Patent Grant
6972720
This application claims the benefit of priority to Japanese Patent Application No. 2003-397293 filed Nov. 27, 2003 and 2004-009552 filed on Jan. 16, 2004, both herein incorporated by reference.
1. Field of the Invention
The present invention relates to a patch-type antenna device suitable to be used as a global positioning system (GPS) antenna, etc.
2. Description of the Related Art
Drawings related to a conventional antenna device will be explained, in which
Next, a construction of the conventional antenna device will be described with reference to
Further, the radiating conductor plate 53 has a square shape. Four corners of the radiating conductor plate 53 are supported by the supporting members 54. Moreover, the radiating conductor plate 53 is connected to a feeding portion 55 such as a conductive line. This feeding portion 55 is inserted through a hole 56 which passes through the ground conductor 52 and the insulating substrate 51, and is connected to an antenna circuit, which is not shown (for example, see Japanese Unexamined Patent Application Publication No. 2002-237714).
Meanwhile, in such a conventional antenna device, even if there is a difference between electrical lengths due to assembling errors, etc., the difference cannot be corrected. In addition, when the antenna device is used in a state in which it is connected to external equipment, the electrical lengths of the radiating conductor plate 53 are subjected to the electrical influence from the electrical equipment and its surrounding environment, and thus the electrical lengths of the radiating conductor plate 53 are varied to cause the deviation of frequency (f0).
In the conventional antenna device, there is a problem in that, even if there is a difference between electrical lengths due to assembling errors, etc., the difference cannot be corrected. There is also a further problem in that, when the antenna device is used in a state in which it is connected to external equipment, the electrical lengths of the radiating conductor plate 53 are subjected to the electrical influence from electrical equipment and its surrounding environment, and thus the electrical lengths of the radiating conductor plate 53 are varied to cause the deviation of frequency.
Therefore, an object of the present invention is to provide an antenna device capable of adjusting the electrical lengths of a radiating conductor plate to adjust a frequency.
As first means to solve the problem, the present invention provides an antenna device comprising a ground conductor plate, and a radiating conductor plate made of a metal plate and spaced from the ground conductor plate. The radiating conductor plate is provided with adjusting means for adjusting an electrical length.
As second means to solve the problem, the present invention provides the antenna device in which the adjusting means is formed in a shape of a ladder obtained by a combination of holes and crosspieces which are provided between a central portion and an outer circumferential edge of the radiating conductor plate, and the crosspieces are cut to adjust the electrical length.
Further, as third means to solve the problem, the present invention provides the antenna device in which the radiating conductor plate has one or two feeding portions, and the ladder-shaped portion is formed at a position along a direction of an electric field generated on the radiating conductor plate.
Further, as fourth means to solve the problem, the present invention provides the antenna device in which the radiating conductor plate has the two feeding portions, and the adjusting means is provided on at least one line extending through a center of the radiating conductor plate from at least one of the feeding portions.
Further, as fifth means to solve the problem, the present invention provides the antenna device in which the radiating conductor plate has the one feeding portion, and the adjusting means is provided along second and/or third lines passing through a center of the radiating conductor plate and offset by 45 degrees with respect to a first line passing through a center from the power feeding part.
Further, as sixth means to solve the problem, the present invention provides the antenna device further comprises a circuit board arranged between the ground conductor plate and the radiating conductor plate. The radiating conductor plate has leg pieces attached to the circuit board, and extending portions provided at ends of the leg pieces and protruding through the circuit board for forming the adjusting means, and the extending portions are cut to adjust the electrical length.
Further, as seventh means to solve the problem, the present invention provides the antenna device in which the circuit board is placed on the ground conductor plate made of a metal plate, the radiating conductor plate has first and second electrical lengths which exists on two lines through the center of the radiating conductor plate orthogonal to each other, two of the leg pieces are arranged correspondingly to the first and second electrical lengths, and the extending portions provided at the respective leg pieces protrude through the radiating conductor plate, and the extending portions protruding through the ground conductor plate are cut to adjust the electrical length.
An antenna device of the present invention comprises a ground conductor plate, and a radiating conductor plate having a metal plate and spaced from the ground conductor plate. The radiating conductor plate is provided with adjusting means for adjusting an electrical length.
As described above, when the radiating conductor plate is provided with the adjusting means for adjusting the electrical lengths of the radiating conductor plate, the correction of the electrical lengths can be made even if a difference between the electrical lengths of the radiating conductor plate is produced due to assembling errors, etc. In addition, when the antenna device is used in a state in which it is connected to external equipment, the adjusting means allows the adjustment of the electrical lengths of the radiating conductor plate even if the electrical lengths of the radiating conductor plate are subjected to the electrical influence from the electrical equipment and its surrounding environment. As a result, it is possible to obtain an antenna device with good performance, which can adjust a frequency.
Further, the adjusting means is formed in a shape of a ladder obtained by the combination of holes and crosspieces, which are provided between a central portion and an outer circumferential edge of the radiating conductor plate, and the crosspieces are cut to adjust the electrical length. Thus, it is possible to obtain an antenna device with simple construction and good productivity.
Further, the radiating conductor plate has one or two feeding portions, and the ladder-shaped portion is formed at a position along a direction of an electric field generated on the radiating conductor plate. Thus, it is possible to obtain an antenna device, which can adjust an electrical length at a position having a great electrical influence, and provide good adjustment effects.
Further, the antenna device in which the radiating conductor plate has the two feeding portions, and the adjusting means is provided on at least one line extending through the center of the radiating conductor plate from at least one of the feeding portions. Thus, it is possible to provide an antenna device, which can easily form the adjusting means, adjust an electrical length at a position having a great electrical influence, and provide good adjustment effects.
Further, the radiating conductor plate has the one feeding portion, and the adjusting means is provided along second and/or third lines passing through the center of the radiating conductor plate and offset by 45 degrees with respect to a first line through the center from the feeding portion. Thus, it is possible to provide an antenna device, which can easily form the adjusting means, adjust an electrical length at a position having a great electrical influence, and provide good adjustment effects.
Further, the antenna device further comprises a circuit board arranged between the ground conductor plate and the radiating conductor plate. The radiating conductor plate has leg pieces attached to the circuit board, and extending portions provided at ends of the leg pieces and protruding through the circuit board for forming the adjusting means, and the extending portions are cut to adjust the electrical length. Thus, it is possible to obtain an antenna device, which can be stably attached, provide a radiating conductor plate of simplified construction, and provide good productivity.
Further, the circuit board is placed on the ground conductor plate made of a metal plate, the radiating conductor plate has first and second electrical lengths which exists on two lines through the center of the radiating conductor plate orthogonal to each other, two of the leg pieces are arranged corresponding to the first and second electrical lengths, and the extending portions provided at the respective leg pieces protrude through the radiating conductor plate, and the extending portions protruding through the ground conductor plate are cut to adjust the electrical length. Thus, the ends of the extending portions can be cut to adjust the electrical lengths of the radiating conductor plate, respectively. As a result, it is possible to obtain an antenna device, which can easily adjust the electrical lengths, provide a radiating conductor plate of simplified construction, and provide good productivity.
The accompanying drawings related to an antenna device of the present invention will now be described.
Further,
Further,
Further,
Further,
Further,
Next, the construction of an antenna device according to a first embodiment of the present invention will now be described with reference to
Further, the ground conductor plate 1 has a plurality of bent pieces 1f which are bent upward, and release portions 1g which are provided at a plurality of spots including portions adjacent to the bent pieces 1f.
Particularly, as shown in
Further, the first and second diagonally opposite electrodes 5a and 5b are formed to have the same area, and the third and fourth diagonally opposite electrodes 5c and 5d are also formed to have the same area, while the areas of the first and second electrodes 5a and 5b are smaller than those of the third and fourth electrodes 5c and 5d.
Moreover, the dielectric substrate 3 has a plurality of penetrating portions 3a such as through-holes which are respectively provided at the positions of the first to fourth electrode 5a to 5d, a plurality of first holes 3b provided in the vicinity of the outer circumferential edge thereof, and a plurality of second holes 3c provided at the central part thereof.
Also, the circuit board 2 is mounted with short chip-type capacitors, etc. and electronic components 6 including a tall dielectric filter 6a, etc., and is formed with electric circuits such as a matching circuit, a filter circuit, and an amplifying circuit.
Further, the tall electronic components 6 including the dielectric filter 6a, etc., are arranged in the vicinity of the outer circumferential edge of the circuit board 2.
In such a circuit board 2, particularly, as shown in
In that case, the bent pieces 1f pass through the first holes 3b such that the ends thereof protrude upward, and the release portions 1g of the ground conductor plate 1 are respectively located below the penetrating portions 3a and the second holes 3c of the circuit board 2 such that they escape from the ground conductor plate 1.
Further, when the circuit board 2 is mounted on the ground conductor plate 1, the first to fourth electrodes 5a to 5d are disposed opposite to the ground conductor plate 1 with the dielectric substrate 3 interposed therebetween, thereby forming capacitors, respectively.
A coaxial cable 7 has a central conductor 7a, and a net-shaped outer conductor 7b to cover the outside of the central conductor 7a with an insulating coating interposed between the central conductor and outer conductor. As shown in
Then, in the state shown in
Particularly, as shown in
Also, an electric field in the radiating conductor plate 8 takes directions along the lines S1 and S2, and has a first electrical length generated in the direction along the line S1 and a second electrical length generated in the direction along the line S2.
Further, the adjusting means Z is provided at positions of the lines S1 and S2 that become the directions of an electric field, and is provided between the central portion and the outer circumferential edge of the radiating conductor plate 8 at spots excluding the central portion thereof.
Moreover, the adjusting means Z is provided at opposing sides past the center C from the first and second feeding portions 9a and 9b, and is formed in a shape of a ladder obtained by combining holes 10a with crosspieces 10b. The electrical length can be adjusted so as to be longer by cutting the crosspieces 10a.
Further, the radiating conductor plate 8 has a pair of first opposing sides 11a and a pair of second opposing sides 11b, which are respectively located on lines S3 and S4 through the center C orthogonal to each other, and four leg pieces 12a, 12b, 12c and 12c, which are provided at spots excluding the central portion of the radiating conductor plate between the first opposites sides 11a on the line S3 and between the second opposing sides 11b on the line S4.
The four leg pieces 12a to 12d are formed to be bent downward at positions where the distances thereof from the center C are equal to each other, and are provided at positions closer to the center C than to the first and second opposing sides 11a and 11b.
Further, the electric field strength of the radiating conductor plate 8 is strong at certain spots at the outer circumferential portion of the radiating conductor plate 8 on the lines S1 and S2. However, the leg pieces 12a to 12d are provided at spots that are located away from the lines S1 and S2 to provide a relatively weak electric field strength.
Further, the respective ends of the leg pieces 12a to 12d are provided with locking portions 13, each of which has a first locking piece 13a that is located at the lowermost portion of each of the leg piece, and second locking pieces 13b which are provided at a distance from the first locking pieces 13a.
Also, the first and second locking pieces 13a and 13b has bent portions which are bent in directions opposite to each other with respect to the respective leg pieces 12a to 12d.
As shown in
Next, as shown in
Thereafter, as shown in
Then, the respective leg pieces 12a to 12d are soldered and connected to the first to fourth electrodes 5a to 5d, and the first and second feeding portions 9a and 9b are soldered to the wiring pattern 4 provided around the third holes 3c. The circuit board 2 and the radiating conductor plate 8 form an antenna body H.
In that case, the first to fourth leg pieces 12a to 12d and the first and second feeding portions 9a and 9b are not electrically connected with the ground conductor plate 1 by means of the escapes holes 1g.
The radiating conductor plate 8 attached to the circuit board 2 in that way is spaced from the ground conductor plate 1 and the circuit board 2 parallel thereto. The first electrical length of the radiating conductor plate 8 is determined depending on the length of the radiating conductor plate 8 on the line S1 and the capacitance of capacitors according to the electrodes 5a and 5b. Furthermore, the second electrical length of the radiating conductor plate 8 is determined depending on the length of the radiating conductor plate 8 on the line S2 and the capacitance of capacitors according to the electrodes 5c and 5d.
In the first embodiment, the length of the radiating conductor plate 8 on the line S1 and the length of the radiating conductor plate 8 on the line S2 are equal to each other. However, since the capacity formed by the electrodes 5a and 5b is smaller than the capacity formed by the electrodes 5c and 5d, the first electrical length is smaller than the second electrical length, a difference is produced between both the first and second electrical lengths. Therefore, a circularly polarized wave antenna device can be obtained.
Further, when the radiating conductor plate 8 is attached to the circuit board 2, the ground conductor plate 1 having a larger area than the radiating conductor plate 8 exists below the entire radiating conductor plate 8, and the circuit board 2 is located in a planar region of the radiating conductor plate 8 between the radiating conductor plate 8 and the ground conductor plate 1.
Moreover, when the radiating conductor plate 8 is attached to the circuit board 2, the top faces of the hooking portions 1a, stopper portions 1c and the tall electronic components 6 are arranged to face the vicinities of the peripheral portion of the radiating conductor plate 8. The ends of the bent pieces 1f are arranged to face the radiating conductor plate 8. Thus, capacitance is generated between the hooking portions 1a, the stopper portions 1c, the tall electronic components 6 and the bent pieces 1f, and the radiating conductor plate 8.
Furthermore, when the radiating conductor plate 8 is attached to the circuit board 2, the hooking portions 1a and the stopper portions 1c are arranged along the outer circumferential edge of the radiating conductor plate 8. Thereby, the hooking portions 1a and the stopper portions 1c can be formed near the center C of the radiating conductor plate 8, so that the antenna device can be made small.
Further, the lengths of the radiating conductor plate 8 on the lines S1 and S2, and the capacitance generated by the first to fourth electrodes 5a to 5d, the capacitance between the hooking portions 1a, the stopper portions 1c, the tall electronic components 6 and the bent pieces if, and the radiating conductor plate 8 can lower a frequency. As a result, the antenna device can be made small.
Particularly, as shown in
When the cover 14 is pushed downward (toward the ground conductor plate 1) in a state in which the entire antenna body H comprised of the radiating conductor plate 8 and the circuit board 2 is received in the receiving portion 14 and in a state in which the locking portions 14e are matched with the hooking portions 1a, the locking portions 14e are locked below the hooking portions 1a by snapping, respectively, and hereby the cover 14 is attached to the ground conductor plate 1.
At this time, the convex portions 14f provided at the lower portions of the side walls 14b are fitted into the holes 1b adjacent to the hooking portions 1a, and the cable 7 is located inside the concave portion 14d, such that the cable 7 is pressed down.
A sealing sheet 15 is formed of a label, etc. on one side of which an adhesive material is applied, and the sealing sheet 15 is adhered to the reverse face of the ground conductor plate 1 so as to block the release portion 1g.
The antenna device according to the first embodiment of the present invention is formed by such construction.
Further,
Also, an electric field of the radiating conductor plate 8 takes directions along lines S3 and S4 offset by 45 degrees with respect to the line S2 and passing through the center C, and has a first electrical length generated in the direction along the line S3, and a second electrical length generated in the direction along the line S4.
Further, adjusting means Z is provided at positions of the lines S3 and S4 that become the directions of an electric field, and is provided at spots excluding the central portion of the radiating conductor plate 8 between the central portion and the outer circumferential thereof. The electrical length can be adjusted so as to be longer by cutting crosspieces 10a of the adjusting means Z which is formed in the shape of a ladder.
Further, the radiating conductor plate 8 has a pair of first opposing sides 11a and a pair of second opposing sides 11b, which are respectively located on lines S3 and S4 through the center C orthogonal to each other, and four leg pieces 12a, 12b, 12c and 12c, which are provided at spots excluding the central portion between the first opposites sides 11a on the line S3 and between the second opposing sides 11b on the line S4.
The four leg pieces 12a to 12d are formed to be bent downward at positions where the distances thereof from the center C are equal to each other, and are provided at positions closer to the center C than to the first and second opposing sides 11a and 11b.
Further, the electric field strength of the radiating conductor plate 8 is strong at certain spots at the outer circumferential portion of the radiating conductor plate on the lines S3 and S4. Accordingly, the leg pieces 12a to 12d are provided at spots that are located on the lines S3 and S4 to provide a relatively strong electric field strength.
Further, the first to fourth electrodes 5a to 5d to which the leg pieces 12a to 12d are respectively connected have different areas. Thus, a difference is produced between the first and second electrical lengths, so that a circularly polarized wave antenna device can be obtained.
The construction other than the above-described construction is similar to the construction in the first embodiment. Thus, the same portions are given the same reference numerals, and the detailed description thereof will be omitted herein.
Further,
The construction other than the above-described construction is similar to the construction in the second embodiment. Thus the same portions are given the same reference numerals, and the detailed description thereof will be omitted herein.
Further,
The construction other than the above-mentioned construction is similar to that in the first embodiment. Thus, the same portions are given the same reference numerals, and the detailed description thereof will be omitted herein.
Further,
Further, the first to fourth electrodes 5a to 5d provided on the circuit board 2 as described above are eliminated in this embodiment. The leg pieces 12a to 12d are respectively locked in penetrating portions 3a of the circuit board 2, or are attached to the circuit board 2 by press fitting or with an adhesive. The extending portions 12e are arranged to pass through the circuit board 2, the ground conductor plate 1, and a sealing sheet 15, and to protrude from the bottom. Also, the protruding ends of the extending portions 12e are cut so that the first and second electrical lengths can be adjusted.
In that case, the extending portions 12e for forming the adjusting means Z may be used together with the adjusting means Z formed in the shape of a ladder obtained by combining holes 10a with crosspieces 10b, which are provided in the radiating conductor plate 8. Otherwise, the extending portions 12e themselves may be separate adjusting means Z.
The construction other than the above-described construction is similar to the construction in the second embodiment. Thus, the same portions are given the same reference numerals, and the detailed description thereof will be omitted herein.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2003-397293 | Nov 2003 | JP | national |
| 2004-009552 | Jan 2004 | JP | national |
| Number | Name | Date | Kind |
|---|---|---|---|
| 4167010 | Kerr | Sep 1979 | A |
| 5410322 | Sonoda | Apr 1995 | A |
| 5442366 | Sanford | Aug 1995 | A |
| 5631660 | Higashiguchi et al. | May 1997 | A |
| 5912647 | Tsuru et al. | Jun 1999 | A |
| Number | Date | Country |
|---|---|---|
| 2002-217637 | Aug 2002 | JP |
| 2002-237714 | Aug 2002 | JP |
| Number | Date | Country | |
|---|---|---|---|
| 20050116868 A1 | Jun 2005 | US |
