FR2612697A1 - JUNCTION BETWEEN A TRIPLAQUE LINE AND A MICRORUBAN LINE AND APPLICATIONS - Google Patents

Abstract

THE INVENTION RELATES TO A JUNCTION BETWEEN A THREEPLATE LINE AND A MICRORIBBON LINE. THE CENTRAL CONDUCTOR 1 OF THE THREEPLATE LINE SHOWS A BEVEL 8 EXTENDED OUTSIDE OF THIS THREEPLATE LINE; THIS GROWTH 8 CROSSES THE GROUND PLANE 6 AND THE DIELECTRIC 7 OF THE MICRORIBBON LINE, THEN IS ELECTRICALLY CONNECTED, BY MEANS OF A WELD, TO THE CONDUCTOR 5 OF THE MICRORIBLE LINE. AN ELECTRICAL INSULATION IS ACHIEVED BETWEEN THE CENTRAL CONDUCTOR 1 AND THE GROUND PLAN 6, BY MEANS OF A SAVINGS 10, FOR EXAMPLE CIRCULAR, PRACTICED IN THIS GROUND PLAN 6. VARIOUS APPLICATIONS OF THIS JUNCTION.

Description

JUNCTION BETWEEN A TRIPLAQUE LINE AND A LINE

MICRORUBAN, AND APPLICATIONS

  The invention relates to a junction between a triplate line and a microstrip line and its application including: - the electrical connection of two superimposed triplic lines; - The electrical connection of two perpendicular triplic lines - to the realization of a power distributor essentially comprising triplic lines; - The realization of a power distributor with triplic lines and a microstrip line; - the realization of an electronic scanning antenna in the site plan; - the electrical connection of microstrip radiating elements to

a triplet line.

  "Fixed" radars, intended to remain on the ground, may have voluminous and heavy antennas. "Embedded" radars, placed on land vehicles or not must instead have the smallest antennas and the lightest possible, without their performances are deteriorated. These criteria of size and weight of antennas forming part of embedded radars are all the more

  important that such antennas are airborne.

  It is therefore essential to have a technology of

  antenna manufacturing using small and light elements.

  In particular, it is interesting to use as microwave lines, triplic lines and microstrip lines, the seconds being the lightest and the most compact, but with more losses than the first ones. It may be necessary to make the electrical connection between such elements.

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  The prior art includes such electrical connections.

  For example, the junction of two superimposed triplic lines is, according to the prior art, using a conductive wire located inside said triplate lines: this conductive wire electrically connects the central conductors each of the two triplic lines, crossing the ground plane common to the two triplate lines and located between said central conductors; electrical insulation means are provided between the conductive wire and the two ground planes through which it passes. A junction of this type has many drawbacks - it requires intervention within the triplic lines, which makes it complicated and therefore expensive; it has significant losses due to the radiation of said conductive wire; - it is cumbersome and heavy, especially because of the shielding that it is necessary to provide to stop the

  radiation described in the preceding paragraph.

  The object of the present invention is a junction between a triplate line and a microstrip line. The central conductor of the triplate line has a protrusion out of this triplate line; this protrusion passes through without electrical contact the ground plane and the dielectric of the microstrip line, and is electrically connected to the microstrip line conductor. Such a junction has the following advantages: - it is made outside the triplate line - it has an "intrinsic" mechanical strength thanks to the crossing of the ground plane and the dielectric of the microstrip line by the protrusion of the central conductor of the Triplate line - it is compact and lightweight; - it presents few losses thanks to a good adaptation of impedance; - it radiates little: a shielding stopping the radiation of this junction is not essential

  - Its principle is simple, so it is inexpensive.

  The invention mainly relates to a junction between a triplate line and a microstrip line, the triplate line being composed of a conductive strip, said central conductor, maintained at a substantially constant distance from two conductive planes, called ground planes, the conductor central being separated from each of the two ground planes by a dielectric, the microstrip line being composed of a metal ribbon, said conductor, and a metal plate, said ground plane, substantially parallel to the conductor, separated by a dielectric, said junction being characterized in that the central conductor of the triplate line has a protrusion out of this triplate line, this protrusion being electrically connected to the conductor of the microstrip line, after passing through the ground plane and the dielectric of the microstrip line, means of electrical insulation being provided between the central conductor of the strip line and the

  ground plane of the microstrip line.

  Precisions, particularities, and various applications of the invention will appear during the

  following description, using the figures that represent

  - Figure 1, a cross section of a strip line - Figure 2, a cross section of a microstrip line; - Figure 3, a perspective view of an embodiment of a junction according to the invention between a triplate line and a microstrip line, before the assembly of these two microwave line elements; - Figure 4, a top view of the previous figure - Figure 5, a side view of Figure 3; FIG. 6, an embodiment of a microstrip line intended to be connected according to the invention to a triplate line, this microstrip line being seen on the side of its ground plane, inside which a circular saving is practiced.

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  FIG. 7, a top view of an embodiment of a junction according to the invention between a triplate line and a microstrip line, after the assembly of these two microwave line elements; FIG. FIG. 9a and 9b, various embodiments of a stripline line intended to be connected according to the invention to a microstrip line, FIG. 10, the analog of FIG. 3 after rotation of FIG. one of the microwave line elements with respect to the other of; FIG. 11, a mode of application of a junction according to the invention, to the electrical connection of two superimposed triplic lines; - Figure 12, a mode of application of a junction according to the invention, the electrical connection of two perpendicular triplic lines; FIG. 13, a mode of application of several junctions according to the invention, to the production of a power distributor essentially comprising triplate lines; FIG. 14, a mode of application of several junctions according to the invention, to the realization of a power distributor comprising triplic lines and a microstrip line; - Figure 15, a schematic diagram of a microstrip radiating element; FIG. 16, a mode of application of a junction according to the invention, to the electrical connection of radiating elements

microstrips with a triplate line.

  In these different figures, the same references are

relate to the same elements.

  FIG. 1 represents a cross-section of an exemplary embodiment of a triplate line, composed of a conductive strip 1, maintained at a substantially constant distance from two conductive planes 2 and 3 which behave like short circuits; the conductive strip 1, also called the central conductor of the strip line, is separated from each of the two planes 2 and 3, also called the ground plane of the strip line, by a dielectric 4. The orientation of a triplate line t is marked in the following by its longitudinal axis, its transverse axis along its thickness, and its transverse axis along its width, respectively noted

tL, tTE and tTL.

  FIG. 2 represents a transverse section of an exemplary embodiment of a microstrip line, composed of a metal strip 5, also called conductor of the microstrip line, and of a metal plate 6, behaving like a short circuit , and also called the ground plane of the microstrip line, the conductor 5 and the ground plane 6 of this microstrip line

  being substantially parallel and separated by a dielectric 7.

  The orientation of a microstrip line m is identified in the following by its longitudinal axis, its transverse axis along its thickness, and its transverse axis along its width,

respectively denoted mL, mTE, mTL.

  FIG. 3 represents a perspective view of an embodiment of a junction according to the invention between a triplate line and a microstrip line, these two microwave line elements being represented before their assembly. This assembly is performed along an axis D parallel to the axis tL of the triplate line, and to the axis mTE of the microstrip line. The dielectric 4 of the triplate line is not shown. The central conductor 1 of the triplate line has an outgrowth 8 outside the triplate line. The width a of this protrusion 8 is smaller than that A of the same central conductor 1 located inside said triplate line. A particular embodiment of this variation of width is obtained by means of a cut for example in bevel 9, which makes it possible to ensure a gradual variation of the width of said central conductor 1. The protrusion 8 of said central conductor 1 is intended to cross the ground plane 6

  and the dielectric 7 of the microstrip line, and then to be fixed.

  mechanically on the one hand, and electrically connected on the other hand, to the conductor 5 of this microstrip line. This mechanical strength and this electrical connection are made, for example, by means of a weld. This welding is made, for example, to the wave by tinning. The electrical insulation between the ground plane 6 of the microstrip line and the protrusion 8 of the central conductor 1 of the triplate line is ensured for example by means of: a saving 10, for example circular, made in the plane mass 6 of the microstrip line; - Variation in width of the central conductor 1 of the triplate line, made for example by cutting for example

bevel 9.

  One of the ends of the conductor 5 of the microstrip line is connected to the remainder of the electrical circuit. The other extremity

is of length b.

  Figure 4 shows the same elements as those of Figure 3, not seen in perspective but seen from above. We see in particular the variation of width of the central conductor 1

of the trefoil line.

  Figure 5 shows the same elements as those of Figure 4 and those of Figure 3, not seen in perspective or seen from above, but seen in profile. It shows in particular the length b of the end of the conductor 5 of the microstrip line

  not connected to the rest of the electrical circuit.

  FIG. 6 represents, in an embodiment of a microstrip line intended to be connected according to the invention to a triplate line. This microstrip line is a side view of its ground plane 6. In this figure, is shown,

  the savings 10 practiced in this mass plan 6.

  FIGS. 7 and 8, respectively show in top view, and in profile view, an embodiment of a junction according to the invention between a triplate line and a microstrip line, after the assembly of these two elements of FIG.

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  microwave line. The soldering with the wave by tinning, which was mentioned previously, is drawn and numbered 11 on

these two figures 7 and 8.

  The junction forming the subject of the present invention, illustrated by FIGS. 3 to 8, is produced without any intervention inside the flat line, and has an "intrinsic" mechanical strength, thanks to the crossing of the plane of mass 6 and the dielectric 7 of the microstrip line by the protrusion 8 of the central conductor i of the triplate line this allows it to be light and compact. Its principle is also extremely simple, its realization is therefore inexpensive. This junction is usable in the frequency band called L, corresponding to 1 GHz, and in the frequency band

said S corresponding to 4 or 5 GHz.

  In addition, this junction has little energy loss, whether radiation losses, or losses due to impedance mismatch, that is to say a rate

  stationary wave (noted TOS) high.

  Such a junction can be optimized by adjusting three parameters which are: the length b, defined above, of the end of the conductor 5 of the microstrip line; the shape and size of the savings 10, practiced in the ground plane 6 of the microstrip line; the embodiment of the width variation of the central conductor 1 of the strip line, namely, for example the shape of the bevel 9 and its position with respect to the edge

from the flat line.

  Figures 9a and 9b show different embodiments of a flat line, seen from above, intended to be connected according to the invention to a microstrip line. These two figures illustrate in particular two different positions of said bevel 9 with respect to said edge of the triplate line. In FIG. 9a, the end of the bevel 9 is located inside the triplate line, and in FIG. 9b the end of the bevel 9 is situated exactly at the edge of the

triplate line.

  The determination of the three parameters listed above was made based on experimental measurements,

particular of the TOS.

  In addition, according to the prior art, it is necessary for the three ground planes of the junction, namely the two ground planes 2 and 3 of the triplate line and the ground plane 6 of the microstrip line, to be in electrical contact

  with each other at the junction.

  Such a junction, optimized by the judicious choice of the three parameters mentioned above, radiates sufficiently little,

  so that a shield is not essential.

  FIG. 10 is the analog of FIG. 3, after a rotation of 90 of one of the microwave line elements relative to the other. The ground plane 6 of the microstrip line is preferably wider in FIG. 10 than in FIG. 3, in order to ensure electrical contact between this ground plane 6 of the microstrip line and the two ground planes 2 and 3 of the triplate line, this electrical contact optimizing the performance of the junction, as has been explained previously. FIG. 11 illustrates a mode of application of a junction according to the invention, to the electrical connection of two triplate lines 30 and 31 superimposed and oriented identically, by means of a microstrip line 32. The trilaminate line 30 is connected electrically, by means of a junction 12, according to the embodiment of the invention illustrated in FIG. 3, to the microstrip line 32, itself electrically connected, by means of a junction 13, in the same mode realization of

  the invention, to the triplate line 31.

  FIG. 12 represents a mode of application of a junction according to the invention to the electrical connection of two perpendicularly oriented triplic lines 33 and 34,

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  so that their tTL axes (transverse along their

width) are parallel.

  The strip line 34 is electrically connected, by means of a junction 15, according to the embodiment of the invention illustrated in FIG. 10, to the microstrip line 35, itself electrically connected, by means of a junction 14. , according to the embodiment of the invention illustrated by the

Figure 3, at the line plate 33.

  In Figures 11 and 12, the various elements of the microstrip lines and triplic lines are not shown. FIG. 13 represents the application of several junctions according to the invention, to the production of a candlestick energy distributor essentially comprising flat lines. The first branch of the candlestick consists of a stripline line 16; this single branch is divided for example into ten at the level of ten electrical connections 17-1, 17-1, ..., 17-10, corresponding to the configuration illustrated in FIG. 12; these ten electrical connections 17-i connect the stripline line 16 to ten triplate lines 181, 18-1, ..., 18-10, substantially parallel to each other, and substantially perpendicular to the stripline line 16; each triplate line 18-i is part of a set i of two superimposed triplic lines, denoted 18-i and 20-i; several, for example eight, electrical connections 19-i-1, ..., 19-ij, 19-1-8, corresponding to the configuration illustrated in Figure 11 connect ends of the central conductor of the strip line 18i to d other ends of the center conductor of the

20-i triplate line.

  FIG. 14 represents the application of several junctions according to the invention, to the production of a candlestick energy distributor comprising triplate lines and a microstrip line, in addition to the microstrip lines forming part of the junctions according to the invention. The first branch of the candlestick consists of a microstrip line 21, pressed against the slices of several, for example ten triplate lines 18-i and several, for example ten lines 20-1 triplicca; this single branch is divided for example into ten at the level of ten junctions 22-1, ..., 22-1, ..., 22-10, according to the invention, corresponding to the configuration illustrated in FIG. 3; these ten junctions 22-i electrically connect the microstrip line 21 to ten identical 18-1, ..., 18-1, ..., 18-10 identical to those of FIG. 13; each strip line 18-1 is part of a set i of two superimposed triplic lines, denoted 18-1 and 20-1, as in FIG. 13; the

  following the description of Figure 14 is the same as that of

Figure 13.

  It is possible to realize an electronic scanning antenna in the site plan, the rotation in the bearing plane being carried out mechanically, this antenna comprising a candlestick energy distributor such as that described in FIG. 13. For this purpose, phase shifters are introduced at the level of the ten electrical connections 17-1, that is to say between the vertical energy distribution and the energy distribution

horizontal.

  An electronic scanning antenna in the site plane, the rotation in the bearing plane being carried out mechanically, can also be carried out from a candlestick energy distributor such as that described in FIG. 14, the phase-shifters.

  are then introduced at the level of the ten junctions 22-i.

  FIG. 16 shows the application of a junction according to the invention, to the electrical connection of microstrip radiating elements, whose diagram is given in FIG. 15, to a triplate line 26, forming part, for example, of a candlestick energy dispenser such as the one illustrated by

  Figure 13, or that illustrated in Figure 14.

  A microstrip radiating element, as schematized in FIG. 15, consists of a metal surface 23, called the pattern of the microstrip radiating element, and of a metal plate 24 substantially parallel to the pattern 23, behaving like a short circuit and called ground plane of the microstrip radiating element, the pattern 23 and the ground plane 24 being separated by a dielectric 25. The pattern 23 may, in principle, have any shape; nevertheless, in practice, it has a simple geometrical shape: it forms, for example, an equilateral triangle, a hexagon, a square, etc. Such microstrip radiating elements are part of the state of the art and are described, for example , in the book "Microstrip Antennas" of IS Bahl and P. Bhartia. The microstrip radiating elements shown in FIG. 16 comprise patterns 23, for example triangular, deposited on a common dielectric 25 separating them from a common ground plane 24. Each pattern 23 is electrically connected to one end of the central conductor of a triplate line 26, by means of a junction according to the invention. In this figure 16, the different elements of the strip line 26 are not shown.

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Claims (11)

  1. Junction between a flat line and a microstrip line, the flat line being composed of a conductive strip (1), said central conductor, maintained substantially constant distance from two conductive planes (2, 3), said plans. of mass, the central conductor (1) being separated from each of the two ground planes (2, 3) by a dielectric (4), the microstrip line being composed of a metal strip (5), said conductor, and of a metal plate (6), said ground plane, substantially parallel to the conductor, separated by a dielectric (7), said junction being characterized in that the central conductor (1) of the triplate line has a protrusion (8) out of this line triplates, this protrusion being electrically connected to the conductor (5) of the microstrip line, after passing through the ground plane (6) and the dielectric (7) of the microstrip line, electrical insulation means being provided between the conductor central (1) of the   triplate line and the ground plane (6) of the microstrip line.   2. Junction according to claim 1, characterized in that the protrusion (8) of the central conductor (1) of the triplate line is of width (a) lower than that (A) of the same central conductor (1) located at the inside of said triplate line, a bevel cut (9) producing this   variation of width in a progressive way.   3. Junction according to one of claims 1 or 2,   characterized in that the isolation means provided between the central conductor (1) of the triplate line and the ground plane (6) of the microstrip line are made by: - a saving (10) made in said plane mass (6)   a bevel cut (9) of said central conductor (1). 26 1 2697   4. Junction according to one of the preceding claims,   characterized in that the electrical connection between the conductor (5) of the microstrip line and the protrusion (8) of the central conductor (1) of the strip line is achieved by means of a solder (11) to the wave by tinning . 5. Electrical connection of two superimposed triplic lines, characterized in that each of said two flat lines is electrically connected to a single microstrip line, each of these two electrical connections (12) and (13) being made by a junction according to the one of the preceding claims.   6. Electrical connection of two perpendicular triplate lines, characterized in that each of said two triplic lines is electrically connected to a single microstrip line, each of these two electrical connections (14) and (15) being formed by a junction according to the invention. one of the preceding claims.   7. Candlestick energy distributor, characterized in. what it comprises: - a triplate line (16), constituting the first branch of the candlestick; a plurality of electrical connections (17-1) according to claim 6, each of these connections connecting said triplate line (16) to a triplate line (18-i), these triplate lines (18-1) being substantially parallel to each other and substantially perpendicular to the strip line (16); a plurality of sets (i) of two superimposed triplic lines (18-i) and (20-1); a plurality of electrical connections (19-i-j) according to claim 5 connecting ends of the central conductor of a triplate line (18-1) to ends of the conductor 26 1 2697   center of the line triplaque (20-i), belonging to the same game   (1) two superimposed triplic lines.   8. Energy distributor candlestick, characterized in that it comprises - a microstrip line (21) constituting the first branch of the candlestick; a plurality of junctions (22-1) according to one of the   Claims 1 to 4, each of these junctions connecting said   microstrip line (21) at a triplate line (18-1), these triplic lines (18-i) being substantially parallel to each other and substantially perpendicular to the microstrip line (21); a plurality of sets (i) of two superimposed triplic lines (18-1) and (20-1); a plurality of electrical connections (19-ij) according to claim 5 connecting ends of the central conductor of a triplate line (18-i) to ends of the central conductor of the strip line (20-i), belonging to the same Thu   (i) two superimposed triplic lines.   An electronic scanning antenna in a plane, characterized in that it comprises: - a candlestick energy distributor according to claim 7; phase shifters located at the level of the ten connections electric (17-i).   An electronic scanning antenna in a plane, characterized in that it comprises: - a candlestick energy distributor according to claim 8;   phase shifters located at the level of the ten junctions (22-i).   11. Electrical connection of microstrip radiating elements (23) to a triplate line (26), characterized in that it is 26 1 2697   performed by means of junctions according to one of claims 1 at 4.