JP2006238430A - Patch antenna - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a patch antenna having satisfactory antenna characteristics that enables sure soldering of feeder pins. <P>SOLUTION: A patch antenna 10 comprises a dielectric block 11, including a through-hole 11h, a radiation electrode 12 formed on an upper surface of the dielectric block 11, a ground electrode 13 formed at the bottom surface of the dielectric block 11, and a feeder pin 14 pulled downward from the feed point of the ground electrode via the through-hole. A notch 11x, of which a cross section is formed into a rectangular shape, is formed at the edge of an opening at an upper end side of the through-hole 11h. When the feeder pin 14 is soldered, an unwanted solder 15 that attempts to flow into the through-hole 11h is made to stagnate within the notch 11x. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a patch antenna, and more particularly, to a structure of a patch antenna in which a feed pin is inserted into a through hole provided in a dielectric block.

  In recent years, portable wireless terminals using GPS (Global Positioning System) have been widely used, and digital satellite radio systems that receive radio broadcasts from artificial satellites have attracted attention. Demand is expected to increase enormously.

  FIG. 8 is an external perspective view showing an example of the structure of a conventional patch antenna. FIG. 9 is a sectional view thereof.

  As shown in FIGS. 8 and 9, the patch antenna 90 is formed on the dielectric block 11 having a through hole 11 h, the radiation electrode 12 formed on the top surface of the dielectric block 11, and the bottom surface of the dielectric block 11. The grounding electrode 13 and the feeding pin 14 drawn downward from the feeding point P of the radiation electrode 12 through the through hole 11h are provided.

  The through hole 11h is provided substantially at the center of the dielectric block 11, and penetrates from the top surface to the bottom surface. An opening 13 h is formed at a position corresponding to the through hole 11 h of the ground electrode 13, thereby preventing contact between the ground electrode 13 and the power feed pin 14.

  A head portion 14b having a diameter larger than that of the through hole 11h is formed at the rear end portion of the power feed pin 14. The feed pin 14 is inserted into the through hole 11h from the upper surface side of the dielectric block 11, and is fixed by soldering in a state where the head portion 14b is in contact with the radiation electrode 12, and is electrically connected to the radiation electrode 12. Connected to. In this state, the tip end portion 14 a of the power supply pin 14 protrudes from the bottom surface of the dielectric block 11 by a predetermined length.

  When the patch antenna 90 is mounted on the wiring board 1, as shown in the drawing, the tip of the feeding pin that protrudes from the bottom surface of the patch antenna 90 into the through hole 2 for feeding pin insertion formed on the wiring board 1. 14a is inserted and connected to the wiring (not shown) on the wiring board 1 by soldering. Thereby, the radiation electrode 12 which is an antenna radiator is connected to the high frequency circuit via the feed pin 14.

  In the manufacture of the patch antenna, after inserting the feed pin 14 into the through hole 11h of the dielectric block 11, solder is placed in advance around the head 14b of the feed pin 14, and the solder is melted by a reflow process. The upper end of the power supply pin 14 is electrically and mechanically connected to the radiation electrode 12 by fixing or soldering by applying a soldering iron to the head 14b of the power supply pin 14.

  The conventional patch antenna 90 described above has the following problems. First, the connection between the radiation electrode 12 and the power supply pin 14 is performed by solder, but when the solder is melted, the power supply pin 14 is pulled upward by the surface tension of the molten solder 15 as shown in FIG. When the flat plate portion 14b of the power supply pin 14 is lifted without being in close contact with the radiation electrode 12 and is fixed at a position higher than usual, a change occurs in the antenna impedance (reflection characteristics), and a desired gain as an antenna is obtained. There was a problem that could not get. Further, the melted solder 15 flows into a slight gap existing between the through hole 11h and the power supply pin 14 due to a capillary phenomenon, and the diameter of the power supply pin 14 is increased, so that the antenna impedance is changed. Again, the desired gain could not be obtained.

  Further, when the patch antenna 90 is mounted on the wiring board 1, the ground electrode 13 and the wiring board 1 are in close contact with each other as shown in FIG. 11A in a normal state, but it flows into the through hole 11h. When the unnecessary solder 15 wraps around to the ground electrode 13 side, the patch antenna 90 is lifted from the wiring board 1 as shown in FIG. As a result, the antenna characteristics deteriorated.

  In order to solve such a problem, a method has been proposed in which a radiation electrode is formed so as to cover the periphery of the upper end portion of the through hole of the dielectric block, and a power supply pin whose upper end portion is tapered and gradually thickened is proposed. (See Patent Document 1). According to this method, the radiation electrode is interposed in the gap between the inner wall of the opening end of the through hole and the power supply pin, and the power supply pin has a fixing force that resists the surface tension when the solder is heated by pressing the radiation electrode. Therefore, the power supply pin is not pulled by the surface tension of the solder during soldering. In addition, the upper end portion of the power supply pin can be attached in close contact with the radiation electrode, and solder can be prevented from flowing into the gap. Therefore, a desired antenna characteristic can be obtained without causing a change in antenna impedance.

In addition, a method of providing a convex portion on the shaft portion of the power supply pin has been proposed (see Patent Document 2). According to this method, since the solder that has melted and flowed into the through-hole is blocked by the convex portion of the power supply pin, it is possible to prevent the phenomenon that the solder protrudes to the ground electrode side. The eccentricity of the power supply pin can also be suppressed.
Japanese Patent Laid-Open No. 9-260933 Japanese Patent Laid-Open No. 2002-353730

  However, both of the above-described two conventional methods require a very high accuracy with respect to the dimensions of the power supply pins, and thus there is a problem that the manufacturing cost is increased. On the other hand, in order to prevent the transfer of solder due to the capillary phenomenon, a method of increasing the diameter of the through hole and increasing the gap (play) between the power supply pin and the through hole is conceivable. Since the eccentricity of the pin increases, the antenna characteristics vary. Conversely, a method is also conceivable in which the diameter of the power supply pin and the diameter of the through hole are made equal to reduce the play as much as possible. However, in this case, the dielectric block may be damaged when the power supply pin is inserted.

  Accordingly, an object of the present invention is to provide a patch antenna with good antenna characteristics that enables reliable soldering of a feed pin.

  The object of the present invention is to provide a dielectric block having a through-hole that opens on the top and bottom surfaces, a radiation electrode formed on the top surface of the dielectric block, and a ground electrode formed on the bottom surface of the dielectric block. And a power supply pin inserted into the through hole and soldered to the radiation electrode, and the dielectric block has a notch in the vicinity of the opening of the through hole on the upper surface side. Is achieved by a patch antenna.

  According to the present invention, a notch portion serving as a solder escape portion is provided at the position of the pin feed point of the dielectric block so that unnecessary solder does not flow into the through hole, thereby preventing deterioration of antenna characteristics. be able to.

  In this invention, it is preferable that the said notch comprises a part of opening part of the said through-hole in the said upper surface side. According to this, a notch part can be formed integrally with a through-hole, and formation of a notch part becomes easy. Moreover, it becomes easy to insert the power supply pin into the through hole.

  In this invention, it is preferable that the outer diameter of the said notch part spreads or is constant as it approaches the said upper surface side. According to this, even if the notch is formed on the dielectric block from the stage of the mold, when the dielectric block 11 is removed from the mold, the part of the mold corresponding to the notch is removed without any problem. Can do. That is, the notch 11x can be formed without difficulty.

  In this invention, it is preferable that the cross section of the said notch part is a rectangular shape. According to this, it is easy to form the notch, and it is possible to increase the amount of solder that accumulates in the notch.

  In this invention, it is preferable that the cross section of the said notch part is a taper shape. According to this, since insertion of the power supply pin is guided in the direction of the central axis of the through hole by the taper, insertion of the power supply pin into the through hole can be facilitated.

  The notch is preferably formed on the upper surface of the dielectric block. According to this, the solder that is about to melt and flow into the through hole accumulates in the cutout part in the middle and stays at the position of the cutout part, so that the antenna characteristics can be prevented from deteriorating.

  In this invention, it is preferable that the said notch comprises the recessed part which can accommodate the head formed in the rear-end part of the said electric power feeding pin. Here, it is preferable that the diameter of the recess is set to be substantially equal to the diameter of the head of the power feed pin, and the depth of the recess is set deeper than the height of the head of the power feed pin. . Moreover, it is preferable that the bottom surface and side surface in the said recessed part are covered with the said radiation electrode. According to this, when the power supply pin is fixed by soldering, if the amount of solder is properly adjusted, the solder will not spread larger than the diameter of the recess. Therefore, variation in antenna impedance can be suppressed, and a patch antenna with good antenna characteristics can be provided. In addition, it is possible to obtain an effect that the fixing of the power feeding pin is further strengthened and the fixing strength is further improved.

  In the present invention, the dielectric block includes a first cutout portion forming a recess capable of accommodating the head of the power feed pin, and a second cutout in the vicinity of the opening of the through hole on the bottom surface in the recess. You may have a notch. According to this, since the solder does not spread larger than the diameter of the concave portion, it is possible to suppress variations in antenna impedance, and the solder that is about to melt and flow into the through-hole is notched in the middle. Therefore, it is possible to further prevent the antenna characteristics from being deteriorated.

  According to the present invention, since the notch portion serving as the escape portion of the solder is provided around the opening on the upper end side of the through hole of the dielectric block, the connection failure between the feed pin and the radiation electrode due to the rise of the feed pin, It is possible to prevent an increase in the apparent diameter of the power supply pin due to the flow of unnecessary solder into the through hole, and poor connection between the power supply pin and the wiring board due to the solder flowing into the through hole reaching the ground conductor side. it can. Thereby, a patch antenna with good characteristics can be provided.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a perspective view showing a structure of a patch antenna according to an embodiment of the present invention. 2 is a cross-sectional view taken along the line AA in FIG.

  As shown in FIGS. 1 and 2, the patch antenna 10 is formed on a dielectric block 11 having a through hole 11 h, a radiation electrode 12 formed on the top surface of the dielectric block 11, and a bottom surface of the dielectric block 11. The ground electrode 13 and the power feed pin 14 drawn downward from the power feed point of the ground electrode through the through hole 11h are provided.

  The material of the dielectric block 11 is not particularly limited, but a Ba—Nd—Ti-based material (relative permittivity of 80 to 120), Nd—Al—Ca—Ti based material (relative permittivity of 43 to 46). ), Li—Al—Sr—Ti (relative permittivity 38 to 41), Ba—Ti based material (relative permittivity 34 to 36), Ba—Mg—W based material (relative permittivity 20 to 22), Mg— Use Ca-Ti-based materials (relative permittivity 19-21), sapphire (relative permittivity 9-10), alumina ceramics (relative permittivity 9-10), cordierite ceramics (relative permittivity 4-6), etc. It can be made by firing using a mold.

The specific material of the dielectric block 11 may be appropriately selected according to the target frequency. However, when the target frequency is 2.33 GHz, for example, the gain decreases as the relative dielectric constant ε _r increases. However, as the relative dielectric constant ε _r decreases, the wavelength shortening rate decreases. As a result, it is necessary to increase the length of one side of the radiation electrode 12. Therefore, in order to avoid an increase in size of the radiation electrode 12 while ensuring a sufficient gain, it is preferable to form the dielectric block 11 using a material having a relative dielectric constant ε _r of about 20 to 25. Preferred examples of the material having a relative dielectric constant ε _r of about 20 to 25 include Mg—Ca—Ti dielectric ceramics. As the Mg—Ca—Ti dielectric ceramic, it is particularly preferable to use a Mg—Ca—Ti dielectric ceramic containing TiO ₂ , MgO, CaO, MnO, and SiO ₂ .

  After the electrode paste material is applied to the top and bottom surfaces of the dielectric block 11 by a method such as screen printing or transfer, the radiation electrode 12 and the ground electrode 13 are formed by baking under a predetermined temperature condition. Silver, silver-palladium, silver-platinum, copper, or the like can be used as the electrode paste material.

  Since the feeding point P is provided in the approximate center of the ground electrode 12, the through hole 11h is also provided in the substantially center position corresponding to this, and penetrates from the top surface to the bottom surface of the dielectric block 11. An opening 13h having a slightly larger diameter than the through hole 11h is formed at a position corresponding to the through hole 11h of the ground electrode 13, thereby preventing contact between the ground electrode 13 and the feed pin 14. One of the corners of the dielectric block 11 is provided with a positioning taper 11t, the orientation of the patch antenna 10 is determined based on this, and the top and bottom surfaces of the dielectric block 11 are also tapered. It is determined on the basis of.

  The shape and area of the radiation electrode 12 are generally determined by the relationship with the operating frequency. Here, as shown in the figure, a rectangular electrode is formed with a certain margin from the periphery of the upper surface of the dielectric block 11. On the other hand, the ground electrode 13 is formed on the entire bottom surface of the dielectric block 11 excluding the through hole 11h and its periphery in order to enhance the ground effect as much as possible.

  As shown in FIG. 2, a cutout portion 11x having a rectangular cross section is formed integrally with the through hole 11h at the periphery of the opening on the upper end side of the through hole 11h. That is, the notch portion 11 x constitutes a part of the opening portion of the through hole 11 h on the upper surface side of the dielectric block 11. Here, the radiation electrode 12 is formed only on the upper surface of the dielectric block 11, and is not formed on the surface of the notch 11x. Further, since the cross section is rectangular, the outer diameter of the notch 11x is constant at any point in the vertical direction. This notch portion 11x serves as a space in which the solder that has melted and flowed into the through hole 11h accumulates. Due to the presence of the notch portion 11x, even if the molten solder 15 flows into the through hole 11h when the power supply pin 14 is soldered, it accumulates in the notch portion 11x and is mixed and the solder 15 flows further beyond. Nothing will happen. For this reason, the antenna impedance changes due to the floating of the feed pin 14 or the diameter of the feed pin 14, or the solder 15 that has flowed into the through hole 11 h further wraps around to the ground electrode 13 side. It is possible to prevent a situation in which connection failure is caused.

  A substantially disc-shaped head portion 14b having a diameter larger than that of the through hole 11h and the notch portion 11x is formed at the rear end portion of the power feed pin 14. That is, the power supply pin 14 is a substantially nail-shaped conductor. Usually, the pin diameter of the power supply pin 14 is uniquely determined from the relationship with the high-frequency component coupled thereto. The diameter of the through hole 11h only needs to be substantially equal to the pin diameter of the power supply pin 14, but in reality, the diameter of the through hole 11h may be smaller than the design value due to the dimensional variation of the dielectric block 11. It is necessary to determine the diameter of the through hole 11h in consideration of variations.

  The feed pin 14 is inserted into the through hole 11h from the upper surface side of the dielectric block 11, and is fixed by soldering in a state where the head portion 14b is in contact with the radiation electrode 12, and is electrically connected to the radiation electrode 12. Connected to. In this state, the tip end portion 14 a of the power supply pin 14 protrudes from the bottom surface of the dielectric block 11 by a predetermined length.

  When the patch antenna 10 is mounted on the wiring board, as described with reference to FIG. 6, the power feeding projecting from the bottom surface of the patch antenna 10 into the through-hole 2 for feeding pin insertion formed on the wiring board 1. The tip end portion 14a of the pin 14 is inserted and connected to the wiring on the wiring board 1 by soldering. Soldering is usually performed by a reflow process, but may be performed using a soldering iron. Thereby, the radiation electrode 12 which is an antenna radiator is connected to the high-frequency circuit on the wiring board 1 through the feed pin 14.

  As described above, according to the present embodiment, since the notch portion 11x serving as the solder escape portion is provided at the periphery of the opening on the upper end side of the through hole 11h of the dielectric block 11, the power supply pin 14 is lifted. This can prevent poor connection between the power supply pin 14 and the radiation electrode 12. Further, it is possible to prevent a change in antenna impedance due to an unnecessary solder flowing into the through-hole 11h and an apparent diameter of the power feed pin 14 becoming thick. In addition, it is possible to prevent a situation in which the solder that has flowed into the through hole 11h further reaches the ground electrode 13 and causes a connection failure with the wiring board. That is, a patch antenna with good characteristics can be provided. Further, according to the present embodiment, the notch 11x constitutes a part of the opening of the through hole 11h, and the outer diameter of the notch 11x is constant in the vertical direction. Even if the notch 11x is formed on the dielectric block 11 from the frame stage, when the dielectric block 11 is removed from the mold, the portion corresponding to the notch 11x can be removed without any problem. That is, the notch 11x can be formed without difficulty.

  In the above embodiment, the case where the cross section of the notch portion 11x is rectangular has been described, but various shapes of the notch portion are conceivable. Hereinafter, other examples of the notch will be described.

  3A to 3E are partial cross-sectional views showing the structure of a patch antenna according to another embodiment of the present invention. FIG. 3 shows a state before the power supply pins are soldered.

  The patch antennas 20 and 30 shown in FIGS. 3 (a) and 3 (b) are described above in that the notch is provided at the periphery of the opening on the upper end side of the through hole 11h and is integral with the through hole 11h. However, the cutout portion 11a of the patch antenna 20 shown in FIG. 3 (a) has a stepped cross section, and the cutout portion 11b of the patch antenna 30 shown in FIG. 3 (b). Is different from the patch antenna 10 described above in that the cross section is tapered. Here, it can be considered that the tapered notch portion 11b is a case where the number of steps of the step-like notch portion 11a shown in FIG. The amount of solder that can be stored in the notch is the largest in the case of a rectangular shape, and decreases as it approaches the taper shape, but conversely, the insertion of the feed pin 14 into the through hole 11h becomes closer to the taper shape. It becomes easier. Further, in the patch antenna 40 of FIG. 3C, a cutout portion 11c having a rectangular cross section is formed independently around the outer side slightly outside the through hole. Such a cut-out portion can also contribute to the accumulation of solder, and can prevent the feeding pin 14 from floating and the solder from flowing into the through hole 11h.

  Also in the patch antennas 20 and 30 shown in FIGS. 3A and 3B, the notches 11a and 11b constitute a part of the opening of the through hole 11h, and the notches 11a and 11b Since the outer diameter becomes wider as it approaches the upper surface of the dielectric block 11, even if the notches 11a and 11b are formed on the dielectric block 11 from the stage of the mold, the dielectric block 11 is removed from the mold. When removing, the part corresponding to the notch 11x can be removed without any problem. In the patch antenna 40 shown in FIG. 3C, the notch portion 11c does not constitute a part of the opening of the through hole 11h, but the outer diameter and inner diameter of the notch portion 11x are constant in the vertical direction. Therefore, when the dielectric block 11 is removed from the mold, the portion corresponding to the notch portion 11x can be removed without any problem.

  Also, the patch antennas 50 and 60 shown in FIGS. 3D and 3E are common to the patch antenna 10 described above in that a notch is provided around the opening on the upper end side of the through hole 11h. However, it differs from the patch antenna 10 described above in that the notch is formed on the inner wall surface of the through hole 11h. Among them, the notch 11d in FIG. 3D has a triangular cross section, and the notch 11e in FIG. 3E has a rectangular cross section. That is, the notch shown in FIGS. 3A to 3C has an opening on the upper surface side of the dielectric block 11, and accumulates solder to flow into the through hole 11h from the upper surface side. 3 (d) and (e), on the other hand, has an opening on the inner wall surface of the through hole 11h, and has a structure for collecting the solder that has flowed into the through hole 11h. . In this way, the solder that has flowed into the through-hole 11h accumulates in the middle and stays at the position of the notch, thereby preventing the power feed pin from floating, the diameter of the power feed pin increasing, poor connection with the wiring board, and the like. be able to.

  In the patch antennas 50 and 60 shown in FIGS. 3D and 3E, there are portions where the outer diameters of the notches 11d and 11e become narrower as they approach the upper surface of the upper surface of the dielectric block 11. It is difficult to form the notches 11d and 11e with a mold. Therefore, in this case, first, a dielectric block having a normal straight through hole may be molded using a mold, and the notches 11d and 11e may be formed in the through hole by subsequent processing.

  Next, still another embodiment of the present invention will be described in detail with reference to FIGS.

  FIG. 4 is a schematic cross-sectional view showing the structure of a patch antenna 70 according to another preferred embodiment of the present invention.

  As shown in FIG. 4, the patch antenna 70 is characterized in that a notch portion 11 f is formed on the upper surface side of the through hole 11 h for passing the power feed pin formed in the dielectric block 11, and the head 14 b of the power feed pin 14 is formed. Is housed in the notch 11f, and at this time, the head 14b of the power feed pin is configured not to protrude from the upper surface of the dielectric block. That is, the notch 11f formed in the dielectric block constitutes a recess that can accommodate the head 14b of the power feed pin (hereinafter referred to as the recess 11f). Here, the diameter of the recess 11f is set substantially equal to the diameter of the head 14b of the power feed pin, and the depth of the recess 11f is set deeper than the height of the head 14b of the power feed pin. Similarly to the seed surface (upper surface) of the dielectric block 11, the inner bottom surface and side surface of the recess 11 f are covered with the radiation electrode 12. With such a configuration, when the power supply pin is fixed by soldering, the solder does not spread larger than the diameter of the recess 11f as long as the amount of solder is appropriately adjusted.

  Thus, according to the patch antenna 70 of the present embodiment, variation in antenna impedance can be suppressed by suppressing the spread of solder, and therefore a patch antenna with good antenna characteristics can be provided. In addition, when desired characteristics are obtained at the time of antenna design, if the diameter of the through hole is calculated in advance, it can be used as an impedance adjusting means. Furthermore, since the through-hole has two steps, the effect of further fixing the power supply pin and further improving the fixing strength can be obtained. As a result, poor conduction caused by solder cracks can be avoided, and the reliability of the antenna can be improved.

  FIG. 5 is a schematic cross-sectional view showing the structure of a patch antenna 80 according to still another preferred embodiment of the present invention.

  As shown in FIG. 5, the feature of the patch antenna 80 is that a notch 11g is provided in the vicinity of the opening of the through hole in the bottom surface inside the recess 11f formed so as to accommodate the head 14b of the feed pin. It is in. This notch portion 11g corresponds to the notch portion 11x shown in FIG. 2, and serves as a space in which the solder that has melted and flowed into the through hole 11h accumulates. Due to the presence of the notch portion 11g, even if the molten solder 15 flows into the through hole 11h when the power supply pin 14 is soldered, it accumulates in the notch portion 11g and is mixed and the solder 15 flows further. Nothing will happen. For this reason, the antenna impedance changes due to the floating of the feed pin 14 or the diameter of the feed pin 14, or the solder 15 that has flowed into the through hole 11 h further wraps around to the ground electrode 13 side. It is possible to prevent a situation in which connection failure is caused.

  The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention, and it goes without saying that these are also included in the scope of the present invention. .

  For example, in each of the above embodiments, the case where the radiation electrode 12 is formed on the dielectric block 11 has been described as an example. However, the present invention is not limited to this, and a flat plate having a smaller thickness. The radiation electrode 13 may be formed on the dielectric.

  In the above embodiment, the case where the ground electrode 13 is formed on the bottom surface of the dielectric block 11 has been described as an example. However, the present invention is not limited to this, and the wiring on which the patch antenna is mounted. It is possible to provide an equivalent to the ground electrode on the substrate 1 side and omit the ground electrode on the dielectric block 11 side.

  Moreover, in the said embodiment, although the case where the shape of the head 14b of a feed pin was a substantially disc shape was demonstrated to the example, this invention is not limited to this, For example, a substantially rectangular flat plate shape is used. It may be a thing.

First, ten patch antennas of examples having the same structure as the patch antenna 10 shown in FIGS. 1 and 2 were produced. Here, (TiO ₂ : MgO: CaO: MnO: SiO ₂ ) is (60.5 ± 0.35: 37.05 ± 0.35: 2.45 ± 0.10: 0) in the dielectric block. A dielectric material having a relative dielectric constant of 21 mixed at a ratio of .17 ± 0.02: 0.20 ± 0.05 was used. The dimensions of the dielectric block were 17.2 [mm] × 17.2 [mm] × 5 [mm] in length × width × height, respectively. Further, a through hole was provided at a predetermined position slightly deviated from the center of the dielectric block, and its diameter was set to 3.0 [mm]. About the notch part, the cross section was made into the rectangular shape, the width of the radial direction was 0.5 [mm], and the depth was 0.5 [mm]. The area of the radiation electrode was 12.7 [mm] × 12.7 [mm]. Moreover, about the electric power supply pin, the diameter was 1.2 [mm] and the diameter and thickness of the flat plate part were 3.0 [mm] and 0.5 [mm], respectively.

  On the other hand, as a comparative example, ten patch antennas having the same configuration as the example were manufactured except that the notch portion was not provided.

And the reflection characteristic was measured about each sample of the patch antenna which concerns on an Example and a comparative example. FIG. 6A shows the measurement result of the patch antenna according to the example, and FIG. 6B shows the measurement result of the patch antenna according to the comparative example. The main parameters of the measurement results are shown together in FIG. In FIG. 7, _{f c} denotes a center frequency _{(f L + f H) /} 2 of reflection loss (return loss) frequency is -10dB low frequency side _{(f L)} and the high frequency side of the frequency _{(f H)} ing. Further, "average", "R" and "sigma" are "average" of the center frequency f _c, shows "the difference between the maximum value and the minimum value" and "standard deviation", respectively.

  As apparent from FIGS. 6 and 7, the patch antenna of the comparative example having no notch has a large variation in reflection loss, whereas the patch antenna of the embodiment having a notch has a variation in reflection loss. Can be confirmed to be small.

FIG. 1 is a perspective view showing a structure of a patch antenna according to an embodiment of the present invention. FIG. 2 is a side sectional view of the patch antenna 10 shown in FIG. 3A to 3E are partial cross-sectional views showing the structure of a patch antenna according to another embodiment of the present invention. FIG. 4 is a schematic cross-sectional view showing the structure of the patch antenna 70 according to the second embodiment of the present invention. FIG. 5 is a schematic cross-sectional view showing the structure of a patch antenna 80 according to the third embodiment of the present invention. FIG. 6 is a graph showing the measurement results of the reflection characteristics of the patch antenna. FIG. 6A shows an example, and FIG. 6B shows a comparative example. FIG. 7 is a table showing the measurement results of the patch antennas according to the example and the comparative example together with their main parameters. FIG. 8 is an external perspective view showing an example of the structure of a conventional patch antenna 90. FIG. 9 is a side sectional view of the conventional patch antenna 90 shown in FIG. FIG. 10 is a cross-sectional side view for explaining the problems of the conventional patch antenna 90. FIG. 11 is a side view for explaining another problem of the conventional patch antenna 90.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Wiring board 2 Feeding pin insertion through-hole 10 Patch antenna 11 Dielectric block 11a Notch part 11b Notch part 11c Notch part 11d Notch part 11e Notch part 11f Notch part (recessed part)
11g Notch 11h Through hole 11x Notch 12 Ground electrode 12h Radiation electrode opening 13 Ground electrode 13h Ground electrode opening 14 Feed pin 14a Feed pin tip 14b Head 20 Patch antenna 30 Patch antenna 40 Patch antenna 50 Patch Antenna 60 Patch antenna 70 Patch antenna 80 Patch antenna 90 Patch antenna

Claims (10)

A dielectric block having a through-hole that opens at the top and bottom surfaces; a radiation electrode formed on the top surface of the dielectric block; and a feed pin that is inserted into the through-hole and soldered to the radiation electrode. Prepared,
The patch antenna according to claim 1, wherein the dielectric block has a notch in the vicinity of the opening of the through hole on the upper surface side.   The patch antenna according to claim 1, wherein the cutout portion constitutes a part of an opening portion of the through hole on the upper surface side.   3. The patch antenna according to claim 2, wherein an outer diameter of the cutout portion increases or becomes constant as it approaches the upper surface side.   The patch antenna according to any one of claims 1 to 3, wherein a cross section of the notch is rectangular.   The patch antenna according to any one of claims 1 to 3, wherein a cross section of the notch is tapered.   The patch antenna according to claim 1, wherein the notch is formed on the upper surface of the dielectric block.   The patch antenna according to claim 2, wherein the cutout portion forms a recess that can accommodate a head portion formed at a rear end portion of the power feed pin.   The diameter of the recess is set to be substantially equal to the diameter of the head of the power feed pin, and the depth of the recess is set deeper than the height of the head of the power feed pin. Item 8. The patch antenna according to Item 7.   The patch antenna according to claim 7 or 8, wherein a bottom surface and a side surface in the recess are covered with the radiation electrode. The dielectric block has a first notch that forms a recess capable of accommodating the head of the power supply pin, and a second notch in the vicinity of the opening of the through hole on the bottom surface in the recess. The patch antenna according to claim 2.

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