JP4205571B2 - Planar antenna - Google Patents

Description

  The present invention relates to a planar antenna that is a microstrip antenna having a dielectric plate interposed between a radiating element and a ground conductor plate, and more particularly to a planar antenna that can ensure impedance matching of a feeder line.

  Conventionally, planar antennas such as microstrip antennas have been used as in-vehicle antennas because of their small size and light weight. FIGS. 24-1 and 24-2 are diagrams illustrating a schematic configuration of a conventional planar antenna. FIG. 24-1 is a plan view of the planar antenna 100, and FIG. 24-2 is a cross-sectional view of the planar antenna 100.

  24A and 24B, the planar antenna has a structure in which a dielectric plate 112 is sandwiched between the radiating element 111 and the ground conductor plate 113. Are arranged substantially in parallel. In the radiating element 111, when a feeder line 117 that supplies power is connected to a certain feeder point, there is a specific portion that matches the impedance of the feeder line 117, a so-called impedance matching point. Further, the impedance of the radiating element 111 tends to increase as the feeding point moves away from the center and approaches the end. For example, when the characteristic impedance of the power supply line 117 is 50Ω and the position PP1 is a matching point of 50Ω, impedance matching is performed when the power supply line 117 is connected to the position PP1, and the characteristic impedance of the power supply line 117 is 300Ω and the position PP2 Is a matching point of 300Ω, impedance matching is performed when the feeder line 117 is connected to the position PP2. Here, when the feed line 117 is 50Ω, the inner conductor 117a of the feed line 117 is connected to the position PP1, and the outer conductor 117b is connected to the ground conductor plate 113 and grounded.

Japanese Patent Laid-Open No. 5-102721 JP-A-11-289216 JP 2000-134028 A Japanese Utility Model Publication No. 5-68108 JP-A-11-220325

  However, in the conventional planar antenna described above, the impedance matching point with respect to the feeder line is only at a specific location, so that the power feeding position of the feeder line becomes inconsistent as the distance from the matching point increases, and efficient feeding cannot be performed. Of course, there was a problem that the degree of freedom in designing the shape of the radiating element was limited.

  For example, as shown in FIG. 25, when a rectangular hole is formed at the center of the radiating element 211 and an impedance matching point exists inside the hole, power cannot be supplied to the hole. For this reason, the feeding point cannot be matched with the matching point and is provided on the radiating element in the vicinity of the matching point. In FIG. 25A, power is supplied from the power supply point PP3 that has moved to the outside of the matching point due to the presence of the hole 211a. In addition, in the radiating element 212 of FIG. 25B, power is fed from the feed point PP4 that has moved further outside the matching point due to the presence of the hole 212a larger than the hole 211a. Here, a simulation of the relationship between the hole size, the feeding point position, and the impedance results in a Smith chart shown in FIG.

  For example, the outside dimensions of the radiating elements 211 and 212 are set to L × L, and the length of one side of the square holes 211a and 212a is changed from 0.15L → 0.2L → 0.25L → 0.3L. The real component of the impedance when the radiating element center to the feed point positions PP3 and PP4 are sequentially changed from 0.1L → 0.125L → 0.15L → 0.175L is 65Ω → 165Ω → 260Ω → 390Ω sequentially. Large value. In such a case, matching is impossible when a 50Ω-type feeder is used, and even if an impedance matching circuit is provided in the vicinity of the feeding point, a high matching circuit is required for conversion to extremely high impedance. Processing accuracy is required, and there are practical limitations when considering the cost. Here, the fact that power supply with matching cannot be performed means that return loss becomes large and it is difficult to obtain practical antenna characteristics.

  The present invention has been made in view of the above, and an object of the present invention is to provide a planar antenna capable of obtaining a shape design freedom of a radiating element while maintaining good antenna characteristics.

In order to achieve the above object, a planar antenna according to the present invention includes one or more radiating elements, a grounding conductor plate provided via the radiating element and a dielectric plate, and the radiating element sandwiching the grounding conductor plate. And one or more power supply conductor plates that are insulated from the ground conductor plate and are electrically connected to each of the radiating elements by two or more conductive portions, and a power supply line connected to the power supply conductor plate. It is characterized by that.

Further, the planar antenna according to the present invention is a planar antenna in which a dielectric plate is interposed between one or more radiating elements and a ground conductor plate, and on the opposite side of the radiating element across the ground conductor plate side. One or more feed conductor plates provided and having a current distribution similar to the current distribution of each of the radiating elements present on the one or more radiating elements, and the feed conductor plate and the corresponding radiating element are connected. And a plurality of conducting portions, and a power supply line is connected to an impedance matching point on the power supply conductor plate.

According to these inventions, a feed conductor plate that is provided outside the ground conductor plate side and has a current distribution similar to the current distribution of each radiating element present on one or more radiating elements, and a corresponding radiating element Are connected by a conduction part, and a power supply line is connected to an impedance matching point on the power supply conductor plate. Therefore, while maintaining good antenna characteristics, it is possible to feed power so as to maintain good antenna characteristics without providing a feed point that matches the matching point on the radiating element. improves. In addition, it is easy to attach and change the power supply line.

The planar antenna according to the present invention is characterized in that, in the above invention, a dielectric plate is interposed between the ground conductor plate and the feed conductor plate.

According to the present invention, the dielectric plate is interposed between the ground conductor plate and the power supply conductor plate so as to have mechanical strength.

Further, in the planar antenna according to the present invention , in the above invention, at least two of the conducting portions have two ends sandwiching an impedance matching point on the radiating element when one end thereof is directly fed to the radiating element. The feeding conductor plate has a strip shape connecting at least two other ends of at least the conductive portion.

According to the present invention, at least two one ends of the conducting portion are connected to two places sandwiching impedance matching points on the radiating element when the radiating element is directly fed, and the feeding conductor plate is At least two of the conducting portions are formed so as to form a band connecting the other ends, so that a feeding point where impedance is matched can be easily found.

In the planar antenna according to the present invention as set forth in the invention described above, at least one of the radiating elements is a frame-shaped radiating element.

According to the present invention, the radiating element is a frame-shaped radiating element, and a hole is provided in the center. However, even in this case, a feeding point that impedance-matches the radiating element is surely provided on the feeding conductor plate. Can be found.

The planar antenna according to the invention, in the above invention, the one or more radiating elements, a first radiating element frame-like, second radiation provided in the frame of the first radiation element And an element.

According to the present invention, the second radiating element is provided in the frame of the first radiating element, the hole of the first radiating element is effectively used, and a plurality of antennas having different characteristics are mounted in a small space. Can do.

In the planar antenna according to the present invention as set forth in the invention described above, the second radiating element is directly fed by the feeding line.

Further, in the planar antenna according to the present invention , in the above invention, the conducting portion that conducts the at least one radiating element and the feeding conductor plate is provided at four places on the radiating element that are approximately 90 degrees rotationally symmetric, A phase difference of 90 degrees is fed to two points on the feeding conductor plate.

In the planar antenna according to the present invention as set forth in the invention described above, the at least one radiation conductor has a rotationally symmetric shape of approximately 90 degrees.

In the planar antenna according to the present invention as set forth in the invention described above, the at least one power supply conductor plate has a rotationally symmetric shape of approximately 90 degrees.

  According to these inventions, impedance matching is possible even when circularly polarized waves are transmitted and received.

The planar antenna according to the present invention is characterized in that, in the above invention, a feed line connection pattern is provided on the at least one feed conductor plate.

  According to the present invention, power can be easily supplied to the power supply conductor plate.

The planar antenna according to the present invention is characterized in that, in the above invention, a notch is provided in the periphery of at least one of the radiating elements.

In the planar antenna according to the present invention as set forth in the invention described above, the cutout is a cross-shaped cutout.

  According to these inventions, notches are provided in the periphery of at least one of the radiating elements to reduce the size of the entire antenna. In these planar antennas, the resonance frequency is determined by the electrical length of the radiating element. However, when the conductor width of the radiating element is narrow, gain may deteriorate and stable transmission / reception may be difficult. Therefore, in the case where a notch is provided around the second radiating element provided in the frame as in the present invention and the electrical length is extended to make it compact with respect to a predetermined resonance frequency, it is formed in a frame shape. The installation space for the first radiating element can be afforded, and the conductor width can be widened to improve the gain. Further, when the size of the first radiating element on the frame determined from the electrical length is large and the size of the second radiating element in the frame is small, the first radiating element is miniaturized to reduce the entire antenna. Can be configured efficiently.

The planar antenna according to the present invention is characterized in that a through hole is provided in at least one of the radiating elements.

  Extending the electrical length of the radiating element without changing the outer dimensions of these planar antennas can be realized by providing notches around the radiating element as described above but also providing a through hole in the radiating element.

The antenna module according to the invention is characterized by comprising a planar antenna according to the invention.

  According to the present invention, an antenna module can be configured using a suitable planar antenna. In particular, an integrated antenna module corresponding to a plurality of wireless systems can be suitably configured.

The radio information terminal according to the invention is characterized by comprising an antenna module according to the invention.

  According to the present invention, a wireless information terminal can be configured using a suitable antenna module. In particular, when an integrated antenna module corresponding to a plurality of wireless systems is used, a multifunctional wireless information terminal can be suitably configured.

Moreover, the automobile according to the present invention is characterized in that the wireless information terminal according to the present invention is mounted.

  According to the present invention, a highly functional automobile can be configured by mounting a suitable wireless information terminal.

  According to this invention, the feeding conductor plate provided on the opposite side of the radiating element across the ground conductor plate side is connected to each of the one or more radiating elements by the two or more conducting portions, and Since the feed line is connected to the impedance matching point, the design element of the radiating element can be obtained while maintaining good antenna characteristics, and the installation and change of the feed line can be easily performed. Play.

  Further, according to the present invention, at least two ends of the conduction portion are connected to two places sandwiching impedance matching points on the radiating element when the radiating element is directly fed, and the feeding conductor plate In addition, at least two of the conducting portions are formed so as to form a band connecting each other end, and there is an effect that it is possible to easily find a feeding point where impedance is matched.

  Further, according to the present invention, the radiating element is a frame-shaped radiating element, and a hole is provided in the center. However, even in this case, a feeding point for impedance matching is surely found on the feeding conductor plate. There is an effect that can be.

  In addition, according to the present invention, the second radiating element is provided in the frame of the first radiating element, the hole of the first radiating element is effectively used, and the entire antenna can be reduced in size. Play.

  In addition, according to the present invention, there is an effect that notches and through holes are provided in the periphery of at least one of the radiating elements, which can promote downsizing of the entire antenna.

  Exemplary embodiments of a planar antenna according to the present invention will be explained below in detail with reference to the accompanying drawings. In the schematic diagram of the planar antenna shown below, the dimensional ratio of the radiating element, that is, the aspect ratio is shown as 1, but the aspect ratio is appropriately changed in accordance with the desired characteristics from the purpose of the present invention. There is no departure.

(Embodiment 1)
1 is a perspective view showing a schematic configuration of a planar antenna according to Embodiment 1 of the present invention. FIG. 2 is a cross-sectional view of the planar antenna shown in FIG. FIG. 3 is a bottom view of the planar antenna shown in FIG. 1 to 3, the planar antenna 1 includes a feeding conductor plate 15, a dielectric plate 14, a ground conductor plate 13, a dielectric plate 12, and a radiating element 11 that are sequentially stacked. At least a substantially parallel positional relationship is maintained between the radiating element 11 and the ground conductor plate 13. The radiating element 11 is a rectangular flat plate or a conductor pattern, and transmits and receives linearly polarized radio waves.

  The two conducting portions 16 are formed in a pin shape, and are connected to the two connection points 16a and 16b that sandwich the impedance matching point when the radiating element 11 and the feeding conductor plate 15 are conductively connected and the radiating element 11 is directly fed. Connected. Here, the ground conductor plate 13 and the conduction portion 16 are maintained in an insulated state. In FIG. 2, the ground conductor plate 13 is provided with a through hole of the conduction portion 16 to maintain an insulating state.

  The dielectric plate 12 is made of a material having a relative dielectric constant εr of 5 or more, and may be realized by, for example, ceramics. Since the wavelength shortening rate of the antenna is proportional to the square root of the relative permittivity εr, the larger the relative permittivity εr, the smaller the radiation element 11 can be realized. On the other hand, the dielectric plate 14 is formed of a dielectric material such as glass epoxy resin having a relative dielectric constant εr smaller than that of the dielectric plate 12. Instead of the dielectric plate 14, it may be realized by air, for example, but in that case, it is necessary to secure the strength of the planar antenna 1 by some other means.

  The feeding conductor plate 15 is a belt-like pattern, and both end sides thereof are connected to the connection points 16 c and 16 d of the conducting portion 16, respectively. Therefore, a band-like continuous conductor is formed between the two points 16c and 16d sandwiching the impedance matching point, and the current distribution on the radiating element 11 between the two points 16c and 16d on the feeding conductor plate 15 is formed. Will be reproduced.

  As a result, a matching point P1 that matches the impedance of the feeder line 17 can always be found on the feeder conductor plate 15. By connecting the inner conductor 17a of the feeder line 17 to this matching point P1, return loss is reduced. Impedance matching can be performed.

  On the other hand, the outer conductor 17b of the feeder line 17 is connected to the ground conductor plate 13 and grounded.

  Further, as shown in FIG. 4, the ground conductor plate 13, the dielectric plate 14, the power supply conductor plate 15, and the second ground conductor plate 18 can be formed of a multilayer substrate. In this case, the inner conductor 17a of the feeder line 17 may be connected to the feeder conductor plate 15 at the matching point P1, and the outer conductor 17b may be connected to the second ground conductor plate 18. The second ground conductor plate 18 is connected to the ground conductor plate 13 through a through hole or a pin (not shown).

  By the way, since an impedance matching point can be obtained on the feeding conductor plate 15 without depending on the shape of the radiating element, for example, as shown in FIGS. 5 and 6, a hole 22 is formed in the central portion of the rectangular radiating element. Even if the radiating element 21 is provided with a true impedance matching point for the radiating element 21 in the hole 22, impedance matching can be performed. That is, even if there is an impedance matching point where the feeder line 17 is matched within the hole 22, impedance matching can be reliably performed on the feeder conductor plate 15.

  In the first embodiment, as described above, since impedance matching can always be performed regardless of the shape of the radiating elements 11 and 21, the degree of freedom in designing the shape of the radiating element can be significantly improved. In addition, it is possible to increase the degree of freedom in selecting the feeder line 17 that can be impedance matched. Further, since the impedance matching point is exposed on the outer surface, the impedance matching can be easily adjusted.

(Embodiment 2)
Next, a second embodiment of the present invention will be described. In the planar antenna 2 shown in the first embodiment described above, the hole 22 is provided inside the radiating element 21. However, in the second embodiment, the hole 22 is positively used, A planar antenna capable of transmitting and receiving radio waves in a frequency band different from that of the radiating element 21 is formed.

  FIG. 7 is a perspective view showing a schematic configuration of the planar antenna according to the second embodiment of the present invention. FIG. 8 is a cross-sectional view of the planar antenna shown in FIG. Further, FIGS. 9-1 and 9-2 are views showing the power supply conductor plates 15a and 15b of the planar antenna shown in FIG. 7, 8, 9-1, and 9-2, the planar antenna 3 is placed in the hole 21 at the center of the radiating element 21 of the planar antenna 2 shown in FIGS. 5 and 6. A radiating element 31 that transmits and receives a frequency band having a higher frequency than the frequency band is provided. The radiating element 21 covers, for example, a GPS frequency band (1.6 GHz), and the radiating element 31 covers, for example, a VICS transmission / reception frequency band (2.5 GHz). As described above, by mounting the antenna having different characteristics necessary for the automobile in a small size, it is possible to contribute to the enhancement of the functionality of the automobile.

  The radiating element 31 is connected to a conduction portion 16Q penetrating the dielectric plate 12, the ground conductor plate 13, and the dielectric plate 14 at connection points 16e and 16f. The conduction portion 16Q is connected to a feeding circuit at connection points 16g and 16h. Connected at 15b. On the other hand, the inner conductor 19a of the feeder 19 is connected to the feeder circuit 15b, and the outer conductor 19b is grounded to the ground conductor plate 13b. This connection can also be realized using a multilayer substrate as described above. Further, the connection points 16e and 16f are positioned so as to sandwich the impedance matching point when the radiation element 31 is directly fed.

  According to the second embodiment, the central hole 22 in the radiating element 21 having the shape shown in the first embodiment can be effectively used, and a plurality of frequency bands can be transmitted and received in a small space.

(Embodiment 3)
Next, a third embodiment of the present invention will be described. In Embodiments 1 and 2 described above, both are planar antennas that transmit and receive linearly polarized radio waves. However, in Embodiment 3, circularly polarized radio waves are transmitted and received with a configuration corresponding to Embodiment 1. The planar antenna which can do is realized.

  FIG. 10 is a bottom view showing the configuration of the planar antenna according to the third embodiment of the present invention. 10, this planar antenna is provided with conducting portions 41a and 41b and conducting portions 42a and 42b corresponding to the conducting portions 16 shown in FIGS. The conducting portions 41a, 41b, 42a, and 42b are provided at locations that are 90-degree rotationally symmetric. Moreover, the feed conductor plates 41 and 42 corresponding to the feed conductor plate 15 shown in FIGS. 1 to 3 are formed in one 90-degree rotationally symmetrical shape that intersects at right angles at the center.

  One implementation method for transmitting and receiving circularly polarized waves is a two-point power feeding method. This forms two current distributions that resonate perpendicular to each other on the radiating element 11. By giving this current distribution a phase difference of 90 degrees, transmission and reception of circularly polarized waves are realized. Note that one side of the radiating element is approximately ½ wavelength. Here, the high-frequency signal delayed by 90 degrees by the 90-degree phase shifter 43 is input to the point P4 that is the impedance matching point, and the high-frequency signal without delay is input to the point P3 that is the impedance matching point. As a result, circularly polarized waves that are turned to the right in FIG. In FIG. 10, impedance conversion is performed so that reflection does not occur at the branch of the feeder line.

  Incidentally, the planar antenna shown in FIG. 10 is provided with a 90-degree phase shifter outside, but as shown in FIG. 11, a 90-degree hybrid circuit 44 may be provided and delayed by 90 degrees.

  In addition, as shown in FIG. 12, a feed line connection pattern 45 having a phase difference of 90 degrees can be provided in an empty space on the same plane as the feed conductor plate. As a result, it is possible to drive circularly polarized waves by connecting only one feeder line 17. Incidentally, a Wilkinson distributor may be used for the power supply connection pattern.

  In Embodiment 3, circularly polarized waves by two-point power feeding can be obtained by forming a power feeding conductor plate having a shape corresponding to the excited state. Also in this case, as in the first embodiment, impedance matching can always be performed regardless of the shape of the radiating element 11, so that the degree of freedom in designing the shape of the radiating element can be remarkably improved. Therefore, it is possible to increase the degree of freedom in selecting a feeder line that can be impedance matched. Further, since the impedance matching point is provided outside the radiating element, the impedance matching can be easily adjusted.

(Embodiment 4)
Next, a fourth embodiment of the present invention will be described. In the third embodiment described above, transmission / reception of circularly polarized waves is realized corresponding to the first embodiment, but in this fourth embodiment, the outer radiating element 21 corresponds to the second embodiment. Can realize transmission and reception of circularly polarized waves.

  FIG. 13 is a bottom view showing the configuration of the planar antenna according to the fourth embodiment of the present invention. In this planar antenna, a conductor pattern having a hole 46 is formed near the center of the planar antenna shown in FIG. Then, power is supplied to the radiating element 31 from the region of the hole 46.

  As a result, circularly polarized waves can be transmitted / received to / from the radiating element 21 and linearly polarized waves can be transmitted / received to / from the radiating element 31. The shape of the power supply conductor plate is realized by having a rotational symmetry of 90 degrees.

  Therefore, the power supply conductor plate may be formed in a diagonal shape as shown in FIG. This also enables transmission and reception of circularly polarized waves by the radiating element 21. The feeding point for the radiating element 31 is arranged at a position shifted from the center.

(Embodiment 5)
Next, a fifth embodiment of the present invention will be described. In the fifth embodiment, the radiating element is a slit loaded antenna, and the planar antenna shown in the first to fourth embodiments is further reduced in size.

  15-1 and 15-2 are plan views showing the configuration of the planar antenna according to the fifth embodiment of the present invention. In FIG. 15A, in this planar antenna, a cutout 62a is provided in the inner radiating element 60, thereby increasing the peripheral length and promoting the miniaturization of the radiating element 60 itself. By downsizing the inner radiating element 60, the outer radiating element 61 can be increased in width d, and the antenna characteristics can be maintained. Further, as shown in FIG. 15-2, the same effect can be obtained by providing the through hole 62b.

  In addition, as shown in FIG. 16, a cutout 66 is provided in the outer radiating element 64 to promote the miniaturization of the entire antenna, and at the same time, a cruciform cutout 65 is provided in the internal radiating element 63, and the radiating element is further provided. The radiating element 63 is downsized by increasing the peripheral length of 63. As a result, sufficient antenna characteristics of the radiating element 64 can be obtained, and downsizing of the entire antenna can be further promoted. Even in this case, the same effect can be obtained by providing a through hole in place of the notches 65 and 66.

(Embodiment 6)
Next, a sixth embodiment of the present invention will be described. Although the above-described circular polarization is mainly realized by the two-point power supply method, the present invention is not limited to this, and can also be realized by a one-point power supply method using a notch as a perturbation element. FIG. 17 shows a rectangular radiating element with diagonal corners cut off. Thereby, a difference is provided in the electrical length in the diagonal direction, and transmission and reception of circularly polarized waves can be realized using the difference in resonance frequency. FIG. 18 shows normalized frequency characteristics of return loss and axial ratio as characteristics when the planar antenna shown in FIG. 17 is operated. f is the measurement frequency, f0 is the frequency at which the axial ratio is minimum, and is normalized by f0. As another example, as shown in FIG. 19, a slit 91 facing a circular radiating element is provided, and circular polarization can also be realized by this. 17 and 19, the radiating element as shown in FIG. 20 is formed in a frame shape by using the feeding conductor plate 15 connected by the conducting portion 16 as in the first embodiment. The degree of freedom in shape design such as

(Example)
FIGS. 21-1 to 21-3 are views showing a configuration of a planar antenna according to an embodiment of the present invention, FIG. 21-1 is a plan view thereof, and FIG. 21-2 is a right side view thereof. FIG. 21-3 is a bottom view thereof. In addition, each entry dimension shows an example of design conditions when the radiating element 71 is adjusted to resonate in the GPS band when the effective wavelengths in the dielectric plates 72 and 74 are λg1 and λg2, respectively. It is a thing. This planar antenna has a feed conductor plate 75 formed in a cross shape with a conductor width of 0.01λg2, a thickness of 0.02λg2, a dielectric plate 74 having a relative dielectric constant εr2, a ground conductor plate 73, 0.63λg1 × 0.63λg1. A dielectric plate 72 having a thickness of 0.09λg1, a relative dielectric constant εr1, a radiation element 71 having an outer size of 0.50λg1 × 0.50λg1, and an inner size of 0.27λg1 × 0.27λg1 are sequentially stacked. Assuming that the resonance wavelength in vacuum is λ, effective wavelengths λg1 and λg2 use the dielectric constant of the dielectric plate 72 as εr1 and the dielectric constant of the dielectric plate 74 as εr2.
λg1 ＝ λ / √ (εr1)
λg2 ＝ λ / √ (εr2)
It is represented by The resonance wavelength λ, the radiating element 71, and the power supply conductor plate 75 were conducted at conduction portions 76a to 76d provided at four positions that were 90-degree rotationally symmetric. A high-frequency signal without delay is input to the matching point P71 on the power supply conductor plate 75, and a high-frequency signal delayed by 90 degrees by the 90-degree phase shifter 76 is input to the matching point P72. FIG. 22 is a diagram showing the directivity at this time. As shown in FIG. 22, the gain of right-handed polarization is about 4 dB on the paper surface of FIG. 22, that is, toward the zenith direction, and functions sufficiently as a planar antenna of circular polarization.

  FIGS. 23A to 23D show an example of the manufacturing process of the planar antenna according to the first embodiment of the present invention. The member shown in FIG. 23A is obtained by integrally forming the radiating element 11 and the conductive portion 16 on the dielectric 12, and there are various methods for forming the member depending on the material of the dielectric 12. For example, a hole having a size capable of inserting the conducting portion 16 is formed in the dielectric 12 in advance, the conducting portion 16 is inserted into the hole, and then connected to the radiating element 11 by 16a and 16b. For example, a method of fixing the film to the dielectric 12 using an adhesive or the like is conceivable. At this time, it is desirable that the gap between the conducting portion 16 and the dielectric 12 is small. Further, as the dielectric 14, a circuit board in which the power supply conductor plate 15 is formed on one surface and the ground conductor plate 13 is formed on the other surface, and the inner surface of the hole through which the conductive portion 16 penetrates the dielectric 14 is used. Also, a metal is provided to form a so-called through hole, and by filling the through hole with solder 20, the conducting portion 16 is fixed to the dielectric 14, and the conducting portion 16 and the feeding conductor plate 15 are fixed. Conduct.

It is a perspective view which shows schematic structure of the planar antenna which is Embodiment 1 of this invention. It is sectional drawing of the planar antenna shown in FIG. It is a bottom view of the planar antenna shown in FIG. It is sectional drawing which shows schematic structure of the planar antenna which is a modification of Embodiment 1 of this invention. It is a perspective view which shows schematic structure of the planar antenna which is a modification of Embodiment 1 of this invention. It is a top view of the planar antenna shown in FIG. It is a perspective view which shows schematic structure of the planar antenna which is Embodiment 2 of this invention. FIG. 8 is a cross-sectional view of the planar antenna illustrated in FIG. 7. It is the figure which showed the electric power feeding conductor plate 15a of the planar antenna shown in FIG. It is the figure which showed the electric power feeding conductor plate 15b of the planar antenna shown in FIG. It is a bottom view which shows schematic structure of the planar antenna which is Embodiment 3 of this invention. It is a bottom view which shows schematic structure of the planar antenna which is a modification of Embodiment 3 of this invention. It is a bottom view which shows schematic structure of the planar antenna which is a modification of Embodiment 3 of this invention. It is a bottom view which shows schematic structure of the planar antenna which is Embodiment 4 of this invention. It is a bottom view which shows schematic structure of the planar antenna which is a modification of Embodiment 4 of this invention. It is a top view which shows schematic structure of the planar antenna which is Embodiment 5 of this invention. It is a top view which shows another general | schematic structure of the planar antenna which is Embodiment 5 of this invention. It is a top view which shows schematic structure of the planar antenna which is a modification of Embodiment 5 of this invention. It is a top view which shows schematic structure of the planar antenna which is Embodiment 6 of this invention. It is the figure which showed an example of the operating characteristic of the planar antenna shown in FIG. It is a top view which shows schematic structure of the planar antenna which is a modification of Embodiment 6 of this invention. It is a top view which shows schematic structure of the planar antenna which is a modification of Embodiment 6 of this invention. It is a top view of the planar antenna which is an Example of this invention. It is a right view of the planar antenna which is an Example of this invention. It is a bottom view of the planar antenna which is an Example of this invention. It is a figure which shows the antenna directivity of the planar antenna shown in FIG. It is a figure which shows an example of the manufacturing process of the planar antenna which is Embodiment 1 of this invention (the 1). It is a figure which shows an example of the manufacturing process of the planar antenna which is Embodiment 1 of this invention (the 2). It is a figure which shows an example of the manufacturing process of the planar antenna which is Embodiment 1 of this invention (the 3). It is a figure which shows an example of the manufacturing process of the planar antenna which is Embodiment 1 of this invention (the 4). It is a top view of the conventional planar antenna. It is sectional drawing of the conventional planar antenna. It is a figure which shows an example of the radiation element which provided the hole in the center part. It is a Smith chart which shows the change of the magnitude | size of the hole of the center part provided in the radiation element, the electric power feeding position, and an impedance.

Explanation of symbols

1, 2, 3 Planar antenna 11, 21, 31, 60, 61, 63, 64, 71 Radiating element 12, 14, 14a, 14b, 14c, 72, 74 Dielectric plate 13, 13a, 13b, 73 Ground conductor plate 15, 15a, 15b, 41, 42, 75 Feed conductor plate 16, 16P, 16Q, 41a, 41b, 42a, 42b, 76a to 76d Conducting portion 17, 19 Feed line 17a, 19a Internal conductor of feed line 17b, 19b Electric wire outer conductor 18 Second ground conductor plate 20 Solder 22, 46 hole 43 90 degree phase shifter 44 90 degree hybrid circuit 45 Feed line connection pattern 62a, 65, 66 Notch 62b Through hole

Claims (16)

In a planar antenna having a dielectric plate interposed between one or more radiating elements and a ground conductor plate,
One or more feeder conductor plates provided on the opposite side of the radiating element across the ground conductor plate and having a current distribution similar to the current distribution of each radiating element present on the one or more radiating elements;
A plurality of conductive portions for connecting between the power supply conductor plate and the corresponding radiation element;
And a feed line connected to an impedance matching point on the feed conductor plate. The planar antenna according to claim 1 , wherein a dielectric plate is interposed between the ground conductor plate and the power supply conductor plate. At least two of the conducting parts are connected at two ends of which sandwich an impedance matching point on the radiating element when one end thereof is directly fed to the radiating element,
3. The planar antenna according to claim 1, wherein the power supply conductor plate has a band shape connecting at least the other ends of the conductive portions. 4. At least one planar antenna according to any one of claims 1-3, characterized in that the frame-shaped radiating element of the radiating element. The one or more radiating elements are:
A frame-shaped first radiating element;
A second radiating element provided within a frame of the first radiating element;
Planar antenna according to any one of claims 1-4, characterized in that it comprises a. The planar antenna according to claim 5 , wherein the second radiating element is directly fed by the feeder line. The conductive portions that conduct the at least one radiating element and the power supply conductor plate are provided at four locations on the radiating element that are approximately 90 degrees rotationally symmetric, and a 90-degree phase difference power supply is provided at two points on the power supply conductor plate. The planar antenna according to any one of claims 1 to 6 , wherein: The planar antenna according to claim 7 , wherein the at least one radiation conductor has a rotationally symmetric shape of about 90 degrees. 9. The planar antenna according to claim 7, wherein the at least one feeding conductor plate has a rotationally symmetric shape of approximately 90 degrees. Wherein the at least one planar antenna according to any one of claims 1 to 9 in which the feed line connection pattern to the feeding conductor plate, characterized in that the provided. Planar antenna according to any one of claims 1-10, characterized in that a notch on the periphery of at least one of said radiating element. The planar antenna according to claim 11 , wherein the cutout is a cross-shaped cutout. At least one of the planar antenna according to any one of claims 1 to 12, characterized in that a through hole in the radiating element. An antenna module comprising the planar antenna according to any one of claims 1 to 13 . A wireless information terminal comprising the antenna module according to claim 14 . An automobile equipped with the wireless information terminal according to claim 15 .

Images