JPH0591019U - Planar array antenna - Google Patents

Abstract

(57) [Summary] [Purpose] After realizing directivity with a desired half-value angle,
To provide a planar array antenna excellent in suppressing side lobes. In a planar array antenna in which a plurality of radiating elements are arranged on an insulating substrate having a ground conductor on the back surface, at least one of the radiating elements is combined to form a set of radiating elements, and the centers of the two radiating elements are arranged. The connecting line and the line connecting the centers of the other two radiating elements are orthogonal to each other, and the lengths of the line segments are different from each other.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a planar array antenna for microwaves, which is excellent in reducing side lobes.

[0002]

[Prior Art]

 As shown in FIG. 9, the array of radiating elements of a conventional planar array antenna has a rectangular center at each radiating element in the horizontal direction (X direction) and the vertical direction (Y direction) in the arrayed plane. Are arranged as follows. Furthermore, the spacings of the arrayed radiating elements 1 in the X and Y directions are selected to match the required directivity in the horizontal plane and directivity in the vertical plane, respectively. If the required half-value angle (the angle from the directivity direction at which the maximum gain half-maximum in the directivity direction) is the required horizontal or vertical directivity, the spacing between the radiating elements to be arrayed is particularly large (wide directivity). Needs to be narrowed.

[0003]

[Problems to be solved by the device]

 In order to have wide directivity using such a conventional planar array antenna, the required half-value angle cannot be obtained even if the spacing between the radiating elements is narrowed so that adjacent radiating elements contact each other. Therefore, it is necessary to reduce the number of radiating elements arranged. Further, in order to reduce side lobes (radio waves radiated in a direction that does not require directivity), in the conventional technology, a method of unequally distributing the power supplied to each radiating element must be adopted. I have to. For example, from the required half-value angle value, when arranged in the rectangular array of the prior art, the rows and columns are as shown in FIG. 8, and at this time, non-uniform power distribution is performed in order to reduce side lobes. If this is done, the directivity will be completely different from the desired directivity. That is, in this example, in order to maintain the desired directivity, it is necessary to feed each radiating element symmetrically with respect to the center line X or Y shown in FIG. 7, but as can be seen from FIG. In the case of 2 rows and 2 columns, it is not possible to make the shape symmetrical with respect to the center line X or Y in terms of the structure, and to divide into non-uniform portions. Therefore, with the conventional arrangement, the desired directivity cannot be obtained while suppressing the side lobes.

It is an object of the present invention to provide a planar array antenna having excellent directivity having a desired half-value angle and excellent suppression of side lobes.

[0005]

[Means for Solving the Problems]

 As shown in FIG. 1, the planar array antenna of the present invention is a planar array antenna in which a plurality of radiating elements are arranged on an insulating substrate having a ground conductor on the back surface thereof. As an array of radiating elements, a line connecting the centers of two radiating elements and a line connecting the centers of two other radiating elements are orthogonal to each other, and the lengths of the line segments are different from each other. It is characterized by having done.

When more radiating elements are required in such an arrangement, as shown in FIG. 5 or 6, a plurality of radiating elements are arranged at the centers of two adjacent radiating elements of the radiating elements. The radiating element may be arranged so that its center is located on the line segment and / or on a line parallel to the line segment connecting the centers of two adjacent radiating elements of the radiating element.

Further, as shown in FIG. 4, a radiating element can be provided at the center of the arrangement of the four radiating elements.

[0008]

[Action]

 The operation of the present invention will be described with reference to FIG. 2. In the X direction, two radiating elements 7 are arranged on the center line 5, and one radiating element 7 is placed symmetrically from the center line 5. Will be placed. In this state, for example, when the power is equally distributed to each radiating element 7, apparently three identical radiating elements 8, 9, 81 are arranged on the center line 6 as shown in FIG. And the ratio of the power supplied to each radiating element is 1 to the radiating element 8, 2 to the radiating element 8 and 1 to the radiating element 81. It becomes a state. That is, with this arrangement, it is possible to equalize the power supply to the center line 5 in a symmetrical manner. Further, in this case, apparently, the feeding ratio is highest on the center line 5. This also applies to the Y direction.

[0009]

【Example】

Embodiment 1 An embodiment of the present invention is shown in FIG. This antenna is a plane array antenna in which four radiating elements 2 for right-handed circularly polarized waves are arranged, and the half-value angle of the directivity in the horizontal plane (X direction) is more than the half-value angle of the directivity in the vertical plane (Y direction). Is also a wide antenna. Here, as shown in the radiating element array model of FIG. 2, the interval ΔX ₁ = 0.3 4λ ₀ (λ ₀ : free space wavelength) between the radiating elements 7 in the horizontal direction and the interval ΔY between the radiating elements 7 in the vertical direction. ₁ = 0.58 λ ₀ . In addition, as shown in FIG. 1, all the radiating elements are fed from the feeding point 4 through the feeding line 3 in equal parts. The substrate material used in this example has a dielectric thickness of 0.8 mm and a relative dielectric constant of 1.77. FIG. 10 shows the measurement result of the directivity of the planar array antenna shown in FIG. From FIG. 10, the half value angle θx ₁ of the directivity 10 in the horizontal plane (X direction) is 50 °, the half value angle θy ₁ of the directivity 11 in the vertical plane (Y direction) is 30 °, and the level of the side lobe 17 is When the peak value is 0 dB, it becomes about -36 dB.

Comparative Example Here, the directivity measurement result of the antenna in which the same half-value angle is obtained by using the same substrate and the conventional technique arranged in a rectangle as shown in FIG. 8 is shown. 11 shows. At this time, the spacing ΔX ₂ = 0.47λ ₀ between the radiating elements 14 in the horizontal direction (X direction) and the spacing ΔY ₂ = 0.81λ ₀ between the radiating elements 14 in the vertical direction (Y direction) shown in FIG. Further, in this case, in order to reduce the side lobe, it is structurally impossible to feed power in a non-uniform manner symmetrically with respect to the center line 12 or the center line 13, so that each radiation is not possible. The element 14 is supplied with power evenly. From FIG. 11, the half-value angle θX ₂ of the directivity 15 in the horizontal plane is 50 °, the half-value angle θY ₂ of the directivity 16 in the vertical plane is 30 °, and the level of the side lobe 18 is the peak. When the value is 0 dB, it is about -12 dB.

Comparing FIG. 10 with FIG. 11, the directional half-value angles in the horizontal plane and the vertical plane of the antenna of the conventional example are almost the same as those of the example according to the present invention, but the side lobe levels are compared. Then, since the peak values are almost the same, it can be seen that the side lobe 17 of the embodiment according to the present invention is about 24 dB smaller than the side lobe 18 of the prior art example.

Embodiment 2 As shown in FIG. 9, the same as Embodiment 1 except that the number of radiating elements is 5 and a horizontal polarization element is used as the radiating element.

As shown in FIG. 10, the same as Example 1 except that the number of radiating elements was 9, and the element for left-handed circularly polarized wave was used as the radiating element.

As shown in FIG. 11, the same procedure as in Example 1 was carried out except that the number of radiating elements was 16 and the elements for both horizontal and vertical polarization were used as radiating elements.

[0015]

[Effect of the device]

 As described above, the present invention has the following effects. (1) Equivalent distribution of power supply to each radiating element can be equivalent to conventional non-uniform power supply in a symmetrical arrangement, and side lobes can be suppressed while maintaining the desired directivity. .. (2) Compared with the rectangular array of the prior art, the range in which horizontal and vertical radiating element intervals can be set is wider without being restricted by the size of the radiating elements, so that directivity, particularly half-value angle setting and Adjustment becomes easy.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of the present invention.

FIG. 2 is a top view showing an arrangement of radiating elements for explaining an embodiment of the present invention.

FIG. 3 is a plan view showing an equivalent arrangement of radiating elements according to an embodiment for explaining the operation of the present invention.

FIG. 4 is a plan view showing an arrangement of radiating elements according to another embodiment of the present invention.

FIG. 5 is a plan view showing an arrangement of radiating elements according to another embodiment of the present invention.

FIG. 6 is a plan view showing an arrangement of radiating elements according to another embodiment of the present invention.

FIG. 7 is a plan view showing a conventional example.

FIG. 8 is a top view showing an arrangement of a conventional example.

FIG. 9 is a top view showing a radiation element array of a conventional example.

FIG. 10 is a diagram showing a directivity characteristic for explaining an effect of one embodiment of the present invention.

FIG. 11 is a diagram showing a directional characteristic of a conventional example.

[Explanation of symbols]

1 ... Radiating element 2 ... Radiating element for right-handed circularly polarized wave 3 ... Feed line 4 ... Feed line 5 ... Center line 6 ... Center line 7 ... Radiating element 8 ... Radiating element 9 ... Radiating element 10 ... Horizontal plane directivity 11 ... Vertical in-plane directivity 12 ... Center line 13 ... Center line 14 ... Radiating element 15 ... Horizontal plane directivity 16 ... Vertical in-plane directivity 17 ... Side lobe 18 ... Side lobe

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Creator Kiichi Kanamaru 1150 Gozamiya, Shimodate City, Ibaraki Prefecture Gotomiya Plant, Hitachi Chemical Co., Ltd.

Claims (3)

[Scope of utility model registration request] 1. In a planar array antenna in which a plurality of radiating elements are arranged on an insulating substrate having a ground conductor on the back surface thereof, at least one radiating element is combined to form a set of two radiating elements. A planar array antenna, wherein a line connecting the centers and a line connecting the centers of two radiating elements other than the center are orthogonal to each other and the lengths of the line segments are different from each other. 2. A line segment connecting a plurality of radiating elements on a line segment connecting the centers of two adjacent radiating elements of the radiating element and / or a line segment connecting the centers of two adjacent radiating elements of the radiating element. The planar array antenna according to claim 1, wherein the planar array antenna is arranged so that its center is placed on a line parallel to the line. 3. The planar array antenna according to claim 1, wherein a radiating element is also provided at the center of the arrangement of the four radiating elements.