JPS6369301A - Shared planar antenna for polarized wave - Google Patents

Abstract

PURPOSE:To attain the sharing of both vertical and horizontal polarized waves by forming an antenna for a vertical polarized wave and a horizontal polarized wave on separate faces and arranging a ground conductor between them. CONSTITUTION:A square or a circular radiation element 11 where a vertical and a horizontal polarized wave coexist independently is to be considered, and feeding points 12, 13 for a vertical and a horizontal linearly polarized wave are formed in the face in two directions orthogonal to each other. As the ground conductor 14, a copper face clad on a separate dielectric base 16 is utilized as it is, and the ground conductor 14 is arranged at a distance (d) with respect to the radiation element 11. in exciting a unit cell 10 of a planar antenna in this way from the feeding point 12, a vertical polarized wave (V polarized wave) is radiated as shown in the arrow V upward in the vertical direction of the radiation element 11, and in exciting the cell 100 from the feeding point 13, the horizontal polarized wave (H polarized wave) is radiated as shown in the arrow H respectively independently.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to an improvement in an unbalanced planar circuit resonant microstrip antenna to enable both vertical and horizontal polarization to be shared.

<Prior Art> As a form of antenna intended for the microwave region and beyond, there is a balanced planar circuit resonant type microstrip antenna.

In this method, a unit cell is a radiating element consisting of a conductor surface forming a ground conductor and a conductor surface of a predetermined area facing each other at a predetermined distance, and multiple unit cells are arranged two-dimensionally side by side. These antennas are generally called simply planar antennas. The purpose of arranging a plurality of unit cells in parallel is to obtain the necessary gain, and in practice, the number can range from several hundred to a small order.

Printed wiring technology is generally used to create such planar antennas. In other words, the ground conductor is configured as a common conductor for each cell by a copper surface attached to the surface of a suitable dielectric substrate, but each radiating element is configured on the other surface of the dielectric substrate or on another dielectric substrate. By etching the copper surface, it is patterned into a predetermined shape. Of course, if each radiating element is formed on a dielectric substrate separate from the ground conductor, the two dielectric substrates may be physically superimposed on each other or supported at a predetermined distance. be done.

As is evident from this manufacturing process, planar antennas are inherently easier to mass produce than other types of aperture antennas, and can also be extremely thin (low profile)!
Recently, Tomi has been attracting attention because of its uniqueness.

<Problems to be Solved by the Invention> As mentioned above, planar antennas have inherently superior aspects, but the problem is that they have conventionally been used exclusively for linearly polarized waves, either vertically or horizontally. It was configured.

In other words, to date, there have been no reports of such planar antennas configured as so-called dual polarization antennas that can share both vertical and horizontal linearly polarized waves.

However, if we are just hypothesizing, we can stack two conventional single-polarized planar antennas, one for vertically polarized waves, and another for vertically polarized waves.
If the feeding points for the radiating elements in each plane for horizontally polarized waves are arranged to be orthogonal to each other, it seems possible to construct a dual polarization planar antenna that can independently radiate both polarized waves. However, even in that case, the ground conductor associated with the radiating element group for one polarization is omitted, and the ground conductor for the other polarization is used in common.

Even if such a planar antenna were to be provided, it would probably not be of practical use as is.

First of all, even if you exclude assembly-related costs, the material cost and manufacturing process will almost double, and the mass production and economic efficiency that are inherent to planar antennas will be lost, and the advantage of thinness will also be lost. It will fade.

In addition, even if the feed line network formed on two surfaces, each of which has dedicated radiating elements for vertical and horizontal polarization, is modified to be optimal for each condition, Since they directly face each other vertically in parallel or perpendicularly via a thin dielectric substrate, it is obvious that they will couple with each other and interfere with each other, making it impossible to align them.

The present invention has been made in view of these conventional circumstances, and is a polarization-sharing type that can share both vertical and horizontal linear polarization without sacrificing mass production and economic efficiency, and without sacrificing the thin feature. The aim is to provide a planar antenna, and in order to achieve this main purpose, the configuration of the feed line network to the radiating elements for each polarization is also devised.

However, according to the well-known reciprocity theorem or reversibility theorem, antennas can be used for both the transmitting system and the receiving system, and this
The situation is exactly the same in inventions. However, as is well known, in general, various explanations of this company's Ambuna technology are often explained on the radiation side for convenience, and this book also follows this.

Means for Solving the Problems> In order to achieve the above object, the inventors of the present invention first determined that, regarding the shape of the radiating element of each unit cell, vertical polarization and horizontal polarization are independent, as shown in the ZS diagram. Consider a square or circular radiating element 11 that can coexist as a radiating element 11, and feed points 12.
13 was created.

The reason why the shape of the radiating element is square or circular is to make the gain or radiation intensity as equal as possible for both vertical and horizontal polarization, in accordance with this kind of common knowledge. It was obtained by etching the copper surface stretched over the substrate 15.

On the other hand, the ground conductor 14 is a copper surface stretched on a separate dielectric substrate 16 and is used as it is, and is arranged so that the ground conductor 14 is at a distance d from the radiating element 11.

In the unit cell lO of such a planar antenna, when excited from the feed point 12, a vertically polarized wave (V polarization) is generated as shown by the arrow V in the figure, and when excited from the feed point 13,
As shown by arrow H in the figure, horizontal polarization (H polarization) is
They were each independently radiated upward in the vertical direction of radiating element +1.

Here, when the distance d was changed and the characteristics in the microwave C band were taken, the bandwidth with a good input standing wave ratio (VSWR) was about 100M11z.

Regarding the coupling of vertical and horizontal double-width waves, if the excitation system is ideal in principle, the amount of coupling should be zero, but i? [Due to the presence of d, both the amount of VH coupling and the cross-polarization protection ratio were about 1 OdB.

These characteristics themselves are certainly not very good. However, the important thing is that when the feeding points are set up on two mutually orthogonal axes in the plane of the radiating element, the excitation from them will cause The fact that it was able to radiate both polarized and horizontally polarized waves shows the feasibility of a dual-polarized planar antenna. Actually, in the present invention,
As will be understood from the description below, this structure is used in principle for the radiating element portion.

Next, based on this result, we conducted further intensive studies and developed this unit cell into a configuration as shown in FIG.

First, from the above knowledge, the smaller the distance lid between the radiating element 11 and the ground conductor 14, the better. Therefore, as shown in FIG. A ground conductor 14 was formed on the other side, and a radiating element 11 was formed on the other side. However, since mechanical strength is also required, the thickness t of the substrate was determined in consideration of this point as well.

In addition, as a measure accepted for conventional single-polarized planar antennas, if a parasitic element with the same planar shape as the radiating element is opposed in parallel to the radiating element, a good range of manual standing wave ratio can be achieved. Due to the fact that the band is widened, this idea was applied to this experimental element, and a parasitic plate 18 was formed on a suitable dielectric substrate 17, and this was placed at a distance from the radiating element 1.
1 was placed facing each other.

As a result of these considerations, the frequency bandwidth with a good input standing wave ratio has expanded to 500 MIIz, which is generally a sufficient value.

Furthermore, in addition to the thickness setting described above, by selecting a dielectric substrate 15 with an appropriate dielectric constant, it was possible to increase the amount of VH coupling and the cross-polarization protection ratio to about 20 dB.

Note that in the case shown in the figure, the parasitic element 18 faces the radiating element 11 with the dielectric substrate 17 on which it is formed interposed, but in the illustration, the parasitic element 18 is arranged so as to directly face the radiating element 11 with a space in between. It may be loaded on the back side of the dielectric substrate 17, and in this case, the substrate 17 can be used as a so-called radome for rain and snow protection. However, the dielectric substrate 17 that forms this parasitic element 18 has a small dielectric loss and only needs to have a small electromagnetic wave transmission loss, so it is cheaper than the dielectric substrate that forms the radiating element and the feed strip line network described later. can be used.

Based on these findings, it has been found that the unit cell IO shown in FIGS. 5 and 6 can sufficiently function as a unit cell for a dual-polarization planar antenna, and in particular, the principle configuration shown in FIG. Accordingly, it can be seen that if the consideration shown in FIG. 6 is added to the embodiment, a dual polarization planar antenna with good characteristics can be provided.

However, the present inventor also considered what would happen to the feed line network when a plurality of antenna cells of this unit were actually arranged two-dimensionally to form one planar antenna.

In other words, when newly configuring a dual-polarized planar antenna according to the present invention, the radiating element structure is determined as described above, and therefore, the optimum physical structure of the feed line network is obtained. In this way, the aim was to achieve the stated objectives on a practical level.

First, in order to simplify the discussion regarding this feeder line network, let us consider a case where four radiating elements 11 shown in FIG. 5 or 6 are used, as shown in FIG. 7.

For example, if it is configured as a planar antenna dedicated to single polarization, as in the past, the feed line network will be as shown in Figure 7 (^)
As shown in Figure 2, it is relatively simple and requires fewer power supply strip lines. That is, it is only necessary to wire the feed strip line 19 from one common terminal Th or Tv to each feed point located only on one axis in the plane of each radiating element 11, and the feed strip line 19 from the common terminal Th or Tv only needs to be wired to The number of lines required between the two lines is actually only two at most.

On the other hand, when a planar antenna for dual polarization is used as directed by the present invention, one for vertical polarization and one for horizontal polarization are formed on two orthogonal axes in the plane of each radiating element 11. As long as each feed point for waves is independently excited to avoid interference, the feed strip lines 1 for vertically polarized waves and horizontally polarized waves are
9.20 must be wired independently and separately from each terminal Th and Tv, making it somewhat complicated. Here, the terminal Th is used for horizontal polarization, and the terminal Tv is used for vertical polarization.

On the other hand, in general, in this type of planar antenna, the center distance between adjacent individual radiating elements 11, 11 is often set to one wavelength or less in the spatial wavelength of the target frequency. For example, if we simply consider 3Gllz in the C band as the target frequency, the center spacing is about 10 cm as a guide. Also, if the radiating element is square as shown,
The length of that side is approximately equal to the local wavelength of the wavelength within the microstrip, so if the permittivity of the dielectric of the substrate is, for example, 2.6, the spacing between adjacent radiating elements is 6. It will be about .2cm.

Furthermore, the line width of the strip line used in the feed line network cannot be made as thin as desired; if the impedance is 50 ohms, the thickness of the dielectric material of the board is 1+
As i+s or less, about 2m- is required. The width of an impedance transformation section such as a T-branch is wider than this. On the other hand, in consideration of coupling and interference between lines, it is desirable that the gap between parallel strip lines be approximately twice the strip line width or the dielectric thickness.

All of this results in physical dimensional constraints.

In the case shown in FIG. 7(B), adjacent radiating elements 11,
The maximum number of power strip lines wired between 11 and 11 is 4". In other words, the four power strip lines 19a
, 19b; 20a, 20b are arranged between adjacent radiating elements 11.11. However, when considering the dimensions required to form them, it is practically sufficient to allocate the width of one track to the lines 19b and 20b, so the required dimension is the width of three strip lines. .

Therefore, with such a pixel element level, it is still possible to form each feeder strip line with the required width within the plane of the pixel. As mentioned above, although the ground conductor is not shown, it is common to each radiating element and can be placed on the back side of the substrate surface on which each of these radiating elements and each feeding strip line is formed, or on another substrate. After being formed on one surface, it is arranged to face each radiating element, and if a parasitic element 18 is required as shown in FIG. They are arranged to keep their distance.

However, as shown in Fig. 8, when the number of elements increases further to 16 elements, as shown in Fig. 8 (^), the present invention In the case of sharing polarized waves directed by , the wiring system of the feeder strip line becomes considerably crowded, as shown in CB of the same figure. In the case shown, adjacent radiating elements 11.1
The maximum line width dimension required between 1 and 1 is five minutes.

However, in reality, even with this number, it is still possible to form them on the same plane.

However, when constructing a TVRO flat antenna for receiving US satellite broadcasting, for example, the number of unit cells required to obtain the necessary gain is at least 1024 (3
There can be 2×32) pieces.

When this happens, the number of strip lines required between adjacent radiating elements 11, 11 increases dramatically to 17, and it becomes impossible to secure the necessary line width for each strip line. In reality, even with 256 elements lower than that, it is no longer possible to secure a sufficient line width.

Therefore, it is possible to form the valley feed line networks for vertically polarized waves and horizontally polarized waves in a plane independent of the radiating element, that is, to form them on another substrate or even on the back side of the same substrate. ), and connect the radiating element to the board using a connecting pin or through hole.

It is true that this method creates some dimensional margin, but considering that the excitation point position for the radiating element is specified and the circuit is simplified, it is necessary to It cannot be prevented that the vertically polarized and horizontally polarized feeder strip traces cross each other.

Therefore, in such a case, a structure is naturally required for one strip line to pass over the other. For such a structure, if we use the known method of this crosspiece technology,
The method shown in FIG. 9 or FIG. 1O can be considered.

The method shown in Fig. 9 is a commonly-called through-hole method;
indicates the other side.

When the line 19 is passed through continuously, the line 20 that is perpendicular to the line 19 is divided at the intersection with the line 19, and the end facing the line 19 is connected to the board by connecting pins or through holes 21 and 21. DHL and connect it to the strip line 22 formed on the opposite side. A ground conductor 14 may be placed around the strip line 22 via a suitable non-conductor region 23.

However, in these experiments, when the substrate thickness is thin,
Even if the insertion loss was suppressed to a certain degree, the amount of VH coupling showed a significant decrease of about 12 dB over the entire band.

Therefore, as shown in FIG. 10, we experimented with a method using jumper wires 24.

That is, the opposing ends of the strip lines 20 that are separated are connected to each other by jumper wires 24 that spatially cross over the other strip line 19.

In the case of this method, if the thickness and length of the jumper wire 24 are designed optimally, the insertion loss can be reduced and the amount of VH coupling can be kept within a satisfactory value. However, this method is not suitable for mass production, and it is not impossible to imagine an accident in which the jumper wire 24 comes into contact with the strip line 19 for some reason.

Therefore, the inventor stopped simply relying on existing technology and searched for a new feeder line network structure.As a result, regarding the wiring system of each feeder strip line for vertical polarization and horizontal polarization,
As for its physical structure, the idea was to form vertically polarized waves and horizontally polarized waves on separate surfaces and place a ground conductor between them to suppress mutual coupling and interference. It's arrived.

The ground conductor is rationally used for two functions: its original function and the separation between the feeder lines.

Taking all of these things into consideration, the present invention provides the following polarized wave dual-plane antenna by making the above-described radiating element structure and feeding line network structure each unique.

A first feed line network, a ground conductor, and a second feed line network independent of the first feed line network are laminated while maintaining mutual insulation via first and second dielectric layers, respectively. Together with: the same surface 1- as the surface on which the first feeder line network is formed;
1 or 3 A radiation book having a predetermined planar shape and having one feeding point on each glaze that is orthogonal to each other within the section plane, on the plane through the third dielectric layer with respect to the first feeding line network. A plurality of radiating elements f are formed at a predetermined distance SS from each other; the connection between one of the two feeding points of each of the radiating elements and the first feeding line network is such that the plurality of radiating elements If the radiating element is formed on the same surface as the surface on which the feed line network is formed, the radiating element is formed by direct battanning, or the radiating element is formed on the surface with the third dielectric layer interposed therebetween. In some cases, the third dielectric layer is formed by a connection means penetrating the third dielectric layer in the thickness direction; Of the two feed points of the radiating element, the other feed point for the one and the second feed line network. The connection with
Penetrating the first and second dielectric layers and penetrating the ground conductor in the thickness direction without touching the ground conductor, or passing through the first, second and third dielectric layers. A dual-polarization planar antenna characterized in that the antenna is formed by a connection means that penetrates the ground conductor and penetrates the ground conductor in the thickness direction without touching the ground conductor.

According to the present invention, each of the radiating elements constituting a bottom antenna as a single device can independently radiate vertically linearly polarized waves and horizontally linearly polarized waves. .

Therefore, there is virtually no need to manufacture separate radiating elements for vertically polarized waves and horizontally polarized waves, so the configuration, cost, and cost are almost the same as those required for conventional planar polarized antennas. The size and manufacturing process can be reduced, and it can also contribute to a thinner product than ever before as a dual-polarization type.

In addition, each feed line network for vertical polarization and horizontal polarization was formed on an independent plane, and the pair of feed line networks was separated by rationally using ground conductors. In addition to being able to sufficiently suppress mutual coupling and interference, even if the number of radiating elements increases considerably, each feed line network is formed in its own plane, so it is not possible to use conventional single-polarized waves. It is as simple as that, and it is also easy to form a sufficient number of lines while ensuring the necessary line width by etching.

Incidentally, as seen in the summary of the present invention, the first feed line network may be formed on the same dielectric layer as the radiating element, or may be formed on another dielectric layer. In either case, a radiating element having two feed points (one each on orthogonal axes in the plane, two in total) is used, and the first and second feed points are rationally separated by a ground conductor. The purpose of the present invention, which is to form each of the feed line networks individually, is satisfied, and the unique and remarkable effects of the present invention described above can also be satisfied.

However, when considering individual differences in effectiveness as a lower-level concept, if the radiating element and the first feed line network are formed on the same surface, they can be made thinner than if they are formed on other surfaces. On the other hand, when forming the parasitic elements on another surface, it is preferable to form the above-mentioned parasitic elements facing the radiating element. An additional advantage is that the overall pattern of the radiating element group can be made the same pattern, and therefore the design and manufacturing regarding etching can be made more rational.

Of course, it is up to you to choose which of the first and second feed line networks in the abstract structure is for vertical polarization and which is for water (Y) polarization, and you can also choose the dielectric layer first. As mentioned in relation to the conventional example, it goes without saying that a dielectric substrate such as a normal printed wiring board can be used as this dielectric layer, and as mentioned above, the distance between the ground conductor and the radiating element is In some cases, shorter lengths are better, so if the mechanical strength is ensured or if such mechanical strength can be guaranteed by a separate reinforcing method, a sheet-like dielectric layer such as a plastic film may be used. It's okay.

Furthermore, although the parasitic element described above is not essential to the present invention, it is a desirable component, and as for the shape of the radiating element, as mentioned above, it is usually vertically polarized or horizontally polarized. It is common knowledge that the radiation conditions or gain are the same for both, so square or circular shapes are common, but for specific applications that may be developed in the future, or when a certain degree of tolerance is expected, Furthermore, even if a non-square or non-circular shape is used for the purpose of intentionally escaping the scope of the present invention, as long as it satisfies the gist of the present invention as described above, both of these are included in the gist of the present invention.

In addition, as Komu has already stated, in the explanation of the present invention, the present invention was mainly explained based on the case where the present invention antenna is used on the radiation side, that is, on the transmitting side, but due to the reciprocity theorem or reversibility theorem, it is It goes without saying that it is possible. The expression "feed point" or "feed line" is a term commonly used when used in such a receiving system, and is not used with the intention of being specific to the radiation side.

Concerning the connection means mentioned in the summary, concrete examples include through holes and connection bins, and the present invention does not specify them.

<Embodiment> FIG. 1 shows a dual polarization planar antenna 30 as a preferred embodiment constructed in accordance with the present invention.
l IF-, only four degree cells are shown in the figure. Further, FIG. 2 shows a cross-sectional structure of a main part of only a single cell portion along line 1-11 in FIG. 1. In the drawings, the same reference numerals are given to components that correspond to or may be the same as those described in FIG. 5 and subsequent figures, including the embodiment shown in FIG. 4 described later. I will explain.

As shown in FIGS. 1 and 2, the illustrated planar antenna 30 first has a first dielectric layer 31, and has a predetermined distance mlI! on its negative surface. A group of radiating elements 11 spaced apart from each other is formed.

Here, for convenience, the dielectric layer 31 and the dielectric layer 3 to be described later will be described.
Regarding the second grade, the surface shown upward in the figure will be referred to as the front surface, and the opposite surface will be referred to as the back surface, and the vertical relationship in the diagram will also be used as is for explanation.

Radiating element 11 formed on the surface of the first dielectric layer
．． In this embodiment, , , , each have a square shape with one side having a length approximately equal to the wavelength of the target frequency in the microstrip, and they are mutually connected to each other by the wavelength of the target radiation wave. They are formed in alignment in two-dimensional directions, with intervals within -wavelength relative to the wavelength.

The first dielectric layer 31 may have a structure similar to that of a normal printed wiring board, and therefore the radiation elements fII, . . .
The individual shapes and arrangement of can be obtained by etching the copper surface covered on the upper surface of the dielectric substrate 31 as the first dielectric layer in accordance with the predetermined pattern.

Each radiating element 11 has one feeding point Fv, F on each axis perpendicular to each other within the plane in which it is formed.
h is set, the feeding point Fv is connected to Fv, Fh is connected to Fh, and the common terminal Tv is connected by the feeding strip line.
A connection is made to Th, but how the connection is made varies depending on the embodiment.

In this first embodiment, the first feed line network 2o which provides continuity between the feed points Fv for vertically polarized waves of each radiating element 0 and the common terminal Tv is connected to the radiating element 11. The radiating elements 11 are formed on the same surface, that is, the surface of the same dielectric substrate 31, on which the radiating elements 11 are formed.
Its overall shape is defined by a direct etching pattern at the same time as the patterning, and this first feed line network 2o includes T-branches 34, 35 and 90° as necessary.
A bend 36 etc. are provided.

On the other hand, continuity from the common terminal "rh to each feed point Fh for horizontally polarized waves is taken via the second feed line network 19,
In accordance with the idea of the present invention, the above-described first feed line w420
A ground conductor 14 is interposed between the second feed line network 19 and the second feed line network 19, which also has the function of suppressing coupling and interference between the two feed line networks 20 and 19.

In other words, the radiating element 11 and the ground conductor 14 fulfill the basic radiation function of the antenna, but in the present invention, in addition to this basic function, the ground conductor 1
4 also has the function of coupling between both feed lines and suppressing interference.

This ground conductor 14 is shown transparently in phantom lines in FIG. 1, but is clearly shown in cross section in FIG.

As particularly well shown in FIG. 2, the ground conductor 14 may be formed on the back surface of the first dielectric layer 32 on which the radiating element II and the first feed line network 2o are formed, or The second feed line network 19 described below may be formed on the surface of the second dielectric substrate 32 formed on the back surface thereof.

The second feed line network 19 is composed of a group of strip lines in a predetermined pattern, T-branches 42, 43, etc. in order to establish continuity between the common terminal Th and the horizontal polarization feed point Fh of each radiating element H. However, a first dielectric substrate 31, a ground conductor 14, and a second dielectric substrate 32 are interposed in the height direction between each terminal point of the feed line network and the feed point Fh of the radiating element 11, Because of the physical distance, the connection between them is made by penetrating the first and second dielectric substrates 31 and 32 in the height direction.
In addition, a connecting means 40 is used which also passes through the ground conductor 14 sandwiched between them without touching the ground conductor 14.

Specifically, the connecting means 40 may be a connecting bottle made of a conductive material with a suitable thickness, and in order to prevent the connecting bottle 40 from touching the ground conductor 14, a hole is formed around the penetrating portion of the ground conductor 14. A non-conductor portion 41 is formed.

Due to this structure, the illustrated planar antenna 30 can independently radiate polarized waves that are orthogonal to each other by excitation from the terminal Tv and excitation from the end fTh. 11 must be excited in the same phase for both vertically polarized waves and horizontally polarized waves.

However, this means that the lengths of the lines on both sides of each T-branch 34, 35, 42, 43 used are equal, as can be seen in the relationship between the lines 37, 37 on both sides of the T-branch 35 in FIG. This can be easily satisfied in terms of design by doing the following.

The only possible problem with the present invention is that the connection means 40, such as connection bins, which extend vertically through the board group and the ground conductor, do not transmit the signal without attenuation. , whether or not the radiation element 11 can be excited efficiently.

However, the applicant's extensive experiments have shown that this problem can be almost completely solved by optimally designing the position of each feeding point of the radiating element, the thickness of the bin used as a connection means, and the width of the feeding strip line. Do you get it.

In fact, the invention! ! ! It has been confirmed that the planar antenna 30 of the first embodiment, which was constructed according to the idea, functions satisfactorily as a dual-polarization type, and has a standing wave ratio of 1.
I was able to easily reduce it to 5 or less.

To describe a specific experimental example, the performance of the four-cell polarized planar antenna 30 shown in FIG. Hereinafter, the gain was 12 dBi, and both the VH coupling amount and the cross-polarization protection ratio were 20 dB or more. However, although not shown in Fig. 1, as shown in Fig. 2, the distance tsD is optimally designed and set opposite to each radiating element.
A parasitic element 18 having the same shape and the same arrangement pattern as the radiating element 11 was placed.

The method of supporting the dielectric substrate 17 for arranging the parasitic elements 18 while maintaining the predetermined distance 111D is completely arbitrary.
This is simply a matter of the physical mechanical structure of the antenna device. In this regard, the structure of a conventional single-polarized antenna device may be used without any problem.

Further developing the above experiment, we were able to maintain the standing wave ratio below 1.5 even with 16 elements and 64 elements, so we also measured the characteristics of 256 elements, which are considered to be at a practical level. .

As a result, the input standing wave ratio was slightly degraded to 2.0, but this was due to the T-branches 34, 35 and 90° bend 36. The design target standing wave ratio is 1 in the case of two radiating elements, which can be considered as unit branches, by improving the characteristics of , , and
．． This can be achieved by setting it to 1 or less, or by making the distance between the radiating element 11 and the corresponding parasitic element 18 uniform, for example, by using an appropriate spacer or the like. These requirements are not difficult at all, and are completely achievable.

Regarding other characteristics of this 256-element flat antenna, the gain is desirably about 30 dB, and the V-H coupling and cross-polarization protection ratio are both 2.
It was possible to secure 0 dB or more, which was a sufficient value for polarization sharing. The measured polarization directivity characteristics are shown in Figure 3 (8), (
As shown in Fig. B), the figure (^) shows the positive polarization directional characteristic, and the figure (B) shows the cross polarization directional characteristic.

From these facts, it is obvious that a planar antenna with up to 1024 elements can be constructed according to the present invention, but in reality, due to the limitations of the etching equipment, the above-mentioned two
In some cases, the size is such that about 56 elements can be etched at one time.

In such a case, the panel with the 256 elements integrated above is used as a unit panel, and these panels are arranged vertically and horizontally in pairs, and the input and output ends of each polarized wave of each panel are connected to a waveguide, semi-rigid cable, or T-branch. It is sufficient to perform in-phase synthesis using .

In addition, in the above description, the number of unit cells or the number of radiating elements 11 constituting the planar antenna is limited to a 2'' square arrangement, where n is a positive integer, but in principle this can be applied. For example, a rectangular array of 2−×2n (l is a positive integer) may be used for fan-shaped beam requirements, but is not limited to this.

In addition, as mentioned earlier, the shape of the radiating element itself is not symmetrical, such as the square or circular shape in the above embodiments, but for example, for frequency sharing, the vertical wave and the horizontal polarization are in different frequency bands. In some cases, it is also possible to apply the present invention as an asymmetrical shape.

As for the ground conductor 14, it is usually easiest and most convenient to use a conductive surface such as a copper surface covered with a dielectric layer as is. However, if necessary, it may be patterned into a necessary pattern.

Furthermore, the parasitic element 18 is often necessary when actually commercialized, but it is not a limiting element. Further, unlike the second illustration, the parasitic element I8 may be disposed on the front surface side of the dielectric substrate 17 instead of the back surface thereof, but as in the illustrated embodiment, the parasitic element 18 is It is reasonable to dispose the dielectric substrate 17 on the back surface or rear surface of the dielectric substrate 17, since the dielectric substrate 17 can also be used as a so-called radome for preventing rain and snow.

This dielectric substrate 17 does not need to have good characteristics as required for the dielectric layer forming the radiating element and each feed line network; it is sufficient that the dielectric loss is small and the transmission loss of electromagnetic waves is small. Therefore, an inexpensive one can be used.

In the case shown, the first,
For the dielectric layers 31 and 32 used to laminate the second feed line network, we assumed that a relatively strong and thick material, such as an ordinary printed wiring board, would be used. The dielectric layer may be made of a thin material such as a plastic sheet, if it can be formed to a sufficient extent, or if mechanical strength can be obtained by additional reinforcing means.

In the embodiments described so far, the radiating element 11 is formed on the same surface as the first feed line network 20.

However, as seen in the gist of the invention, the radiating element 11 can also be formed on a separate plane from the first feed line network 20.

Such an embodiment is shown in FIG. 4 as a cross section of the main part.

Corresponding components are designated by the same reference numerals as those used up to now, and some explanations may be omitted below to refer to the previous explanation, but in this embodiment, the radiating element 11 is the first one. A suitable third dielectric layer 33, such as a printed circuit board or a plastic sheet, is laminated on the surface of the first feed line W419 in order to be formed on a different surface from the feed line network 19. A radiating element 11 is formed on the surface of the body layer 33.

Due to this structure, each feed terminal of the second feed line network 19 formed on the back surface of the second dielectric layer 32 shown at the bottom in the figure is connected to the corresponding feed point of the radiating element 11. In addition to the third dielectric layer 331, the ground conductor 14, and the second electrical layer 32, the connection bin 40 that forms the structure penetrates this third dielectric layer 33 as well. The connection between the line network 20 and the corresponding feed point of the radiating element is left to a suitable heightwise connection means 44 such as a connection bottle or a through hole that penetrates the third dielectric layer 33 in the height direction. It looks like this.

in this way,? j! 3rd MP, radiating element 1 on electric layer 33
In the case where it is only necessary to pattern the parasitic element 18, the shape and arrangement pattern of the parasitic element 18 can be made substantially the same as that of the radiating element, thereby simplifying the manufacturing process. In extreme cases, both layers may be completely the same.

Furthermore, unless you are particular about the wiring pattern as in the example shown in FIG. 1, it is also possible to make the wiring patterns of the first feed line 1L'120 and the second feed line 1/A19 exactly the same. It is sufficient to simply make them orthogonal and overlap them. In such a case, the patterning required to construct the planar antenna can be limited to two types, one for both feed line networks and one for the radiating element and the screen feed element.

However, if such incidental effects are not required, as is obvious from FIG. The ground conductor 14 may be formed on the back surface of the added third dielectric layer 33, and similarly, the ground conductor 14 may be formed on the back surface of the first dielectric layer 33, as described in the first embodiment. It may be formed on either surface of the surface.

It should be noted that the considerations in each section described above regarding the first embodiment can be applied as they are to the second embodiment, except for the structural differences.

[Brief explanation of the drawing]

Fig. 1 is a perspective view schematically showing the first embodiment of the dual polarization planar antenna of the present invention, Fig. 2 is a sectional view taken along the line ■-■ in Fig. 1, and Fig. An actually measured directivity characteristic diagram of a 256-element planar antenna constructed in accordance with the embodiment; FIG. 4 is a cross-sectional view of a main part of a dual-polarization planar antenna as a second embodiment of the present invention; FIGS. 5 and 6 is a schematic structural diagram of the radiating element portion considered in the process leading to the present invention, FIGS. 7 and 8 are explanatory diagrams of the feed line network similarly considered in the process leading to the present invention, and FIG. 9 and 1θ The figure is an explanatory diagram of a conventional strip line crossing structure that was also taken into consideration in the process of arriving at the present invention. In the figure, 11 is a radiating element, 14 is a ground conductor, 19 is a second feeder line network, 20 is a first feeder line network, 30 is the entire dual-polarization planar antenna according to the present invention, and 31 is the first feeder line network. 32 is a second dielectric layer, 33 is a third dielectric layer, and 40.44 is a connection means. Fig. 1 Fig. 2 Fig. 4 Fig. 6 Fig. 9 Fig. 2 Fig. 10 Procedural amendment (voluntary) Date: October 15, 1986

Claims (1)

[Claims] A first feed line network, a ground conductor, and a second feed line network independent of the first feed line network are insulated from each other via first and second dielectric layers, respectively. and on the same surface as the surface on which the first power supply line network is formed,
Alternatively, a radiating element of a predetermined planar shape having one feed point on each axis perpendicular to each other within the plane is provided on a plane with a third dielectric layer interposed in relation to the first feed line network. a plurality of radiating elements are formed at a predetermined distance from each other; the connection between one of the two feeding points of each of the radiating elements and the first feeding line network is such that the plurality of radiating elements are connected to the first feeding line network; When the radiating element is formed on the same surface as the surface on which the net is formed, by direct patterning, and when the radiating element is formed on the surface with the third dielectric layer interposed therebetween. one made by a connection means penetrating the third dielectric layer in the thickness direction; a connection between the other one of the two feed points of the radiating element and the second feed line network; teeth,
Penetrating the first and second dielectric layers and penetrating the ground conductor in the thickness direction without touching the ground conductor, or passing through the first, second and third dielectric layers. A dual-polarization planar antenna, characterized in that the connection is made by a connecting means that penetrates the ground conductor and penetrates the ground conductor in the thickness direction without touching the ground conductor.