JP4732321B2 - Antenna device - Google Patents

Description

  The present invention relates to an antenna device that can be suitably used as a base station antenna device for a mobile communication system or the like. More specifically, the present invention relates to a function that shares three frequency bands and two orthogonal polarizations that are transmitted and received independently. The present invention relates to an antenna device having a polarization sharing function capable of obtaining a diversity effect.

  In the mobile communication system, a plurality of frequency bands such as a 0.8 GHz band, a 1.7 GHz band, a 2.0 GHz band, and the like are assigned. In this mobile communication system, it is not desirable to individually install the antenna devices for the respective frequency bands for forming a service area because it causes congestion of a steel tower or the like. Therefore, a frequency sharing antenna device that can share a plurality of frequency bands is required.

  On the other hand, in the antenna device used in the mobile communication system, the space diversity method is used in order to increase the radio wave reception efficiency. There is. Therefore, recently, it has become the mainstream to adopt a polarization diversity system that can simplify base station facilities such as the upper part of a steel tower.

In the case of adopting this polarization diversity method, a polarization sharing antenna apparatus having the same horizontal plane beam width for both vertical polarization and horizontal polarization is required. For example, in the case of a 6-sector configuration, a dual-polarized antenna having horizontal plane directivity corresponding to the sector division angle (60 °), that is, horizontal plane directivity in which both vertical and horizontal polarizations have a beam width of 60 °. Equipment is needed.
In the high frequency band, it is necessary to set the beam width in the horizontal plane of the base station antenna device to 45 ° for the purpose of further increasing the subscriber capacity accompanying the increase in the number of users.

By the way, as a multi-frequency shared antenna apparatus using a single polarization (for example, vertical polarization), for example, a multi-frequency shared dipole antenna apparatus according to Patent Document 1 has been proposed. When this pole antenna antenna device is applied to, for example, three frequency bands, the first dipole element having a length resonating with the center frequency of the first frequency band and the center frequency of the second frequency band are resonated. The configuration includes a second dipole element having a length and a third dipole element having a length that resonates with the center frequency of the third frequency band.
The first dipole element is formed of a metal foil on a dielectric substrate. The second dipole element is formed by providing a cut in the first dipole element, and the third dipole element is formed by providing a cut in the second dipole element.

A vertically polarized antenna device in which a plurality of these three-frequency shared antenna devices are arranged in an array in the vertical direction is configured, and the first dipole element, the second dipole element, and the third dipole element of each multi-frequency shared antenna device are configured. When resonating in the frequency band of _0.8 GHz (with a wavelength of λ _0.8 ), 1.7 GHz (with a wavelength of λ _1.7 ) and 2.0 GHz (with a wavelength of λ _2.0 ), respectively, A typical arrangement interval of the frequency sharing antenna apparatus is about 150 mm. This spacing corresponds to 0.44λ _0.8 , 0.91λ _1.7 and 1.02λ ₂ for the _0.8 GHz band, 1.7 GHz band and 2.0 GHz band, respectively.

When configuring an arrayed base station antenna device, the interval between the individual antenna devices arranged in the vertical direction is usually selected between about 0.5λ and 0.9λ (where λ is the wavelength of the target frequency). Is done.
This is because when the arrangement interval is short (less than 0.5λ), the degree of mutual coupling between the antenna elements of adjacent antenna devices increases, so that the impedance of the antenna elements can change greatly and the directivity can change greatly. This is because when the arrangement interval is long (exceeding 0.9λ), there is a disadvantage that the grating lobe is strongly generated.

Therefore, when the arrayed base station antenna device is configured using a multi-frequency shared dipole antenna device as described in Patent Document 1, when each target frequency band is more than twice apart, The arrangement interval in the vertical direction becomes inappropriate in each frequency band, and the following inconvenience occurs.
That is, when the target frequency bands are 0.8 GHz band, 1.7 GHz band and 2.0 GHz band, inconveniences such as degradation of VSWR occur in the 0.8 GHz band, and 1.7 GHz band and 2 GHz band In the .0 GHz band, inconveniences such as a decrease in gain due to the generation of grating lobes and an increase in gain fluctuation during beam tilt occur.

On the other hand, as an antenna device that shares a single frequency vertical polarization and a horizontal polarization, for example, there is a polarization sharing antenna device according to Patent Document 2 including a vertical polarization dipole element and a horizontal polarization dipole element. Proposed.
This antenna apparatus is applied to three frequency bands by replacing the vertically polarized dipole element and the vertically polarized dipole element with the first, second and third dipole elements described in Patent Document 1, for example. be able to.
Here, considering a case where a plurality of three-frequency dual-polarization antenna devices configured as described above are arrayed in the vertical direction, the arrangement interval of the antenna devices is set to a low frequency band and a high frequency band. You must choose to be appropriate in both.

However, since the above-described three-frequency dual-polarization antenna device applies the technique described in Patent Document 1, when each target frequency band is more than twice as far away, the antenna described in Patent Document 1 Similarly, there arises a problem that the arrangement interval for arraying must be inappropriate. The antenna device according to Patent Document 2 is basically unsuitable as an antenna device for realizing a 6-sector configuration because the horizontal plane beam width is wide.
Japanese Patent No. 3628668 Japanese Patent Laid-Open No. 2000-091843

The conditions required for the antenna apparatus suitable for the current six-sector configuration are as follows.
(1) The frequencies of 0.8 GHz band, 1.7 GHz band and 2.0 GHz band are shared.
(2) Both vertical polarization and horizontal polarization are shared.
(3) The horizontal plane beam width in the 0.8 GHz band is approximately 60 °, and the horizontal plane beam widths in the 1.7 GHz band and the 2.0 GHz band are approximately 45 °, respectively.

FIG. 18 shows an example of an antenna device configured to satisfy the above conditions.
As shown in the figure, in order to realize a 60 ° beam in the 0.8 GHz band, a pair of vertically polarized dipole elements 101 that resonate at _0.8 GHz are arranged in the horizontal direction with an interval of 0.5λ0.8. It is necessary to arrange a pair of horizontally polarized dipole elements 201 that resonate at 0.8 GHz in the same manner.

In order to realize a 45 ° beam in the 1.7 GHz band, a pair of vertically polarized dipole elements 102 that resonate at 1.7 GHz are arranged in the horizontal direction with an interval of 0.772λ _1.7 = 0.35λ _0.8. In addition, a pair of horizontally polarized dipole elements 202 that resonate at 1.7 GHz must be arranged in the same manner.
Furthermore, in order to realize a 45 ° beam in the 2.0 GHz band, a pair of vertically polarized dipole elements 103 resonating at 2.0 GHz are arranged in the horizontal direction with an interval of 0 · 72λ _2.0 = 0.35λ _0.8. In addition, it is necessary to arrange a pair of horizontally polarized dipole elements 203 that resonate at 2.0 GHz in the same manner.

However, considering that the three-frequency dual-polarization antenna device having such a configuration is housed in a cylindrical radome so that it can be used outdoors, its size (antenna device inner diameter) is 1.0λ _0.8. That's it.
Furthermore, the base station antenna apparatus has a configuration in which the vertical plane beam width is sharpened and the array is formed in the vertical direction for the purpose of increasing the gain, but the antenna having the dipole elements 101 to 103 and 201 to 203 is provided. The device is not suitable for this arraying.

That is, as described above, when configuring an arrayed base station antenna device, the interval between the individual antenna devices arranged in the vertical direction is approximately 0.5λ to 0.9λ (λ is the target frequency). It is desirable to select between these wavelengths. However, if the above-described three-frequency dual-polarization antenna device is arranged at an ideal interval of 0.5λ to 0.9λ for arraying, inconveniences such as contact between dipole elements occur. In addition, it is clear that the configuration is further complicated when the feeding system is taken into consideration.
Therefore, it is practical to configure a single antenna having a function of sharing three frequencies and a function of sharing both vertical polarization and horizontal polarization and having a horizontal plane beam width suitable for a six-sector configuration. Is very difficult.

The present invention has been made in view of such a situation, and an object thereof is to realize a function of sharing three frequencies and a function of sharing vertical polarization and horizontal polarization with a compact configuration. Another object of the present invention is to provide an antenna device that can be arrayed while maintaining an ideal vertical arrangement interval for sharing a frequency.
Another object of the present invention is to provide an arrayed three-frequency shared polarization antenna device that can be effectively applied as a three-frequency shared polarization antenna for mobile communication.

  According to the present invention, in order to achieve the above object, a pair of first horizontally polarized dipoles having a length resonating at the frequency f1 and arranged horizontally and at a predetermined interval in the horizontal direction A pair of first vertically polarized dipole elements having a length that resonates at a frequency f1, oriented vertically and at a predetermined interval in the horizontal direction, and a frequency f2 (> f1), a pair of second horizontally polarized dipole elements having a length resonating at f3 (> f2) and arranged horizontally and at a predetermined interval in the horizontal direction, and at least one of the pair of the frequency f2 , F3 has a length that resonates, and the other has a length that resonates with the other of the frequencies f2 and f3, and is arranged in a vertical direction and at a predetermined interval in the horizontal direction. Second vertically polarized dipole element and horizontal from branch point And at least one second vertical polarization dipole element is connected to one branch line, and the other second vertical polarization dipole element is connected to the other branch line. An antenna device is provided. In this antenna device, the pair of first horizontal polarization dipole elements is set such that the length of the element conductor located on the outside is larger than the length of the element conductor located on the inside, and the pair of second dipole elements. The horizontally polarized dipole elements and the three or more second vertically polarized dipole elements are disposed between the pair of first vertically polarized dipole elements.

The first horizontal polarization dipole element, the first vertical polarization dipole element, the second horizontal polarization dipole element, and the second vertical polarization dipole element are respectively first and second. , And can be formed on the third and fourth dielectric substrates.
In this case, a first horizontally polarized dipole element and the first first feeding dielectric substrate formed with feed line for feeding the dipole elements for vertical polarization, the second horizontal polarized And a second feeding dielectric substrate having a feeding line for feeding power to the wave dipole element and the second vertically polarized dipole element, and the first feeding dielectric substrate provides the first feeding dielectric substrate. The first and second dielectric substrates can be supported, and the third and fourth dielectric substrates can be supported by the second power feeding dielectric substrate.

  Baluns can be formed on some or all of the first, second, third and fourth dielectric substrates. In this case, the dipole element formed on the dielectric substrate on which the balun is formed is configured to supply power via the balun.

  The second horizontal polarization dipole element may be formed by bending the element conductor so as to form an umbrella shape. Further, the outer element conductor of the first horizontally polarized dipole element may be formed with a curved end along the inner peripheral surface of the dielectric cover.

  According to the present invention, there is provided an antenna device in which a plurality of antenna devices having the above-described configuration are arrayed in the vertical direction. The arrayed antenna device and the above-described antenna device can be provided with a reflector if necessary.

  According to the antenna device of the present invention, the function of sharing three frequencies and the function of sharing vertical polarization and horizontal polarization can be realized by a compact configuration, and ideal for sharing frequencies. It is possible to achieve an array while maintaining a typical vertical arrangement interval.

  The arrayed antenna apparatus according to the present invention can be effectively applied as, for example, a three-frequency shared polarization antenna for mobile communication. That is, in the case of the 6-sector configuration, it is possible to realize an optimal area by realizing an optimal horizontal plane beam width for the 6-sector configuration in each frequency band. Moreover, while being able to obtain favorable vertical surface directivity, it is possible to reduce the size so that it can be stored in a radome with a small inner diameter.

Embodiments of an antenna device according to the present invention will be described below in detail with reference to the drawings. In the following description, the wavelengths for the frequencies 0.8 GHz, 1.7 GHz, and 2.0 GHz are λ _0.8 , λ _1.7, and λ _2.0 , respectively.
FIG. 1 shows an example of an antenna block for f1 band. This antenna block has a pair of horizontally polarized dipole elements 10 and a pair of vertically polarized dipole elements 20 having a length that resonates at a frequency f1 (0.8 GHz in the present embodiment).

The pair of horizontally polarized dipole elements 10 are horizontally arranged so that the polarized waves are horizontal with respect to the ground, and have a predetermined interval in the horizontal direction so as to be symmetrical with respect to the vertical central axis L. (In this embodiment, the center points are arranged at intervals of 0.29λ _0.8 ).
The outer element conductor 10a and the inner element conductor 10b that constitute each horizontal polarization dipole element 10 have different lengths. That is, in this embodiment, the length of the outer element conductor 10a is set to 0.18Ramuda _0.8, the length of the inner element conductor 10b is set to 0.14λ _0.8.

On the other hand, each of the vertically polarized dipole elements 20 has a length (0.46λ _{0.8 in} this embodiment) that resonates at the frequency f1, and is oriented vertically so that the polarization is perpendicular to the ground. In addition, the center point is arranged in a form separated from the horizontal polarization dipole element 10 to the ground side by a predetermined distance (0.44λ _{0.8 in} this embodiment). The vertically polarized dipole elements 20 are arranged at predetermined intervals (0.5λ _{0.8 in the} present embodiment) in the horizontal direction so as to be positioned symmetrically with respect to the vertical central axis L.

In the present embodiment, as shown in FIG. 2, the pair of horizontally polarized dipole elements 10 are printed on a common dielectric substrate 11. That is, in the right dipole element 10 in the figure, the outer element conductor 10a and the inner element conductor 10b are formed on one and the other surfaces of the dielectric substrate 11, respectively, and the left dipole element 10 includes the inner element conductor 10b and the outer element 10b. Conductors 10a are formed on one and the other surfaces of the dielectric substrate 11, respectively.
The feed points of the outer element conductor 10a of the right dipole element 10 and the inner element conductor 10b of the left dipole element 10 are connected to branch feed lines 12 formed on one surface of the dielectric substrate 11, respectively. The feeding points of the inner element conductor 10b of the right dipole element 10 and the outer element conductor 10a of the left dipole element 10 are connected to a branch feeding line 13 formed on the other surface of the dielectric substrate 11, respectively. Yes.
The dielectric substrate 11 and each element printed on the dielectric substrate 11 constitute a horizontally polarized antenna unit H-1 for f1 band.

In the present embodiment, each of the vertically polarized dipole elements 20 is individually printed on the dielectric substrate 21 shown in FIG. That is, in the dipole element 20, one element conductor 20a and the other element conductor 20b are formed on one and the other surfaces of the dielectric substrate 21, respectively. The feeding point of one element conductor 20 a is connected to a branch feeding line 22 formed on one surface of the dielectric substrate 21, and the feeding point of the other element conductor 20 b is the other surface of the dielectric substrate 21. It is connected to the branch feeding line 23 formed in.
The dielectric substrate 21 and each element printed on the dielectric substrate 21 constitute a vertically polarized antenna unit V-1 for f1 band.

FIG. 4 shows a state in which two sets of one f1 band horizontal polarization antenna unit H-1 and two f1 band vertical polarization antenna units V-1 are arranged on the dielectric substrate 30 in the vertical direction. Is shown. The horizontal polarization antenna unit H-1 for the f1 band and the vertical polarization antenna unit V-1 for the f1 band in each set have a dipole element 10 for horizontal polarization and a dipole element 20 for vertical polarization in FIG. The arrangement position is set so as to constitute the illustrated f1 band antenna block. The individual groups are arranged at an interval of 0.88λ _0.8 , and together with the power supply dielectric substrate 30, constitute an f1 band subarray.
The dielectric substrate 11 of the antenna unit H-1 and the dielectric substrate 21 of the antenna unit V-1 are fixedly supported vertically on the surface of the feeding dielectric substrate 30, respectively. A power feeding circuit (not shown) for feeding power to each antenna unit H-1 and V-1 is printed on the back surface of the dielectric substrate 30.

  FIG. 5 shows an example of an antenna block for the f2 and f3 bands shared by the frequency f2 (1.7 GHz in the present embodiment) and the frequency f3 (2.0 GHz in the present embodiment). This antenna block includes a pair of horizontally polarized dipole elements 40 having a length resonating at frequencies f2 and f3, two vertically polarized dipole elements 51 and 54 having a length resonating at frequency f2, and a frequency Two vertically polarized dipole elements 52 and 53 having a length resonating with f3 are provided.

The pair of horizontally polarized dipole elements 40 are disposed horizontally so that the polarized waves are horizontal with respect to the ground, and have a predetermined interval in the horizontal direction so as to be positioned symmetrically with respect to the vertical central axis L. (In this embodiment, the center points are arranged at intervals of 0.24λ _0.8 (= 0.5λ _1.7 = 0.56λ _2.0 )).
The outer element conductor 40a and the inner element conductor 40b constituting each horizontal polarization dipole element 40 have different lengths. That is, in the present embodiment, the length of the outer element conductor 40a is set to 0.09λ _0.8 (= 0.19λ _1.7 = 0.21λ _2.0 ), and the length of the inner element conductor 40b is 0.08λ _0.8 ( = 0.17λ _1.7 = 0.19λ _2.0 ).

On the other hand, the vertically polarized dipole elements 51 to 54 are vertically oriented so that the polarized waves are perpendicular to the ground, and their center points are 0 to .0 from the horizontally polarized dipole elements 20. 14λ _0.8 (= 0.3λ _1.7 = 0.34λ _2.0 ) is arranged in the form of being separated to the ground side.
The vertically polarized dipole elements 51 and 54 have a length that resonates at the frequency f2 (in this embodiment, 0.25λ _0.8 (= 0.51λ _1.7 = 0.58λ _2.0 )). They are arranged at predetermined intervals in the horizontal direction (0.37λ _0.8 (= 0.76λ _1.7 = 0.85λ _2.0 )) in the horizontal direction so as to be symmetrically positioned. In addition, the dipole elements 52 and 53 have a length (0.21λ _0.8 (= 0.44λ _1.7 = 0.49λ _2.0 ) in this embodiment) that resonates at the frequency f3, and with respect to the vertical central axis L. They are arranged at predetermined intervals in the horizontal direction (in this embodiment, 0.19λ _0.8 (= 0.39λ _1.7 = 0.44λ _2.0 )) so as to be positioned symmetrically.

  In the present embodiment, as shown in FIG. 6, the pair of horizontally polarized dipole elements 40 are printed on one surface of a common dielectric substrate 41. The printed dipole element 40 is bent toward the lower end side of the dielectric substrate 41 so that the outer element conductor 40a and the inner element conductor 40b form an umbrella shape. The outer element conductor 40a has an outer edge formed in a curved shape, and the dielectric substrate 41 has a corner shaped so as to follow the outer edge shape of the element conductor 40a.

From the feeding point portions of the element conductors 40a and 40b, the ground conductors 42a and 42b extend toward the lower end side of the dielectric substrate 41 in a form in which a slit 43 is formed therebetween.
On the other hand, a feed line conductor 44 is formed on the other surface of the dielectric substrate 41. The feed line conductor 44 extends from the lower end of the dielectric substrate 41 to the back of the feeding point portion of the element conductor 40b (element conductor 40a) in a form facing the back surface of the ground conductor 42b (ground conductor 42a), and further from there. The former part is formed to bend toward the element conductor 40 a (element conductor 40 b) and cross the upper part of the slit 43, and then extend toward the lower end of the dielectric substrate 41. That is, the feed line conductor 44 has a substantially inverted U shape that turns back with the central portion of the dipole element 40 as the top.
The feed line conductor 44 may be formed so as to extend toward the element conductor 31a (element conductor 31a) without folding the front end half, that is, to have an L shape. The element conductors 40a and 40b may be formed horizontally without being bent into an umbrella shape. The reason for forming the umbrella shape will be described later.

The horizontally polarized dipole element 40 is fed via the ground conductors 42 a and 42 b and the feed line conductor 44. At this time, since the ground conductors 42a and 42b are separated by the slits 43, the directions of the currents flowing through the ground conductors 42a and 42b are reversed. Then, no current flows through the base ends of the ground conductors 42a and 42b coupled to each other. Therefore, the feed system composed of the ground conductors 42a and 42b and the feed line conductor 44 constitutes a balun (balanced / unbalanced converter) for converting the potential.
The dielectric substrate 41 and the elements printed on the dielectric substrate 41 constitute a horizontally polarized antenna unit H-2 for f2 and f3 bands.

On the other hand, in the present embodiment, the vertically polarized dipole elements 51 to 54 are printed on the dielectric substrate 55 shown in FIG.
In the dipole elements 51, 52, 53 and 54, one element conductors 51a, 52a, 53a and 54a are formed on the surface of the dielectric substrate 55, and the other element conductors 51b, 52b, 53b and 54b are formed on the dielectric substrate 55. It is formed on the back side.
A feed line 56 is formed on the dielectric substrate 55. The feed line 56 includes a line conductor 56a formed on the front surface of the dielectric substrate 55 and a line conductor 56b formed on the back surface of the substrate 55, and extends in the arrangement direction of the dipole elements 51 to 54 from the central branch point 56c. Branched.
Line conductors 56a and 56b constituting one branch line portion of the feed line 56 are respectively connected to element conductors 51a, 52a and 51b, 52b, and line conductors 56a and 56b constituting the other branch line portion are element The conductors 53a and 54a are connected to 53b and 54b, respectively.

A dielectric substrate 57 is in contact with the back surface of the dielectric substrate 55. On the front and back surfaces of the dielectric substrate 57, line conductors (not shown) constituting the feed line are respectively printed and formed on the line conductors 56a and 56b of the feed line 56 formed on the dielectric substrate 55, respectively. They are connected at the branch point 56c.
The dielectric substrates 55 and 58 and the elements printed on them constitute a vertically polarized antenna unit V-2 for f2 and f3 bands.

FIG. 8 shows a state in which three sets of the horizontally polarized antenna unit H-2 and the vertically polarized antenna unit V-2 are arranged on the dielectric substrate 60 in the vertical direction.
The horizontal polarized wave antenna unit H-2 and the vertical polarized wave antenna unit V-2 in each set have the horizontally polarized dipole element 40 and the vertically polarized dipole elements 51 to 54 shown in FIG. The arrangement position is set so as to constitute the f3 band antenna block. The individual sets are arranged at an interval of 0.29λ _0.8 (= 0.6λ _1.7 = 0.68λ _2.0 ), and constitute a subarray for the f2 and f3 bands together with the dielectric substrate 60 for power supply.

  The dielectric substrate 41 of the antenna unit H-2 is fixed and supported perpendicularly to the surface of the feeding dielectric substrate 60, and the dielectric substrate 55 of the antenna unit V-2 is a dielectric substrate 57 shown in FIG. And fixedly supported in parallel to the surface of the dielectric substrate 60 via the. A power feeding circuit (not shown) for feeding power to the antenna units H-2 and V-2 is printed on the back surface of the dielectric substrate 60.

The vertical length of the f2 and f3 band sub-arrays shown in FIG. 8 is 0.87λ _0.8 (= 0.29λ _0.8 × 3), and therefore the f1 band sub-array shown in FIG. Is possible.
FIG. 9 shows an example in which two f1 band subarrays and two f2 and f3 band subarrays are combined, and FIG. 10 shows the antenna units H-1, V− of the f1 band subarray in this combination example. 1 shows the relative positional relationship between the antenna units H-2 and V-2 of the subarray 1 for the f2 and f3 bands.

As shown in FIG. 10, the relative positional relationship between the f1 band sub-array and the f2 / f3 band sub-array located on the upper side (left side in FIG. 10) when viewed from the ground side is the same as that of the former horizontal polarization antenna unit H-1. horizontal uppermost latter polarized antenna unit dipole elements 40 of the H-2 is 0.07Ramuda _0.8 relative to the dipole elements _{10 (= 0.15λ 1.7 = 0.17λ 2.0} ) only to be positioned displaced to the earth side Is set to
The relative positional relationship between the f1 band sub-array and the f2 and f3 band sub-arrays located on the lower side (right side in FIG. 10) as viewed from the ground side is also the same.
The relative positional relationship between the upper f1 band sub-array and the lower f1 band sub-array is such that the distance between the dipole elements 10 is 0.29λ _0.8 × 3 = 0.87λ _0.8. Is set.

  In the antenna apparatus of FIG. 9 in which the antenna assembly (which also constitutes one antenna apparatus) composed of the f1 band subarray and the f2 and f3 band subarrays is arranged in two stages as described above, the upper f2 A part of the lowermost dipole elements 51 to 54 of the f3 band sub-array is located on the ground side with respect to the dipole element 10 of the lower f1 band sub-array. Therefore, as shown in FIGS. 2 and 9, in order to insert a part of the lowermost dipole element 40 of the sub-array for the f2 and f3 bands into the dielectric base slope 11 of the horizontally polarized antenna unit H-1. The holes 14, 15 and 16 are formed through.

According to the antenna device of FIG. 9, an ideal spacing of 0.29λ _0.8 (= 0.6λ _1.7 = 0.68λ _2.0 ) in the vertical direction even in the antenna elements (dipole elements 40, 51 to 54) in the high frequency band. Can be maintained.
11, FIG. 12 and FIG. 13 show vertical polarization with respect to the f1 band frequency (0.885 GHz), f2 band frequency (1.8125 GHz) and f3 band frequency (2.045 GHz) of the antenna apparatus of FIG. And horizontal directionality of horizontally polarized waves are illustrated.
As described above, in the mobile communication antenna apparatus suitable for the current 6-sector configuration, the horizontal plane beam width in the 0.8 GHz band is approximately 60 °, and in the 1.7 GHz band and the 2.0 GHz band. Each horizontal plane beam width is required to be approximately 45 °.
As is apparent from FIGS. 11, 12, and 13, the antenna apparatus shown in FIG. 9 can sufficiently satisfy the above conditions.

  On the other hand, FIG. 14 and FIG. 15 illustrate the VSWR characteristics of the vertically polarized wave and the horizontally polarized wave with respect to the f1 band frequency and the f2 / f3 band frequency (2.045 GHz) of the antenna apparatus of FIG. In FIG. 14, 0.91f1 and 1.08f1 are 0.810 GHz and 0.960 GHz, respectively. In FIG. 15, 0.96f2 and 1.03f1 are 1.745 GHz and 1.880 GHz, respectively, and 0.94f3 and 1.06f3 are 1.940 GHz and 2.170 GHz, respectively.

As is clear from these figures, according to the antenna apparatus shown in FIG. 9, the ratio band satisfying VSWR 1.5 is about 17% at the frequency of the f1 band, and at the frequency of the f2 / f3 band, The specific bandwidth that satisfies VSWR 1.5 is about 22%. That is, this antenna device has a function as a wideband antenna device.
1 and the f2 / f3 band antenna block shown in FIG. 5 and the f1 band subarray shown in FIG. 4 and the f2 / band shown in FIG. Even in the antenna device combined with the f3 band sub-array alone, the horizontal plane orientation and the VSWR characteristic according to the above can be obtained.

  The antenna apparatus shown in FIG. 9 has an arrayed configuration. However, for example, when used as a base station antenna device for mobile communication, it is desirable to further increase the number of arrangement stages of the f1 band subarray and the f2 and f3 band subarrays. Such an arrayed antenna apparatus can be configured easily and without wasteful space by connecting a plurality of (for example, three) antenna apparatus shown in FIG. 9 in the vertical direction.

The arrayed antenna device configured as described above and the antenna device shown in FIG. 9 are used in a state of being housed in a cylindrical dielectric cover (radome) 70 as shown in FIG. The diameter of the dielectric cover 70 is desirably as small as possible in order to reduce weight and wind pressure load and to reduce the size.
In the configuration of the antenna device according to the present embodiment, the shape of the f1 band horizontally polarized antenna unit H-1 having a long applicable wavelength is an element that determines the inner diameter of the dielectric cover 70. The horizontal polarization antenna unit H-1 for the f1 band shown in FIG. 16 is formed by bending the tip of the outer element conductor 10a of each dipole element 10 in a curved shape so as to follow the inner peripheral surface of the dielectric cover 70. Therefore, even when a small-diameter dielectric cover 70 as shown is used, interference between the outer element conductor 10a and the inner peripheral surface of the dielectric cover 70 is avoided.

Since the horizontal polarization antenna unit H-2 for the f2 / f3 band has the dipole element 40 formed in an umbrella shape, even when the small-diameter dielectric cover 70 is used, as shown in FIG. Interference between the outer element conductor 40a of the dipole element 40 and the inner peripheral surface of the dielectric cover 70 is avoided. When using such an antenna unit H-1, H-2, the inner diameter of the dielectric cover 70 shown in FIG. 16 and 17 can be set to about 0.7λ _0.8.

  The dipole element 10 of the horizontally polarized antenna unit H-1 for f1 band may be formed in an umbrella shape like the dipole element 40 of the horizontally polarized antenna unit H-2 for f2 and f3 bands. The dipole element 40 of the horizontally polarized antenna unit H-2 for f2 and f3 bands may be formed like the dipole element 10 of the horizontally polarized antenna unit H-1 for f1 band shown in FIG.

The present invention is not limited to the above-described embodiment, and includes, for example, the following various modifications.
(A) The antenna device and arrayed antenna device according to the above embodiment can be provided with a reflector as shown in FIG. 9 as necessary.
(B) In the horizontally polarized antenna unit H-1 for f1 band shown in FIG. 2, each dipole element 10 is formed on a common dielectric substrate 11, but each dipole element 10 is formed on a separate substrate. May be. The same applies to the horizontal polarization antenna unit H-2 for the f2 and f3 bands shown in FIG. 6 (c) the dipole element 10 of the horizontal polarization antenna unit H-1 for the f1 band and the vertical polarization for the f1 band shown in FIG. The dipole element 20 of the wave antenna unit V-1 may be configured as the dipole element 40 of the horizontally polarized antenna unit H-2 for f2 and f3 bands that is fed via a balun. The dipole element 40 of H-2 may be configured like the dipole element 10 of the antenna unit H-1.
(D) At least one of the vertically polarized antenna units V-2 for f2 and f3 bands shown in FIG. 7 has a length that resonates with one of the frequencies f2 and f3, and the other has the frequencies f2 and f3. And at least one dipole element connected to one branch line, and the other branch line connected to the other branch line. The point that a vertically polarized dipole element is connected may be satisfied. Therefore, the number and arrangement form of the dipole elements of the antenna unit V-2 are not limited to those illustrated.
(E) The antenna of each embodiment is configured to be applied to the 0.8 GHz band, the 1.7 GHz band, and the 2.0 GHz band, but the present invention is also applicable to other frequency bands.

It is a conceptual diagram which shows the structure of the antenna block for f1 bands. It is a side view which shows the structural example of the horizontal polarized-wave antenna unit for f1 bands. It is a side view which shows the structural example of the vertically polarized-wave antenna unit for f1 bands. It is a perspective view which shows the structure of the subarray for f1 belt | band | zones. It is a conceptual diagram which shows the structure of the antenna block for f2 / f3 zone | bands. It is a side view which shows the structural example of the horizontal polarization antenna unit for f2 / f3 zone | bands. It is a top view which shows the structural example of the vertically polarized antenna unit for f2 / f3 zone | bands. It is a perspective view which shows the structure of the subarray for f2 / f3 belt | band | zones. It is a perspective view which shows the antenna assembly which consists of a subarray for f1 bands, and a subarray for f2 * f3 bands. FIG. 10 is a conceptual diagram showing a relative positional relationship between an antenna unit of the f1 band sub-array and an antenna unit of the f2 / f3 band sub-array in the antenna assembly of FIG. 9; It is a characteristic view which illustrated the horizontal polarization in the horizontal plane with respect to the frequency of a 0.8 GHz band, and horizontal polarization. FIG. 6 is a characteristic diagram illustrating horizontal polarization and horizontal polarization in a horizontal plane with respect to a frequency of 1.7 GHz band. FIG. 6 is a characteristic diagram illustrating horizontal polarization and horizontal polarization in a horizontal plane with respect to a frequency of 2.0 GHz band. It is the graph which illustrated the VSWR characteristic of the horizontal polarization and horizontal polarization with respect to the frequency of 0.8 GHz band. It is the graph which illustrated the VSWR characteristic of the horizontal polarization with respect to the frequency of 1.7 / 2 GHz band, and a horizontal polarization. It is a side view which shows the horizontal polarized-wave antenna unit for f1 band | bends which formed the front-end | tip part of the element conductor in the curve shape so that the inner peripheral surface of a dielectric cover might be followed. It is a side view which shows the arrangement | positioning form of the horizontally polarized wave antenna unit for f2 * f3 bands in a dielectric cover. It is a conceptual diagram which shows an example of the conventional antenna apparatus comprised in order to satisfy | fill the conditions requested | required of the antenna apparatus suitable for the present 6 sector structure.

Explanation of symbols

10, 40 Horizontally polarized dipole element 11, 21, 41, 55 Dielectric substrate 20, 51-54 Vertically polarized dipole element 30, 60 Feeding dielectric substrate 70 Dielectric cover 80 Reflector H-1 f1 band Horizontally polarized antenna unit for V-1 f1 band Vertically polarized antenna unit for H-1 f2 and f3 bands Horizontally polarized antenna unit for V-1 f2 and f3 bands

Claims (8)

A pair of first horizontally polarized dipole elements having a length resonating at the frequency f1 and arranged horizontally and at a predetermined interval in the horizontal direction;
A pair of first vertically polarized dipole elements having a length resonating at the frequency f1 and arranged vertically and at a predetermined interval in the horizontal direction;
A pair of second horizontally polarized dipole elements having lengths that resonate at frequencies f2 (> f1) and f3 (> f2), and are horizontally oriented and arranged at predetermined intervals in the horizontal direction;
At least one has a length that resonates with one of the frequencies f2 and f3, and the other has a length that resonates with the other of the frequencies f2 and f3, with a predetermined interval in the vertical direction and in the horizontal direction. Three or more second vertically polarized dipole elements arranged in a line;
At least one second vertical polarization dipole element branches horizontally from the branch point and is connected to one branch line, and the other second vertical polarization dipole is connected to the other branch line. A feed line to which the element is connected,
The pair of first horizontal polarization dipole elements is set such that the length of the element conductor located on the outside is larger than the length of the element conductor located on the inside.
The pair of second horizontal polarization dipole elements and the three or more second vertical polarization dipole elements are disposed between the pair of first vertical polarization dipole elements. An antenna device characterized by that.   The first horizontal polarization dipole element, the first vertical polarization dipole element, the second horizontal polarization dipole element, and the second vertical polarization dipole element are respectively first and second. The antenna device according to claim 1, wherein the antenna device is formed on the third and fourth dielectric substrates. A first dielectric substrate for feeding that forms a feeding line for feeding power to the first horizontally polarized dipole element and the first vertically polarized dipole element; and the second horizontally polarized dipole. And a second dielectric substrate for feeding that forms a feeding line for feeding power to the element and the second vertically polarized dipole element,
The first and second dielectric substrates are supported by the first power feeding dielectric substrate, and the third and fourth dielectric substrates are supported by the second power feeding dielectric substrate. The antenna device according to claim 2, wherein:
  A balun is formed on some or all of the first, second, third, and fourth dielectric substrates, and the dipole element formed on the dielectric substrate on which the balun is formed is provided via the balun. The antenna device according to claim 2, wherein the antenna device is configured to feed power.   3. The antenna device according to claim 2, wherein the outer element conductor of the first horizontal polarization dipole element has a tip formed in a curved shape so as to be along the inner peripheral surface of the dielectric cover. .   The antenna device according to claim 2, wherein the element conductor of the second horizontally polarized dipole element is bent to form an umbrella shape.   7. An antenna device comprising a plurality of antenna devices according to claim 1 arranged in an array in the vertical direction.   8. The antenna device according to claim 1, further comprising a reflector.

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