EP0886887B1 - Planar emitter - Google Patents

Abstract

A planar emitter equipped with planar resonators that is simple, small in construction and consists of few, easily manufactural components, while at the same time having high frequency dependent system quality with the widest possible spectral range, has a plurality of sandwich-like layers (4, 5, 6, 7, 8) that are planned parallel to each other with the layer (5) being made of two different dielectric materials (14) and (15). The thickness (L1) of layer (14) is greater than the thickness (L2) of layer (15) with layer (4) having a plurality of spaced, thin layer, electrically conductive planar resonators (4) in contact with one side of layer (15). One side of layer (14) is in contact with an electrically conductive thin layer (6) that defines a common earthing member that has its opposite side in contact with layer (17) made of a dielectric material. A coupling network (3) is included in layer (8) and comprises microstrip circuits (3a-3f) in contact with layer (7). Means in the form of pins (9) extends through the layers (5, 6, 7) from said coupling network (3) to said planar resonators (4) to couple said planar resonators (4) electrically in phase.

Description

The invention relates to a planar radiator with a Radiator level having surface resonators and a Coupling network having network level, the Area resonators with each other via the coupling network are coupled galvanically and in phase.

For communication services, in particular multipoint multichannel communication services, the reception or the Radiation of directed electromagnetic radiation fields linear polarization in the microwave spectrum will be required today reflector antenna or planar antennas or radiators used. The radiation properties of the reflector antennas is based on the generation of a corresponding amplitude and Phase assignment of the electromagnetic Radiation field components on the reflector surface by means of suitable pathogen. The reflectors used are here either in the form of closed surfaces of defined curvature and border are designed or are latticed Arrangements of discrete conductive linear elements defined Length and spacing carried out. Known planar solutions are based on the arrangement of galvanically and parallel fed Area resonators of defined group size and spacing to each other.

EP 0 200 819 describes a planar array antenna in Stripline technology known. The mechanical structure is there from a first substrate plate as a carrier for Antenna elements under the second substrate plate as a carrier for the couplers and the signal processing. Both substrate plates are connected by a thick metal plate, where the thickness of the metal plate is half Operating wavelength corresponds. The electrical connection between the antenna elements on the front of the antenna and put the couplers on the back of the antenna Conductor pieces, which are isolated by holes in the Metal plate.

A planar antenna is known from EP 0 383 292, in which Antenna elements on the ground surface of a two-sided coated circuit board are glued on which the Coupling network and additional electronics is located. The Antenna element consists of a surface resonator plate, which is applied to a dielectric substrate layer is. The substrate layer of the antenna element is made of "glass epoxy ".

A planar antenna is known from WO 95/09455, which is also sandwich-like, and where the die Layer carrying antenna elements for manufacturing reasons two layers of the same material because the Antenna elements are capacitively coupled.

A disadvantage of the known planar antennas is that mostly high system quality only in a small spectral range and therefore only with restrictions for use Suitable for multipoint multichannel communication services are, because of the small bandwidth, only relatively few Frequency bands can be transmitted with a single antenna.

It is therefore an object of the invention to provide a planar radiator to provide with surface resonators that are simple and small is in its structure and from a few easy to manufacture and there are inexpensive parts and at the same time in one if possible wide spectral range a high frequency independent System quality is such that it is for multi-channel point-to-point transmission especially in the frequency range between 2,500 GHz to 2,686 GHz is suitable.

This object is achieved by a planar Radiator according to claim 1 solved.

The planar emitter according to the invention advantageously only needs a common ground area for the emitter and network level, which significantly reduces the overall height of the emitter compared to known planar emitters and reduces the manufacturing material costs. The bandwidth of the radiation field to be transmitted and received by the radiator can also be varied without influencing the characteristic impedance of the coupling network by suitable choice of the thickness of the first dielectric layer, a high system quality being achieved in the entire spectral range at the same time. It is necessary for a planar radiator that the first layer is made of a material with the smallest possible dielectric constant (ε _r → 1). Due to the two-layer structure of the first layer, it is possible to manufacture the thin layer supporting the resonator surfaces from a heat-resistant material such as polyethylene terephthalate, on which the resonator surfaces can be applied permanently. The first layer can be made from an inexpensive foamed material. So that the planar radiator becomes flexible or pliable, the thickness of the first layer is greater than the thickness of the second layer. The first layer forms the actual base material of the planar emitter and essentially determines the properties of the emitter plane with its ε _r and loss angle tan δ _ε . The material of the first layer is advantageously the cheap material polystyrene, which is flexible in its foamed form and in particular has a specific volume weight of 20kg / m ³ . The second layer is advantageously formed by a polyethylene terephthalate film which is glued to the first layer. The advantage of this polyethylene terephthalate film is that it forms a firm and permanent connection with copper, which means that the resonator surfaces have firm adhesion.

Each surface resonator is electrical by means of an conductive connecting pin with the coupling network in electrically conductive connection, the electrically conductive Connecting pin in a perpendicular to the radiator and Through hole located at the network level.

Due to the disproportionate thickness of the first dielectric layer, the connecting pins are relatively long, as a result of which the pins themselves have an electrically transforming effect. The inductive reactive component represented by the pen can therefore no longer be neglected and must be compensated for. This can be done on the one hand by means of a sleeve which at least in sections envelops the pin and is made of a material, in particular Teflon, which has a higher dielectric constant than the materials forming the dielectric layers, which serve as the base material for the radiator and network level. By adjusting the wall thickness, the height and the ε _{r of} the sleeve, the capacitance of the pin-sleeve combination can be adjusted, whereby the inductive blind component of the pin is compensated.

On the other hand, however, the compensation of the inductive blind component of the pin by means of the Coupling network done by the transforming Effect of the length and width ratios of the used Microstrip lines are used. Such Transformations using microstrip lines are sufficient known from the relevant literature. Can on a sleeve in this case, if necessary, be waived.

It is also required that the electrically conductive thin Layer in the areas where the electrically conductive pins pass through the layer, especially circular has window-like recesses, such that the pins with the electrically conductive layer not in electrical connection are. Form these circular window-like recesses Apertures, by means of the diameter of the recesses Coupling factor is adjustable. The coupling factor determines the portion of the signal intensity, which of the Radiator level is led to the network level. The optimal one Diameter of the orifices can be obtained by simulation or experimental tests.

Another advantage of using the above described Sleeves result from the fact that the stiffly executed Sleeves the distance between the emitter and the Network level at least in the areas of the pens also below Influence of external forces as well as during antenna assembly remains constant. The system quality also changes with Do not bend and compress the planar radiator.

The surface resonators can be shaped and arranged as desired become. To generate the necessary impedance profile along the line of symmetry of the Area resonators, as well as to generate the necessary radiation-related individual characteristic of Area resonators it is recommended that Surface resonators to be rectangular, the Broadside is identical to the radiant edge. The Surface resonators are advantageously matrix-shaped arranged to each other. It has been shown that it is for most areas of application is sufficient, only eight Area resonators in particular in two lines and four Arrange columns. Also for the sake of simple Predictability and minimizing the dimensions of the planar emitter, it is advantageous if line and Column spacing of the matrix Area resonators are equal to each other.

To ensure good decoupling or coupling of the received or signals to be sent with existing ones if possible The planar has to enable components and plug-in systems Spotlights an extension that carries a wave path that a coupling point of the coupling network with a Connector connects. At the connector is one commercially available N socket, which is modified in this way is that the inner conductor of the socket with the Microstrip line on the extension of the dielectric carrier of the coupling network is applied, is connected, and that the ground plane of the extension, the at the same time the extension of the electrically conductive layer is, with the outer surface of the socket by means of of a dielectric press block generated press pressure is. The wave path is through a microstrip line, the second dielectric layer and the ground surface, connected to the coaxial connector accordingly is.

Below are some embodiments of the invention explained in more detail with reference to drawings.

Figur 1:

Eine Querschnittsdarstellung des planaren Strahlers;

Figur 2:

eine Draufsicht auf die Strahlerebene;

Figur 3:

eine Draufsicht auf die Netzwerkebene;

Figur 4:

eine Draufsicht auf die elektrisch leitende Massefläche;

Figur 5:

eine Querschnittsdarstellung des Wellenpfades und des Anschlußstücks;

Figur 6:

eine Querschnittsdarstellung des erfindungsgemäßen Strahlers, mit zwei die erste dielektrische Schicht bildenden Lagen;

Figur 7:

eine Darstellung gemäß Figur 6, wobei die Länge der Hülse verkürzt und ihre Wandstärke vergrößert ist.

Show it:

Figure 1:

A cross-sectional view of the planar radiator;

Figure 2:

a plan view of the radiator level;

Figure 3:

a top view of the network level;

Figure 4:

a plan view of the electrically conductive ground plane;

Figure 5:

a cross-sectional view of the wave path and the connector;

Figure 6:

a cross-sectional view of the radiator according to the invention, with two layers forming the first dielectric layer;

Figure 7:

a representation according to Figure 6, wherein the length of the sleeve is shortened and its wall thickness is increased.

1 shows an embodiment of the invention. Radiator, in which the first dielectric layer 5 one material. On top of layer 5 are made of a thin layer of copper Resonator surfaces 4 applied. Between the first dielectric layer 5 and the second dielectric Layer 7 is the conductive ground plane 6. The ground plane 6 is an approx. 17-18µm thick copper layer. On the the The flat side of layer 7 facing away from the ground surface is the Microstrip lines 8 or the coupling network 3 arranged. The coupling points 12 and 13 are by means of a electrically conductive pin 9 in connection. The pin 9 has a small diameter so that by the location of the Coupling point 12 determined input impedance of the Surface resonator 4 is not due to large-area contact of pin 9 with the resonator surface is undetermined. Of the The diameter of the pin 9 should therefore be chosen so small that the strip width of the coupling network 3 is not is exceeded. The thickness of the pin 9 should therefore be 1 mm do not exceed. The pen is used for fixing purposes and better permanent contact with the copper layers the network and the radiator level are soldered and is one Surround sleeve 11, which stiffens the radiator.

The thickness D2 of the layer 5 essentially determines that Total height of the planar emitter.

The ground surface 6 has in the areas in which the pin 9th a circular one passes through the ground surface 6 Recess 10, the diameter of which is larger than that Outside diameter of the pin 9. Is the length of the sleeve 11 equal to the lengths D2 plus D3, the diameter is the Recess 10 at least as large as the outer diameter of the To choose sleeve 11.

Layer 5 is made of polysterol, which is foamed in State is flexible, which makes the planar emitter in certain Is flexible. This bendability is only marginal through the thin copper layers 4, 6 and 8 and the layer 7 impaired.

As can be seen from FIG. 2, the coupling point 12 not be arranged centrally to the resonator surfaces 4. With With the help of known simulation methods, it can be used for frequency and bandwidth required Calculate the input impedance of the surface resonators, from which the Location of the coupling point 12 can be derived.

In Figure 3 is the coupling network 3 with which the signals Coupling or decoupling wave path 16 shown. The Network 3 consists of striplines 3a-3f and 16. Die Stripline sections have different lengths and Widths to the inductive portion, which is determined by the length of the Pen 9 was caused to compensate as well impedance-matched merging of the to Allow surface resonators to guide waveguide paths.

In Figure 4, the conductive copper layer of the ground surface 6th shown. The black dots represent 10, 19 and 20 places where the copper was cut out. By these points are also holes of the appropriate diameter provided so that the pins 9 and 21, sleeves 11, and Fastening screws for the connector 18 through the Can reach through ground surface 6.

Figure 5 shows a cross-sectional view of the Wave path 16 and the connector 18 carrying projection 24. The projection 24 lies between the connector 18 and the pressure block 22. The connector 18 and the pressure block 22 are by means of the projection 24 and the provided holes 23 cross fastening screws screwed together so that the connector 18 with the Projection 24 is in firm connection.

The following are exemplary geometric data listed, by means of which the planar emitter in Frequency spectrum from 2,500 GHz to 2,686 GHz a high System quality.

The resonator surfaces have a length of 47 mm, a width of 53 mm and a row and column spacing of 87 mm. The feed or coupling point 12 is located approximately 2 mm from the center of the broad side within the surface. The thicknesses D1, D3 and D5 of the copper layers are approximately 18 µm thick. As shown in FIG. 6, the layer 5 has two layers, the first layer 14 having a thickness L1 equal to 10.5 mm and consisting of foamed polystyrene, the spec. Volume weight is 20kg / m ³ . The second layer 15 has a thickness L2 of 100 μm and consists of polyethylene terephthalate. The second dielectric layer 7 consists of glass fiber reinforced polytetrafluoroethylene with a thickness of 381 μm.

All layers are fixed together, the Layer 14 is glued to the layer 15 and the adhesive connection has a thickness of 7 µm.

The pin 9 has a diameter of 1.2 mm and lies with its one end in the bore of layer 7, whose Diameter is also 1.2 mm and passes through Coupling point 13. The layers 5 and 6 have in the area of Pins 9 also on holes, the diameter of Recording of the pin 9 and the sleeve 11 is 4.2 mm.

The coupling network 3 is constructed symmetrically, such that all resonator surfaces are in phase from coupling point 17 be fed. The coupling points 13 have one Inner diameter of 1.2 mm and an outer diameter of 2.1 mm.

Starting from each coupling point 13 goes in the direction of the line adjacent feed point 13 a conductor 3a of Width 0.49 mm for a length of 27 mm. This head 3a then jumps into a conductor 3b with a width of 1.15 mm over which is 31 mm long. Then the head 3b again in a width of 0.49 mm across to the neighboring one To reach feeding point 13 after a length of 27 mm. On This way, the dining points are outside in every row lying resonator surfaces 4 with the feed points 13 of the in each case in the row adjacent and below Resonator surfaces 4 connected. From the center of the conductor 3b closes in the direction of the opposite one in the column Conductor 3b a conductor 3c of 1.88 mm in width and 22.3 in length mm, which then jumps to a width of 1.15 mm for a distance of 42.45 mm (3d conductor) passes. The leader then expands again to a width of 1.88 mm to after a length of 22.3 mm with the center of the in the Column opposite conductor 3b to meet together. On the center of the 3d conductor closes in the direction of the opposite conductor 3d a line 3e of width 1.88 mm and the length 22.3 mm. Then the conductor 3e opens a width of 1.15 mm for a length of 129.4 mm over (Head 3f). The width of the conductor 3f changes to 1.88 mm for a length of 22.3 mm. This is the middle of the opposite conductor 3d reached. To the middle of the 3f includes a waveguide 1.88 mm wide as well the length of 22.3 mm to then jump in width to 1.15 mm and to the decoupling point 21 of the Network 3 to be managed.

By means of the coupling network 3 described above, the inductive dummy components of the pins 9 by the Dimensions of the elongated pins 9, which in turn from the Thickness D2 of the first dielectric layer 5 are conditional, compensated.

In Figure 7 it is shown that the sleeve 11 does not overlap the entire height of layers 5 and 6 must extend. By the choice of the wall thickness WS and the length LS of the sleeve 11 can whose capacitive coating are influenced, whereby the long pin 9 inductive reactive power component is canceled and a component that compensates for the blind components Network 3 is no longer required.

Reference symbol list:

1

Spotlight level

2nd

Network level

3rd

Coupling network

3a-3f

Stripline sections

4th

Area resonators

5

First dielectric layer

6

Electrically conductive thin layer; Ground plane

7

Second dielectric layer

8th

Microstrip lines

9

Connecting pin

10th

Window-like recesses

11

Sleeve

12th

Feed point of the surface resonator

13

Coupling point

14

first layer

15

second layer

16

Wave path

17th

Common coupling point

18th

Connector; N socket

19th

Cut-out for through pin

20th

Cut-out for fastening screw

21

Through pin

22

Contact block

23

Hole for fastening screws

24th

Extension for wave path

Claims (15)

1. Planar radiator with a radiator plane (1) comprising large-area resonators (4) and with a network plane (2) comprising a coupling network (3), in which the large-area resonators (4) are coupled to one another galvanically and in phase via the coupling network (3), characterised in that

   the planar radiator is constructed in a sandwich manner of plies (4, 5, 6, 7, 8) plane-parallel to one another, and

   that a first dielectric ply (5) is separated from a second dielectric ply (7) by means of an electrically conductive thin ply (6), which forms the common earthing surface for the radiator plane (1) and the network plane (2), and

   that the first dielectric ply (5) bears on its side facing away from the electrically conductive ply (6) the large-area resonators (4), wherein

   the first dielectric ply (5) is composed of two dielectric materials which form a layer (14, 15) for one another, wherein the thickness (L1) of the first layer is greater than the thickness (L2) of the second layer, and the second layer (15) bears on its side facing away from the first layer (14) the large-area resonators (4), and

   that the second dielectric ply (7) bears on its side facing away from the electrically conductive ply (6) the coupling network (3), which is formed from microstrip lines (8).
2. Planar radiator according to claim 1, characterised in that the first layer (14) is formed from polystyrene, which is flexible in its expanded form, and in particular has a specific weight by unit volume of 20 kg/m³, wherein the first layer (14) has in particular a thickness (L1) of 10.5 mm.
3. Planar radiator according to one of claims 1 or 2, characterised in that the second layer (15) is formed by a polyethylene terephthalate film in particular of thickness (L2) equal to 100 µm, which is bonded to the first layer (14).
4. Planar radiator according to one of the preceding claims, characterised in that the electrically conductive thin ply (6) has a thickness of approx. 18 µm.
5. Planar radiator according to one of the preceding claims, characterised in that each large-area resonator (4) is in electrically conductive connection with the coupling network (3) by means of an electrically conductive connecting pin (9), wherein the electrically conductive connecting pin (9) lies in a continuous bore situated at right angles to the radiator plane (1) and the network plane (2).
6. Planar radiator according to claim 5, characterised in that the electrically conductive thin ply (6) has in the areas where the electrically conductive pins (9) pass through the ply (6) in particular circular window-type recesses (10), such that the pins (9) are not in electrical connection with the electrically conductive ply (6).
7. Planar radiator according to claim 6, characterised in that the circular window-type recesses (10) form masks, and by means of the diameter of the recesses (10) the reflection and transmission factor between the coupling network and the respective large-area resonators is adjustable.
8. Planar radiator according to one of claims 5, 6 or 7, characterised in that each electrically conductive pin (9) is in the area between the conductive ply (6) of the large-area resonators (4) and the conductive ply (6) of the microstrip lines (8) surrounded at least in certain sections by a sleeve (11).
9. Planar radiator according to claim 8, characterised in that the sleeve (11) is of a dielectric material, in particular Teflon, whose dielectric constant ε_r is in particular greater than the dielectric constant ε_r of the material of the dielectric plies (5, 7) which surrounds the sleeve (11).
10. Planar radiator according to one of the preceding claims, characterised in that by means of suitable selection of the wall thickness (WS), the height (LS) and the dielectric constant ε_r of the sleeve (11) the inductive reactive component occasioned by the thickness (D2) of the first dielectric ply (5) is compensatable by means of the sleeve (11).
11. Planar radiator according to claim 9 or 10, characterised in that the length (LS) of the sleeves (11) holds the distance between the radiator plane (1) and the network plane (2) constant at least in the areas of the continuous bores (10) or pins (9) even under the effect of external forces, and in particular forms defined support points for the assembly.
12. Planar radiator according to one of the preceding claims, characterised in that by means of the coupling network (3) the inductive reactive component of the pin (9), occasioned by the thickness (D2) of the first dielectric ply (5), and the capacitive covering of the sleeve (11) are compensatable.
13. Planar radiator according to one of the preceding claims, characterised in that the large-area resonators (4) are arranged rectangular and matrix-shaped in particular in two lines and four columns.
14. Planar radiator according to claim 13, characterised in that the line and column distances of the large-area resonators (4) arranged in a matrix shape are identical.
15. Planar radiator according to one of the preceding claims, characterised in that the network plane (3), consisting of the microstrip lines (8), the second dielectric ply (7) and the earthing surface (6), is prolonged in the form of a wave path (16) between the common coupling point (17) and a terminal fitting (18) in such a way that the coupling on the waveguide side takes place directly onto the terminal fitting (18) in coaxial layout without separation of the waveguide plane.

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