copper atom gives a superconductor composed of flat particles having a broad C plane. The dimensional ratio defined by l/d is at least 6.7 in the case of the 124-type or is at least 8.4 in the case of the 123-type. It shows a superconducting property at a liquid nitrogen temperature. This superconductor shows a higher critical current density than one obtained by a sintering method.

Abstract: In the production of a 124-type or 123-type superconductor by a sol-gel method using alkoxides of respective metals, the use of a compound wherein a sec-butoxy group and a hydroxy group are coordinated with a copper atom gives a superconductor composed of flat particles having a broad C plane. The dimensional ratio defined by l/d is at least 6.7 in the case of the 124-type or is at least 8.4 in the case of the 123-type. It shows a superconducting property at a liquid nitrogen temperature. This superconductor shows a higher critical current density than one obtained by a sintering method.

Abstract: A superconductive material is disclosed which has the following composition:(R.sub.1-x Ca.sub.x)(Ba.sub.1-y La.sub.y).sub.2 Cu.sub.4 O.sub.8wherein R is at least one element selected from Y, Nd, Sm, Eu, Gd, Dy, Ho, Er, Tm, Yb and Lu, x is a number in the range of 0-0.3 and y is a number in the range of 0.001-0.3 with the proviso that y is not greater than 0.2 when x is not 0.