JPH04105402A - Integrated magnetostatic wave filter - Google Patents

Abstract

PURPOSE:To reduce number of components and to decrease the assembly cost by providing a region roughened mechanically the surface of a ferromagnetic thin film between components of the integrated magnetostatic filter in which at least two sets of transmission and reception transducers or over are formed on one board. CONSTITUTION:A region 6 mechanically roughened the surface of a Y.I.G thin film is provided between filter elements to prevent interference between the filters. Moreover, as an example, #600 sand paper is used to form the region 6. In this case, the degree of the roughened region is a degree of making the surface white or obscure glass. Thus, a magnetostatic wave is reflected irregularly in the Y.I.G thin film and attenuated. As a result, the interference between the filters is prevented and number of components is remarkably reduced through the constitution of the filters. Thus, the manufacture cost is considerably reduced.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a magnetostatic wave filter used in microwave communication equipment, and in particular, to a magnetostatic wave filter used in microwave communication equipment, and in particular, to a magnetostatic wave filter for use in microwave communication equipment. This invention relates to a magnetostatic wave filter that integrates.

(Conventional technology) A conventional integrated magnetostatic wave filter is shown in FIG.

In the figure, 1 is a dielectric substrate, 2 is a single crystal substrate with a ferromagnetic single crystal thin film formed on one side (hereinafter referred to as a sample), 3 is a metal thin film pattern formed on the dielectric substrate 1, 4 is a ground conductor, 5 is a transducer. As sample 2,
For example, gadolinium, gallium, garnet (G, G,
G,) yttrium/iron/garnet (Y,
1. G, ) A thin film is formed, and the thin film side is arranged to face the dielectric substrate 1. The dielectric substrate 1 is made of, for example, alumina ceramics. The metal thin film pattern 3 and the transducer 5 are formed, for example, on the dielectric substrate 1 using a photoetching method, and the metal thin film pattern 3, the dielectric substrate 1, and the ground conductor 4 constitute a microstrip line. .

In the above configuration, the high frequency signal input from point A is transmitted along the microstrip line to the transducer 5 installed below the sample 2. Here, a DC magnetic field is applied to the sample 2 beak to magnetize it. The high frequency magnetic field generated by the transducer 5 excites magnetostatic waves on the ferromagnetic thin film of the sample 2, and the magnetostatic waves propagate in the direction of the other transducer 5. Next, the energy of the static magnetic wave is converted into a high-frequency magnetic field by the transducer 5, and transmitted to point B along the microstrip line. Therefore, the transmission characteristics from point A to point B are determined by the magnitude of the applied DC magnetic field, the magnitude of saturation magnetization of the ferromagnetic thin film, and the shape of the input/output quadrant transducer. Indicates passing characteristics.

(Problems to be Solved by the Invention) In the conventional filter having the above configuration, a plurality of transducers 5 are formed on a dielectric substrate 1, and a plurality of samples 2 are placed thereon. This is to prevent the static magnetic waves excited in a filter from mixing with adjacent filters and causing spurious responses in the filter's pass characteristics when multiple filters are configured on a single ferromagnetic thin film. .

Therefore, a plurality of ferromagnetic thin films must be placed on a dielectric substrate, resulting in an increase in the number of parts and an increase in assembly costs.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an integrated magnetostatic wave filter that can form a plurality of magnetostatic wave filters on one circuit board without increasing the number of parts, that is, without increasing the number of assembly steps. It is.

(Means for Solving the Problems) In order to achieve the above object, the present invention uses a single crystal substrate on which a ferromagnetic single crystal thin film is formed, and at least two or more sets of transmitting and receiving transducers are connected to one In the integrated magnetostatic wave filter formed on the two substrates, a region where the surface of the ferromagnetic thin film is mechanically roughened is provided between each filter element.

(Function) The integrated magnetostatic wave filter configured as described above actively utilizes the fact that the propagation intensity of static magnetic waves can be significantly attenuated by mechanically roughening the surface of the ferromagnetic thin film. . Because magnetostatic waves concentrate their energy and propagate within the ferromagnetic thin film, they respond sensitively to the mechanical condition of the surface of the ferromagnetic thin film. In conventional integrated magnetostatic wave filters, individual ferromagnetic thin film chips are arranged in order to prevent interference between filters, but according to the present invention, between each filter there is an area where the surface of the ferromagnetic thin film is mechanically roughened. By providing this, it is possible to attenuate the energy of static magnetic waves and prevent interference between filters as in the conventional case.

(Example) Next, examples will be described with reference to the drawings.

FIG. 1 is a perspective view showing an embodiment of the integrated magnetostatic wave filter of the present invention, in which 1 is a dielectric substrate, and 2 is a single crystal substrate (sample ),
3 is a metal thin film pattern formed on the dielectric substrate 1, 4 is a ground conductor, and 5 is a transducer. Here, the sample 2 is of an appropriate size spanning, for example, two or more sets of transmitting/receiving transducers 5, and is grown by liquid phase growth on a G, G, G (gadolinium gallium garnet) single crystal plate. G (yztrium, iron, garnet)
A single crystal thin film is formed. In addition, the transducer 5 is formed by forming an aluminum thin film by vacuum evaporation.
Patterns are formed by photoetching. A spacer (not shown) is placed so that the surface on which the ferromagnetic single crystal film of sample 2 is formed faces the transducer.
However, between each filter element, a region 6 is provided where the surface of Y, LG, and thin films are mechanically roughened to prevent interference between the filters. Note-
For example, area 6 is formed using 600-grit sandpaper.

In this case, the roughness of the area should be such that the surface becomes white or frosted glass. In this way, the static magnetic wave becomes Y,
1. It is diffusely reflected at the GJl end and attenuated. However, if it is peeled off, the edge of the film becomes a reflective surface and returns to the surface, so there is no effect.

For example, Y, 1. As shown in Figure 2, the insertion loss characteristics of the untreated G membrane edge and the surface roughened with #600 sandpaper as in the present invention are as shown in Figure 2.The former (Figure 8) has a lot of noise, and the latter (Figure In the case of (Fig.), no noise appeared at all, and a good filter was obtained.The main dimensions of each device are as follows.

Saturation magnetization...1520G, YIG Jli thickness...
19μm, Width of the area where the surface is roughened...IWll, External magnetic field...7000e, Propagation path length...6.5m, Transducer...Single strip, strip width 0.4mm (Effects of the invention) As described above As described above, according to the present invention, in order to prevent interference between the filters of an integrated magnetostatic wave filter, a region with a roughened surface of a ferromagnetic thin film is provided between each filter without using a plurality of ferromagnetic substrates. By providing this, it is possible to prevent interference between the respective filters and to significantly reduce the number of component parts of the filter.

Therefore, the production cost can be significantly reduced, and there is a great economic effect.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an embodiment of the integrated magnetostatic wave filter of the present invention, and FIGS. 2(a) and 2(b) are Y, 1. G
FIG. 3 is a perspective view of a conventional integrated magnetostatic wave filter. DESCRIPTION OF SYMBOLS 1... Dielectric substrate, 2... Single crystal substrate (sample) with a ferromagnetic single crystal thin film formed on one side, 3... Metal thin film pattern, 4... Ground conductor, 5... Transducer , 6...A region where the surface of the ferromagnetic thin film is mechanically roughened. Figure (0) N class l large, GHz Figure (b) Voice Sakaga, GHz

Claims (1)

[Claims] In an integrated magnetostatic filter in which a single-crystal substrate on which a ferromagnetic single-crystal thin film is formed, and at least two sets of transmitting and receiving transducers are formed on the single substrate, there is a gap between each filter element. An integrated magnetostatic wave filter characterized by providing a mechanically roughened area on the surface of a ferromagnetic thin film.