Array antenna with reflecting plate

[Detailed Description of the Invention]

[Industrial Application] The present invention relates to the array antenna in wireless communications. Within the plane which has the shape of a radiation beam especially, it has a spread of a sector and is related with the contoured beam antenna which has different beam shape from the above-mentioned plane within the plane which intersects perpendicularly with this. The present invention is used for the wireless communications between one key station and a plurality of child offices. [Description of the Prior Art] Since a radio station and a radio station communicate by carrying out a right opposite in communicative wireless communications, generally at the antenna used, it is a thing of the characteristic of a low side lobe in high gain. However, to communicate between a plurality of child offices and one key station which are scattered in a certain area, the antenna of a key station needs to have what is called a forming beam that irradiates with the area where child offices are scattered efficiently. The top view and Drawings 10 and 11 where the key station and child office where Drawing 9 performs wireless communications are arranged illustrate the effect of beam fabrication using Then and these with the side view. That is, when B, C, D, and E office are made into a child office by making A office into a key station, respectively, in the shape of the beam of the antenna of a key station, it is desirable in the level surface to have a spread of a sector which covers all the child offices to Drawing 9 as dashed line 1 shows. It is desirable to have a forming beam as shown in dashed line 3 of Drawing 11 rather than the usual pencil beam as shown with dashed line 2 of Drawing 10 according to the difference of distance with the ground vertical interval and key station where a child office is arranged on the other hand as a vertical plane shows to Drawings 10 and 11. Drawing 12 is a top view in case the communication range of the key station shown in Drawing 9 and a child office adjoined and has been arranged. In such a case, Polarized wave which intersected perpendicularly mutually will be used and the quality of the degree of rectangular cross of Polarized wave, i.e., the cross polarization characteristic of beam 1 and 1', will influence the quality of a circuit directly so that forming beam 1 and 1' may not interfere. As a method of compounding such a forming beam conventionally, a contoured beam antenna like patent application Japanese Patent Application No. 58-202372 (it is unpublished at the time of this application application) by the same applicant was able to be considered, for example. The front view of this conventional example antenna, the sectional view in the level surface, the sectional view in a vertical plane, and the explanatory view of the radiation property in a vertical plane are shown in Drawing 13 and Drawings 14, 15, and 16, respectively. An antenna comprises primary radiation machine 20 and main reflector 30. The main reflector 30 is set to parabola mirror surface part 35-1 of Taurus mirror surface parts 34, 37, and 38 of the central part, and both ends, 36-1, and 39-1 from 35-2, 36-2, and 39-2, The first mirror surface part 34, 35-1, and 35-2 are symmetrical about the level surface and a vertical plane, and the second mirror surface part 37 and 38, 36-1, 36-2, 39-1, and 39-2 are asymmetrical structures about the level surface. When the radiation property in the level surface of this antenna is explained using Drawing 14, numerals 34 in the first mirror surface part are angles theta to the circumference of a vertical axis about the cutout line of Drawing 15.₀They are the Taurus specular surface which carried out Only rotation, and a parabola specular surface which numerals 35-1 and 35-2 use axis P35-1 and P35-2 as a rotation center axis, respectively, and uses point F as a focus. The spherical wave emitted from primary radiation machine 20 is reflected by the Taurus mirror surface part 34 in the level surface, It passes along a passage as shown with dashed lines 4 and 5, and becomes a concentric circular radiation wave face centering on the starting point, and parabola mirror surface part 35-1 and the electric wave reflected by 35-2 pass along a passage as shown with dashed lines 6 and 7, and is changed into the plane wave which advances in the direction of axis P35-1 and P35-2. Therefore, the radiation property in the level surface is ±theta from a mirror axis as composition of each above-mentioned wave face.₀It has the characteristic almost uniform in Angle within the limits, and the absolute value of the angle from a mirror axis is theta.₀Above, it has the characteristic decreased rapidly and can compound what is called a sector beam. Next, if Drawings 16 and 17 explain the radiation property in a vertical plane, the cutout line of the first mirror surface part 34 of Drawing 15 is a parabola which uses point F as a focus and sets a central axis as a mirror axis, and is symmetrical about a mirror axis. The cutout line of the second mirror surface part 37 and 38 is a parabola which uses point F as a focus and sets a central axis as axes P37 and P38, respectively. Therefore, the electric wave reflected by the Taurus specular surface 34 of the spherical wave emitted from primary radiation machine 20 passes along dashed line 8-1 and the passage shown in 8-2, for example, and is emitted as the direction of a mirror axis, i.e., a wave face which he follows horizontally. The electric wave reflected by specular surfaces 37 and 38 is emitted as a wave face which he follows in axis P37 and the P38 direction through the passage shown, for example in dashed lines 9 and 10, respectively. The radiation property in a vertical plane becomes settled as composition of each above-mentioned wave face, and as solid line 12 of Drawing 16 shows, an asymmetrical beam is compounded about the plane of zero angle, i.e., the level surface, from a mirror axis. Dashed lines 13 and 14 are the main Polarized wave and the cross polarization characteristics of an electric wave which were reflected by the first mirror surface part 34 in Drawing 16, and dashed line 15 is the main polarization component of the electric wave emitted from the second mirror surface part 37 and 38. As dashed line 14 of Drawing 16 shows, on a mirror axis, the cross polarization ingredient which mirror surface part 34 generated in the specular surface about this axis since it was symmetrical is offset, and the cross polarization characteristic turns into the good characteristic. Since the maximum radial direction of the main polarization component has separated the cross polarization ingredient which occurs in asymmetrical mirror surface parts 37 and 38 about a mirror axis from the mirror axis, respectively, it does not have big influence to up to a mirror axis, but the whole cross polarization characteristic turns into the best characteristic in a mirror-axis top after all, as solid line 16 shows. The characteristic in the above vertical plane is ±theta so that clearly also from explanation of Drawing 14.₀Since it is almost the same at Angle within the limits, the cross polarization characteristic serves as best in the level surface which contains a mirror axis as a result. [Problem(s) to be Solved by the Invention] However, as solid line 16 of Drawing 16 shows in the conventional contoured beam antenna explained above, the fault from which the cross polarization characteristic deteriorates rapidly except a mirror axis, i.e., the level surface, and the good cross polarization characteristic is acquired only very for the neighborhood of the level surface is Oh. As a problem of a circuit, when carrying out selection of A office of Drawing 12, C office and A office, and A' office, for example, this fault cannot take the large ground vertical interval between each office, and if vertical intervals, such as actual geographical feature or a building, are taken into consideration, it may be unable to select an office. A tower special to solving this must be provided independently. That is, it is ±beta about the angle range where the cross polarization characteristic good in Drawing 16 is acquired.₀When it carries out, the ground vertical interval allowed on a circuit design is permission ground vertical interval =. (Horizontal distance between each office) xtanbeta₀......(1) A next door, angle beta₀The size of affects circuit composition directly. The above-mentioned angle beta₀The greatest factor that determines The size of is a size of the cross polarization ingredient which occurs in a specular surface. Drawing 17 is an explanatory view of a cross polarization ingredient generated in a specular surface. In the figure, only the inner first mirror surface part 34 top of the specular surface of explanation shown in Drawing 13 for convenience is shown, and dotted lines 17 and 18 show the example of the flow of the current induced on a specular surface by the electric wave which came from primary radiation machine 20. When this current ingredient is made into magnetic field vector ingredient = of an incidence wave, and unit method line vector = of a specular surface as everyone knows, induction current phasor = on a specular surface is, ===x= ...... (2) It becomes. When a front view shows like [ magnetic field vector ingredient = is a spherical wave here and since it has three ingredients by a rectangular-coordinates system from Normal vector = being the above-mentioned composition, respectively, induction current phasor = also has three ingredients and ] Drawing 17, it is the main polarization component M.₁~M₄Cross polarization ingredient C₁~C₄of -- it can express like. That is, the current ingredient itself induced on a specular surface becomes a thing containing a cross polarization ingredient, and the main Polarized wave and the amount of cross polarization of a radiation property are proportional to the size of this induction current, respectively. It is C, when mirror surface part 34 is considered about the level surface and a vertical plane in the level surface, for example since it is symmetrical as described above.₁C₂Orientation is reverse, the distance to the level surface is the same, and it is C.₃C₄connection of is also the same. Therefore, a formula (1) is materialized in the level surface. However, except the level surface, it is C.₁C₂Since there is a distance difference from an ingredient to the level surface, a formula (1) will not be materialized, but a cross polarization ingredient will remain, and as dashed line 14 of Drawing 16 shows after all, the characteristic will deteriorate except the level surface. At the circuit which needs the cross polarization characteristic of 20 dB or more, for example in the conventional antenna of composition of having been practically shown in Drawing 15 from Drawing 13, it is beta.₀Only about 0.5 But can be taken but they are big restrictions and intermediary There was on physical circuit composition. In conventional Athena, primary radiation machine 20 exists in the passage of an electric wave, and it blocks a part of electric wave so that clearly also from the composition. For this reason, another fault in which it is difficult to compound the beam shape of the level surface and a vertical plane in a desirable form is Oh. Since composition of the reflective wave from each mirror surface part performs fabrication of a beam so that clearly also from explanation of Drawings 14 and 15, required composition will be barred by the above-mentioned blocking and the degree of beam fabrication will deteriorate. The especially big problem in the vertical plane which is going to fabricate a beam to the level in which this influence is comparatively low, and intermediary There was. Creating the specular surface of composition as furthermore shown in Drawing 15 from Drawing 13 has the difficulty which fabricates a complicated field by three dimensions also technically, and it generally needs an expensive tool. The fault which will become expensive as the whole antenna -- the man day of the fabrication [ itself ] is also large -- is Oh. An object of the present invention is to provide the antenna of a new structure with a beam molding characteristic and the good cross polarization characteristic. The present invention does not need a tool special to manufacture, but a manufacture man day is small and aims at providing a cheap antenna. [Means for Solving the Problem] The present invention compounds beam fabrication in a vertical plane with an array antenna not using a light reflector, Fabrication of a beam in the level surface is compounded by the main light reflector which comprised a plurality of conductor plates attached so that blocking might not be caused to an array antenna, Taking advantage of the radiation property of an array antenna, and the characteristic of the main light reflector, both the cross polarization characteristic and the degree of beam fabrication obtain a good antenna. Namely, an array antenna with which a radiating element of plurality [ present invention / top / rectangular / plane ] was arranged, In an array antenna with a light reflector which was provided with the main light reflector back arranged to a radial direction of the above-mentioned radiating element of this array antenna, and the main reflective surface of this main light reflector comprised with a plurality of conductor plates, The center of the above-mentioned rectangle of the above-mentioned array antenna is made into the starting point, and the X-axis is provided in a longitudinal direction of the rectangle, If the Z-axis is defined in the direction which intersects perpendicularly with a plane of the rectangle and keeps away to the above-mentioned main light reflector through the starting point and the Y-axis is defined in the direction which intersects perpendicularly with the X-axis and the Z-axis through the starting point, it is the above-mentioned main light reflector, Each central axis of each conductor plate is parallel to the X-axis, and is symmetrical and shape convex to a negative direction of the Z-axis about a Then XZ plane, and it is a radiating element of the above-mentioned Arrain antenna, The excitation amplitude is symmetrical about YZ plane, it is arranged so that the excitation phase may become anti-symmetry about YZ plane, and it is a radiating element of the above-mentioned array antenna further, A radiation beam formed from the above-mentioned main light reflector has been arranged so that asymmetrically [ it may be symmetrical about the Z-axis on YZ plane and / about the Z-axis ] on YZ plane. a conductor added to an end of the main light reflector at the main light reflector -- it is preferred that that a board is included includes preferably mounting structure which attaches an array antenna in the main light reflector. [Function] By the array antenna and the light reflector which fabricates this radiation beam, it is a symmetric figure horizontally and can obtain the radiation beam which is an asymmetrical form perpendicularly. [Example] Drawing 1 is a perspective view showing present invention example device structure, and Drawing 2 is the front view. In this example, array antenna 40 is constituted by the waveguide slot antenna as a radiation machine, and the main light reflector comprises a light reflector which comprises partial light reflectors 50, 51, 52, and 53 which are conductor plates. Conversion part 42 is provided in the main light reflector as mounting structure which attaches the above-mentioned array antenna. In the field where the radiating element is arranged, array antenna 40 is a rectangle, and termination machine 41 is connected to the end. Rectangular-coordinates axis X, Y, and Z made the starting point the center of the opening side that the slot of the array antenna was provided, respectively, and has defined the Y-axis in the direction which intersects perpendicularly in the direction which intersects perpendicularly with the longitudinal direction of an array antenna in the X-axis and an opening side, and keeps away to a main light reflector at the Z-axis, the Y-axis, and the Z-axis. That light reflector axis, i.e., the axis which becomes always the same [ the cutout line of each partial light reflector in the plane which intersects perpendicularly with this axis ], is arranged at the X-axis and parallel, and partial light reflectors 50, 51, 52, and 53 of the whole light reflector are symmetrical about XZ plane. Drawings 3 are some enlarged drawings of an array antenna, multiple slots of an elliptical form as shown in a figure in parallel with a tube axis, i.e., a longitudinal direction, in what is called a magnetic field side of a waveguide are provided, and the electric wave which has advanced the waveguide is emitted from each slot. Although each slot is excited by the current of the direction of the Y-axis which flows through the wall in a waveguide, it is adjusted with size S of the slot and the X-axis which show the relative excitation phase between each slot mainly in Drawing 3 again with size L of the direction of X between the slots which show the amplitude mainly in Drawing 3. If the case where an asymmetrical beam is compounded centering on the Z-axis like solid line 60, i.e., the axis of zero angle of Drawing 5, which are shown in Drawing 5 within a vertical plane is explained in Drawing 1 when YZ plane is made into the level surface and XZ plane is used as a vertical plane, in this case -- although the excitation amplitude of each slot becomes symmetrical about YZ plane, an excitation phase is related with YZ plane -- anti- -- it becomes symmetrical. The absolute value of a phase is the same and it means here that numerals are reversed as anti-symmetry. The example of Drawing 5 becomes as in a table to the slot of the 10th upper part, when Example shudder amplitude of the slot of the central part is set to 1 and a total of 21 slots, amplitude, and a phase make a Example shudder phase 0 times. Numerals reverse only the phase of the value of a table to the slot 10th below a table. What the above-mentioned numerical example can realize beam fabrication for with an array antenna to the last [Table]

It is a Indicates example and other Example shudder are possible. when compounding a beam like solid line 60 of Drawing 5, excitation amplitude is symmetrical about XZ plane -- an excitation phase -- anti- -- it becomes symmetrical. Drawing 4 is a figure showing other examples of composition of an array antenna. Numerals 43, 46, and 47 are the metallic strips on dielectric substrate 44 in the figure, and numerals 45 are metal conductors. Square strip 43 is a radiating element in the figure, and metallic strips 46 and 47 are the electric supply lines for supplying electric power in two Polarized wave which intersected perpendicularly to this radiating element. The electric field ingredient of metallic strip 46 is an electric supply line of Polarized wave of the direction of the X-axis, and metallic strip 47 is an electric supply line of Polarized wave of the direction of the Y-axis. These are connected to connectors 48 and 49 by which the input-and-output end was fixed to metal conductor 45, respectively. Respectively the conductor was connected to metal conductor 45 outside the same axle, the central conductor was connected to metallic strips 46 and 47, and connectors 48 and 49 are electrically combined with the electric supply line. The excitation amplitude and the phase to each radiating element are controllable by this structure by change and the track length of the strip width of metallic strips 46 and 47. Unlike fabrication by the specular surface explained in Drawing 13, if cross polarization discrimination uses a good element as each radiating element, the beam fabrication of the feature of the beam fabrication by the above array antenna will be fundamentally attained at Source excluding a cross polarization ingredient. Therefore, as explanation of Drawings 16 and 17 described, even if it does not negate the cross polarization ingredient contained in Source using the symmetry of the main reflector, it has the big feature that the good cross polarization characteristic is acquired. The present invention can be carried out using radiating elements, such as for example, a dipole array and a crossed dipole array, besides the example of composition shown in Drawings 3 and 4 as composition of an array antenna. Drawing 6 is a diagram of a section of YZ plane of the example shown in Drawing 1, and Drawing 7 is a figure explaining the radiation property in the level surface. Composition and intermediary To have which what is called a corner reflector transformed as the whole although partial light reflectors 50, 51, 52, and 53 contributed array antenna 40 separately as a flat reflector made into Source in the example of Drawing 6, respectively. As everyone knows, like a dipole antenna, in the beam width of large Source of a beam width, a corner reflector is used in order to form the strong radiation beam of Narrowing down directivity. In this case, the beam shape formed is adjusted with the interval of a light reflector and Source, or the Expansion angle of the light reflector of two sheets. This principle was applied in the present invention. therefore, an electric wave emitted from array antenna 40 should pass a passage shown in dashed lines 70 and 71 -- it is alike also in what is emitted directly, and being reflected by each partial light reflector as dashed line 72~75 shows, and divides, and the whole radiation property becomes settled as these composition [ all ] waves. That is, the beam shape in YZ plane, i.e., the level surface, can be molded into various forms by adjusting the angle of inclination to the perpendicular distance and the Z-axis from the starting point of each partial light reflector 50, 51, 52, and 53 of Drawing 6. In the example of Drawing 6, the energy emitted directly [ of an array antenna ] turned the maximum radial direction in the zero angle [ in / it is largest and / the direction of the Z-axis, i.e. Drawing 7, ] direction, What the radiation wave from very small Source like metallic strip 43 of a slot or Drawing 4 has a large radiation property for within YZ plane, About concentrating in the same direction generally, and an antenna XZ plane, since each of reflective waves of partial light reflectors 50 and 51 and reflective waves of partial light reflectors 52 and 53 is symmetrical, they obtains the thing of a symmetrical radiation property about the Z-axis with a spread of a sector like solid line 61 of Drawing 7 within YZ plane. Although beam fabrication of the main polarization component was explained as mentioned above, the cross polarization characteristic is explained below. The current induced by the Reason on each partial light reflector as explanation of the cross polarization discrimination of conventional technology described becomes settled by a formula (2). They are X, Y, Z ingredient, and J about a formula (2), respectively._XJ_YJ_ZIt comes out, and it will become a formula (3) if shown. J_X=n_YH_Z-n_ZH_YJ_Y=n_ZH_X-n_XH_ZJ_Z=n_XH_Y-n_YH_X......(3) However, n_Xn_Yn_ZX of Is =, Y, Z ingredient. As for magnetic field vector = and electric field vector =, since it has a rectangular relation, when the electric wave by which the main Polarized wave turns to what is called vertical polarization, and the electric field vector is suitable in the direction of the X-axis, for example is emitted from the array antenna, the incidence electric field vector to a light reflector is H._yAn ingredient becomes main. As explanation of Drawing 5 also described this, the radiation wave from an array antenna originates in the cross polarization characteristic being good from the first. On the other hand, Normal vector = of a light reflector is n so that clearly also from the composition._XThere is the feature whose ingredient is zero. Therefore, the current induced in this case is J._X=n_YH_Z-n_ZH_YJ_Y=n_ZH_X≒0 J_Z=n_yH_X≒0 ...... It is set to (4). As for the current induced by each partial light reflector so that more clearly than this formula (4), the direction ingredient of Y of the main Polarized wave serves as a subject. If this result is compared with the current distribution of the conventional technology shown in Drawing 17, it is clear that an improvement of the cross polarization characteristic is expected. In example computation, when that in which, as for the cross polarization characteristic of 20 dB or more, the antenna shown in Drawing 15 from Drawing 13 can take only the range of ±0.5-degree perpendicular angle as mentioned above used the present invention, it was checked that it can take to the range of about ±5 degrees. The Reason can explain that it is good in the cross polarization characteristic when the main Polarized wave turns to what is called vertical polarization and the electric field vector is suitable in the direction of the X-axis having drawn the formula (4). Although Drawing 6 furthermore explained the case where partial light reflectors were three examples, the flexibility of beam fabrication further increases by considering it as two pieces or four partial light reflectors or more. Since the main light reflector does not block the radiation wave of an array antenna in the composition of the present invention, there is an advantage which does not degrade the degree of fabrication of a beam as compared with Athena of conventional technology, and especially this effect has a large effect to the beam fabrication within XZ side. Because, since the case of Drawing 5 needs to make a beam fabricate to a level quite weaker than the case of Drawing 7 clearly even if it compares Drawing 5 with Drawing 7, the degree of fabrication of a beam is greatly influenced by slight influence like blocking. That is, with the antenna of the present invention, the composition of the whole light reflector becomes concave to the maximum radial direction, i.e., the positive Z-axis, of an array antenna, it is the composition of not causing blocking and the feature that those of the radiation wave from each light reflector for the maximum people in general are also in less than ±90 degrees to the Z-axis is acquired. Drawing 8 is a top view showing other examples of the present invention, and adds two-sheet side board 54 made from a conductor parallel to the Y-axis to the upper and lower sides of the main light reflector of the example of Drawing 1. Electrically, the book side board has an effect which increases the intensity in a field structurally parallel to XZ plane of the main light reflector while it covers physically the unnecessary radiation wave to the horizontal direction from an array antenna and makes the radiation property of a wide angle good. Using the word of "radiation", the above-mentioned explanation was explained as if it was a transmitting antenna, but since the direction of movement of an electric wave is reversible, the antenna of the present invention is applicable to both a transmitting antenna and a receiving antenna. [Effect of the Invention] As explained above, by carrying out the present invention, the degree of beam fabrication is good, and can realize the antenna which was excellent in cross polarization discrimination. And since the reflective surface is planate, there is an advantage which can be manufactured cheaply rather than manufacturing the specular surface of conventional technology. The present invention is used for the antenna of the key station which needs to perform wireless communications with a plurality of offices which are scattered in a certain area, and produces a big effect.

[Brief Description of the Drawings]

Drawing 1 is a perspective view showing present invention example device structure. Drawing 2 is a front view of the above-mentioned example. Drawings 3 are some enlarged drawings of the above-mentioned array antenna. Drawing 4 is a perspective view of other constructional examples of an array antenna. Drawing 5 is an explanatory view of the radiation property in the vertical plane of the antenna by the above-mentioned example. Drawing 6 is a horizontal sectional view of the above-mentioned example. Drawing 7 is an explanatory view of the radiation property in the level surface of the antenna by the above-mentioned example. Drawing 8 is a top view of other examples of the present invention. Drawing 9 is a plane arrangement plan of a key station and a child office which performs wireless communications. Drawing 10 is a vertical section relation figure of Drawing 9 by a pencil beam. Drawing 11 is a vertical section relation figure of Drawing 9 by a forming beam. Drawing 12 is a plane arrangement plan when the communication field shown in Drawing 9 adjoins. Drawing 13 is a front view of the contoured beam antenna of conventional example structure. Drawing 14 is a horizontal sectional view of the above-mentioned conventional example. Drawing 15 is the vertical cross section of the above-mentioned conventional example. Drawing 16 is an explanatory view of the radiation property in the vertical plane of the antenna of the above-mentioned conventional example. Drawing 17 is an explanatory view of the Polarized wave characteristic of the antenna of the above-mentioned conventional example. 1, 1′,2,3, 12~16,60,61 ...... A radiation property, 4~7, 8-1, 8-2,9,10, 70~75 ...... The passage of an electric wave, 20 ...... A primary radiation machine, 30 ...... The main reflector, 34, 37, 38 ...... The Taurus mirror surface part, 35-1, 35-2, 36-1, 36-2, 39-1, 39-2 ...... A parabola specular surface, 40 ...... The array antenna, 41 which have a waveguide slot ...... A termination machine, 42 ...... A conversion part, 43, 46, 47 ...... A metallic strip, 44 ...... A dielectric substrate, 45 ...... A metal conductor, 48, 49 ...... A connector, 50~53 ...... A partial light reflector, 54 ...... The side board made from a conductor, P35-1, P35-2, P37, P38, P50, P51, P52, P53 ...... the central axis of a parabola, A, and A' ...... a key station, B, B', C, C', D, D', E, and E' ...... a child office and F ...... a focus, S, and L ...... the size which shows a slot interval and a position.