Non-reciprocal circuit element

Abstract

There is provided a non-reciprocal circuit element which has a simple structure and superiority in assembly and allows easy achievement of height reduction and size reduction while preventing fracture of a ferrite plate. In the present invention, a central conductor 1 in which respective resonators 3 extending outward are formed between I / O terminals 2a to 2c extending outward in a Y-shape from a central portion, upper and lower ferrite plates 5 and 6 between which the central conductor 1 together with the resonators 3 is sandwiched, and upper and lower magnetic metal plates 7 and 8 between which the upper and lower ferrite plates are sandwiched are stacked, a magnet 10 is arranged on the upper magnetic metal plate 7, and bent portions 4 which are bent in out-of-plane directions and form an interstice G between the central conductor 1 and the upper ferrite plate 5 are formed at respective distal end portions 3a of the resonators 3 of the central conductor 1 such that the upper ferrite plate 5 is provided to be capable of coming into and out of contact with the central conductor 1 due to the elasticity of the bent portions 4. The prevent invention also provides a non-reciprocal circuit element which can obtain good circulator characteristics without excessively increasing the magnetic field strength of a magnet and can be used in a wide band including a high frequency band in particular. To this end, in a non-reciprocal circuit element in which the I / O terminals 2a to 2c are integrally formed, and the upper and lower magnetic metal plates 7 and 8 form a closed magnetic circuit via side plates 9, the upper magnetic metal plate 7 is formed of a material having magnetic permeability lower than that of pure iron and / or is formed to have a thickness t smaller than a thickness T of the lower magnetic metal plate 8.

Description

technical field [0001] The present invention relates to a non-reciprocal circuit element such as an isolator or a circulator, which is incorporated in various microwave devices and rotates and changes the transmission path of microwaves through gyromagnetic phenomena. Background technique [0002] Generally, non-reciprocal circuit elements such as isolators and circulators are mounted on circuit boards of microwave devices such as microwave amplifiers and microwave oscillators. These non-reciprocal circuit elements have a structure in which a magnetic field in one direction is applied through a permanent magnet to the inside of a magnetic body such as ferrite for microwave magnetic resonance, and a center with input and output terminals is arranged on the surface of the magnetic body. The conductor rotates and changes the propagation path of the microwave input from the above-mentioned input-output terminal to the other input-output terminal according to the law of right-han...

AI Technical Summary

Problems solved by technology

[0007] However, in the above-mentioned conventional nonreciprocal circuit element, since many holes for inserting the input and output terminals or holes for penetrating the side walls are perforated on the thin-plate-shaped relatively brittle lower ferrite plate, etc. The opening of the opening, the side wall is used to connect the upper and lower conductor plates to form a closed magnetic circuit, so there are the following problems: the processing of the opening is difficult, the manufacturing cost is high, and if the above-mentioned circuit board is mounted on the surface after surface mounting If bending stress or warping occurs, it is easy to cause cracks starting from the edge of the opening.

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