JP5289282B2 - Planar antenna - Google Patents

Description

  According to the present invention, an elastic member is provided in a laminated portion, and a planar antenna is formed in which a desired surface pressure is generated on the contact surface of each laminated plate by the elastic force of the elastic member and the laminated plate is brought into close contact therewith.

  For example, as shown in FIGS. 9 and 10, the conventional laminated antenna includes an antenna element 201 and a waveguide 20 (thick line portion) formed by flat laminated plates 01 to 04 made of a conductor or a dielectric, and further a waveguide. The electromagnetic wave generated by the high-frequency circuit including the base table 05 that forms the wave is transmitted to the antenna radiation surface of the laminated plate 01 through the waveguide 20 and radiated from each antenna element 201 to the space.

  In the above configuration, when the waveguide 20 formed of a flat plate is fixed with a fixing screw or rivet 10, the stress is generated in the laminated plates 01 to 04, so that a portion other than the fixed portion is lifted, and the laminated plate (conductor or dielectric) Since a gap g is formed between the contact surfaces 21), for example, Patent Document 1 (Japanese Patent No. 3356866) proposes a manufacturing method in which a slot plate or a substrate on a ground conductor surface is fixed with rivets with high accuracy. .

Japanese Patent No. 3356866

  FIG. 9 and FIG. 10 show the case where a method of laminating flat plates is used as a method of inexpensively constructing a waveguide or antenna having a complicated shape. A waveguide 20 composed of such a laminated plate is desired. In order to exhibit performance, it is necessary that the laminated plates are in close contact with each other even in an environment where vibration impact acts on the laminated plates and there is a temperature change.

When the electromagnetic wave is transmitted through the waveguide 20 with the gap g between the laminated plates, the electromagnetic wave leaks from the gap g, increasing the transmission loss and deteriorating the isolation from other waveguides. Further, when an antenna is constituted by these laminated plates, there is a problem that electromagnetic wave leaks from the gap g between the laminated plates, thereby causing an excitation phase error and lowering the directivity characteristics of the antenna.
In order to solve this problem, it is necessary to eliminate the gap g between the laminated plates and to make close contact so as to ensure conduction.

  In the above-mentioned Patent Document 1 (Japanese Patent No. 3356866), a method of fixing a slot plate or a substrate on a ground conductor surface with a rivet is adopted. However, fixing with a screw or a rivet increases the number of parts. There is a high probability that gaps and distortion will occur due to variations. Therefore, as a bonding method other than fixing with screws or rivets, diffusion bonding in which the entire contact surface of the laminated plate is bonded is conceivable. However, diffusion bonding also requires a long time for processing (conductive) materials are limited. And other problems such as difficulty in joining between dissimilar metals.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to obtain a joint structure that reduces the number of parts and processing time and does not cause a gap or distortion between laminated plates. Another object of the present invention is to obtain a fixing means that has no problem such as peeling after joining and has high reliability.

A planar antenna according to the present invention includes a laminated portion in which a plurality of flat plate-like members including a flat plate-like member having a transmitting / receiving antenna element are laminated, and a fixing member for assembling and fixing the laminated portion to a base table in a pressed state. The flat plate member having a transmitting / receiving antenna element is formed of a curved metal member, and at least one flat plate member of the laminated portion excluding the flat plate member is formed of an elastic member, and the elastic member and by an elastic restoring force of the plate-like member is intended to adhere the respective plate member.

  According to the planar antenna of the present invention, a desired surface pressure can be generated on the contact surface of each laminated plate constituting the waveguide and the antenna by the elastic restoring force of the laminated plate constituted by an elastic member such as a resin film. Therefore, even in an environment where there is a change in temperature due to vibrations or shocks acting on the laminated waveguide or antenna, there is no gap between the laminated plates, and the laminated plates can be held in close contact with each other and the conduction of the contact surface can be ensured. Electromagnetic leakage from the contact gap can be prevented.

  Further, since rivets, screws, and the like are not required, the number of parts and processing time can be reduced, and floating and distortion between laminated plates caused by rivet and screw stress can be prevented. Further, since the laminated plates are only in surface contact, various conductive materials can be selected without limiting the material constituting the waveguide as compared with diffusion bonding or the like.

It is the perspective view which showed the planar antenna in Embodiment 1 of this invention. It is a perspective view for demonstrating the assembly process of the planar antenna in Embodiment 1 of this invention. It is the perspective view which showed the planar antenna in Embodiment 2 of this invention, and sectional drawing for demonstrating the surface pressure state of a laminated board. It is a perspective view for demonstrating the assembly process of the planar antenna in Embodiment 2 of this invention. It is the perspective view which showed the planar antenna in Embodiment 3 of this invention, (a) showed the example at the time of welding a laminated part end surface over the whole surface, (b) showed the example at the time of partially welding It is. It is a perspective view for demonstrating the assembly process of the planar antenna in Embodiment 3 of this invention. It is the perspective view which showed the planar antenna in Embodiment 4 of this invention. It is a perspective view of the planar antenna in Embodiment 4 of this invention, (a) is an assembly process, (b) is a perspective view which shows the state just before an assembly. It is the figure which showed the assembly process of the conventional laminated body waveguide and antenna, (a) is a top view, (b) is sectional drawing which looked at the AA line | wire of FIG. 9A is a side sectional view after the antenna of FIG. 9 is assembled, FIG. 9A is a sectional view of the AA line in FIG. 9A viewed in the direction of the arrow, and FIG. FIG.

  The planar antenna in each embodiment according to the present invention has a configuration in which a laminated portion in which a plurality of flat plate-like members are laminated is assembled and fixed to a base table in a pressed state by a fixing member, and at least one of the laminated portions is further fixed. The flat plate member is composed of an elastic member (for example, a laminated resin film having elasticity), and the elastic member is elastically deformed by pressurizing the upper and lower surfaces of the elastic member. The basic structure is to make it closely contact.

The uppermost flat plate member is composed of a flat plate (metal or resin) or a metal curved plate in order to pressurize the elastic member (laminated resin film), and does not have the curvature of the end of the flat plate or the metal curved plate. The edge portion is fixed by assembling it on a flat base base together with other laminated plates. In addition, when the uppermost part is a metal curved plate, the straight edge without curvature is fixed to a base stand made of metal or resin with a fixing means such as a spring or caulking, welding, or press fitting. Is done.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
In addition, the same code | symbol shows the same or an equivalent part between each figure.

Embodiment 1 FIG.
FIG. 1 is a perspective view showing a planar antenna according to Embodiment 1 of the present invention, and FIG. 2 is a perspective view for explaining a manufacturing process of the planar antenna according to Embodiment 1 of the present invention.
1 and 2, the planar antenna according to the first embodiment includes a rectangular plate member (hereinafter referred to as “a conductive member (metal) or a dielectric member (resin)) that forms an antenna element and a waveguide. A laminated portion is formed by laminating a plurality of (01 to 04) (referred to as “laminated plates”).
The laminated plate arranged at the uppermost part of the laminated portion is made of metal (hereinafter referred to as “metal flat plate”), and this metal flat plate 01 is provided with a slot (antenna element) 201 and is used for an electromagnetic wave transmission / reception antenna element to space. Each of the laminated plates 02 to 04 is provided with a slit 301, and by laminating them on the base table 05, a waveguide for transmitting electromagnetic waves is formed in the laminated plate.
The antenna element is formed by the slot 201 of the laminated plate 01 arranged at the uppermost part of the laminated portion. However, the waveguide is formed by a plurality of laminated plates in order to freely set the shape and the route, and has a cross section. In order to change the shape and route, a plurality of laminated plates such as those having different widths and lengths of the slits 301 and those obtained by dividing the slits 301 in the longitudinal direction are used.
In the first embodiment, the metal flat plate 01 is used for the flat plate member disposed at the uppermost part of the laminated portion. However, the metal flat plate 01 may be formed of a hard resin with conductive coating.

Next, the configuration of the laminated part will be described in detail.
In the first embodiment, the waveguide and the antenna are configured by combining two or more kinds of laminated plates. Among the laminated plates 02 to 04 other than the uppermost metal flat plate 01, at least one laminated plate is made of a resin film. It consists of elastic bodies such as.
As a resin film material, it has high tensile strength, moderate elongation, resin film with good mechanical properties, especially firmness, excellent elastic recovery, and handling from the viewpoint of processing technology. Easy to use PET (polyethylene terephthalate) or PI (polyimide) with a thickness of about 0.1 mm. Alternatively, each of the laminated plates 02 to 04 may be formed of a plurality of resin films such that the laminated plates 02 to 04 have a desired thickness.

Thus, the laminated part which has arrange | positioned the resin film is the state which compressed the laminated part by pressing the metal flat plate 01 with the lamination | stacking part fixing jig | tool (for example, 12 of FIG. 6), and the metal flat plate 01 and the base stand 05. The base table 05 is assembled and fixed by elastically holding the gap between both ends 11a1 and 11b1 of a pair of fixing members 11 (hereinafter referred to as “fixing tools”). The fixture 11 is a leaf spring or the like and has a cross section formed in a wave shape as shown in FIGS.
At this time, by pressing the upper and lower surfaces of the resin film and elastically deforming the resin film, the laminated plates can be brought into close contact with each other by the elastic restoring force. That is, after assembly, a stress corresponding to the amount of deformation of the resin film is generated as a surface pressure between the laminated plates, so that the contact surfaces between the laminated plates can be in close contact with each other, and conduction can be reliably ensured.
Further, since the resin film has higher flexibility than the metal plate, the resin film can be adhered in a shape along the shape of the metal flat plate 01 or the base base 05. The base table 05 is made of a member (metal or resin) having a sufficiently high bending strength with respect to the laminated plate so that the shape of the metal flat plate 01 and the laminated plates 02 to 04 is maintained after the laminated portion is fixed. The

In order to prevent the resin film from breaking within the service life after assembly, the maximum value of the stress received by the resin film needs to be a certain value or less. For creep fracture at high temperatures, the fracture stress decreases with time, so the critical stress that does not break is determined according to the service life. In particular, since a resin has a low elastic modulus, it is necessary to consider strain (deformation) rather than fracture.
In the resin, a 1% strain or a stress corresponding thereto is set as the creep limit, and also in the first embodiment, the surface pressure is set below the creep limit using the following formula (1).
In the case of non-reinforced resin, the elastic modulus at room temperature is about 2 to 5 GPa, but especially at high temperatures,
Since the strength is reduced to half or less, the stress at the time of assembling the resin film, that is, the surface pressure, needs to be 10 to 25 MPa or less.

P = σ = E * ε = F / A (1)
P: surface pressure, σ: stress, E: elastic modulus,
ε: strain, F: assembly force, A: contact area,

  On the other hand, considering the effects of disturbances such as vibrations and impacts, the surface pressure during assembly must be set as high as possible. It is necessary to assemble with. In order to satisfy these contradictory conditions, as shown in FIGS. 1 and 2, in the first embodiment, the fixture 11 is a spring, so that the surface pressure is reduced even if creep deformation occurs in the resin film. It was possible to prevent.

Antenna elements and waveguides are formed on the resin film by punching holes such as slots and slits with a YAG laser on the resin film, and metallizing methods such as sputtering and electroplating to form metal on the sidewalls of the holes and the upper and lower surfaces of the resin film A method of attaching a film is used. The method of forming a metal layer by drilling a hole in the resin film first, forming a film later, and simultaneously performing electroplating (metallization) on the front, back, and holes is a technology that has already been mass-produced. Therefore, if this manufacturing method is used, an antenna element and a waveguide can be formed at low cost.
In the case of an antenna element, the slot 201 formed in the laminated plate 01 arranged at the uppermost part of the laminated portion is formed by making a hole in the resin film and covering the front and back surfaces of the laminated plate including the cross section with a conductor. Form.
In the case of a waveguide, it is formed in a tubular shape by slits 301 and laminates 01 and 05 provided in the laminated laminates 02 to 04, and the slit 301 is also formed of a laminate including a cross section of a long hole provided in a resin film. A tubular waveguide is formed by covering the front and back surfaces with a conductor.

Embodiment 2. FIG.
In the planar antenna according to the second embodiment, a rectangular flat plate is adopted as the uppermost metal flat plate 01.
FIG. 3A is a perspective view showing a planar antenna according to Embodiment 2 of the present invention, FIG. 3B is a sectional view showing a surface pressure state when a waveguide using a resin film is formed, and FIG. ) Is a cross-sectional view showing a surface pressure state when a coaxial line is formed using a resin film, and FIGS. 4A and 4B are perspective views for explaining a manufacturing process of the planar antenna according to the second embodiment. FIG.

  In FIG. 4A, a rectangular metal curved flat plate (hereinafter referred to as “metal curved plate”) 01 is a plate having a curvature only in one direction, and the curved surface was calculated by the following equation (2). Formed with curvature.

Y = 16YmaxX (X ^ 3-2LX ^ 2 + L ^ 3) / (5L ^ 4) ………… (2)
Y: deflection amount, Ymax: maximum deflection amount, L: fixed point interval of metal curved plate,
X: position in a direction connecting two fixed points of the plate-like member (any distance from the fixed point),

In this equation (2), the deflection amount Y is a function of the distance X from the curved plate fixing point (curved plate end), determines the maximum deflection amount, derives the deflection amount at each location, and the deflection amount is a fixed point ( The surface pressure is evenly distributed by forming a curved plate so as to be farther away from the end of the curved plate and maximizing at the center, and fixing the curved plate to be a flat plate.
Further, in order to make the contact surface pressure generated by the pressing of the metal curved plate 01 evenly distributed, two sides (straight edge portions) 01a facing in a direction having no curvature are fixed by the fixing tool 11, and 1 The fixing force K per side is not more than the value of the following equation (3).

K = 192Ebh ^ 3Ymax / (60L ^ 3) ………… (3)
E: longitudinal elastic modulus of the plate material, b: length of the side 01a having no curvature at the end of the metal curved plate,
h: thickness of metal curved plate, Ymax: maximum deflection,
L: Fixed interval of the metal curved plate,

This metal curved plate 01 can be applied not only to a waveguide but also to a coaxial line, a planar line, etc., a waveguide feeding antenna, a coaxial line feeding antenna, a planar circuit antenna, and the like. Further, in any of the waveguides or antennas constituted by the laminated plates, the contact surface pressure can be made equal by configuring the uppermost portion of the laminated plate with the metal curved plate 01.
That is, as shown in FIGS. 3B and 3C, the laminated plates 01 to 05 in the tube wall (a, b, c) portion are in contact with each other in both the waveguide and the coaxial line. By pressing and fixing to the laminated plate 05 side until the laminated plate 01 becomes flat, a surface pressure is generated on the tube walls (a, b, c). Here, by forming the uppermost curved laminated plate 01 by the formula (2), the surface pressures a, b, and c are evenly distributed at any position in the longitudinal direction of the tube wall. Similarly, in the planar circuit antenna, the surface pressure of the contact portion can be made uniform by forming the uppermost laminated plate with a curved plate.

Next, the fixing means by the caulking method will be described based on FIG.
In the fixing means based on this caulking method, a laminated portion fixing jig (hereinafter referred to as “fixing jig”) 12 is used, and a two-side peripheral portion (straight edge portion) having no curvature of the metal curved plate end portion. ) The laminated plates 01 to 04 are integrated and fixed by crimping 01a.
In FIG. 4A, first, the laminated plates 02 to 04 and the uppermost metal bent plate 01 are laminated on the base table 05 in accordance with the fixture 11 inserted and implanted in the base table 05 in advance.
Next, the fixing jig 12 is pressed against the base table 05 until the curved metal plate 01 becomes flat. In this pressing state, as shown in FIG. The tip 11a2 of 11 is bent and fixed. In addition, in order to make the fixing tool 11 easy to bend (crimp), a V-groove (notch) may be provided on the outer surface of the distal end portion 11a2 of the fixing tool 11. Further, heat may be applied to the fixing tool 11 for heat caulking.

  After fixing the laminated portion, it is necessary to fix the laminated plate so that the surface pressure between the laminated plates becomes uniform. Therefore, when caulking, the metal bent plate 01 and the laminated plates 02 to 04 can be fixed without applying excessive force. The jig 12 must be used. Further, as shown in FIG. 4B, the fixing jig 12 has the tip 12b of the fixing jig 12 in a state where the pressed metal curved plate 01 is pressed against the base base 05 and becomes flat. Was to hit the base stand 05.

In the second embodiment, as shown in FIG. 3, the uppermost metal bent plate 01 is elastically deformed after the fixing portion 12a2 is bent (crimped), that is, after the fixing jig 12 is removed. Therefore, the laminates 01 and 02 to 04 and the base base 05 are pressed together by the action of the restoring force (elastic force) and the elastic restoring force of the inner resin film. It becomes a state.
With this configuration, the resin film can be brought into close contact with the metal curved plate 01 and the shape of the base base 05, and the elasticity of the metal curved plate 01 can be achieved even if creep deformation occurs in the resin film. With force, it was possible to prevent a decrease in surface pressure. Therefore, the laminated plates can be kept in close contact even in an environment where vibration impact acts on the laminated plates and there is a temperature change.

Embodiment 3 FIG.
In the planar antenna according to the third embodiment, two side peripheral portions (straight edge portions) c that do not have the curvature of the metal curved plate end are welded, and the laminated plates are integrated and fixed.
5 (a) and 5 (b) are perspective views showing the welding completion state of the two modes of the planar antenna according to the third embodiment of the present invention. FIGS. 6 (a) and 6 (b) are views according to the third embodiment of the present invention. It is a perspective view for demonstrating the manufacture process of a planar antenna.

Hereinafter, the means for integrally fixing the laminated plate by welding will be described with reference to FIG.
First, similarly to the caulking fixing means of the second embodiment, the laminated plates 02 to 04 and the metal curved plate 01 are laminated on the base table 05 with the metal curved plate 01 as the uppermost portion.
Thereafter, as shown in FIG. 6 (b), the fixing jig 12 is pressed against the base table 05 until the uppermost metal curved plate 01 becomes flat, and the metal curved plate 01 does not have a curvature in the pressed state. The straight edge c, the edge d of the laminated plates 02 to 04, and the end side e of the base base 05 are welded and fixed.
As a welding method, welding using a laser or the like, brazing, soldering, or the like is performed. As a welding mode, as shown in FIG. And (cde) are integrally fixed, and as shown in FIG. 5 (b), a part of the side surface of the base base 05 and the laminated plates 01 to 05 are welded and integrally fixed by partial welding (cde). There is a case.

After the lamination portion is fixed, the uppermost metal curved plate 01 is elastically deformed and flattened like the caulking of the second embodiment, so that its restoring force (elastic force) and the elastic recovery of the resin film that is the inner layer Due to the force, each of the laminated plates 01 and 02 to 04 and the base base 05 is pressed.
Also in this third embodiment, the resin film can be brought into close contact with the metal curved plate 01 and the shape of the base base 05, and the elasticity of the metal curved plate 01 can be achieved even if creep deformation occurs in the resin film. It is possible to prevent a decrease in surface pressure with force.
Therefore, as in the second embodiment, vibration impact acts on the laminated plates, and the adhesion between the laminated plates can be maintained even in an environment where there is a temperature change.

Embodiment 4 FIG.
In the planar antenna according to the fourth embodiment, the two-side peripheral portion (straight edge portion) 01a having no curvature of the end portion of the metal curved plate is formed by the convex portions 11a4 and 11b4. The laminated plates 01 to 04 and the base base 05 are integrated and fixed by press-fitting into the recess 11c.
FIG. 7 is a perspective view showing a state where the planar antenna is fixed in the fourth embodiment of the present invention, and FIGS. 8A and 8B are diagrams for explaining the manufacturing process of the planar antenna in the fourth embodiment of the present invention. FIG.

Hereinafter, the integrated fixing means of the laminated plate by the U-shaped fixture 11 will be described with reference to FIG.
First, similarly to the fixing means of the second and third embodiments, the laminated plates 02 to 04 and the metal curved plate 01 are laminated on the base table 05 with the metal curved plate 01 as the uppermost portion. Thereafter, as shown in FIG. 8 (b), the fixing jig 12 is pressed against the base table 05 until the uppermost metal curved plate 01 becomes flat, and the metal curved plate 01 does not have a curvature in the pressed state. The straight edge portion 01a, the edge portions of the laminated plates 02 to 04, and the end side surface of the base base 05 are press-fitted into the concave portion 11c of the fixture 11 and fixed together, and assembly is performed as shown in FIG. Complete.

As described in the first to fourth embodiments, after assembling the laminated plates 02 to 04 including the metal bent plate 01 to the base base 05, the metal bent plate 01 is used to keep the excitation phase of the antenna opening surface uniform. Need to be held in a plane. For this purpose, the base body 05 of the laminated waveguide is configured with a sufficiently high section modulus compared to the metal curved plate 01 and the laminated plates 02 to 04.
Further, according to the first to fourth embodiments, since the waveguide and the antenna opening surface can be held in a straight line without a gap, the excitation phase can be made uniform on the waveguide and the antenna opening surface.

01 Top laminate (flat plate, metal curved plate)
01a Straight edge portion having no curvature of metal curved plate 01 (periphery of two sides)
02 to 04 Multiple laminated plates (flat plate member, resin film)
05 Base stand 201 Antenna element (slot)
301 Slit 10 Fixing screw (rivet)
DESCRIPTION OF SYMBOLS 11 Fixing tool 11a1, 11b1 Both ends of fixing tool 11a2 Tip part of fixing tool 11 c Straight edge part which does not have the curvature of metal curved plate 01 d End edge part of laminated plates 02-04 e End of base stand 05 Side surface 11a4, 11b4 Convex part of U-shaped fixture 11 11c Concave part of fixture 11 12 Laminated part fixing jig 12a Concave part of laminated part fixing jig 12b Tip part of laminated part fixing jig 12 (with base base 05) Contact surface)
20 Waveguide 21 Laminate contact surface 30 Lamination gap.

Claims (4)

A laminated portion in which a plurality of flat plate members including a flat plate member having a transmission / reception antenna element are laminated, and a fixing member for assembling and fixing the laminated portion to the base table in a pressed state;
The flat plate member having a transmitting / receiving antenna element is formed of a curved metal member, and at least one flat plate member of the laminated portion excluding the flat plate member is formed of an elastic member, and the elastic member and planar antenna, characterized in that adhering the above plate member by the elastic restoring force of the plate member.   The planar antenna according to claim 1, wherein the elastic member is made of a resin film. The planar antenna according to claim 1 or 2, wherein the fixing member is configured by a plate spring that elastically sandwiches between the flat plate member having a transmitting and receiving antenna element and the base base . The planar antenna according to claim 1 or 2, wherein the fixing of the laminated portion to the base table by the fixing member is performed by any of fixing means of welding means, press-fitting means, or caulking means .

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