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(11) | EP 1 291 972 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Radioholographic aerials apparatus and method therefor |
| (57) The invention concerns to a radio engineering and can be used for construction of
radioholographic aerials with the required diagram of an orientation (D.O.) mainly
in a range of a MICROWAVE, including flat radioholographic aerials for satellite communication. The application of a way provides expansion of classes of created aerials, high accuracy of reproduction required D.O., opportunity of reduction of the sizes of flat radioholographic aerials. Record of the radiohologram carry out by an electrical way. Thus use a subject radiowave as a field complex-connected required D.0. The binary radiohologram, made by results of record, reproduces required D.0. In the flat radioholographic aerial irradiator (receiver) 3 is placed at an end face flat binary radiohologram and is combined by the phase centre with the centre O; the concentric circles which have been carried out with a step, equal to length wave λ of irradiator. On concentric circles are located or arc metal strips 18, or strips 18 and arc of crack 21, or arc of crack 20, displaying structure of radiohologram. The introduction of the metal screen 16 provides sharp-directed D.O. in perpendicular plane; direction and opportunity of reduction of thickness radiohologram up to a level commensurable with λ/4 , where ε - dielectrical permeability of dielectrical material of substrate 17. |
[0001] The invention concerns to a radio engineering, and is concrete, to ways of construction of radioholographic aerials, including secondary aerial devices used for change of a direction of distribution and - or of polarization of radiowaves and can be used at creation and manufacturing aerial devices for various assignment, mainly in a range of superhigh frequencies, for example, radioholographic aerials of superhigh frequencies used in reception systems of satellite TV, broadcasting or communication.
The way of record of the radiohologram by an electrical way is known [1]. In a known way the hardware method of record of the radiohologram is applied.
Written down as set of video signals the radiohologram, then will be transformed to the optical hologram, which can not be used as the radioholographic aerial. By virtue of it the known way can not supply construction of radioholographic aerials.
The way of record of the radiohologram with application of basic and subject radiowaves is known and registration of a radioholographic relief received at interfere of basic and subject radiowaves [2]. In a known way record of a radioholographic relief carry out on special environment, for example, on liquid crystals. However, the irradiation of the written down in such way radiohologram as the device on liquid crystals, or on other environment, does not provide reproduction of the image in a radiorange. Thus the task of formation of amlitude-phase distributions of fields, ensuring formation of the required diagram of an orientation of the aerial.
Closest to declared, is the way of construction of the radioholographic aerial consisting in formation of a subject radiowave according to the required orientation diagram of the aerial, records of the radioholograms with the help of subject and basic radiowaves in a near zone of the projected aerial and manufacturing of the radiohologram intended for formation of the required diagram to an orientation by results of record [3].
In a known way the formation of a subject wave according to the required orientation diagram is created by imitation of the required orientation diagram. The imitation is carried out by an artificial way with application of masks and screens, and correction by their peak and phase headers by consecutive selection. The mixing received by such receptions, field of the given orientation diagram with a basic bunch from cogerent source allows to write down the hologram. The hologram, written down on the material carrier, use as the shaper of the orientation diagram of the aerial. Thus, for use of the hologram, received in an optical range, as the shaper of the orientation diagram it is enough to illuminate the hologram by a basic wave.
In a range of superhigh frequencies (MICROWAVE) manufacturing of peak and phase headers for imitation of required fields represent an independent difficult task. On the other hand opportunities of imitation are limited to the orientation diagram of radiator of a subject wave. By virtue of it, the known way allows to simulate, and then to receive, limited number of types (classes) of radioholographic aerials, mainly of aerials with the "needle" form of the orientation diagram (Further - OD). The record of the radiohologram in a known way is carried out in a near zone cogerent basic radiator, i.e. in free space of a near zone it radiator. In case of accommodation of the radioholographic aerial created on a known way, on object having high reflective properties and the complex geometrical form, for example, on a vehicle, on a metal surface of a technical structure etc., the distortions O.D. will be observed. Thus in a number of cases the radioholographic aerial will not ensure reproduction required O.D. The specified reasons also limit an opportunity of reception on a known way radioholographic aerial systems such as "object - radiohologram", secondary radioholographic devices having ability of given change of a direction of radioradiation. For this reason the known way does not allow to ensure creation of a class of radioholographic aerials which are taking into account influence of object, on which they are placed or are with it in strong electromagnetic connection, aerial systems such as "object - radiohologram", in particular, creation of not acting aerials, for example, flat radioholographic aerials of a MICROWAVE, secondary radioholographic devices having ability of a given direction of radioradiation. In a known way the record of the radiohologram in a range of a MICROWAVE is carried out on thermoplastic material. Received thus radiohologram has rather low ability to reproduction as because of unsufficient sensitivity of a material at record, and because of weak interaction with a basic radiowave. For reception of the radioholographic aerial with the required orientation diagram the application of artificial receptions of display of the written down radioholographic relief received by interfere of subject and basic radiowaves, i.e. manufacturing of the radioholographic shaper of the orientation diagram of aerial is necessary. However unsufficient accuracy of registration of a radioholographic relief caused by unsufficient sensitivity of a thermoplastic material, limits accuracy of reproduction of the given orientation diagram, that in turn complicates manufacturing the radioholographic shaper (radiohologram) by the most simple receptions of display. The application of record radiohologram on thermoplastic limits an opportunity of realization of a known way in more low-frequency ranges of radiowaves, i.e. limits creation in these ranges of radioholographic aerials.
The problem of creation small-sized, in particular, flat aerials is urgent in radioastronomy, in engineering of satellite communication, in other areas of a radio engineering.
The flat aerial of a MICROWAVE containing waveguide, flat dielectric substrate located on the metal screen, and on its opposite party dielectric of a plate metal strips, forming asymmetrical strip lines and terminating resonant radiators also of strip type [4] is known. The known aerial is used for satellite TV and has system of excitation as asymmetrical strip lines, moving to everyone elementary radiator. The orientation diagram of such aerial has enough high level of lateral petals, the reception only of one polarization of an electromagnetic signal is possible which depends on the form elementary radiator. Besides as making pathes to elementary radiator it is a lot of (how many elementary radiator), the electrical characteristics of the known aerial sharply depend on losses in dielectric and metal of strip lines.
[0002] As losses from elementary radiator up to a point of input of a MICROWAVE of a signal in a path, as a rule, not less than 1-1,5 dB, also efficiency of such aerial makes 35-50 percents [4]. Technically it is possible for flat aerials with a strip path of excitation to make on a surface dielectric various configurations elementary radiators, that allows to carry out reception of all kinds of polarization of signals, but the microprocessor management for switching of polarization is required, that sharply will lift cost of manufacture and operation of aerials of the given type [4]. By virtue of the listed lacks the known aerial has high cost, as limits its application.
[0003] The radioholographic aerial containing irradiator of waveguide type and the flat radiohologram, including dielectrical substrate with located on its surface by metal conductors, executed in the form of concentric arches of circles established from each other with a constant step [5]. In the known radioholographic aerial the flat radiohologram consists of two flat dielectrical substrates with structures of concentric metal conductors, and distance between planes of an Arrangement of structures of conductors not less quarter of wave length, and irradiator is located with some angel to a plane of the radiohologram. The specified reasons limit an opportunity of reduction of dimensions of the known aerial.
[0004] Closest to declared on technical essence is flat radioholographic aerial containing the radiohologram, including the metal conductors having the form of concentric located arches of circles and placed with a step to multiple length of a wave, on the one party of flat dielectric substrate, and also by irradiator of waveguide of a type established by the phase centre at the centre of concentric arches of conductors [6].
[0005] The known flat radioholographic aerial consists of a package flat dielectric substrates, laying one from another on distance not less than one quarter of wave length of the irradiator. On each substrate the structure from thin metal conductors in the form of circle arches, concentric located from each other is placed, and the radiuses of concentric arches are increased by depth of a package on a quarter of wave length.
[0006] Thus the thickness of the radiohologram is commensurable with wave length. The radiohologram is raised from an edge of a plane its arrangement and by virtue of it forms fields of radiation and diagram of an orientation till both parties of a plane of the radiohologram, it is perpendicular to plane. The increase of number dielectric substrates with structures of concentric conductors increases an one-orientation of a field of radiation. However, the return radiation in back half-plane remains significant, that worsens the power characteristics of the known aerial. Thus, at an arrangement of the known aerial on metal object, the distortions of the diagram of an orientation are possible, as known aerial system in any way did not take into account diffraction of it field on object.
[0007] The presence several flat dielectric substrates with different radiuses of metal conductors complicates design of the aerial and technology of it manufacturing.
[0008] The known aerial has linear polarization of radiation. However it is rather important in a number of cases, for example, in engineering of satellite communication and TV, to have the flat aerial of reduced volume with circular polarization of radiation - reception.
[0009] According to the invention the task of creation of a universal way of construction of radioholographic aerial with the required orientation diagram is decided.
[0010] The basic technical result of the invention consists in expansion of classes of created aerials, including, in creation of flat radioholographic aerials of reduced volume at preservation of high accuracy of reproduction of the required diagram of an orientation. The additional technical result of the invention consists in an opportunity of creation of the flat radioholographic aerial of reduced volume with circular polarization of radiation. The second additional technical result consists in a possibility of expansion of a strip of working frequencies of flat radioholographic aerials received according to a declared way.
[0011] The decision of the put task and achievement of the basic technical result is provided with that in a way of construction of radioholographic aerials consisting in formation of a subject radiowave according to the required diagram of an orientation of the aerial, the records of the radiohologram with the help of subject and basic radiowaves in a near zone of the projected aerial, manufacturing of the radiohologram by results of record, subject wave form by a superposition of bunches quasiflat radiowaves with amplitude-phase distribution of a field complex-connected to the required diagram of an orientation of the aerial, the radiation of bunches quasiflat of waves is carried out from a surface of sphere, the size of which radius corresponds to a distant zone of the projected aerial, the record of the radiohologram is carried out by an electrical way, and the radiohologram make as the binary radiohologram. Besides record of the hologram carried out on a surface or near to object intended for accommodation of the radioholographic aerial, in area interfere of a subject radiowave with the part, reflected from object, of a subject radiowave and basic at the combined phase centres of subject and basic radiowaves.
The achievement of the basic technical result is provided with that in flat radioholographic aerial containing the radiohologram, including the metal conductors, which are executed in the form of concentric located arches of circles and placed on one side of flat dielectric substrate with a step to multiple wave length. The irradiator, established by the phase centre at the centre of concentric arches of conductors, the radioholographic aerial in addition contains the flat metal screen located on free side from conductors dielectric substrate, with an opportunity of contact with waveguide path of irradiator. As conductors use metal strips, and the average radiuses of concentric arches metal strips or cracks, dividing them, executed in the form of concentric arches of circles, are increased from the centre of concentric arches of circles of conductors with a step equal λ the thickness of dielectric substrate does not exceed
. Where ε - dielectric permeability of a substrate material, and λ, - working length of wave of irradiator, thus at end faces of the radiohologram directly contiguous to waveguide, are placed with an opportunity of contact with the metal screen and ends metal strips additional metal strips or metal layers ensuring reception of the resonator, closed on perimeter. Besides the achievement of the basic and additional technical result is provided with that in each of realizing the binary radiohologram metal strips, arch, having strict radius, of a circle to a multiple integer of working lengths of waves. Between the ends of metal strips and with deviation from them the crack having the form of an arch of a circle, is executed and average radius of an arch of a crack is equal to average radius of an arch metal strip. The achievement basic and additional technical results is provided also with that width H by each of archtype cracks, average radius of which arch is multiple to an integer of working lengths of waves and executed or in metal strip, or between metal strips there corresponds to expression 0,05λ < H < 0,07λ, where λ - working wave length of irradiator.
[0012] According to the invention it is offered a universal way of manufacturing of the radioholographic aerial allowing to expand a class of created aerials with the given diagrams of an orientation, to increase accuracy of reproduction of the required diagram of an orientation.
The essence of an offered way is, that:
1. At record of the radiohologram the subject wave formed as a result of a superposition
of bunches quasiflat waves with spatial structure is used which reproduces a field
complex-connected to a field of the required orientation diagram of the projected
aerial.
Physically as a subject wave the field is used, which analytical representation looks
like
where F (r) required complexmean vector diagram of an orientation of the future aerial.
The radiation of quasiflat waves bunches of a subject radiowave is carried out from
a surface of sphere with radius appropriate to a distant zone of the projected radioholographic
aerial.
In an offered way it is supposed of an orientation, known only the diagram, which
should have the radioholographic aerial. The required diagram of an orientation is
set in this case as vector complexmean function of spherical coordinates (r,θ,ϕ). At such method of formation of a subject wave the universality of a choice
anyone of the beforehand given diagram of an orientation is provided according to
the tactikal-technical requirements to the aerial of this or that radio engineering
system. The practical realization of a subject wave at all is not connected to presence
of the aerial having desirable diagram of an orientation.
The ways of technical realization of such subject field are known. For these purposes
in a declared way the known devices (simulators) are used which provide formation
beams of quasiflat waves appropriate to the required diagram of an orientation [7-8].
2. The record of the radiohologram is carried out with the help of subject and basic radiowaves in any place of a near zone of the projected aerial. Thus the field of a basic radiowave is necessary for forming by such irradiator (radiator), which subsequently is used in quality irradiator of the radiohologram. The geometrical arrangement radiator of a basic wave at record of the radiohologram should correspond to its given coordinates in the radioholographic aerial. In result interfere of basic and subject radiowaves in a near zone of the aerial the holographic relief is formed.
3. The registration one or several radioholographic reliefs in a plane of the hologram is carried out by an electrical way - way of sounding. The registration (record) provides by an electrical way necessary accuracy of measurement of amplitude-phase distribution of a field, both in free space, and at registration of amplitude-phase distribution on a surface of object or near to a surface of this object, on which form the radioholographic aerial. Thus the electrical way of registration allows to use not only for construction of radioholographic aerials of a MICROWAVE of a range, but also for other ranges of radiowaves or wave processes of any physical nature. The electrical methods of registration are widely used at record of the radioholograms (see, for example, [1,9]).
4. The registered radioholographic relief is displayed on metallize surface dielectrical layer as the binary peak hologram by photolitographic, photoseal or as the phase radiohologram (binary or multigradation) by the appropriate modulation of a phase radiotransparent dielectrical. Made by such way amplitude and phase radioholograms serve as radioholographic aerials having the required diagram of an orientation.
[0013] Use of an offered way of construction of a MICROWAVE holographic aerials, allows to create such radiating system, which provides a field of radiation with the required diagram of an orientation. Due to this way technology of manufacturing of radioholographic aerials essentially becomes simpler and becomes more universal at the expense of exception operations of experimental selection and manufacturing of headers, masks, screens, and operations connected to scaling in an optical range, imitation of required amplitude-phase distribution in a near field, absence of operations connected with scaling and increasing of the optical holograms at carry them on a MICROWAVE range.
[0014] The offered way allows essentially to expand a class of created radioholographic aerials:
1. Allows to make any aerial of a radioholographic type, for which it is not obviously possible to make analytical account of the radiohologram;
2. It is possible to make the aerial having the required diagram of an orientation and not having not holographic analogue, That its their practical realization by other ways is impossible;
3. The given way allows to form as sharp-orientation, so weak-orientation diagram;
4. Applying the same technology, the way enables to form the various radioholograms on any other businesses required D. O., applying same irradiator to receive aerials with the essentially different required characteristics;
5. The way allows to make the radioholographic aerial containing in single radiator or group diverse radiator, but in aggregate ensuring reception given D.O.
6. The way allows to create a new class of radioholographic aerials such as "object - hologram" with given D.O. In last case the record of the radiohologram is carried out in a near zone of system " object - basic irradiator (radiator) ", understood as a near zone of the projected aerial, thus formation and registration of a radioholographic relief carry out in counter beams of a subject wave and part of a subject wave reflected from object, and wave basic irradiator (radiator). It phase centre is combined with the phase centre of a subject wave, and the registration of a radioholographic relief is made on a surface or near to object in area difraction subject and reflected of waves.
[0015] The offered variant of a way of construction of the radioholographic aerial, which is intended for accommodation on object, consists in the following:
1. A subject radiowave form by a superposition beams of quasiflat waves with amplitude-phase distribution of a field complex-connected to the required diagram of an orientation. The radiation of beams of quasiflat waves is made from a surface of sphere, the size of which radius corresponds to a distant zone concerning the created aerial in system " object - basic irradiator (radiator)". Last is rather essential for weak-orientation aerials placed on objects.
2. The object, intended for accommodation of the aerial, have near to the centre of sphere so that the phase centre of a beam of quasiflat waves got inside of object and was combined with the phase centre of irradiator (radiator), which is intended for an irradiation of the radiohologram-shaper required D. O.
3. The formation of a radioholographic relief is made by an irradiation from a surface of sphere of object by a subject wave and it interfere with a wave reflected from object and wave of basic radiator. Thus, the formation of a holographic relief is carried out in view of all electrodynamic features of object and system of excitation of a basic wave.
4. Formed from interfere falling and reflected from object part of a subject wave and the waves basic irradiator (radiator), radioholographic relief register close or on a surface of object by sounding or other method.
5. The registered radioholographic relief by a method, for example, photolithographic
is displayed on sheet metallize surface of object as binary peak or phase radiohologram
by modulation of thickness of a layer radiotransparent dielectric.
The binary peak and phase radioholograms made on described variant of a way, have
property to form the required diagram of an orientation at an irradiation by radiowave,
therefore can serve as radioholographic aerials placed on the object - carrier of
the aerial. The opportunity of reproduction of a subject wave with the undistorted
diagram of an orientation follows from conditions of realization of holographic process,
as at a stage of restoration of a field under the radiohologram there is a transformation
of wave front of a wave, irradiating the radiohologram wave to a wave with front appropriate
required D.O.
The efficiency of offered variant of a way consists, for example, in an opportunity
of creation of not acting aerials, that is such aerials, the geometrical surface apperture
which coincides (combined) with the geometrical form of a surface of object, for example,
flush flat radioholographic aerials.
On a figure 1 the block diagram of the device for record of the radioholograms is
given according to a declared way. On a figure 2 the diagram of an orientation of
megaphone-type irradiator, used for formation of a basic radiowave is represented
at construction of the radioholographic aerial having weak-orientation D.O. in width
120 degrees in a horizontal plane. On a figure 3 the results of experimental measurements
(record) and account of the radiohologram in a near zone of the projected aerial with
irradiator as sector megaphone by the size in five lengths of waves -160 mm (frequency
9375 MHz) in a plane H and in a plane E in height 10 mm are submitted., brazed in
the metal screen. The accounts and measurements of the radiohologram are executed
in a plane XY of a perpendicular plane of the screen and parallel axis of megaphone-type
irradiator at given sector plane H to the diagram of an orientation of width in 120°.
The figures 4,5,6,7 illustrate changes of intensity of a field in areas interfere
electrical maximum of a making field registered on a figure 3, depending on angular
coordinate appropriate to radiuses with kρ1= 3,14 (fig. 4), kρ2= 6,91 (fig.5), kρ3= 8,16 (fig.6), kρ4=11 (fig. 7), accordingly, and also principle of a choice of angular width of metal
plates, accordingly, Δϕ1, Δϕ2,Δϕ3,Δϕ4, used for manufacturing the binary radiohologram. On a figure 8 the breadboard model
of the radioholographic aerial such as "object - radiohologram" constructed according
to a declared way is represented. As object the metal plane with brazed in it by a
megaphone is used which is simultaneously basic irradiator. Raising cogerent system
the megaphone brazed in the screen and group of radiators, simulating the required
diagram (realizing an irradiating bunch of quasiflat radiowaves from sectors in 120°),
in a zone in front of the screen is fixed the radiohologram, the binary radiohologram
is made, as provides realization of an offered way. On a figure 9 the real experimentally
measured diagram of an orientation of the mentioned breadboard model of the radioholographic
aerial such as " a megaphone brazed in the metal screen - radiohologram " is represented.
On a figure 10 the orientation diagram of the mentioned breadboard model constructed
radioholographic aerrial is represented.
[0016] The figure 11 illustrates a mutual arrangement basic and subject irradiators at record radiohologram for construction of the flat radioholographic aerial with sharp-orientation diagram according to a declared way.
[0017] On figures 12-14 the flat radioholographic aerial constructed according to a declared way is represented: fig. 12 - top view, fig.13 - side view in a cut on an axis of irradiator (is increased); fig. 14 - side view A. On a figure 15 the diagram of an orientation of the aerial is given.
[0018] On figures 16-17 the variant of performance of the flat radioholographic aerial ensuring radiation and reception of radiowaves with circular polarization is represented: fig. 16 - top view; fig. 17 - side view, in a cut on an axis of irradiator (is increased). On a figure 18 the orientation diagram of the mentioned variant of the aerial is given. On figures 19-22 the variant of performance of the flat radioholographic aerial as the flat radioholographic aerial of a slot-hole type is represented: fig. 19 - top view; fig. 20 - side view in a cut on an axis of irradiator (is increased). On a figure 21 view B (is increased). On a figure 22-variant of performance of the device, in which the continuous crack is replaced by set of resonant cracks.
[0019] According to a declared way, formation of a subject wave appropriate required diagram of an orientation, and record radiohologram carry out with the help of the device, which block diagram is given on a figure 1. The device contains of radiator 1, placed on a spherical surface 2 with radius appropriate to a distant zone of the projected aerial, basic irradiator (radiator) 3, established in the centre of a spherical surface O.4 - shaper of radiator signals, which each output is connected to the help waveguide with one of radiators 1,3, measuring probe 5, having an opportunity of moving in a near zone of the projected aerial, with the help of unit of moving 6 probes, generator of a MICROWAVE 7. One of which outputs is connected to the first input of the shaper of signals 4 of irradiators, block of registration and management 8, the first and second inputs/outputs which are connected, accordingly, to an input/output of the generator of a MICROWAVE 7 and unit of moving 6. The input is connected to an output of a measuring probe 5, and output with the second input of the shaper of signals 4. The position 9 marks object, on which the projected aerial can be placed (is marked by a dotted line).
The radiators 1,3, probe 5, unit of moving 6 are placed in without-ehso chamber 10. The shaper of signals consists from circulator, coordinated loadings controlled phase shifters controlled jet dividers and switchboards. The shaper of signals 4 provides formation on an input of each of radiators 1 of MICROWAVE signal with amplitude and phase appropriate to given data. The block of registration and management is realized on the basis of the electronic computer connected with amplitude-phase-meter and supplied means for display of the information.
[0020] Formation of a subject radiowave and record of the radioholograms according to a declared way are carried out as follows.
[0021] Under the program entered into the block 8, the shaper of signals 4 establishes the given data of amplitudes and phases on inputs of radiators 1, field, appropriate to amplitude-phase distribution, complex-conjugate required diagram of an orientation of the projected aerial. Given meanings of amplitude and phase basic irradiator (radiators) 3 with the help of switchings, divisions and changes of phases of a MICROWAVE signal which has acted from the generator 7. Each of radiators forms quasiflat radiowave directed to the centre O sphere 2. Thus the arrangement radiators 1 on sphere 2 allows to generate from quasiflat waves beams displaying primary directions of radiation of the required diagram of an orientation. At a simultaneous irradiation by radiators 1 from near zone of radiator 3, the amplitude-phase distribution of a fields complex-connected required D.O. is formed.
[0022] Registration of interfere picture (radioholographic) relief received at an irradiation of a near zone irradiator (radiator) 3 subject and basic radiowaves, carry out with the help of a probe 5, relocatable in a plane of registration with the help of unit of moving 6 under the given program and controlled by the block 8.
[0023] If necessary creations of the radioholographic aerial placed on object, before record of the radiohologram basic irradiator (radiator) 3 have on object so that its phase centre coincided with the centre of sphere O, subject radiowave, being the phase centre. The record of the radiohologram is carried out on a surface or near of object 9. The written down radiohologram make as the physical body - binary peak or phase radiohologram, at which accommodation in a place of record of the radiohologram the probe 5, provides creation of the radioholographic aerial with required D.O.
[0024] Examples of realization of a way.
Example 1. Construction of the radioholographic aerial with required weak-orientation of sector diagram of an orientation having width 120 degrees. In quality of irradiator is used sector-type megaphone, brazed in the metal screen (the kind of a megaphone with the screen and radiohologram is given on a figure 4). The diagram of an orientation of megaphone-type irradiator is submitted on a figure 2. Polarization of radiation is vertical (EZ-polarization). Amplitude-phase distribution of a field in a distant zone appropriate to the required diagram of an orientation, and record of the radiohologram were carried out with the help of the device, which block diagram is given on a figure 1. The subject wave was formed as a beam of quasiflat waves from symmetric, rather normal to apperture of megaphone, sector of width 120 degrees in a horizontal plane, at the given EZ-polarization.
[0025] For formation of a subject radiowave was used 33 radiators. The record of the radioholograms was carried out with the help of a probe, relocatable in a plane XY, perpendicular plane of the metal screen. Working length of a wave basic and subject radiators made 3,2 centimeters (9375 MHz). Mathematically required D.O. was set as
With a field of a basic source, as a first approximation, as a flat wave from a direction ϕ = π. As D.O. F(ϕ) is given on amplitude, it is possible to consider, that it D.O. within the limits of sectors of the task has 'in phase' characteristic, i.e. argF(ϕ) = const. Then the subject field near to a metal plane looks like
Basic field with individual amplitude (field from a megaphone)
Develops (interfere) with a subject field and gives the radiohologram near to a metal surface
[0026] The results of accounts of the radiohologram near to a metal plane are submitted on a figure 3 as continuous isoline (left half). By virtue of symmetry rather normal to the screen, the right half of diffraction picture is not given. On the same figure 3 dotted isolines, radiohologram received by experimental measurements (in polar system of coordinates) is submitted. The difference designed and received as a result of experiment, structures of the radioholograms does not surpass 10 percents. It is explained to that the aperture, in which the radiohologram was measured, has the size (6 lengths of waves, and also limited number of radiators.
[0027] The written down radiohologram was made as binary peak hologram. As D.O. of megaphone-type irradiator (see figure 2) has on capacity width of 40-45 degrees on a level 0,1, the binary radiohologram was displayed in a plane XY in symmetric, rather normal to a plane of the screen, execution. Manufacturing metal scatter, realizing the binary peak radiohologram, carried out, on the basis of estimations of the written down radiohologram; as follows.
[0028] Let's draw half-circles with the centre in the beginning of coordinates of structure of the radiohologram (see figure 3) with radiuses kρ1=3,14; kρ2=6,91; kρ3=8,16; kρ4=11 so that they passed through points of relative maxima, accordingly, level individual, level 0,5, level 0,6 and level 0,4. On figures 4-7 the character of change intensity of diffraction picture is shown graphically depending on a corner, on each of k ρ , and principle of a choice of angular width of each metal plate realizing an element of the peak radiohologram. The angular sizes of arches with various radiuses chose on a level 0,4 intensities of the radiohologram. They were accordingly equal degrees 90,29,20,0. Metal scatters were made as plates bent on arches with the angular sizes of arches -90, 29, 20, 0 degrees with radiuses of arches - 3,14 6,91; 8,16; 11, accordingly. And, scatter with the angular sizes 0 is carried out as thin metal cores with radiuses much less than length of a wave. The task of reception required D.O. was considered only in a horizontal plane with angular dependence on ϕ, at meaning θ =
. Metal scatters established before aperture of sector-type megaphone, which width made 160 mm, and distance from flange of waveguide in throat of a megaphone up to it apperture was equaled 140 mm. On a figure 8 the design of the constructed radioholographic aerial is given.
[0029] The aerial is executed as a basic irradiator-megaphone 3 specified sizes, brazed in the metal screen 11, and metal scatter as plates bent on arches 12 and cores 13, fixed in a near zone of a megaphone 3 in places with above-stated coordinates with the help of dielectrical substrate 14 and dielectrical holders 15 (the part of the holders on a figure is not shown).
[0030] On a figure 9 the orientation diagram of the constructed radioholographic aerial exited on frequency 9375 MHz and measured in without-echo chambers is given. As the accuracy of approximation of the experimental D.0. follows from a figure 9. At removal from the radiohologram metal scatters with radiuses kρ =3,14 and 8,16 there is a disorder D.0. on some petals (see figure 10), i.e. reduction number of diffraction elements of radiohologram less number basic of diffraction maxima, conducts to deterioration of approximation to required D.0.
[0031] The coordination of the aerial with all constructive elements of the radiohologram on frequency 9375 MHz and coordination of a megaphone, brazed in the screen without presence of the radiohologram before it apperture on the same frequency is investigated. The measurements have shown, that CSWC of the megaphone-type aerial, brazed in the screen without the radiohologram, is equal 1,44, and CSWC of the radioholographic aerial on same frequency is equal 1,24. At measurements in a strip of frequencies of waveguide, the coordination of the radioholographic aerial is improved. Achieving meanings 1,05-1,1.
Example 2. Construction of the flat radioholographic aerial with sharp-oriented diagram of an orientation from 2 up to 6 - 12 degrees on a level 0,5, on capacity, with a direction of radiation to a perpendicular plane of the hologram. According to a declared way, for formation of a subject radiowave and record of the radiohologram, the device represented on a figure 1 was used. In quality basic irradiator (radiator) was used waveguide of standard section 10mm on 23mm, which radiates a spherical radiowave established flush with the flat metal screen 11 (see figure 11), having the form of a plate. The subject wave was formed with the help of megaphone-type radiator 1, established by the axis of radiation, lengthways normal to the metal screen. Such megaphone-type radiator sends in the party of the screen a flat electromagnetic wave from sectors equal to the angular sizes, under which its seen from the centre of the metal screen lengthways normal to it, i. e. from 2 up to 12 degrees, depending on distance between a plane of the screen both plane aperture of a megaphone and dimensions of a megaphone.
[0032] At cogerent excitation basic and subject radiators from the generator of a MICROWAVE on frequency 9375 MHz, in area above metal screens arises interfere of cooperating radiowaves. At measurements by a probe of diffraction structure of picture above the screen on the area of a square of 600 mm on 600 mm, structure of the radiohologram as system of maxima and minima having character of arches of circles with the centre in middle aperture of a plane waveguide radiator (irradiator) and with distance between maxima of a field in one length of a wave along radius from the centre aperture waveguide precisely appears that has made 3,2sm. And, height of maxima of a field diffraction plane of the metal screen is within the limits of 0,25 lengths of a wave. Thus, the radiohologram looks like alternating zones of minima and maxima as concentric rings well keeping this structure in angular sector from an axis of waveguide ±45 °. The radiuses of rings of maxima carried out from the phase centre About irradiator (radiator) 3, were increased from it with a step equal to length of a wave. Abundantly clearly, that the similar configuration of the written down radiohologram corresponds to theoretical representations about the form of interfere picture from spherical and flat waves (by virtue of it, written down radiohologram on figures is not given).
[0033] Thus, outside the specified sector, the change of the form of interfere strips dependent on width of the diagram waveguide or a megaphone is observed with which can come to an end of the waveguide, and also from the sizes and form of the screen. Materialising of the hologram as binary structure is most simple technologically. The question of use of zones of maxima or minima is not basic, by virtue of property of any hologram equally to reproduce a field both from a positive, and from a negative of the hologram [1].
[0034] The manufacturing of the binary hologram requires a choice of width of elements simulating structure of the radiohologram, and distance between them. For spatial (volumetric holograms) the approach (see example 1), ensuring overlapping binary structure of angular width interfere of a field from a maximum up to a level 0,4-0,5 on intensity was used. At realization of the radioholograms for flat aerials, width of a binary element got out proceeding from reasons of technological realization it and width of a strip of reproduced frequencies, i. e. from resonant properties.
[0035] The written down radiohologram was made as the peak binary radiohologram placed above the metal screen. Thus radiohologram was carried out or as metal strips (arches or other resonant elements), or as cracks in a metal sheet located above the screen. Also were applied combined structures, when in metal strip the crack was cut in addition, or the slot-hole element looked like a loop etc. In any case, the aerial was under construction by a principle "radiohologram-object-irradiator ", i.e. in view of electrodynamic interaction of all features of the system.
[0036] The following features of manufacturing of the peak binary radiohologram close or on a metal surface are experimentally established:
1. Use of thin metal conductors, for example, metal delays of the circles, bent as arches, and located in the field of maxima intefere strips of the radiohologram, does not provide about sufficient accuracy of reproduction D.O. both on width, and in a strip of frequencies. The best reproduction D.O. is observed at use as metal elements of the binary radiohologram metal strips, circles, bent as arches, and, width of strips gets out of a condition of overlapping of interfere maxima on a level up to 0,5 on capacity. Such constructive decision at the choice of width irradiator provides also expansion of a strip of frequencies, on which the aerial system should work [10].
2. The flat metal screen or other form, when the aerial is placed on object with the complex form of a surface, is a component of the radioholographic aerial, as essentially depends on its spatial configuration structure of the radiohologram. As the metal screen the metal surface of object can be used flat or curve-line, on which then is put dielectrical layer and on this layer the metal strip structure displaying a radioholographic relief settles down. At manufacturing the radioholographic aerial as the separate flat system which has been not connected to object. For example, aerial for satellite TV with the narrow diagram of an orientation of width from 2 up to 7 degrees, as the metal screen the metal layer put on one of the parties of flat dielectrical plate can be used. The structure of the radiohologram is put on the opposite party of this dielectrical plate. It is expedient to make radioholographic aerials of satellite TV, as follows from the above resulted description, from 2-side folied dielectrics, one of metalize of which parties serves the screen, and on opposite metalize side the binary peak radiohologram is carried out by photolithographic way. At realization of the phase binary hologram, it is necessary to modulate discretely dielectrical permeability it dielectric.
[0037] The diagrams of an orientation for satellite systems of communications received at use of various constructive variants of manufacturing of the flat binary radioholograms, are submitted on figures 15,18. As follows from figures 15,18, the good symmetry of the diagrams and sufficient accuracy of reproduction of the form and width required D.O. is achieved.
[0038] Using, at manufacturing the binary radiohologram as elements realizing its structure resonant radiating elements dipole or slot-hole, is possible to received a new class of the flat radioholograms and, accordingly, new class of flat radioholographic aerials of minimal volume with the required diagram of an orientation, having high factor of amplification.
[0039] The designs of flat radioholographic aerials of small volume intended for satellite systems to a radio communication are below given.
[0040] Declared, according to the invention, flat radioholographic aerial (see fig. 12,13,14.) consists from waveguide 3, carrying out function irradiator (radiator) or reception element, and the radioholograms, are contained by the metal screen 16, located in a plane of an internal wide wall of waveguide 3, with an opportunity of contact with last, i.e. (connections) with a wall of waveguide waveguide 3, flat dielectrical substrate 17, connected by one of the side with the screen 16, metal strips 18, located on second, opposite to the screen 16 side of a substrate 17, in a plane parallel to the screen 16, additional strips 19, at end faces of the radiohologram directly contiguous to waveguide 3, and it opposite, contacting on all perimeter with the screen 16 and with waveguide 3, in a place of its connection to system radiohologram-screen, forming resonant cavity having on the one hand the screen 16, with opposite the parties radiohologaphic structure 18, contacting with strips 19, and through them and with the screen. Metal strips 18 have the form of arches located on concentric circles, the average radiuses of arches are increased from the centre of concentric circles O with a step, equal to length of a wave. The centre of a plane aperture of waveguide 1 is combined with the centre O of the concentric circles. If in quality of irradiator of the radiohologram, instead of the open end of the waveguide other is used radiator, its phase centre is combined with the centre O. Thickness of a dielectrical layer is equal
where λ - working length of a wave of system, ε - dielectrical permeability of a material substrate 17.
[0041] Depending on technology of manufacturing of the aerial, instead of metal strips 19 the metal layers put on end faces of dielectrical plate 17 or other shielding metal surfaces can be used.
[0043] At an irradiation of the radiohologram from its end face by an electromagnetic wave from waveguide 3 (irradiator) the spherical radiowave, being distributed along the metal screen 16, raises metal strips 18, which radiate electromagnetic waves perpendicularly planes of the screen. The excitation metal arc strips occurs in phase, as distance up to each of its from the phase centre of radiation is multiple to length of a wave, on which the system functions. Therefore in a direction normal to a plane of radiation of a field in a distant zone develop in phase, i. e. the maximum of a field of radiation of such radioholographic aerial is normal to a surface of the flat radiohologram, than the reception required D.O. is achieved.
[0044] At work in a mode of reception, the flat radiowave, falling normally on a plane of the radiohologram, simultaneously raises all metal strips 18, radiation from which, being distributed along the screen 16 reproduces in aggregate spherical radiowave converging in the centre O of reception plane (a plane of aperture waveguide), i.e. is focused in the centre O metal arc strips 18, getting in waveguide 3. At work in a mode of reception - transfer of electromagnetic waves by the aerial system, the metal screen carries out a role of a mirror, on which the image of structure of the radiohologram removed from its real image on half-waves is formed.
[0045] Such system, the screen (mirror) - hologram, provides unilateral radiation of the radioholographic aerial only in one party from a surface aperture of the aerial and, accordingly, mode of reception with a direction of a signal from a aperture surface in waveguide 3. Due to an arrangement of the screen on distance in a quarter of a wave from a plane of the radiohologram, the reduction of dimensions of the aerial is provided. At use dielectrics with dielectrical permeability ε > 1, filling space between the screen and the radiohologram there are more the depth of the resonator of the radioholographic aerial becomes equal
The arrangement irradiator 3 in an end face of the radiohologram, also promotes reduction of dimensions of the aerial.
[0046] The described variant of a design of the declared holographic aerial provides reception - transfer of radiowaves mainly with linear polarization of radiation. Factor of amplification of such aerial depends on the area it aperture. At the sizes of aperture 20 x 20 lengths of waves width of the main petal D.O. is equal 2,5 degrees. At the sizes of aperture 12 x 12 lengths of waves width of the main petal D.O. is equal 4 degrees.
[0047] The variant of a design of the declared radioholographic aerial ensuring reception radiowaves from elliptic polarization of radiation with reproduction sharp-oriented D.O. is below given, perpendicular plane of the screen (see figures 16,17). The difference of the given variant of the radioholographic aerial from above described consists that inside everyone metal strips 18 between its ends, and with deviation from them, the cracks 21 are executed is equal to average radius of an arch strips 18. The number of cracks 21 is equal to number of strips 18.
[0048] The described variant of a design of the reception aerial works as follows. The flat electromagnetic wave, falling on the aerial, with two orthogonal component (speech goes about the wave, polarized on a circle,) raises a crack (component of a vector E, normal to wide wall of a crack in metal strip). And the component of a vector E, parallel of tangent line to metal strip in a plane of the radiohologram, raises a current in metal strip. As the orthogonal components are moved not only in space, but also in time, in a direction of the reception device 3 the accepted signal is transferred [11].
[0049] Use metal strip, bent on concentric arches and located with backlashes as concentric cracks on flat dielectrical substrate, at others, than above described variants of meanings of width of arches and cracks, allows to make the flat radioholographic aerial of a 'slot-hole'- type of small volume (see fig. 19-21).
[0050] Differences of declared variant of radioholographic aerial from above described consists in the following (see figures 19,20,21). Metal strips 18 do not contain cracks. Narrow cracks of 20 width H = (0,05-0,1)λ between strips 18 has the form of arches located with the centre O, and, the average radiuses of arches of cracks 20 are multiple to working length of a wave and is increased from the centre O with a step equal to length of a wave. In rest, the design of described variant is similar considered above.
[0051] The declared variant of the flat radioholographic aerial of a 'slot-hole' type works as follows.
[0052] In a mode of radiation the spherical electromagnetic wave radiated waveguide 3, transforming in a TEM - wave, extending in the resonator, formed by the metal screen 16, structure of the radiohologram as set metal strips 18 and cracks 20 and additional strips 19. In a mode of transfer the TEM wave raises cracks 20, and the cracks are raised by an electrical component of a field normal to a wide wall of a crack. In a distant zone the radiation from all cracks develops in phase, normal to a surface of the radiohologram. Thus the reception sharp-oriented D.O is provided., normal to aperture of the aerial.
[0053] For reception of large factor of amplification, with enough small sizes of aperture of the radiohologram, perimeter of each of cracks 20 to execute as discrete set of resonant cracks (see fig. 22). is necessary. Each resonant element as a crack has a configuration and sizes ensuring work of this element in a strip of frequencies. The radioholographic aerial with resonant cracks and aperture 8λ x 8λ has factor of amplification 24-28 dB. The work of such radioholographic aerial is similar of the described above radioholographic aerial. Differences in work consists that each crack from set is raised resonantly, that strengthens a total signal of the aerial, increases factor of amplification of the aerial as a whole.
[0054] In described variants of flat radioholographic aerials, as stimulating, irradiating radiohologram element, can be used standard waveguide of a working range of radiowaves for the aerial given system, thus one of wide walls of waveguide is carried out flush with the metal screen; square waveguide, one of which parties is executed flush with the metal screen; coaxial waveguide, strip waveguide and other types of devices ensuring radiation (reception) of electromagnetic waves.
SOURCES OF THE INFORMATION
[0055]
1. G.S. Safronov, A.P. Safronova. Introduction in radioholgraphia. M., " the Soviet radio ". 1973, p. 210-211.
2. Ampere-second. Kluchnikov. Radiooptics and holograms. Mn., "University", 1989, p.154-156.
3. The copyright certificate USSR Nº 358746, HO1Q 3/00, is published 3.11.1972 (prototype).
4. V.N. Levchenko. Satellite TV in your house. St.-Petersburg, "Range" 1998. p.106.
5. The application of Japan Nº 58-38961, HO1Q 19/06, HO1Q 15/02, is published 26.08.83.
6. K.Iizuka, V.Vizusava, S.Urasaki, H.Ushigome. Volume type hologram antennas. IEEE. Trans. Antennas and Propagat., 1975, vol. AP-23, pp. 807-810 (prototypes)
7. The copyright certificate USSR Nº 1184036, HO1Q 17/00, is published 7.10 85.
8. The copyright certificate USSR Nº 1415291, HO1Q17/00, is published 7.08.88.
9. L.D. Bahrah, A.P. Kurochkin. Holograms in microwave engineering. M., " Soviet radio ", 1979, p. 150-160,186,190-192.
10. M.S. Bug, YU..B. Molochkov. Designing of aerial-feeder devices. M., "Energy" .1966. p. 181-227.
11. M.S. Bug, YU..B. Molochkov. Designing lenses, scanning, widerange aerials and feeder devices. M., "Energy" 1973, p. 136-138.
, where ε, - dielectrical permeability of material of dielectrical substrate, λ - working length of waveguide wave, thus at two end faces of the radiohologram directly contiguous to waveguide, are placed with an opportunity of contact with the metal screen and ends metal strips additional metal strips or metal layers.
0,05λ< H < 0,07 λ, where
- λ - working length of wave waveguide.