DE1766058A1 - Microwave antenna with adjustable directional diagram - Google Patents

Description

Applicant: Stuttgart, March 25, 1968

Hughes Aircraft Company ^{p 1} ? 74 Centinela and Teale Street
Culver City, Calif., VoSt "A.

Microwave antenna with changeable flow diagram

The invention relates to a microwave antenna with a variable directional diagram, consisting of an arrangement to emit linearly polarized electromagnetic waves in a certain direction with a certain Rioht diagram and an arrangement for optionally changing the Hichtdlagramaeso

209812/0333

BATH ORIGINAL

There is often a need for a single microwave antenna for two or very different purposes. This can be the case with aircraft, for example It would be an advantage »to use a single antenna which provides a first radiation diagram for target acquisition has a second radiation diagram on tracking and a third radiation diagram on operator observation.

Ee oind antenna system known that optionally old one can be operated from two different flow charts are «these known antennas make a parabolic deflector Used which has a small articulated portion that is attached to the remainder of the Beflektors can be pivoted. When the articulated Absohnitt is in the normal division, asked the Antenna a diagram with the narrow puncture lobe that is common referred to as the "pencil club". By pivoting the hinged sections, part of the dsr Club "falsified (spoiled * and daduroh the radiation diagram changed so that there is one for ground observation or the survey of the terrain gives a suitable flattened diagram.

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BAD ORIQ) NAt.

Although parabolic reflectors have been used extensively as elements of directional microwave antennas and are able to provide narrow beam radiation patterns, the operation of the antenna in the adulterated mode leaves much to be desired. The drawback is that only a little _f possibilities for varying the shape of the deflected club exist because the · * he pivotable section a part of a paraboloid ieto Moreover, with this technique, the widening of the antenna diagram in only a single plane möglichο

In contrast, the invention is based on "■" <* task, Γ to create a microwave antenna that is improved in Way with a variety of selectable radiation diagrams is operable.

This object is achieved according to the invention in that the arrangement for changing the directional diagram comprises at least one polarization-sensitive lens, which in the Arranged along the way of the emitted waves and rotatable about an axis parallel to the direction of the beam in the weeantliahen

209812/0333

BATHROOM ORIGINAL ¹

The polarization-sensitive lens provided according to the invention can be designed in such a way that in one position it does not influence the radiated, linearly polarized waves, so that the arrangement for the radiation of these waves can be designed with a view to a first unsuitable directional diagram. This directional diagram can be then depending on the position of the twisted lens and the design of this lens influence in any way ο In particular, it is auoh possible _t; with help

the lens from a Blelsttftkeule an ooseo θοοβθ diagram how it is used to map the terrain «while the pencil diagram is needed for target tracking will. The well-known ones were primarily for this purpose Parabolic antenna with a swiveling Absohnltt provided »

In a preferred embodiment of the invention An antenna with a sbtnsn radiation arrangement made use of a linearly polarized plane beam arrangement will generally have better properties «u» written as a parabolic reflector because sit one higher efficiency, reduced overflow (spillover) and have a tolerable life apex level.

209812/0333 ^{# / i}

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K-,

There is at least one in front of the plane radiator arrangement Lens arranged »for example from a YielEahl VGn arranged at a distance from one another parallel conductive May consist of plates separated by a dielectric medium.

The lenses are held in such a way that they can be rotated through an angle of 90 ° around an axis which is perpendicular to the plane of the emitter arrangement. If one of the lenses is aligned in such a way that the parallel plates are perpendicular to the electrical vector of the radiated electromagnetic waves, they have no influence on the radiation pattern of the planar array of radiators. This is due to the fact that in this alignment the waves run along the line Im _x TKM-Hodua at a speed equal to the speed of the light in the dielectric medium is ₁ because the parallel plates separate 1Mb of turning the line * + at an angle of 90 ° the parallel plates are parallel to the electrical

Vector aligns the radiated waves and it becomes • obtained in deformed diagram. When dl · lens on dl · »« Weis · aligned let »pass through the from the flat

ι; .'.-. ■ ■ " - ^Λ ■■" ■ '

BAD ORfQfNAL

Emitter arrangement graining electromagnetic waves the lens in the fundamental TE mode »Depending on the distance between the parallel plates of the lens and the properties of the dielectric medium that separates the plates», the base speed of the electromagnetic waves penetrating the lens can be made much greater than the phase velocity in free space "the geometry of the lens can werdenι chosen in a known manner so DAFL calibrating a wide variety of results Strahlungadiagrammen _β

Further features and configurations of the invention are see the following description, in which the invention is based on the exemplary embodiments shown in the drawing is described and explained in more detail «The description and the drawing below Features can be used in other embodiments of the invention Can be used individually for calibration or several in any combination · It seigern

FIG. ₉ 1 is a simplified representation of an application of the Invention with two rereobleden radiation diagrams,

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BAD ^; ORIGINAL

fig. 2 some simplified representation of another Application of the invention with an additional radiation diagram

3 shows a simplified, schematic representation of an embodiment of the invention.

4 and 5 are views of the lens of the embodiment form

see Fig. 3 for the Yeranso construction of the lens positions aur the appearance of the two radiation channels naoh Fig. t and

6 shows a simplified, diagrammatic representation of a further embodiment of the invention

Fig. 1 shows all aircraft a flight 10, that is, with an antenna near the Xrfindmng ut. Ha first · radiation diagramÄ 1 Toraneohaulioht a naoh rom directed pencil club, which is particularly suitable for target tracking. A wide 8-radiation adiagraaa 2 represents a so-called es ooeeo ² Pocee-Dißgramin, which can be used for observation or on the surface of the terrain. J) Is lan *

101112/0333

BATH ORIGINAL

Diagraamee 2 is because et resembles the curve that resembles a plot of the function ooseo βοοβθ in polar coordinates, in which the angle θ is measured from the eighth of the antenna looking in the forward direction, as shown in FIG. This radiation diagram is characterized by an essentially uniform gain in a large angular range in a plane which extends parallel to the flight line of the aircraft 10. 'Sas erfindungsgemäBe antenna system is optionally either dta bltlttiftfuralgen diagram 1, or the f \ lr the bottom receiving suitable diagram 2 operate old au able.

Also 71g. 2 ttlgt "wel different radiation diagram", which are honored as diagram 1 * and 2 *. As in 71g. Ί illustrates the diagram 1 'singled out by the antenna Pencil club · Dae diagram 2V illustrates on the other hand, it is united by a broad, forward-facing 6trafalunge lobe. Since * Diagram 2 is used, for example, to show Aiming useful «those« are located in a larger sector can. When bran old help the wide radiation diagraemee 2 * have been found, the antenna can point to the bleed if t lobe geaftfi diagram 1 'uogtto be held »if, - tint target pursuit take place great *. ■■ -

208812/0333 t *

BATH

Although there are only three different radiation patterns in the fig 1 and 2 have been shown Bind, it goes without saying üa lot of and ac Q radiation? liagramine can be used, if so desired. For example, at rielen Application awakening aektorförraige Streiilrnigadiagrfcaime Bit larger or smaller club width may be an advantage.

the one in Flg. 3 shown in simplified form .iuaführungshorn the invention, a planar Strahlernnordiv ar.i 30 is provided which aue a plurality geeohlitzter Hohlleitorabaohnitte and is provided with a suitable feed IBt _1, for example a Hchlleiterabsohaitt 31 "Dae open end of the Hohlleiterabsohnittes 31 let nit a Ansohlußfl & Nsoh yi provided, which facilitates the connection of the antenna with the syatesi in which aie is to be turned. In front of the planar "radiator arrangement 30, a rotatable lens 33 consisting of parallel flats is arranged by way of the radiated waves. The lens 33 is rewarded in FIG. 3 at a certain distance from the radiator arrangement 30, but this is only for solar purposes In practice, the clearer position can be the lens 33 and the planar radiator arrangement 30 in a common frame or

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Framework fastened sain and an abetand together have a wavelength that is somewhat less let ale «, Bei If necessary, the whole frame mechanism can be designed or arranged, because the said antenna can be lowered can be granted.

Pie Llnee 33 let rotatably vm a Aebae · the eteht eenkreoht on the flat Stranleranordnung 30th The rotation is achieved with the help of a bearing ring, which has a section 35 similar to that of a gear wheel. Sin Ritsel 36 »dae» dt help a shaft 37 old elnea Oakehraotor 38 connected iet _? provides the necessary Lelung for the rotation of the lens 33. As stated above, the lens needs to be rotated 33 mm from an angle ▼ of 90 °. In the length shown and the plates 59 dor linae parallel to the Yektor 1 dea electrical 7eldea of the waves that are emitted by the planar radiator arrangement 30. Bio fora dor lens 33, which In TIg. 3 aoheaatlsoh reproduced lot »delivers in the illustrated position of the lens an ooseo OooeO radiation diagraaou

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BADORIGfNAl

The parallel conductive plates 39 "which form the lens 33 ". For the sake of clarity, however, the dielectric material has been shown in the illustration in FIG. 3 omitted «The number of parallel conductive plates 39 and their spacing is essentially determined by the frequency at which the antenna is operated. In general, the distance between adjacent parallel plates must be large enough to be able to transmit the electromagnetic waves polarized in the direction shown in the first order ΈΕ mode, but small enough to suppress higher order TE modes. The distance between the adjacent conductive plates 39 will therefore usually be in the range of 0.5 and 1 wavelengths of energy passing through the dielectric medium separating the plates * «Radiation Laboratory 8eri *,. ToI. 12, MoGraw-Hill Book Co., Inc., New York, 1949, 8pages'4O2 and the following and the references cited therein.

2Οβ812 / 0333

BAp

Although the effect of the antenna according to FIG. 3 will now be described for the transmission mode, ee eioh. that the antenna is also suitable for reception and works in an analogous manner. In operation, the energy to be emitted is fed to the planar radiator arrangement 30 with the aid of the waveguide section 31. Eats oriented in the rtrtikalek plane as the arrow E shows. In the absence of the line, the wavefront, which is generated by a plane radiator arrangement 30, results in a radiation <! Iftgream n & oh kind of a pencil club. When passing through the lens 33, the phase speed dtr radiated well is increased. By selecting the suitable distance and the shape of the parallel plates 39, the phase front dtr corrugation, which emerges from the linst 33, can be changed to tints sth big btrtion. The flow rate diagram, which is required for the generation of ink, can be calculated in a known manner. Details about the payment can be found in "Aufeats von AS Dunbar mit dt" Title "On the Theory of AntsiU / ü Beam Shaping", Treohitntn Ia Journal.: Of AppXitd Phynio ", Vol. 23, August 1952" Atittn 847-853, * will. $ 209 ^ 12/013. _{: <} ·, «-. · · '. »·· *

BATH ORIGINAL

The mode of operation of the embodiment according to Flg. 3 will when considering the Aneich tone according to FIGS. 4 and 5 easier to understand. Fig. 4 is a view of the line β 33 In RiohtuL-g the Aohee the antenna arrangement. In Fig. 4 let the lens 33 be shown so that its plates 39 parallel sub vector S of the electric field of the radiated Vtlle are aligned. In this position the line «τοη the electroaagnetiacben waves in run through fundamental IB modules. Sa the Fbeaengesofewlndigkelt the energy in this mode is greater than ale Ib free house, the lens has an effective refractive index, the smaller than Eint ict. When the dielectric constant of the material that separates the plates, the tjlei is like yen air, is the refraction «? index η given by the following equation»

In these aieiobun ^ is λ ₀ the wavelength ia free space and ^ the distance that separates the exposed plates 39.

Dureh rotation of the peeping 33, inter alia, an angle 90 ° τοη ait Help i · ·· Amtriebtoetore 36 Lag shown to be 5 · dl parallel conductive plates 39 in the FIG. Gebraoht.

BAD ORiG) NAt.

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In this position, the conductive plates 39 are vertically perpendicular to the tactor B because the electrical field of the radiated energy. The wave energy is transmitted through the Ida «· ie TEIMfodua. Since the port planting speed is 6mv wave in the modulus Ib essentially equal to that of the free space, there is essentially no relative phase shift of the wave energy emerging from different sections of the lens in fig. 5, the pencil-lobe-like radiation pattern of the quake radiator arrangement remains unchanged.

The mode of operation of the invention antenna is based on the use of a line that is only apfindlioh for components of the wave energy, which have a beatlaexte polarization, and aneapfindlleh la Beaug on coaponents, which are then orthogonally polarized and · Oh, the radiation adiagraaei dia antenna according to fig. 3 By selecting a rotation of the lens in accordance with the fixed emitter arrangement, it can be retrofitted, AmM it is also aQgliob in manual applications to rotate the flat emitter arrangement and arrange the lens firmly,

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BAD ORiQiNAt.

If the optional use τοη s »hr old ewei rerechiedenen 8 Radiation diagrams are required, the invention can can also be extended to a multiline arrangement, as in the simplified diagram of FIG. 6 shown iet. The antenna according to Pig. 6 has a planar radiator arrangement 60, the bit a Einpeiee * waveguide 61 Tereehen iet. In front of the level array of radiators 60 three lenses 62, 63 and 64 are arranged axially one behind the other because of the radiated wave energy In Pig. 4 are lenses 62, 63 and 64 for simplicity half of all cylindrical disks shown in the alignment of the parallel plates that are in each of the lenses Find use are on the T ^ - * derflachen of the linen indicated by arrows 65 or 66 and 67.

The lines 62 and 63 are shown in Fig. 6 so that they have essentially no effect on the energy emitted by the plane beam order 60. The line6 64, on the other hand, is bit of such an alignment shown that it exerts an effect on the emitted energy. As in the case of the implementation examples In Fig. 5 are uske Jurbare J & trlebaaötore * 68, 69 and 70 Yorgesbhen, which with the lenses 62 bsw. 63 and 64 in

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BATH ORIGINAL

Are active connection and the lenses the desired ·. Provide orientation * By optionally pressing this Drive motors can be any or a combination Several lenses can be adjusted in such a way that they absorb the energy emitted by the planar array of radiators influenced.

It should be understood that those described and illustrated Execution examples only a small number of the many possible execution forms veranoobaulionen, the naoh of the invention can be implemented. Numerous other arrangements of the most varied kinds, which also contain sources other than a flat radiator arrangement may include those skilled in the art according to the teachings of the invention can be easily created without the orbits of the invention «u leaving"

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BATH ORIGINAL

Claims (1)

Claims ο microwave antenna bit changeable »direction diagram», Consisting of an arrangement for linear radiation polarized electromagnetic waves in a beatintea Direction old of a starry directional diagram wad an arrangement for the optional change of the directional orientation, It is characterized by the fact that the arrangement for changing the directional diagram has at least one polar sensitivity Lens (33) uafaflt in the Arranged away from the stripped waves and around an essentially parallel axis is rotatable o 2ο antenna according to claim 1, characterized in that dafl the arrangement sur radiation linearly polarized electromagnetic waves from a planar radiator arrangement (30). 3 antenna according to claim 1 or 2, characterized by that the polarization-sensitive lens (33) consists of one There is a multiplicity of parallel conductive plates (39) arranged at a distance from one another 209812/0333 BAD ORtGJNAt. Blank page