Parabolic antenna and method of manufacturing reflector body of the same

Abstract

 A reflector body (43) for a parabolic antenna is fabricated by preparing a sheet-like reflector section (35) by providing a metal material (33) as a reflector on one surface of a support film (31), cutting the reflector section to a size appropriate for the size of the antenna to be obtained and molding an antenna base (36) of a synthetic resin integral with the support film of said cut sheet-like reflector section in a pair of upper and lower dies (41, 42) with the cut sheet-like reflector section inserted between the dies.

Description

[0001] This invention relates to a parabolic antenna and a method of manufacturing the reflector body of the same.

[0002] The reflector-type parabolic antenna comprises a reflector body, a converter, an arm having one end connected to the reflector body and the other end connected to the converter so as to hold the converter secured at a position corresponding to the focal point of the reflector body, and a support pole for supporting the reflector body, the reflector body including a reflector section and an antenna base holding the reflector section thereon. In this specification, by the term "reflector section" is meant a reflector reinforced with a synthetic resin or like reinforcing material and not supported on the antenna base.

[0003] Although the arm which holds the converter secured in a position corresponding to the focal point of the reflector body is a press molded metal member with a rust-proof coating, it is nevertheless susceptible to rusting because it is used outdoors. Besides, it is expensive and heavy. Further, when the metal support pole of the antenna is stuck by lightning, the electric surge flowing through the pole, holder, bracket and arm is apt to destroy the converter and BS tuner it seves.

[0004] Japanese Patent Application Public Disclosure No. 58-161404 discloses a method of manufacturing a reflector body. In the disclosed method, an aluminum sheet having a thickness of 0.3 to 0.6 mm is formed into a rotational paraboloid reflector having a concave front surface and a convex rear surface. Then, the entire reflector is formed with small holes having a diameter of about 1.25 mm or less. Thereafter, a reflector body is formed using a lower die and an upper die respectively having a concave portion and a convex portion complementary to the convex rear and concave front surfaces of the reflector. More specifically, a synthetic resin sheet is placed on the concave portion of the lower die, then the reflector is placed with the convex rear surface down on the synthetic resin sheet, then a separate synthetic resin sheet is placed as an antenna base on the concave front surface of the reflector, and then the upper die is lowered onto the lower die while heating both the synthetic resin sheets, thus integrating the two synthetic resin sheets and the reflector sandwiched therebetween to thereby obtain the reflector body.

[0005] However, the above prior art method requires three pairs of upper and lower dies, one for forming an aluminum sheet into the reflector, another for forming small holes over the entire surface of the reflector and the remaining one for press forming the reflector body. This increases the cost of the equipment and processing. In addition, the small holes formed in the reflector, which are for making the two synthetic resin sheets integral with each other, should have a size not greater than one-twentieth the received wavelength in order to avoid deterioration of the antenna characteristics (this is why the diameter of the small holes is set in Japan to about 1.25 mm or less), but with such small holes, the mechanical strength of coupling of the two synthetic resin sheets is low, and the synthetic resin sheets are liable to detach from the reflector.

[0006] It is a first object of the invention to provide a parabolic antenna which can be manufactured at low cost and can protect its converter and the BS tuner connected with the parabolic antenna against destruction by lightning.

[0007] It is a second object of the invention to provide a method of readily manufacturing the reflector body of a parabolic antenna using a single pair of dies.

[0008] A third object of the invention is to provide a method of manufacturing the reflector body of a parabolic antenna having a reflector section and an antenna base, with the opposite side films of the reflector section coupled strongly to each other so as not to detach and with the reflector section and the antenna base coupled firmly so as not to detach.

[0009] To attain the above objects of the invention, there is provided a parabolic antenna comprising a reflector body having a focal point, a converter and an arm having one end connected to said reflector body and the other end connected to said converter so as to hold said converter at a fixed position corresponding to the focal point of said reflector body, characterized in that said arm is a hollow cylindrical plastic member.

[0010] Since the arm is a hollow cylindrical plastic member, it is safe from rusting, light in weight and obtainable at a low cost. Further, in the event that the support pole is struck by lightning, the converter and BS tuner are protected against destruction owing to the electric insulating action of the arm.

[0011] According to the invention, there is also provided a method of manufacturing the reflector body for a parabolic antenna, which comprises the steps of forming a sheet-like reflector section by providing a metal material on one surface of a support film made of a synthetic resin material, cutting the sheet-like reflector section to a size appropriate for the size of an antenna to be fabricated, and forming an antenna base of a synthetic resin material on the support film of the cut sheet-like reflector section with the reflector section held between dies for molding the antenna.

[0012] As explained above, in the method of manufacturing the reflector body of the parabolic antenna according to the invention, the sheet-like reflector section is prepared and then cut to the antenna size, and finally the synthetic resin antenna base is molded in the dies with the cut sheet-like reflector section inserted therebetween, such that the antenna base is formed integrally with the synthetic resin support film of the reflector section. Thus, only a single molding step is necessary in the manufacture. In addition, since the reflector section and the antenna base comprise synthetic resin films of the same kind, it is safe from inter-film detachment.

[0013] The above and other objects and features of the invention will become more apparent from the following description with reference to the accompanying drawings.

Figure 1 is a schematic side view showing a parabolic antenna according to the invention;

Figure 2 is a partially sectioned side view showing an arm of the parabolic antenna shown in Figure 1;

Figure 3 is an enlarged sectional view showing a state of assembly of the arm and a converter in the parabolic antenna shown in Figure 1;

Figure 4 is a sectional view taken along line IV-IV in Figure 2;

Figure 5 is a sectional view taken along line V-V in Figure 2;

Figure 6 is a sectional view taken along line VI-VI in Figure 2;

Figure 7 is an end view taken along line VII-VII in Figure 2;

Figure 8 is a front view showing a first embodiment of a reflector body obtained by the method according to the invention;

Figure 9 is a fragmentary enlarged sectional view taken along line IX-IX in Figure 8;

Figure 10 is an explanatory view showing a support film having a Celite primer attached thereto;

Figure 11 is an explanatory view showing the support film of Figure 10 having a metal deposited thereon;

Figure 12 is an explanatory view showing the state after the support film of Figure 11 has been washed with water to remove the Celite primer;

Figure 13 is an explanatory view showing a sheet-like reflector section obtained by laminating the support film of Figure 12 with an outer film;

Figure 14 is an explanatory view showing an antenna base molded in a pair of upper and lower dies with the sheet-like reflector section of Figure 13 inserted between the dies;

Figure 15 is a fragmentary enlarged sectional view showing a second embodiment of a reflector body obtained by the method according to the invention;

Figure 16 is an explanatory view showing another support film having a Celite primer deposited thereon;

Figure 17 is an explanatory view showing the support film of Figure 16 having a metal deposited thereon;

Figure 18 is an explanatory view showing a sheet-like reflector section obtained by washing the support film of Figure 17 with water to remove the Celite primer;

Figure 19 is an explanatory view showing an antenna base molded in a pair of upper and lower dies with the sheet-like reflector section of Figure 18 inserted between the dies;

Figure 20 is a front view showing a third embodiment of a reflector body obtained by the method according to the invention;

Figure 21 is a fragmentary enlarged sectional view taken along line XXI-XXI in Figure 20;

Figure 22 is an explanatory view showing still another support film having a metal net mounted thereon;

Figure 23 is an explanatory view showing a sheet-like reflector section obtained by laminating the support film of Figure 22 with an outer film;

Figure 24 is an explanatory view showing an antenna base molded in a pair of upper and lower dies with the sheet-like reflector section of Figure 23 inserted between the dies;

Figure 25 is a front view showing a fourth embodiment of a reflector body obtained by the method according to the invention;

Figure 26 is a fragmentary enlarged sectional view taken along line XXVI-XXVI in Figure 25;

Figure 27 is an explanatory view showing a sheet-like reflector section obtained by locally providing a support film with a metal film layer;

Figure 28 is an explanatory view showing an antenna base molded in a pair of upper and lower dies with the sheet-like reflector section of Figure 27 inserted between the dies;

Figure 29 is a front view showing a fifth embodiment of a reflector body obtained by the method according to the invention;

Figure 30 is a fragmentary enlarged sectional view taken along line XXX-XXX in Figure 29;

Figure 31 is an explanatory view showing a metal-deposited film formed with a plurality of small holes;

Figure 32 is an explanatory view showing a sheet-like reflector section obtained by laminating the metal-deposited film of Figure 31 with an outer film; and

Figure 33 is an explanatory view showing an antenna base molded in a pair of upper and lower dies with the sheet-like reflector section of Figure 32 inserted between the dies.

[0014] Figure 1 schematically shows the construction of a parabolic antenna according to the invention, in which reference numeral 1 designates a reflector body (a BS antenna), numeral 2 a bracket secured to the back of the antenna, and numeral 3 a support pole. Two holder plates 4 are secured to the upper end portion of the support pole 3 in a clamping fashion with bolts 5 and nuts. The bracket 2 is mounted at an adjustable angle on one of the holder plates. The above structure is well known. The bracket, support pole and holder plates are all made of metal.

[0015] The anttena further comprises an arm 10. As shown in Figure 2, the arm 10 is shaped substantially like the letter J. It has an upright straight portion 11, an curved portion 13 and an oblique straight portion 14 extending obliquely upwardly. The upright straight portion 11 has an upper end portion secured by a pair of upper and lower screws 9' to the back side of the bracket 2. The obliquely straight portion 14 has a free end portion 15 to which a converter assembly 7 including a converter 6 is secured. The upright and oblique straight portions 11 and 14 make an angle which is prescribed in Japan to be about 66° 43'. When the converter assembly 7 is secured to the free end portion 15 of the oblique straight portion 14 of the arm 10, the end 6' of the converter 6 facing the reflector body 1 is located at the focal point of the antenna. As shown in Figure 3, the converter assembly 7 has a projection 8 which projects into and is secured by a pair of upper and lower screws 9 to the free end portion 15 of the arm 10.

[0016] The arm 10 is a plastic molding. It is desirably formed by the blow molding method utilizing gas injection so that it has a large wall thickness and high mechanical strength.

[0017] The upper end portion 12 of the upright straight portion 11 of the arm has a D-shaped hollow sectional profile (Figure 4) such that it has a flat and wide surface 12' in contact with the bracket 2. This sectional profile permits the upper end portion 12 to be secured firmly by the pair of upper and lower screws 9' to the bracket 2, with the surface 12' in contact with the bracket 2. To this end, two screw holes 16 are formed in each of the contact surface 12' and the surface of the upper end portion 12 opposite the contact surface 12', and the screws 9' are passed through the screw holes 16. This arrangement permits the upper end portion 12 to be secured firmly to the bracket by two screws. Optionally, solid cylindrical pieces 17 of a metal may be pressure fitted in the holes 16 to reinforce the mechanical strength of securement.

[0018] The portion of the upright straight portion 11 exclusive of the upper end portion 12, the arcuate portion 13, and the portion of the oblique straight portion 14 exclusive of the free end portion 15 have a substantially oval hollow sectional profile with the four corners radiused large (Figure 5).

[0019] The free end portion 15 of the oblique straight portion 14 has a hollow portion 19 made blind by an inner transversal wall 18 and is substantially quadrangular in sectional profile with the corners radiused small (Figure 6). Further, it has two inner ridges 20 for positioning the projection 8 of the converter assembly 7 and an engagement projection 21 fitted to a small extent in an end portion of the assembly 7 (Figure 7). Thus, the projection 8 of the converter assembly 8 is fitted in the blind hollow portion 19 of the free end portion 15 such that it is found in a space defined by the two ridges 20 and inner wall surface therebetween, while the engagement projection 21 is fitted in the end portion of the assembly 7. In this way, the free end portion 15 and assembly 7 are abutted end to end, and in this state they are secured to each other by the pair of upper and lower screws 9. Any load exerted to the converter 6 tends to cause the projection 8 to deform the wall of the blind hollow portion 19 so as to cause a deviation of the end 6' from the focal point. However, the two ridges 20 have an effect of preventing the deformation of the wall of the blind hollow portion because they firmly support the projection 8. In addition, the ridges 20 permit snug insertion of the projection 8 without play into the free end portion of the arm. This has an effect of improving the operation of the screw attachment. The holes for passage of the screws 9, and also a drain hole 22 in the wall of the arcuate portion 13, may be formed after molding the arm from a plastic material.

[0020] As explained above, the entire arm of the antenna according to the invention is constituted by a plastic cylindrical member. It is thus free from rusting and light in weight and can be provided at low cost. Further, in the event that the metal support pole is struck by lightning, the arm serves as an electric insulator to prevent a surge of electricity from flowing to the converter and thus protects the converter and the BS tuner against destruction.

[0021] Now, a first embodiment of the method of manufacturing the reflector body 43 for a parabolic antenna according to the invention will be described with reference to Figures 8 to 14.

[0022] Designated at 31 is a support film which is desirably a polycarbonate plastic film having a thickness of 0.2 to 0.3 mm and exhibiting high impact strength and high heat resistance. A Celite primer 32 is attached to one surface 31a of the support film 31 at portions other than those on which a metal is to be deposited in a subsequent metal deposition step (Figure 10). In this embodiment, the primer 32 is attached in the form of circular dots with a diameter of 1.25 mm or less, the dots being distributed uniformly over the surface 31a of the support film 31. Instead of dots, the primer may be attached in a pattern of lines which may, for instance, be a lattice pattern of vertical and horizontal lines or oblique lines. The primer can be attached accurately using a printing technique.

[0023] After the primer 32 thus attached has been dried, the surface 31a of the support film 31 is entirely covered with a metal layer 33 formed by depositing aluminum or like metal as a reflector (Figure 11). Then, the resultant support film is washed with water to remove the primer 32 together with the portions of the metal layer deposited thereon, thus leaving the metal layer 33 deposited directly on the surface 31a (Figure 12).

[0024] Then, the surface 31a provided with the deposited metal layer 33 is laminated with an outer film 34 of synthetic resin using heat rollers, thus obtaining a sheet-like reflector section 35 having a sandwich structure (Figure 13). The outer film 34 is a polycarbonate plastic film with a thickness of 0.2 to 0.3 mm. The support film 31 is transparent, and the surface of the outer film 34 may be provided in advance with a color print of the trade name of the manufacturer or the like.

[0025] The sheet-like reflector section 35 is then cut to a size appropriate for the size of the parabolic antenna being fabricated. The cut reflector section 35 thus obtained is inserted between a pair of upper and lower dies 41 and 42 for molding a reflector body. The reflector body 43 is obtained by injecting synthetic resin into the dies to mold an antenna base 36 that is integral with the inserted sheet-like reflector section 35. When molding the antenna base, the sheet-like reflector section 35 is inserted such that the outer film 34 thereof faces the convex portion 42' of the lower die 42 complementary to the concave surface of the reflector body (Figure 14), and the antenna base 36 is made integral with the other surface 31b of the support film 31.

[0026] The antenna base 36 is molded from polycarbonate plastic. Core press molding is adopted to provide air pockets 37 in the antenna base at suitable sites thereof (Figure 9). In this way, a paraboloid free from sink marks or warpage can be obtained. The edge of the antenna base may be provided with an integral raised portion 38 to reinforce the reflector body 43.

[0027] Figures 15 to 19 show a second embodiment of the reflector body 43 of a parabolic antenna obtained by the method according to the invention, which is a slight modification of the first embodiment. As in the first embodiment, a Celite primer is attached to one surface 31a of a support film 31 at portions other than those on which a metal is to be deposited in a subsequent metal deposition step (Figure 16).

[0028] After the Celite primer 32 thus attached has been dried, the surface 31a of the support film 31 is entirely covered with a metal layer 33 formed by depositing aluminum or like metal as a reflector (Figure 17), and then the resultant support film is washed with water to remove the primer 32 together with the portions of the metal layer deposited thereon, thus leaving the metal layer 33 deposited directly on the surface 31a. In this way, a sheet-like reflector section 35 is formed (Figure 18).

[0029] The support film 31 may be transparent, or it may be colored, and its other surface 31b may be provided in advance with a color print of the trade name of the manufacturer or the like.

[0030] The sheet-like reflector section 35 is then cut to a size appropriate for the size of the parabolic antenna to be fabricated. The cut reflector section 35 is then inserted between a pair of upper and lower dies 41 and 42 for molding a reflector body. The reflector body 43 is obtained by injecting synthetic resin into the dies to mold an antenna base 36 that is integral with the inserted sheet-like reflector section 35. When molding the antenna base, the sheet-like reflector section 35 is inserted such that the other surface 31b of the support film 31 faces the convex portion 42' of the lower die 42 complementary to the concave surface of the reflector (Figure 19), and the remaining portions of the support film provided with the deposited metal layer 33 is brought into contact with the synthetic resin injected onto the side of the surface 31a of the support film.

[0031] The antenna base 36 is molded from a synthetic resin thermally fusible to the support film 31, for instance the same type of polycarbonate plastic as that of the support film. Thus, the portions 33' of the surface 31a of the support film 31 which are exposed by the removal of the primer and deposited metal layer are directly thermally fused to and made integral with the antenna base 36 while the remaining deposited metal layer 33 left attached to the surface 31a is surrounded by the integral antenna base portions. The antenna base is desirably molded by gas-assisted injection molding wherein the resin is pressed with a low pressure against the surface 31a of the support film 31 while the resin is injected. The edge of the antenna base may be provided with an integral raised portion 38 to reinforce the reflector body 43.

[0032] Figures 20 to 24 show a third embodiment of the reflector body of a parabolic antenna obtained by the method according to the invention. In this case, a metal net 39 is mounted as a reflector on one surface 31a of a support film 31. The metal net 39 is mounted by suitable means such as bonding or fusing. It is made of brass, and its mesh size is about #100.

[0033] The surface 31a provided with the metal net 39 is laminated with an outer film 34 using heat rollers, thus obtaining a sheet-like reflector section 35 having a sandwich structure. The outer film 34 is desirably made of polycarbonate plastic and has a thickness of 0.2 to 0.3 mm.

[0034] The sheet-like reflector section 35 is cut to a size appropriate for the size of the parabolic antenna to be fabricated. The cut reflector section 35 is then inserted between a pair of upper and lower dies 41 and 42 for molding the reflector body. The reflector body 43 is obtained by injecting a synthetic resin into the dies to mold an antenna base 36 that is integral with the inserted sheet-like reflector section 35. When molding the antenna base, the reflector section 35 is inserted such that the outer film 34 thereof faces the convex portion 42' of the lower die 42 complementary to the concave surface of the reflector body (Figure 24), and the antenna base 36 is made integral with the other surface 31b of the support film 31.

[0035] The antenna base 36 is molded from polycarbonate plastic. Core press molding is adopted to provide air pockets 37 in the antenna base at suitable sites thereof. In this way, a paraboloid free from sink marks or warpage can be obtained. The edge of the antenna base may be provided with an integral raised portion 38 to reinforce the reflector body 43.

[0036] Figures 25 to 28 show a fourth embodiment of the reflector body of a parabolic antenna obtained by the method according to the invention. In this case, a plurality of closely spaced metal film layer portions 32 are provided as a reflector on one surface 31a of a support film 31 by sputtering using a mask (Figure 27).

[0037] The support film 31 is desirably molded from polycarbonate plastic, has high impact strength and large heat resistance and is of a thickness of about 0.5 mm. In the illustrated embodiment, a plurality of concentric annular metal film layer portions 32 are provided on the support film 31. The distance between adjacent annular metal film portions 32 is set to 1.25 mm or less.

[0038] The sheet-like reflector section 35 thus produced is then cut into a size appropriate for the size of the parabolic antenna to be fabricated. The cut reflector section 35 is then inserted between a pair of upper and lower dies 41 and 42 for molding the reflector body. The reflector body is obtained by injecting a synthetic resin into the dies to mold an antenna base 36 that is integral with the inserted sheet-like reflector section 35. When molding the antenna base, the sheet-like reflector section 35 is inserted such that the support film 31 thereof faces the convex portion 42' of the lower dies 42 complementary to the concave surface of the reflector body (Figure 28), and the antenna base 36 is made integral with the surface 31a of the support film 31 that is provided with the metal film layer portions 32.

[0039] The antenna base 36 is molded from polycarbonate plastic. Core press molding is adopted to provide air pockets 37 in the antenna base at suitable sites thereof. In this way, a paraboloid free from sink marks or warpage can be obtained. The edge of the antenna base may be provided with an integral raised portion 38 to reinforce the reflector body 43.

[0040] Figures 29 to 33 show a fifth embodiment of the reflector body for a parabolic antenna obtained by the method according to the invention. In this case, a metal layer 33 is deposited on one surface of a support film 31. The support film 31 is of polycarbonate plastic and has a thickness of about 0.25 mm, and the deposited metal layer 33 is of aluminum and has a thickness of 1,500 angstroms. After the deposition of the metal layer 33, the support film 31 and the metal layer 33 are press-stamped to form small holes 40 over their entire area. The holes 40 may be circular with a diameter of 1.25 mm (Figure 31), may be slits having a width of 1.25 mm or less or may be square with each side measuring 1.25 mm.

[0041] Then, the other surface of the metal-deposited support film 31 is laminated with an outer film 34 to close the opening of the holes 40 at the other surface of the support film, thus obtaining a sheet-like reflector section 35 (Figure 32). The outer film 34 is of polycarbonate plastic and has a thickness of about 0.3 mm.

[0042] The sheet-like reflector section 35 is then cut into a size appropriate for the size of the parabolic antenna to be fabricated. The cut reflector section 35 is then inserted between a pair of upper and lower dies 41 and 42 for molding the reflector body. The reflector body is obtained by injecting a synthetic resin into the dies to mold an antenna base 36 that is integral with the inserted sheet-like reflector section. When molding the antenna base, the sheet-like reflector section 35 is inserted such that the outer film 34 thereof faces the convex portion 42' of the lower die 42 complementary to the concave surface of the reflector body (Figure 33), and the antenna base 36 is made integral with the surface of the support film 31 provided with the deposited metal layer 33.

[0043] The antenna base 36 is molded from polycarbonate plastic. Core press molding is adopted to provide air pockets 37 in the antenna base at suitable sites thereof. In this way, a paraboloid free from sink marks or warpage can be obtained. The edge of the antenna base may be provided with an integral raised portion 38 to reinforce the reflector body 43.

[0044] As has been described in the foregoing, in the method of manufacturing the reflector body of a parabolic antenna according to the invention, unlike the prior art method of fabricating a reflector with small holes from a thin metal plate, a sheet-like reflector section is produced. Thus, the method requires only a single pair of upper and lower dies for molding the reflector body and thus permits reduction of the cost of equipment and processing. Further, the support film, outer film and antenna base constituting the reflector section are all of the same synthetic resin material. Thus, very strong fusion can be obtained, and there is no possibility of detachment even with small bonding area.

Claims

1. A parabolic antenna comprising a reflector body (1) having a focal point, a converter (6) and an arm (10) having one end connected to said reflector body (1) and the other end connected to said converter (6) so as to hold said converter at a fixed position corresponding to the focal point of said reflector body, characterized in that said arm (10) is a hollow cylindrical plastic member.

2. The parabolic antenna according to claim 1, wherein said arm (10) is substantially J-shaped and has an upright straight portion (11) and an oblique straight portion (14), said reflector body (1) being connected to an upper end portion of said upright straight portion (10), said converter (6) being connected to an upper end portion of said oblique straight portion (14).

3. A method of manufacturing a reflector body (43) of a parabolic antenna, comprising the steps of:
   forming a sheet-like reflector section (35) by providing a metal material (33) as a reflector on one surface of a support film (31) of a synthetic resin;
   cutting said sheet-like reflector section (35) to a size appropriate for the size of the antenna to be obtained; and
   molding an antenna base (36) of a synthetic resin integral with said support film (31) of said cut sheet-like reflector section (35) with said cut reflector section inserted between dies (41, 42) for molding the reflector body (43).

4. The method according to claim 3, wherein said support film (31) is of polycarbonate plastic.

5. The method according to claim 3, wherein said antenna base (36) is of polycarbonate plastic.

6. The method according to claim 3, wherein said sheet-like reflector section (35) has a sandwich structure obtained by attaching a Celite primer (32) to part of one surface of said support film (31), depositing a metal (33) on said surface and said attached primer (32), washing the resultant reflector section (35) with water to remove said primer and said metal deposited thereon and laminating said surface and the remaining deposited metal with an outer film (34) of a synthetic resin.

7. The method according to claim 6, wherein said primer (32) is attached in the form of circular dots with a diameter of not more than 1.25 mm.

8. The method according to claim 6, wherein said antenna base (36) is molded such that it is integral with the other surface of said support film (31) from the surface provided with said deposited metal (33).

9. The method according to claim 6, wherein said outer film (34) is of polycarbonate plastic.

10. The method according to claim 3, wherein said sheet-like reflector section (35) is obtained by attaching a Celite primer (32) to part of one surface of said support film (31), depositing a metal (33) on the entire support film surface with said attached primer and washing the resultant reflector section with water to remove said primer and the deposited metal thereon.

11. The method according to claim 10, wherein said primer (32) is attached in the form of circular dots with a diameter of not more than 1.25 mm.

12. The method according to claim 10, wherein said antenna base (36) is molded such that it is integral with the support film surface with the remaining deposited metal thereon.

13. The method according to claim 3, wherein said sheet-like reflector section (35) has a sandwich structure obtained by mounting a metal net (39) on one surface of said support film (31) and laminating the support film surface having said metal net mounted thereon with an outer film (34).

14. The method according to claim 13, wherein said metal net (39) is of brass and has a mesh size of about #100.

15. The method according to claim 13, wherein said antenna base (36) is molded such that it is integral with the other surface of said support film (31) from the surface with said metal net (39) thereon.

16. The method according to claim 13, wherein said outer film (34) is of polycarbonate plastic.

17. The method according to claim 3, wherein said sheet-like reflector section (35) is obtained by forming a plurality of metal film layer portions (33) by sputtering on part of one surface of said support film (31).

18. The method according to claim 17, wherein said metal film layer portions (33) are provided in a concentric annular form.

19. The method according to claim 17, wherein said antenna base (36) is molded such that it is integral with the support film surface with said metal film layer thereon.

20. The method according to claim 3, wherein said sheet-like reflector section (35) is obtained by depositing a metal film (33) on one surface of said support film (31), forming a number of small holes (40) in the support film and said deposited metal film and laminating an outer film (34) onto the other surface of said support film from the surface with said deposited metal film thereon.

21. The method according to claim 20, wherein said metal film (33) is of aluminum and has a thickness of 1,500 angstroms.

22. The method according to claim 20, wherein said small holes (40) formed in said deposited metal film are circular and have a diameter of 1.25 mm.

23. The method according to claim 20, wherein said small holes (40) formed in said deposited metal film are quadrangular with each side measuring 1.25 mm.

24. The method according to claim 20, wherein said antenna base (36) is molded such that it is integral with the support film surface with said deposited metal film thereon.

25. The method according to claim 20, wherein said outer film (34) is of polycarbonate plastic.

Drawing