WO1997009748A1

WO1997009748A1 - Dielectric waveguide

Info

Publication number: WO1997009748A1
Application number: PCT/EP1996/002369
Authority: WO
Inventors: Lutz Rothe
Original assignee: Pates Technology Patentverwertungsgesellschaft Für Satelliten- Und Moderne Informationstechnologien Mbh
Priority date: 1995-09-06
Filing date: 1996-06-01
Publication date: 1997-03-13
Also published as: ZA967040B; HRP960407A2; DE19532780A1; YU49896A; EP0848860A1; CN1148279A; UY24324A1

Abstract

The invention concerns a dielectric waveguide (1), in particular one which is planar or essentially planar, with at least one dielectric structure (2) at least part of which consists of a material whose permeability or permeability tensor and/or permittivity or permittivity tensor can be changed by a magnetic field which penetrates at least parts of the structure (2). The waveguide also includes at least one means (6) for generating at least one magnetic field (9) by means of which the permeability tensor and/or the permittivity or permittivity tensor of at least parts of the structure (2) can be changed.

Description

Dielectric waveguide

The invention relates to a dielectric, in particular planar or quasi-planar waveguide, which has at least one dielectric material arrangement.

Planar waveguide is the term used to refer to surface-shaped line forms in which a dielectric carrier plate (substrate) is coated with metallic conductor structures (strip and slot line) or which carry dielectric structures on a metallic base plate (dielectric dummy lines). In this form, there are open management structures. With the planar lines, the high accuracy requirements are transferred to the planar structures. With the help of photo-etching technology, however, these requirements can be met simply, cheaply and reproducibly. The technology of planar circuits offers advantages compared to waveguide technology. For example, several planar circuit components can be integrated into a system to save space and weight on a carrier plate. Reduce by the short connections between the individual components the line losses and the number of connecting elements and thus joints. Semiconductor elements can also be installed more easily. In addition, planar structures often have a higher uniqueness bandwidth than waveguide circuits.

A disadvantage of such planar waveguides, however, is that the line impedance depends on the selected dimensions of the substrate conductor arrangements and on the dielectric substrate itself, and the line impedance can no longer be changed after the waveguide has been produced.

The object of the invention is therefore to provide a dielectric waveguide, the line impedance of which can be changed or set after the waveguide has been finished.

According to the invention, this object is achieved both by the features of the characterizing part of claim 1 and by the features of the characterizing part of claim 2. In both embodiments according to the invention, the field-generating means are advantageously in direct contact with the waveguide, the field-generating means being galvanically separated from the metallic conductor structures and / or the base plane of the waveguide. By changing the permeability and / or the permittivity or the dielectric properties of the dielectric substrate or the dielectric material arrangement between the base plane and conductor structures by means of magnetic fields or electrical fields, the wave resistance of the dielectric waveguide can be changed in sections depending on the strength of the fields generated. The previously passive electronic component waveguide thus advantageously becomes an active component in which the transmission behavior of the waveguide can be influenced in a targeted manner by means of the field-generating means. In a further preferred embodiment, a layer adjoins the waveguide, the layer having the field-generating means. A particularly good control of the line wave resistance of the waveguide is obtained if the field-generating means are arranged in the form of a matrix or a grid in the adjacent layer. By using several field-generating means, it is possible to set the line impedance precisely for certain areas.

In particularly preferred embodiments, the fire-generating means are induction coils or capacitors. The induction coils have m turns, the induction coils being oriented in space in such a way that parts of the magnetic fields generated by the current-carrying induction coils at least partially penetrate the dielectric material arrangement. The induction coils are advantageously connected to control electronics, wherein the control electronics can be used to impress a current of predeterminable strength and direction in each induction coil, as a result of which the magnetic field generated by the induction coil is determined in terms of direction and amount.

When using capacitors as field-generating means, it is advantageous if the direction of the electric field vector of the electric field generated by the capacitor is essentially parallel to the structural plane of the waveguide. However, it is also conceivable that the capacitors generate an electric field perpendicular to the structural plane of the waveguide if this is necessary due to the choice of the dielectric substrate used.

It is particularly advantageous if, by means of such a dielectric waveguide, the wave resistances in two adjoining regions or sections are adapted to one another in such a way that one differs from the first Area to the second area propagating wave results in a certain reflection factor r.

It is also advantageous if the length L, the width B and / or the amount of the wave resistance Z _{L of} the section or region can be set by means of the field-generating means, such that the length L, the width B and / or the Amount of the wave resistance Z _L only the field-generating means each generate a field of predeterminable strength, the fields of which at least partially penetrate the dielectric material arrangement of the waveguide in the area or section.

The dielectric material order or the dielectric substrate between the structure and the base plane is advantageously made of a gyromagnetic or gyroelectric material, the amount of the dielectric constant ε _{r of} the dielectric material arrangement being in the range between 3 and 5, which results in a particularly good quality of the waveguide can be achieved for the microwave range. It is also advantageous if the material arrangement is an yttrium iron garnet layer. Such an yttrium-iron garnet layer is characterized in that when a constant magnetic field is applied, the permeability or the permeability tensor changes in the area penetrated by the magnetic field, which also changes the line impedance of the waveguide.

When using an yttrium-iron-garnet layer, it is advantageous if there is a layer of gallium-gadolinium-garnet of the thickness L _ggg between the dielectric material _arrangement or the yttrium-iron-garnet layer and the base plane. The base plane is advantageously a copper layer which is applied to the side of the gallium-gadolinium garnet layer facing away from the yttrium iron garnet layer. A quartz layer can advantageously be provided between the dielectric material arrangement or the yttrium-iron garnet layer and the structural plane Thickness L _{q can be} arranged, the structure plane being able to be produced photolithographically from the quartz layer. The field-generating means are advantageously arranged on the side of the base level facing away from the structural level, the field-generating means being galvanically separated from the conductive base level by means of an insulating layer, in particular a polystyrene layer. The field-generating means can advantageously lie in a thin layer or rest thereon.

In a likewise preferred embodiment, the control electronics for the field-generating means are arranged on the side of the thin layer having the fire-generating means facing away from the conductive base plane, the control electronics being in electrical connection with the field-generating means. Such an arrangement is particularly compact and inexpensive to manufacture. The direct connection of the control electronics to the thin layer having the field-generating means reduces the connecting lines between the control electronics and the field-generating means to a minimum.

Such a waveguide is a magnetically or electrically controllable reflection attenuator. It can also be used advantageously as a magnetically or electrically controllable bandstop or as a filter. The effect is exploited here that the line impedance of a dielectric waveguide is frequency-dependent. If an adjustment is made between two waveguides, this can only be done for a narrow frequency band. For frequencies outside of this frequency band, an adjustment has so far not been possible after the filter has been manufactured. Due to the possibility of changing the wave resistance by means of the field-generating means, an adaptation between two dielectric waveguides for different frequencies can advantageously be carried out in succession with one and the same waveguide. So is it is possible to carry out a spectral analysis with the waveguide according to the invention.

Such a waveguide can also be used advantageously, for example, as a variable transverse capacitance or series inductance in a waveguide arrangement. For this purpose, the electrical waveguide has a strip-shaped conductor section which has a width Bi at its end sections and the width B ₂ in the middle section. To generate a specific transverse capacitance or series inductance, the effective width B _{2 of} the central section is changed accordingly by means of the field-generating means. To reduce the width B ₂ , fields of predeterminable strength are generated by means of the field-generating means, the fields at least partially penetrating the edge regions of the dielectric material arrangement of the central section, as a result of which an in the edge regions of the central section of the strip-shaped conductor section

Line impedance is adjustable, which is close to zero or infinity.

The dielectric waveguide can also be a stub, the length L of which can be changed by means of the field-generating means as described above.

It is also advantageous if another waveguide adjoins the end of the stub line, the wave impedance of which can be changed by means of the field-generating means, in such a way that the stub line runs empty at a wave resistance Z _L - »00 and is short-circuited at a wave resistance Z _L -» 0 .

The dielectric waveguide according to the invention is thus an active electronic component, any possible application being possible by means of the variable line impedance. By means of the positionally adjustable impedance profile of the waveguide, it can be used as a reflection attenuator. there the damping is not based on the principle of absorption, but on the basis that the intensity of the backscattered field is varied and the intensity of the transmitted field is controlled in connection therewith.

Possible embodiments are explained in more detail below with reference to the drawings.

Show it:

1 shows a dielectric waveguide with an integrated induction plane;

FIG. 2 shows a dielectric waveguide with an integrated induction plane, the induction coils generating a magnetic field H in the central region;

Figure 3 is a cross-sectional view of a commercially available stripline;

FIG. 4 shows a cross section through the waveguide according to the invention;

FIG. 5 shows a cross section through a waveguide with an yttrium iron garnet layer;

FIG. 6 shows a plan view of the induction plane with induction coils arranged in a matrix;

Figures A plan view of a waveguide with a 7a-7c central region, the width of which is variable by field-generating means;

Figures A dielectric waveguide, the 8 and 9 dielectric properties of which can be changed by means of an electric field. Figures 1 and 2 show a dielectric waveguide

1, which is designed as a microstrip line. The waveguide 1 has a conductive base plane 3, which is attached to a dielectric layer 2. A strip-shaped conductor 4 is arranged on the side 2a of the dielectric substrate layer 2 facing away from the base plane 3 and is prepared by means of a photolithographic process. The dielectric substrate 2 has a relative permeability μ _r and a dielectric constant ε _r . A thin layer 5, in which induction loops 6 are embedded, is attached to the base plane 3 on the side facing away from the dielectric substrate 2. The induction loops 6 of the thin film 5 are connected to the control electronics 7 by means of connecting lines 6c (not shown). Using the control electronics 7, ring currents of a certain strength and direction can be impressed into the ring coils 6. The ring coils 6 can have a plurality of turns in order to generate a larger magnetic field H.

As can be seen from FIG. 6, the induction coils 6 are arranged in a matrix and parallel to the base plane 3 such that the magnetic field 9 generated by them passes through the base plane 3 and penetrates the immediately adjacent area in the dielectric 2. This changes the dielectric property of the dielectric 2, as a result of which the line impedance Z _{L of} the dielectric waveguide changes in certain areas. As shown in FIG. 2, the line impedance Z _{L is changed} in a central region by impressing a current in the coils 6b, which results in a wave resistance Z _{LV that} is different from Z _L.

The size of the change in the wave resistance Z _L depends on the size of the magnetic field generated and on the material used for the dielectric material arrangement

2, as well as their dimensions and must be for everyone Individual cases can be determined using suitable tests or determined mathematically.

A dielectric waveguide 1 is shown in FIG. 3, two strip-shaped conductors 4 being arranged parallel to one another. FIG. 3 shows the E field 8 of an electromagnetic wave propagating in the microstrip line.

FIG. 4 shows a cross-sectional representation through a dielectric waveguide 1 according to the invention. It is conceivable that the thin layer 5 (induction plane) has induction coils 6 only at certain positions for changing the dielectric property of the dielectric substrate 2. The induction coils 6 are only arranged at the points at which certain microstrip lines of the structural level are to be influenced.

FIG. 5 shows a further waveguide 1 according to the invention using microstrip line technology. The waveguide

1 has a gallium-gadolinium garnet support 11, on which a homogeneous monocrystalline and gallium-doped yttrium-iron garnet layer 2 is epitaxially produced, which is dielectric in the unmagnetized state. The yttrium iron garnet layer produced by means of liquid phase epitaxy

2 facing surface is covered over the entire extent of this coating with a quartz layer 10, the surface facing away from the composite surface is homogeneously copper-coated. The surface of the gallium-gadolinium garnet support 11 which is repelled by this copper coating 4 is homogeneously copper-coated in the same way. The layer thickness of the copper coating is measured at 17.5 micrometers, the copper coating of the quartz layer 10 forming the structural level 4. This structural level 4 is processed photolithographically, so that strip lines 4 of certain geometrical dimensions are created. The induction plane or thin film 5 is arranged on the side of the base plane 3 facing away from the structural plane 4, the thin film 5 Has inductors 6 in the form of induction loops 6a, 6b, which are in electrical connection with control electronics 7 by means of connecting lines 6c, not shown. As can be seen from FIG. 6, the induction coils 6a, 6b are arranged in a matrix. A polystyrene layer 12 for the galvanic separation of the induction level 5 and the base level 3 is arranged between the thin layer 5 and the base level 3. The magnetic field 9 generated by means of the induction coils 6a, 6b penetrates the base plane 3 as well as the gallium-gadolinium garnet support layer 11 and changes the dielectric property of the yttrium iron garnet layer 2. By changing the dielectric property of the yttrium iron garnet layer 2 changes the line wave resistance Z _{L of} the stripline.

FIGS. 7a to 7c show a dielectric waveguide 1, the strip-shaped conductor section 4 of which is divided into three areas 13, 14, the two end sections 13 having a width Bi and the middle section having a width B ₂ , with B ₂ greater than or less than or equal to Bi. In particular in the middle section 14, induction coils 6 are arranged in the induction layer 5 such that the effective width B _{2 of} the middle line section 14b can be changed by means of the magnetic fields generated. By varying the width B ₂ , it is possible to vary the wave resistance Z _{L of} the central region, which makes it possible to generate a series inductance L (FIG. 7b) or a transverse capacitance C (FIG. 7c) by means of such a waveguide. By means of the induction coils 6, the line wave resistances Z _{L of} the lateral regions 14a of the central region 14 can be set such that they correspond to an open or short-circuited line end.

FIGS. 8 and 9 show a dielectric waveguide which has a dielectric substrate layer 2, on one side of which the conductive base plane 3 is arranged and on the surface 2a of which the structural plane 4 is photolithographically is made. Capacitor plates 6 are arranged on the sides of the waveguide 1, by means of which an electric field 15 can be generated transversely to the direction of propagation of the wave guided in the strip conductor. The dielectric properties of the dielectric substrate layer 2 are changed in regions by means of the generated electrical field 15, which results in a new characteristic impedance Z _LV in this region. The capacitor plates 6 are electrically connected to a voltage source U via switching elements S, such that electrical fields of a definable direction and size can be generated by means of the opposing pairs of capacitor plates. Depending on the direction and size of the electrical field, a desired line impedance Z _LV is set in the respective field-penetrated area.

Claims

claims

1. Dielectric, in particular planar or quasi-planar waveguide (1), which has at least one dielectric material arrangement (2), characterized in that the dielectric material arrangement (2) is at least partially made of a material whose permeability or permeability tensor and / or permittivity or Permitivity tensor can be changed by means of a magnetic field (9) penetrating the material (2) in some areas and that at least one means (6) for generating at least one magnetic field (9) is provided, with the magnetic field (6) 9) the permeability or the permeability tensor and / or the permittivity or the permittivity tensor of the material arrangement (2) can be changed at least in certain areas.

2. Dielectric, in particular planar or quasi-planar waveguide (1), which has at least one dielectric material arrangement (2), characterized in that the material arrangement (2) is at least partially made of a material whose permeability or permeability tensor and / or permittivity or permittivity -Tensor can be changed by means of an electrical field (15) penetrating the material (2) in some areas and that at least one means (6) for generating at least one electrical field (15) is provided, with the electrical generated by the means (6) Field (15) the permeability or the permeability tensor and / or the permittivity or the permittivity tensor of the material arrangement (2) can be changed at least in certain areas.

3. Dielectric waveguide (1) according to one of claims 1 or 2, characterized in that on the waveguide (1) the field-generating means (6) abuts and the field-generating means (6) galvanically from the metallic conductor structures (4) and / or Base plane (3) of the waveguide (1) is separated and the galvanic separation takes place in particular by means of a polystyrene layer.

4. Dielectric waveguide (1) according to claim 3, d a d u r c h g e k e n n z e i c h n e t that at least one layer, in particular thin layer (5) adjoins the waveguide (1), in which the field-generating means (6) lie, rest or rest.

5. A dielectric waveguide (1) according to claim 4, d a d u r c h g e k e n n z e i c h n e t that in the adjacent layer (5) the field-generating means (6) are arranged in a matrix or grid pattern, in particular in the areas of the metallic conductor structures (4).

6. Dielectric waveguide (1) according to claim 5, characterized in that the magnetic field generating means (6) is an induction coil with m turns, the induction coil being oriented in space such that a part of the magnetic field (9) generated by the current-carrying induction coil dielectric material arrangement (2) at least partially penetrates and the induction coil is arranged on the side of the base plane (3) facing away from the strip-shaped conductor (4).

7. Dielectric waveguide (1) according to claim 6, characterized in that the induction coil (s) (6) is / are connected to control electronics (7), and by means of the induction coil (s) (6) at least one magnetic field (9) of a predeterminable strength and / or direction can be generated and the

Control electronics (7) for the induction coil (s) (6) abuts on the side of the thin layer (5) facing away from the conductive base plane (3) and is / are in electrical connection with the induction coil (s) (6).

8. A dielectric waveguide (1) according to claim 5, characterized in that the electric field (15) generating means (6) is a capacitor, the direction of the electric field vector of the electric field generated by the capacitor (15) in particular approximately parallel to the structural plane of the waveguide (1).

9. A dielectric waveguide (1) according to claim 8, d a d u r c h g e k e n n z e i c h n e t that the

Capacitor (6) is a plate capacitor, the plates of which are arranged transversely to the direction of propagation of the electromagnetic waves and the plate capacitor is connected to control electronics (7).

10. A dielectric waveguide (1) according to the preamble of claim 1 or one of the preceding claims, characterized in that the amount of the wave resistance Z _{L of} the waveguide (1) by means of at least one field-generating means (6) can be changed at least in sections or sections.

11. A dielectric waveguide (1) according to claim 10, characterized in that the length L, the width B and / or the amount of the wave resistance Z _{L of} the section or region can be determined or set by means of the field-generating means (6), such that that to adjust the length L, the width B and / or the amount of the wave resistance Z _L only the field-generating means (6) produce a field (9, 15) of predeterminable strength, the field (9, 15) of which at least partially penetrate the dielectric material arrangement (2) of the waveguide (1) in the region or section.

12. A dielectric waveguide (1) according to claim 11, characterized in that the waveguide (1) has a characteristic impedance Z _LI in a first region or section (13), a second region or the region adjoining the first region (13). Section (14) of the waveguide (1) has a characteristic impedance Z _{L2 which can be} changed by means of the field-generating means (6), and a specific predeterminable reflection factor r can be set by means of the second characteristic impedance Z _L 2, the reflection factor r being derived from the quotient

^ L2 ~ ^ L \

Z _L2 + ^ ι calculated.

13. A dielectric waveguide (1) according to one of the preceding claims, characterized in that the dielectric material arrangement (2) is made of a gyromagnetic or gyroelectric material and the amount of the dielectric constant «- _{r of} the dielectric material arrangement (2) in particular in the range between 3 to 5 is.

14. Dielectric waveguide (1) according to claim 13, d a d u r c h g e k e n n z e i c h n e t that the

Material arrangement (2) is an yttrium iron garnet layer.

15. A dielectric waveguide (1) according to one of the preceding claims, characterized in that the dielectric waveguide (1) has a conductive base plane (3) and at least has a strip-shaped conductor (4) or a structural plane (4), and between the base plane (3) and the strip-shaped conductor (4) or the structural plane (4) is the dielectric material arrangement (2) and between the dielectric material arrangement (2) and the base plane (3) is a layer (11) made of gallium-gadolinium garnet of the thickness L _GGG .

16. A dielectric waveguide (1) according to claim 15, characterized in that between the dielectric material arrangement (2) and the strip-shaped conductor (4) or the structural plane (4) is a quartz layer (10) of the thickness L _Q.

17. Dielectric waveguide (1) according to one of the preceding claims, d a d u r c h g e k e n z e i c h n e t that the waveguide (1) is a magnetically or electrically controllable reflection attenuator or a magnetically or electrically controllable bandstopper or a filter.

18. A dielectric waveguide (1) according to claim 17, characterized in that each frequency value f _t of the wave guided by the dielectric waveguide (1) can be assigned and adjusted a wave resistance Z _Lf , in which the assigned frequency f _{t is} only slightly attenuated and all other frequencies f ≠ f _t dampened more.

19. Dielectric waveguide (1) according to one of the preceding claims, characterized in that a strip-shaped conductor section (4) at its end sections (13) has a width Bi and in the central section (14) the width B ₂ , and that to produce a specific one Cross capacitance or series inductance the width B _{2 of} the central section (14b) can be changed by means of the field-generating means (6), such that to reduce the width B ₂ the field-generating means (6) produce fields (9, 15) of predeterminable strength, the fields (9 , 15) at least partially penetrate the edge regions (14a) of the dielectric material arrangement (2) of the central section (14).

20. A dielectric waveguide (1) according to one of the preceding claims, that the waveguide (1) is a stub whose length L can be changed by means of the field-generating means (6).

21. A dielectric waveguide (1) according to claim 20, characterized in that at the end of the stub another waveguide (1 ') is adjacent, the wave resistance Z _{L can be changed} by means of the field-generating means (6), such that the stub at a wave resistance Z _L -> 00 is idling and is short-circuited with a characteristic impedance Z _L -> 0.