JP4287492B1 - Antenna device - Google Patents

Abstract

An object of the present invention is to reduce the influence of interference or the like with a small and simple configuration in wireless communication using a wide band.
An annular parasitic electrode 3 and a ground electrode 1 are connected at equal intervals by connecting elements 4a to 4d. Stubs 7a to 7d are provided in the middle of the connection elements 4a to 4d. The plurality of stubs 7a to 7d is a part of the operation band, and generates a stop band at a frequency corresponding to the electrical length of the stubs 7a to 7d.
[Selection] Figure 1

Description

  The present invention relates to an antenna device having a stop band.

  A high-speed wireless communication system using a wide frequency band such as UWB (Ultra Wide Band) is being put into practical use, and research and development of an antenna device corresponding to the entire band of this communication method is underway. On the other hand, the communication speed of the UWB may decrease due to interference with other communications (for example, a 5 GHz band wireless LAN) using a part of the UWB frequency band.

  When a conventional broadband antenna device is used, in order to reduce interference with other communications and suppress a reduction in communication speed, a radio frequency band steep band rejection filter used for other communications is required on the radio side. I was trying.

In addition, as a well-known document relevant to the present application, for example, the following is known (see Non-Patent Documents 1 to 4 and Patent Document 1).
Shigenori Fujita, Iichi Wakasei, Masahiko Ozawa, Hideaki Iwaoka, Hisamatsu Nakano, “Low-Bandwidth Wideband Antenna” 2006 IEICE Communication Society Conference, Proceedings BS-1-11, pS-16 Shigenori Fujita, Itaichi Wakasei, Masahiko Ozawa, Hisamatsu Nakano, "Low Profile Wideband Antenna 2nd Report" 2007 IEICE General Conference, Proceedings B-1-81, p81 Takeshi Tanaka, Itaichi Wakao, Shizunori Fujita, Hisamatsu Nakano, "Low-Bandwidth Wideband Antenna 3rd Report" 2007 IEICE Society Conference, Proceedings B-1-93, p93 Hideaki Iwaoka, Junji Yamauchi, Hisamatsu Nakano, “Ultra Wideband PSP Antenna” 2006 IEICE General Conference, Proceedings B-1-100, p100 JP 2007-97115 A

  As described above, when a conventional broadband antenna is used, a steep band rejection filter that blocks only external interference waves is required, and the substrate can be enlarged or return loss can be increased depending on the pattern constituting the filter. There is sex.

  The present invention has been made paying attention to the above circumstances, and an object of the present invention is to provide an antenna device capable of reducing the influence of interference or the like with a small and simple configuration in wireless communication using a wide band. There is.

In order to achieve the above object, a first aspect of an antenna device according to the present invention has a symmetric structure with respect to a conductor plate and an axis orthogonal to the conductor plate, and is disposed to face the conductor plate. A radiating element, a plurality of connecting elements that connect the conductor plate and the radiating element at a distance corresponding to 1/16 to 1/10 of the wavelength at the lowest frequency of the operating band, and each of the plurality of connecting elements and a plurality of open stubs provided on the way, the plurality of open stubs, rise by a predetermined distance toward the shaft from the respective connecting element, causes laid to connecting elements in the direction of the radiating element middle in is bent provided by crawl to the radiating element has a longer electrical patiently than the distance, a part of the operating band as it causes the stop band to a frequency corresponding to the electrical length That.

According to a second aspect of the antenna device of the present invention, in the antenna device according to the first aspect, the radiating element is formed radially by the same number of lines as the connection element, and the radiating element is formed at the radial central portion. An annular element is formed which forms a power feeding portion and abuts on the radial edge portion around the axis.

Furthermore, a third aspect of the antenna device according to the present invention is the antenna device according to the second aspect , further comprising a feeding path having a shape widened from a feeding point provided on the conductor plate toward the feeding portion.

  In the antenna device having the above-described configuration, a stub serving as a stop band generating unit is provided in each connection element, so that other communication using a part of the operating band of the antenna device with a small and simple configuration (for example, 5 GHz band) It is possible to reduce interference with a wireless LAN).

  Therefore, according to the present invention, it is possible to provide an antenna device capable of reducing the influence of interference or the like with a small and simple configuration in wireless communication using a wide band.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
In addition, a numerical value is an example and is accept | permitted within the predetermined range containing the numerical value.
(First embodiment)
FIG. 1 is a perspective view schematically showing the basic structure of the patch antenna according to the first embodiment of the present invention. 2A is a plan view of the antenna, and FIG. 2B is a cross-sectional view taken along line AA in FIG. 2A.
As shown in FIGS. 1 and 2A, the patch antenna according to the first embodiment is provided on the ground electrode 1 so as to surround the ground electrode 1, the radiation electrode 2 provided on the ground electrode 1, and the radiation electrode 2. The ring-shaped passive electrode 3 provided, the connection electrodes 4a to 4d, the feeding point 5, the feeding path 6 that connects the feeding point 5 and the radiation electrode 2, and the connection electrodes 4a to 4d are provided. Stubs 7a to 7d are provided.

The ground electrode 1 is a disk-shaped conductive flat plate formed on a predetermined xy plane, and has a diameter D _GP larger than at least the outer diameter Dout_ring of the parasitic electrode 3. A larger area of the ground electrode 1 is preferable in terms of directivity, but in practice it may be about 3 to 4 times the outside diameter of the parasitic electrode 3.

The radiation electrode 2 is a disk-shaped conductive flat plate formed on an xy plane that is a distance H away from the ground electrode 1, has the same central axis as the ground electrode 1, and has an outer diameter Dout_ring of the parasitic electrode 3. or having 0.2 to 0.5 times the diameter D _R of the average diameter. The distance (height) H is about 0.3 to 0.5 times the outer diameter Dout_ring.

  The parasitic electrode 3 is an annular conductive flat plate provided on the same plane and the same central axis as the radiation electrode 2 so as to surround the radiation electrode 2 and has an outer diameter Dout_ring. Dout_ring is basically set so that the outer perimeter of the parasitic electrode 3 substantially matches the wavelength λL of the lowest frequency in the use frequency band of this antenna, and appropriately covers the frequency band even when used for UWB. Set to do.

  The inner diameter Din_ring of the ring is basically set so that the inner peripheral length of the parasitic electrode 3 is about half of the wavelength λ (that is, ½ of Dout_ring). A predetermined gap is generated between the electrodes 2. The parasitic electrode 3 essentially acts on the formation of a conical beam and facilitates impedance matching to the radiation electrode 2.

  The connection electrodes 4a to 4d connect the outer peripheral end of the parasitic electrode 3 to the ground electrode 1 directly below the connection electrode 4a to 4d. One end of each of the connection electrodes 4a to 4d is connected to a part obtained by dividing the outer peripheral end into four equal parts. Thereby, the effect that a frequency band is expanded is acquired.

  The feed point 5 is provided near the center of the ground electrode 1 and receives power from a feed line (not shown) such as a coaxial cable. As shown in FIG. 2B, when the power supply line is on the back surface of the ground electrode 1, the coaxial connector 12 is attached to the center of the back surface of the ground electrode 1, and the power supply line is connected to the coaxial connector 12. The coaxial connector 12 includes an outer conductor 13 and a center conductor 14. The outer conductor 13 is electrically connected to the ground electrode 1. The central conductor 14 passes through a through hole provided in the central portion of the ground electrode 1 and is connected to the top of the exponential function curve located below the power supply path 6 by soldering or the like.

  The feeding path 6 is a cup-shaped conductor that divides the spindle shape into two, and is provided on the same central axis as the radiation electrode 2 and the like. The bottom of the cup (the tip of the spindle) serves as a feeding point, and the upper end of the cup radiates. It has the same diameter as the electrode 2 and is joined and integrated with the radiation electrode 2. The spindle shape is generally exponentially similar to a λ / 4 transformer using a nonuniformly distributed constant line (for example, Japanese Patent Application Laid-Open No. 59-146201) or a tapered slot antenna. 6 contributes to widening the bandwidth.

  FIG. 3 is a side view of the power feeding path 6. The outer peripheral surface of the power feeding path 6 is obtained by rotating a bus obtained by the following formula around a vertical axis.

x =-[exp {-a (z-z1)}-1] + x1
However, as shown in FIG. 3, the (x, z) coordinate position on the upper side of the feeding path 6 is (x1, z1), and the (x, z) coordinate position on the lower vertex is (0, z2). A is a constant.

Here, the stubs 7a to 7d serving as stop band generating means will be described.
As shown in FIGS. 1 and 2B, one end of the stub 7a is connected to a position in the middle of the connection electrode 4a, and rises from there toward the Z axis (perpendicular to the connection electrode 4a) by an interval S, and then Z It extends in the axial direction (the direction in which the parasitic electrode 3 is present) by a length h, and its tip is open without contacting the parasitic electrode 3. The spacing S affects the width of the stop band. The stub length h (or the sum of the interval S and the stub length h) is about ¼ of the wavelength λ _S at the center frequency of the stop band. Therefore, the height H of the connection electrode 4a must be at least larger than h. The same applies to the stubs 7b to 7d. By adjusting the electrical length of the stubs 7a to 7d, a stop band can be generated in an arbitrary frequency band of a part of the operation band.

  The patch antenna according to the first embodiment as a whole has a four-fold (90 degrees) rotationally symmetric structure with the Z axis as the central axis. (Rotational symmetry). For reasons such as design, the elements other than the connection electrode 4 and the stub 7 can also have a rotationally symmetric structure (for example, a hexagonal shape) four times or more (90 degrees or less). Further, an arbitrary dielectric material may be filled from the ground electrode 1 in the Z-axis direction by a height H (that is, the ground electrode 1 and the radiation electrode 2 may be provided on each surface of the dielectric disk). At that time, the height H becomes thinner in accordance with the relative dielectric constant.

FIG. 4 shows frequency characteristics of the VSWR (Voltage Standing Wave Ratio) of the patch antenna according to the first embodiment.
Assuming that the diameter D _GP of the ground electrode 1 is about 137 mm, Dout_ring = about 40 mm, the diameter D _R of the radiation electrode 2 is about 7 mm, H = about 15 mm, h = about 13 mm, S is 1.67 mm, 1.25 mm, and. It was changed to 83 mm. It can be confirmed that a stop band (stop band) satisfying VSWR> 10 is formed in the 5 GHz band of the wireless LAN, and VSWR <2 is obtained over 2 to 10 GHz at other frequencies. Further, the smaller the S, the narrower the stop band, and the center frequency tends to shift slightly to the high frequency side. When S = 0.83 mm, the stop bandwidth (specific bandwidth) is about 8%.

  FIG. 5 is a radiation pattern of the patch antenna according to the first embodiment. At 3 GHz (FIGS. 5A and 5B) and 10.6 GHz outside the stopband (FIGS. 5C and 5D), there is no conical directivity in the z-x plane and no in the xy plane. Directivity can be confirmed.

  As described above, in the first embodiment, the annular parasitic electrode 3 and the ground electrode 1 are connected at equal intervals by the connection elements 4a to 4d, and in the middle of each of the connection elements 4a to 4d. Are provided with stubs 7a to 7d serving as stop band generating means. The stubs 7a to 7d are part of the operation band and generate a stop band at a frequency corresponding to the electrical length of the stubs 7a to 7d.

  Therefore, according to the first embodiment, a stop band can be generated in an arbitrary frequency band corresponding to the electrical length of the stubs 7a to 7d. Thereby, it becomes possible to generate a stop band at a frequency used for existing wireless communication (for example, 5 GHz band wireless LAN), and to reduce interference. In addition, since a steep band elimination filter that has been conventionally provided to reduce interference with an existing communication system is not necessary, it can be realized with a small and simple configuration.

(Second Embodiment)
FIG. 6 is a perspective view showing a basic configuration of an antenna apparatus according to the second embodiment of the present invention. 7 is a cross-sectional view taken along line AA in FIG.

6 and 7, the conductor plate 11 is formed of, for example, a square ground plate, and the length W1 of one side thereof is set to about 0.5λ _L or more (λ _L is the wavelength of the lowest frequency in the used frequency band). The

  For example, an NJ type coaxial connector 12 is attached to the lower surface center portion of the conductor plate 11 as a power supply terminal. Although not shown, the coaxial connector 12 is connected with a power feeding coaxial cable from an antenna input circuit of the wireless device. The coaxial connector 12 includes an outer conductor 13 and a center conductor 14. The outer conductor 13 is electrically connected to the conductor plate 11. The center conductor 14 passes through a through hole provided in the central portion of the conductor plate 11, is provided to protrude upward by a predetermined length in a state of being insulated from the conductor plate 11, and is used as a power feeding path.

An antenna element 15 is provided above the conductor plate 11. The antenna element 15 has two or more, for example, four radiating elements 16a to 16d. The radiating elements 16a to 16d are provided radially at an equal angle or substantially the same angle, and a feeding point 18 is provided at the radial center, that is, the starting end side of the radiating elements 16a to 16d. When the antenna element 15 includes four radiating elements 16a to 16d, the arrangement angle of each element is 90 ° and is formed in a cross shape. The radiating element 16a~16d, for example a width W2, which was formed by using a plate-shaped element of length L, a width W2 is set to about 0.055λ _L. The length L of the radiating element 16a~16d is basically set to about lambda _L / 4, and preferably about lambda _L / 4 from the set to 10% of long 0.275λ about _L.

Further, for example, plate-like short-circuit elements 17 a to 17 d are provided at the respective ends of the radiation elements 16 a to 16 d so as to be perpendicular to the conductor plate 11. The short-circuit elements 17a to 17d are formed, for example, by means such as bending the ends of the radiating elements 16a to 16d downward at right angles, and in FIG. 6, have the same width as the width W2 of the radiating elements 16a to 16d. . However, these widths are not necessarily set to be the same. The short-circuit elements 17a to 17d are connected to the conductor plate 11 by welding or screwing, and the height H thereof is set to about λ _L / 10 to λ _L / 16.

  As described above, the radiating elements 16a to 16d are provided in parallel with the conductor plate 11 in more detail, and the central conductor 14 of the coaxial connector 12 is connected to the feeding point 18 by screwing or soldering. The In this case, the radiation elements 16a to 16d are provided with tip portions on the short-circuit elements 17a to 17d side corresponding to, for example, the respective corners (four corners) of the conductor plate 11 so that the conductor plate 11 can be formed as small as possible.

In addition, as a feature of the present embodiment, as shown in FIG. 7, stubs 21a to 21d are provided in the middle part of the short-circuit elements 17a to 17d. In FIG. 7, the stubs 21a to 21d extend in the Z-axis direction into the space between the conductor plate 11 and the antenna element 15 in the same manner as the stubs 7a to 7d shown in the first embodiment, but λ _S / 4 As long as it is substantially an open stub having an electrical length, it may be provided in any manner, for example, it may be extended toward the center of the coaxial connector 12. Alternatively, as shown in FIG. 8, it may be bent halfway and placed over the radiating element 15 or the short-circuiting element 17 with a predetermined interval. The locations where the stubs 21a to 21d are connected to the short-circuit elements 17a to 17d may be determined by trial so that the characteristics of the antenna are not impaired and the VSWR in the stop band is increased.

  Specific examples of dimensions of the antenna element 15 include, for example, when the minimum frequency in the use frequency band is 470 MHz, the length W1 of one side of the conductor plate 11 is 300 to 400 mm, and the width W2 of the radiating elements 16a to 16d is About 35 mm and height H are set to about 40 mm.

  The antenna device configured as described above is preferably used with the xy plane parallel to the surface of the communication area to be covered, and is usually installed parallel to the ground. As an example, when installed on the ceiling of a building such as a television station, a plurality of antenna elements 15 are installed at intervals of several tens of meters with the antenna element 15 on the lower side and the conductor plate 11 on the upper side. In this case, the antenna device is provided with a protective cover (radome) for protecting the antenna element 15 as necessary. Then, a UWB video signal transmitted from the television camera is received, or a return video signal to be displayed on the viewfinder is transmitted to the television camera.

  Alternatively, as another example, an antenna built in a portable (portable) device such as a video projector, which is installed on a desktop and receives a UWB video signal transmitted from a personal computer around it (may be right next to it). To do. In this antenna device, the omnidirectionality is obtained with respect to the horizontal plane directivity. Regarding the vertical directivity, the directivity in the Z-axis direction is the weakest, and a substantially constant maximum gain is obtained in the range of 45 to 90 degrees (the same as the xy plane direction at 90 degrees) with the Z-axis being 0 degrees. can get.

  In order to widen the communicable area, a beam pattern is desired in which the gain is high with respect to a distant communication target rather than simply having a high gain (strong directivity). The loss (dielectric loss) due to the VSWR and the antenna itself needs to be suppressed over a wide band. According to the second embodiment, it is possible to realize an antenna device close to such ideal.

(Third embodiment)
Next, an antenna device according to a third embodiment of the present invention will be described.
FIG. 9 is a perspective view of an antenna device according to the third embodiment, and FIG. 10 is a perspective view showing a parasitic element portion of the antenna device. The present embodiment is different from the second embodiment in that it further includes a line connecting between adjacent ends of the radiation elements 16a to 16d of the antenna device according to the second embodiment. For example, a circular ring-shaped element 25 is provided in parallel with the conductor plate 11 above the radiating elements 16a to 16d so that good impedance characteristics can be obtained over a wider band.

  In the third embodiment, short pins 19a to 19d are used in place of the short-circuit elements 17a to 17d shown in the second embodiment. The diameters of the short pins 19a to 19d are set to about ½ of the width W2 of the radiating elements 16a to 16d, for example. The short pins 19a to 19d are provided between the radiation elements 16a to 16d and the conductor plate 11 by screwing or welding. The short-circuit elements 17a to 17d and the short pins 19a to 19d have an electrically equivalent action, and any of them may be used.

  The ring-shaped element 25 is disposed on the upper side of the radiating elements 16a to 16d, and is fixed to the upper end portions of the short pins 19a to 19d, for example, by screwing or welding. Since other configurations are the same as those of the second embodiment, the same portions are denoted by the same reference numerals, and detailed description thereof is omitted.

The ring-type element 25 is formed in a ring shape using a metal plate, and its dimensions are set, for example, to an inner diameter of about 0.303λ _L and an outer diameter of about 0.359λ _L. The width of the ring-type element 25 is set to the same or substantially the same value as the width W2 of the radiating elements 16a to 16d.

  Further, in the third embodiment, one or more, for example, four matching parasitic elements 22a are arranged on the concentric circle with the feeding portion, that is, the central conductor 14 of the coaxial connector 12 protruding on the conductor plate 11 as the center. To 22d are provided at equal intervals (equal angles).

  By arranging the parasitic elements 22a to 22d in the vicinity of the central conductor 14, the vertical portions of the parasitic elements 22a to 22d and the central conductor 14 are electromagnetically coupled. The parasitic elements 22a to 22d include horizontal portions 23a to 23d. The horizontal portions 23a to 23d are formed on or near each line so as to be capacitively coupled to the line connecting the short-circuited portions of the radiating elements 16a to 16d and the feeding point 18. For example, as shown in FIG. 10, the horizontal portions 23 a to 23 d are formed in an inverted L shape by folding the upper portion about 90 ° in the outward direction, that is, in the direction opposite to the center conductor 14 using a metal plate. It is.

The parasitic elements 22a to 22d have, for example, an interval SD from the center of about 0.026λ _L , a width SW of 0.019λ _L , a height SH of about 0.055λ _L , and a length SL of the horizontal portions 23a to 23d. It is set to about 0.023λ _L. The parasitic elements 22a to 22d can be installed at arbitrary positions without any problem even if they are installed at a rotated position as long as they are concentric. The characteristics of the parasitic elements 22a to 22d can be finely adjusted according to their installation positions.

  As specific dimensions of the parasitic elements 22a to 22d, for example, when the lowest frequency in the use frequency band is 470 MHz, the distance SD from the center is about 17 mm, the width SW is 12 mm, the height SH is about 36 mm, and the horizontal The length SL of the part is set to about 15 mm.

  In the antenna device according to the third embodiment, the parasitic elements 22a to 22d act as stubs. That is, by providing the parasitic elements 22a to 22d, the horizontal portions 23a to 23d and the current line flowing through the radiating element can be capacitively coupled. Further, by arranging the parasitic elements 22a to 22d in the vicinity of the central conductor 14, the vertical portions of the parasitic elements 22a to 22d and the central conductor 14 can be electromagnetically coupled. As a result, the number of setting parameters for determining the impedance characteristics increases, and it is possible to maintain a stable state over a wide band.

  In the third embodiment, the ring type element 25 is formed in a circular shape. However, the ring type element 25 can be formed in an arbitrary shape such as a square or a polygon. In addition, although the case where the horizontal portions 23a to 23d of the parasitic elements 22a to 22d are formed in a square shape has been shown, other shapes such as a triangle and a sector may be formed. The parasitic elements 22a to 22d may be formed in a T shape, for example.

  As described above, also in the configuration of the antenna device according to the third embodiment, the same effect as in the second embodiment can be obtained, and further, the number of setting parameters for determining impedance characteristics increases. It is possible to maintain a stable state over a wide band.

(Fourth embodiment)
An antenna device according to a fourth embodiment of the present invention will be described.
FIG. 11 is a perspective view of an antenna device according to the fourth embodiment. In the antenna device described above, for example, in the antenna device shown in FIG. 6 in the second embodiment, each of the radiating elements 16a to 16d is inclined to the conductor plate 11 side, and the tip of the antenna device is placed on the conductor plate 11. The short-circuit elements 17a to 17d are omitted by direct connection. Further, as a feature of the present embodiment, stubs 21a to 21d as stop band generating means are provided on the same plane as the width direction of the radiating elements 16a to 16d. Since other configurations are the same as those in the above-described embodiments, detailed description thereof is omitted.

  Thus, arrangement | positioning of the stubs 21a-21d is not limited to the electric power feeding side direction. Further, stubs for the same shape or different element frequencies may be additionally provided on both sides of each radiating element.

  In addition, the power supply path 6 used in the first embodiment can be applied to the second to fourth embodiments. In the first embodiment, the power supply path 6 has an outer peripheral surface formed with an exponential function curve, but is not limited thereto, and may be configured in a semi-elliptical shape, for example. Alternatively, as shown in FIG. 12, a plurality of circular plate-like members 30a, 30b,... Having different diameters are overlapped so that the outer peripheral surface approximates an exponential function curve or a semi-elliptical shape (the upper end 31Bb is wider than the lower end 31Ba). It is also possible to form a feeding path 31B having a shape. Furthermore, as shown in FIG. 13, as the power feeding path 6, an outer peripheral surface is formed as an exponential function curve. In other words, from a plurality of, for example, four metal plates 32 a to 32 d with the upper end 31 Cb wider than the lower end 31 Ca. A feeding path 31C may be used. Even when configured as in FIGS. 12 and 13, substantially the same characteristics as those of the antenna device shown in the first embodiment can be obtained.

  That is, the feeding path 6 has a shape other than the above-described shape as long as the end on the side of the radiation electrode 2 is wider than the end on the side of the feeding point 5 (coaxial connector 12). May be. 14 and 15 are perspective views showing other configuration examples of the power feeding path 6. FIG. 14 (a) shows a case where the power feeding path 6 is formed in a conical shape (triangular shape in a side view). The feeding path 6 is hemispherical (semicircular in side view), and FIG. 10C shows a case where the widened portion and the vertical portion are combined so that the side view is substantially pentagonal.

  FIG. 15 is a diagram illustrating a shape example in the case where the feeding path 6 is formed in a polygonal pyramid such that the top view is a polygonal shape. FIG. 15A is a triangular shape (triangular pyramid shape) when viewed from above, and FIG. This is a case of forming a triangular shape (quadrangular pyramid shape) when viewed from above. The feed path 6 in FIG. 15 is formed in a shape in which the end on the radiation electrode 2 side is widened compared to the end on the feed terminal side. For example, a part of the width from the lower end to the upper end is narrow. It may be.

  When the feeding path 6 shown in (a) or (b) of FIG. 15 is used, the number of the radiating elements 12 may be three or four. That is, three radiating elements 12 are provided when the triangular pyramid-shaped feed path 6 of FIG. 15A is used, and four radiating elements 12 are provided when the quadrangular pyramid-shaped feed path 6 of FIG. When the radiation element is provided, the symmetry (omnidirectionality) of the horizontal plane directivity is improved. More generally speaking, the same number of radiating elements 12 as the number of polygonal pyramids are provided, and the polygonal pyramid corners and the radiating elements are arranged at the same or staggered positions with respect to the central axis (Z axis). Keep the same rotational symmetry as the polygonal pyramid. However, the number of radiating elements and the number of corners of the feeding path do not necessarily need to match.

  The present invention is not limited to the above-described embodiments as they are, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. Moreover, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the above embodiments. For example, some components may be deleted from all the components shown in each embodiment. Furthermore, you may combine suitably the component covering different embodiment.

The perspective view which shows typically the basic structure of the patch antenna which concerns on 1st Embodiment. The top view of the antenna device which concerns on the same embodiment. The side view of the antenna apparatus which concerns on the same embodiment. The side view of the feed path of the antenna apparatus which concerns on the same embodiment. The frequency characteristic figure of VSWR of the patch antenna which concerns on the same embodiment. The figure which shows the radiation pattern of the patch antenna which concerns on the same embodiment. The perspective view of the antenna device which concerns on 2nd Embodiment. The side view of the antenna apparatus which concerns on the same embodiment. The side view of the other structural example of the stub of the antenna apparatus which concerns on the same embodiment. The perspective view of the antenna device which concerns on 3rd Embodiment. The perspective view which shows the arrangement configuration of the parasitic element part of the antenna device which concerns on the same embodiment. The perspective view of the antenna device which concerns on 4th Embodiment. The perspective view and side view of the other structural example of the electric power feeding path. The perspective view of the other structural example of the electric power feeding path. The perspective view of the other structural example of the electric power feeding path. The bottom view and perspective view of the other structural example of the electric power feeding path.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Ground electrode, 2 ... Radiation electrode, 3 ... Parasitic electrode, 4a-4d ... Connection electrode, 5 ... Feeding point, 6 ... Feeding path, 7a-7d ... Stub, 12 ... Coaxial connector, 13 ... Outer conductor, 14 DESCRIPTION OF SYMBOLS ... Center conductor, 11 ... Conductor plate, 15 ... Antenna element, 16a-16d ... Radiation element, 17a-17d ... Short-circuit element, 18 ... Feed point, 21a-21d ... Stub, 19a-19d ... Short pin, 22a-22d ... Parasitic element, 25 ... ring-shaped element, 31B, 31C ... feeding path.

Claims (3)

A conductor plate;
A radiating element having a symmetric structure with respect to an axis orthogonal to the conductor plate and disposed opposite the conductor plate;
A plurality of connecting elements that connect the conductor plate and the radiating element at a distance corresponding to 1/16 to 1/10 of the wavelength at the lowest frequency of the operating band ;
A plurality of open stubs provided in the middle of each of the plurality of connection elements;
The plurality of open stubs are provided so as to rise from the respective connection elements toward the axis by a predetermined interval, bend toward the connection element in a certain direction of the radiating element, and bend halfway along the radiating element. has a longer electrical length than the distance, a part of the operating band antenna apparatus characterized by causing stopband frequency corresponding to the electrical length. The radiating element is formed radially by the same number of lines as the connection elements, and includes a ring element that forms a feeding portion at the radial center and abuts against the radial edge around the axis. The antenna device according to claim 1. 3. The antenna device according to claim 2 , further comprising a feeding path having a shape widened from a feeding point provided on the conductor plate toward the feeding section.

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