DE2421494A1 - ANTENNA DEVICE - Google Patents

Description

Antenna device

The invention relates to an antenna device and in particular on a deflectable gerlohte antenna device for operation at very high or microwave frequencies

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for applications such as ζ.B ^ radiometers and radar object detection systems. The invention relates in particular "but not exclusively to antenna devices" in which a fast Wide-angle deflection In one or at right angles to each other Directions is possible and which have a construction * the mechanically simple and electrically practical 1st.

So far there have been many uses for directional antennas, that the deflection of a radiation or reception diagram via enabled a spatial angular sector that is slightly larger than the opening angle proved to be useful * the entire antenna (both its food = and its collimation elements) in one piece over the to move the desired deflection angle »If this method is due to the relatively large size and inertia of an antenna cannot be used "was the deflection achieved" by placing the feeder opposite the collimator j was moved such as along a focal point

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of the collimator or around a small circle centered on this focal point · Alternatively a number of Spelseeinriohtungen along the said line or arranged along the circle «with these food units successively connected to a transmitter or a receiver with the help of a complicated !! ■ switch » Both possibilities require that the effective center of rotation of the feed element is at the vertex of the colli ■ ators and both possibilities call serious

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steering angles approaching. Even fun the distraction in a single Plane are the mechanical difficulties encountered in attempting a high speed wide angle deflection ■ to achieve such known antenna devices » severe, and you experience excessive weight and height problems on·

An antenna device designed according to the invention comprises dielectric electromagnetic wave collation devices with a substantially cylindrical or spherical interface, distribution devices for electromagnetic Lights with an energy exchange opening that can be moved along an essentially cylindrical or partially spherical interface, and multiple transmission line connections, which are in energy exchange relationship between a Part of the interface of the collimation devices and part of the essentially partially cylindrical or partially spherical Extend boundary surface

In the preferred embodiment, according to the invention, a device for the child's wide-angle deflection with minimal Distortion of a directional radiation or reception diagram Created in one or more planes in space by the fact that

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a moving feed device for switching the energy flow With respect to repeatedly selectable parts of a waveguide and deflection transmission line order is used that with a cylindrical or spherical energy collimator cooperates.

Further advantageous refinements and developments of the invention result from the subclaims

The invention is illustrated below with reference to in the drawing Execution examples explained in more detail.

Point in the drawing Fig. 1 is a plan view partially shown in cross section

a first embodiment of the antenna device;

Flg. Fig. 2 is a top plan view partially shown in cross section a second embodiment of the antenna device;

Figo 3 is a plan view of a waveguide arrangement which

in the design of the antenna installation Fig. 2 can be used.

The deflection antenna device according to FIG. 1 comprises three essential interacting elements, nHmlioh an Ablerik distributor element 1, a deflection reversing or reversing element 2 and an energy collimation element 3. As explained below the antenna device can be in the form of special exemplary embodiments designed for the deflection of a radiation or reception diagram in a single plane or for deflection in mutually perpendicular or other planes

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Signet are. In general, the single-plane energy deflection distribution element 1 has a shell element such as a pyramidal horn 4 for the propagation of a plane electromagnetic wave front in relation to an opening "which can be moved cyclically and continuously along a partially cylindrical interface 5 into successive positions, such as positions 6 and 7, which are shown in dashed lines. The horn 4 is mounted on a waveguide 8 opposite a conventional transmission line rotary joint 9 in such a way that the opening of the horn 4 can be rotated along the curve of the interface 5 about the operating axis 10 of the transmission line rotary joint 9.

The or ent surface 5 is in the one-plane deflection system by the Ends of a number of waveguides defined which form the main part of the deflecting Uskehreleeen tee 2, the element 2 being a plane symmetry u »has the central plane, which is indicated by the dash-dotted line Line 15 shown 1st. The element 2 consists of a stack of rectangular waveguides that are a first pair from side by side arranged central waveguides 16 fell asleep, dl "to a subsequent pair of hollow conductors 17" border on the In the same catfish «waveguide pairs l8, 19, 20, 21 and 22 follow. The number of waveguide pairs 16 to 22 ends at the ends opposite the interface 5 in a partially cylindrical shape Interface 25, the centers of interfaces 5 and 2J falling into SynoMtrleplane 15. Every ending The waveguide 16 to 22 is old an "IapedanzanpaBelenent such as elements 24 and 25 which are provided in the opposite Ends of the waveguide 22 are arranged. In the drawing - these impedance matching transformers are in the form of an example of blocks of dielectric material, although other types of impedance matching devices are also used can be. The waveguides preferably conduct waves whose electrical vector E lies in the plane of the drawing, like this in connection with the waveguide 22 is shown.

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The task of the deflecting-reversing element a 2 is realignment the direction of expansion of the flat wall, which spreads in dam horn 4When al oh for example daa horn 4 in the in Pig. 1 is located around the waveguide 21 and 22 on the extreme left side of the deflection reversing element a 2, so the energy passing through the waveguide becomes diverted so that it continues to run like the one indicated by the dash-dotted line Line JO is shown «in order to form the radiation or reception diagram 31 on this orphan · Daa diagrams 32 is generated« if βloh the horn 4 at position 6 on the plane of symmetry of the system is "while diagram 33 is generated in the same way" when the horn is at position 7.

The deflection of the flow of energy will star in the AbI enk reversal system 2 supported by a system of pairs of waveguide delay elements 36 to 41, each with the waveguide pairs 16 to 21 are connected · The delay elements further contribute to "that the deflection-reversing system is relatively short" so that the gas control system is compact and has a simple structure. With the exception of the outermost pair of waveguides 22, the waveguides are 16 to 21 each with electrical delay elements 36 up to 4l loaded «so that every electrical path length is equal to that electrical path length of the outer pair of waveguides 22 is. Therefore, a relatively smaller delay is required for each of the delay elements in the waveguide pair 21 than for the waveguide pair l6 in the cement. The waveguide pair 21 thus requires relatively short delay elements can be made of a material with a relatively low electrical constant. Daa same material can be used for Manufacture of the progressively longer delay elements 39 and 40 are used in the waveguide pairs 19 and 20, respectively. This continuous extension of the delay elements can to be continued up to the waveguide pair 16 arranged in the middle. a material with a larger dielectric constant

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for the verifying element pairs 36, 37 and 38 according to FIG. 1 to select. The dielectric materials are selected from commercially available materials that have relatively low loss properties at very high or microwave frequencies.

In the sine plane deflection systems according to FIG. 1, the energy collation can be used 3 into an "exemplary embodiment from a" Solid dielectric material also with low loss properties and with the shape of a straight circular cylinder " · The curvature of the cylindrical surface 26 of the element 3 etlmnt with that of the interface 23 of the deflection-reversing element 2 over a. The Spelsehorn runs through in operation

4 Lyüisoh the boundary surface 5 «On the basis of the above-mentioned equilibrium the path lengths in the waveguide pairs en 16 to 23 are the Phases of inergy at the waveguide openings at the interfaces

5 and 23 are not shifted relative to one another. Due to the physical oeonetrle of the system becomes a phase front In the raised position of the horn 4 from the axis of rotation 10 is routed away «at the Oberfllohen-Orensfläohe 23 and along the dash-dotted line 30 is unguided and runs through the Center 42 of the cylinder lens, which is the inergle colliBation element 3 forms "as is necessary for an aberration-free deflection" u "the desired undistorted radiation" - or Bmpfangsdlagranii 31 below form · Ss is understandable that the movement of the horn 4 are cyclically reversed at the end positions can »or that the horn 4 continuously focuses on one Circle can move and is switched to an inactive state »if the opening of the horn 4 is not on the interface 5 is located. Ss is still understoodIioh> that the figure, like many other figures, is drawn in such proportions the basic idea of the invention became clearly recognizable is, and that · these proportions are not necessarily proportions are «which have been used in practice.

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As already indicated above, the Ahtennenelnrlohtung Include a Spelsehorn 4, which as in Flg. 2 for a spatial angle scanning around two mutually perpendicular Axes such as the azimuth and elevation angles are arranged is. For this purpose, the deflection plate element 1 uses a conventional gimbal ring system which includes deflection shafts 10 and 45. The horn 4 is held on a radar or radiometer receiver 46 "which is stored in cardan rings" to In a given azimuth topic with the help of a motor 47 to move the shaft at the Aohse 10 when the engine is excited in the usual way by azimuth deflection voltages » which are fed to the motor lines 48 «those of the axis 10 The associated shaft can be mounted in a cardan ring (not shown), which in turn can be rotated on a shaft Axle 45 is fastened in bearings 49 »50 and can be driven by a motor 51 1st «The motor 51 can according to a prescribed scheme by applying suitable elevation angle deflection voltages which are fed to the lines 53 of the motor 51 are operated will. The deflection about axes 10 and 45 can be regular and in cyclically synchronized catfish are correspondingly well known Procedures are carried out »in order to achieve a raster and an associated roughness angle deflection of a directional antenna.

In the solid angle deflection system naoh Flg. 2 1st the opening or Aperture of the Spelsehorn 4 designed so "that it" I in two Dimensions adjacent to a teflsphere claw QrenzflKohe 55 moves »those from a multitude of openings in a two-dimensional stacked arrangement using a variety of planar arrangements consists of waveguide pairs 16 to 25 » those of the planar arrangement shown in Fig. 1 are ibnlloh. the different hollow liner delay elements are used Arranged in a similar way "in order to create equal propagation times for the energy" that the deflection-reversing element 2 for Any azimuth or elevation position offset of the

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Horns 4 runs through opposite the Aohse 36 of the antenna system. This antenna system now has a symmetry axis 36 which the plane of symmetry 13 in the antenna deflection system according to Pig. I replaced. .

Each end of the deflection-reversing element is in the shape of a concave partially spherical surface, so that the interface 33 a concave, partially spherical end boundary surface 37 lies opposite, which is adapted to the curvature of the partially spherical dielectric lens which forms the energy collimation element 3. It Is readily apparent that the essential elements 1, 2 and 3 of the solid angle deflection system according to FIG. 2 in one Catfish work, which is analogous to that of the components of the system according to FIG. 1, with these elements, however, a deflection of the radiation or reception diagrams such as diagrams 31 * 32 and 33 both in the elevation angle and in the azimuth direction.

Although the exemplary embodiment according to FIG. 2 can be operated in a satisfactory manner with a two-dimensional arrangement of rectangular waveguides, other shapes of waveguides which have smaller deviations from the rectangular shape can also be used in the system according to FIG. For example, the two-dimensional arrangement may be used of generally hexagonal hollow conductors through a ttbllohe aluminum honeycomb plate is formed _p as shown in Fig. 3. In this case, the hexagonal waveguide 60 can form the only centrally arranged waveguide, which is then provided with a delay element (not shown) for maximum delay. The waveguides 61, which directly surround the waveguide 60 arranged in the middle, require a delay element with a slightly smaller delay. The waveguides 62 which directly surround the waveguides 61 * require a delay element

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with less delay than the waveguide 6l, etc., to to the outermost circle of waveguides 64, in which dielectric delay elements can be omitted »if this is desired.

The energy collimation element used in the Einaohaen deflection system shown in FIG 3 can have the shape of a cylinder lens, which is a microwave analogue to the usual krelssylindrisohen optical Luneberg lens is, and in which the dielectric medium has an effective broadening index with low losses, which is in radial direction near the outside of the axis of the cylinder from changes · The index η therefore changes with the normalized Radius r according to the relationship)

η - \ J2 - r ² (1)

Such cylindrical lenses were produced by the fact that a long tape of constant width made of one material with it progressively soothing dielectric properties was made and this tape was then wound into a spiral, to form the desired cylinder. The tape can be made of artificial low loss dielectric material composed of an array of randomly oriented metal « Controlled density immersion consists in a dielectrisohen Pearl matrix with low diohte are supported. The particles can be insulated silver or aluminum needles with a length that is less than 1 / B of the operating wavelength and these needles can be embedded in foamed polystyrene. Spherical lenses for use as the energy collimation element 3 naoh Fig. 2 are suitable and a si oh In Have radial direction changing broadening index, were produced in the same way by that a number of such short cylinder was stacked on top of each other to get the desired approximate spherical shape or an arrangement of pyramidal sectors was produced, each in the radial direction had graded dielectric properties and

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each with a Soheitelpunkt at the center of the sphere were arranged that make up them as a whole. Such spherical ones Lenses have the desired Eigensohafydafi they have a plane wave » as it is generated, for example, by the Spelaehorn 4, exactly focus on a point on the sphere that is diametrically opposite to the tangent point of the plane phase front when entering the sphere.

Accordingly, it can be seen that the preferred embodiments a fast wide-angle spatial scan with minimal distortion of a directional radiation or Enable bmpfangdiagrams. The operation of the deflector can be done in one or in two mutually perpendicular directions, being a simple, lightweight feed element deflection mechanism is used in an antenna system that requires very little space and is very lightweight on » exhibits as well as low costs.

Claims;

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Claims (1)

Claims t 'Antenna installation, marked you oh a dielectric collimation device (3) for electromagnetic The shaft is essentially cylindrical or spherical interface (26), distributor devices (8) for electromagnetic waves with an energy exchange rate (4), which can be moved along a substantially partially cylindrical or partially spherical Orenz surface (5, 55), and Multiple transmission line devices (2), see in energy exchange relationship between part of the Orenzfläohe (26) of the collimation units (3) and a part of the essentially partially cylindrical or partially spherical Extend Qrenzflache (5, 55). 2 · Antenna device according to claim 1, characterized in that the multifunctional transmission line units (2) an array of waveguides (16 to 22) old parallel alignment comprise that each waveguide (16 to 22) has wall elements that rest against wall elements of adjacent waveguides (16 to 22), and that delay devices (36 to 41) in the arrangement of cave ladders (l6 to 22) are provided which have essentially the same propagation time for the electromagnetic waves through all waveguides (16 to 22). J. Antenna device according to claim 2, characterized in that g e k e η η ζ e i chnet that the arrangement of waveguides (16 to 22) first and second opposite concave energy exchanges (2J5, 5) has that the first energy exchange end (2?) In energy exchange relationship with the dielectric 409-84 8/0992 Kollimationselnriohtung (3) is arranged for the electromagnetic waves «and that the second energy exchange end (5) forms part of the part-cylindrical or part-spherical interface (5, 55). 4. Antenna device according to claim 3, daduroh characterized »that the arrangement of waveguides (16 to 22) with impedance matching devices (24, 25) on the first and second opposite Energieaus exchanging (23, 5) provided is. 5. Antenna device according to claim 3 or 4, characterized in that the delay devices (36 to 41) comprise dielectric phase retarders. 6 antenna device according to one of the preceding claims, daduroh characterized in that the distributor = devices (8) for the electromagnetic waves waveguide elements comprise, which are rotatably mounted for a movement about at least one axis (10). 7 antenna device according to one of the preceding claims, daduroh marked »that the first and second concave energy exchanges (23« 5) each the Have the shape of a partially spherical surface. 8. Antenneneinriohtung according to any one of the preceding claims, daduroh characterized »that the dielectric Collimation device (3) for the electromagnetic waves, a massive ball made of dielectric material with low Losses is. 9 · Antenna device according to claim 8, characterized in that the solid ball (3) is made of dielectric Material with low losses an effective refractive 409848/0992 _o /. Has index η, which is equal to the radius of the sphere r naoh the following equation changes; η -. \ J2 - r ² . 10. Antenneneinriohtung naoh claim 8 or 9, characterized in »that the distribution devices (8) for the electromagnetic waves include waveguide elements which are perpendicular to each other by the first and second
Axes (10, 45) are rotatably mounted. 409848/0992