EP2936613B1 - Arrangement and method for electronically tracking rf reflector antennas - Google Patents

Description

The invention relates to a high-frequency reflector antenna, comprising a main reflector, at least one sub-reflector and at least one horn, wherein in the beam path between the main reflector and horn stationary elements for influencing the directional receiving characteristic are present, further comprising a method for electronically tracking such antennas.

For the automatic alignment of high-frequency reflector antennas in the direction of their signal source in the field of radio technology, communication technology and military technology, it is known to track these with the aid of mechanical or opto-electronic gyroscopes the target relative to the antenna or the signal source. However, the compass-based tracking has the disadvantage that the location of the target or the signal source must either be known, or at least be predictable, in order to be able to use the compass information to locate the location of the target or the signal source. In addition to the compass-based target or signal source tracking, it is also known to vary the directional characteristic in the antenna pattern of radio frequency reflector antennas cyclically or in recurrent patterns, and from the correlation of the received signal behavior directional information of the spatially varying in relation to the antenna orientation target or in relation to the antenna orientation Derive locally changing signal source.

In the German Offenlegungsschrift DE 198 48 202 A1 discloses a high-frequency reflector antenna, which in the immediate vicinity of a subreflector has a mechanically encircling, passive element, which deliberately disturbs the directional receiving characteristic in the antenna diagram of the entire antenna system. If a targeted signal source or a targeted target is in the center or in the focus of the antenna arrangement, the disturbance of the circulating element does not lead to a noticeable change in the received signal because the intensity distribution of the received signal in focus has circularly symmetrical properties. But if the target or the signal source is out of focus of the reflector antenna is arranged and thus the antenna assembly has a misalignment, so correlates the signal reception strength of the antenna assembly with the instantaneous position of the rotating interference element. In the brief moment in which the interference element covers the direction of the target or the signal source from the viewpoint of the central horn, the received signal strength decreases and, if the circulating interference element is outside the direction of the signal source, the received signal strength increases again. With a circulating interference element, the reception strength is cyclically varied and mechanical modulation of the reception signal takes place. The use of the mechanical circulating passive interferer results in useful results that can be used for automatic target or signal source tracking. Nevertheless, the constant presence of the circulating interfering element means a constant, not disconnectable signal receiving interference, whereby the receiving power is unnecessarily reduced permanently. For strong signal sources, the deliberately induced disturbance is acceptable. For weaker signals or signals that can easily be disturbed, this type of generation of a tracking signal is less well suited. Since the rotating interference element after the above-mentioned DE 198 48 202 A1 is arranged in the immediate vicinity of the subreflector, the geometric dimensions and thus the disturbing properties of the interfering element must be very carefully selected because in the near and mid-field of the horn of the electrical and magnetic vector of the received signal are no longer perpendicular to each other and the electromagnetic wave properties in this Range of high-frequency reflector antenna only very complex theoretically modelable and therefore are very difficult to predict. In the immediate vicinity of a horn, in general a high-frequency reflector antenna so the interference of a perturbation element is difficult to predict and with very little change in the properties of the perturbation element very large changes in the interference can be caused.

According to the teaching of the German Offenlegungsschrift DE 100 41 996 A1 was the method according to the above-mentioned DE 198 48 202 A1 further trained. Instead of a mechanically rotating interference element, which is constantly in the near field between the horn and subreflector, a selected only for this polarization stationary arrangement of elements was proposed for a preselected polarization of the received signal, which are electronically switchable. For this purpose, according to the teaching of the DE 198 48 202 A1 In the midfield between the main reflector and subreflector, so in the beam path away from the horn, a host of small electronically switchable dipole antennas placed in the beam path. The small dipole antennas can be switched, for example via a PIN diode in resonance condition with the received signal and turned off again. Through a circumferential activation of the electronically switchable dipole antennas so the antenna diagram of the high-frequency reflector antenna is deliberately changed. The circulating, electronically switchable change in the directional characteristic can then be correlated with a synchronous to this internally electronically circulating vector signal with the variation of the received signal strength. From the correlation of the temporally and locally activated interfering elements with the synchronously varying target or received signal strength, as in the mechanically rotating interfering element, directional information can be derived, in which there is a target located outside the focus of the high-frequency reflector antenna or the signal source present. This further developed high-frequency reflector antenna has the advantage that the interfering elements, the electronically switchable dipole antennas, are electronically activated and deactivated. However, the use of this high frequency reflector antenna is reduced to a preselected polarization of a transmission signal. For the reception of a differently polarized signal source, it is therefore necessary to mechanically change the electronically switchable elements between the subreflector and the main reflector and to align them with the new polarization.

A high-frequency reflector antenna, which is used simultaneously for receiving and for transmitting, has differences in the spatial power densities of the high-frequency field between reception and transmission in the near and mid-field range, which differ by up to 120 dB. If only the reception is to be influenced for direction detection, the arrangement according to the teaching of DE 100 41 996 A1 sufficient. However, if the high-frequency reflector antenna is switched simultaneously or alternately in the transmission mode, the electronically switchable interfering elements and / or present in the immediate vicinity of electronic interconnections can also receive the transmission power of the high-frequency reflector antenna in an undesirable manner. Therefore, it is necessary to select the spatial positioning of the electronically switchable interfering elements extremely precisely. Even with minor changes in the spatial position of the electronically switchable interference elements, beispielswese with strong vibration or improper adjustment of the high-frequency reflector antenna, the mispositioned, electronically switchable interfering elements by the high transmission power in the best case, the transmission power undesirably receive the transmission power and feed back into the antenna electronics and destroy the electronics of the high-frequency reflector antenna in the worst case.

As a result, experimental measurements of midfield field characteristics between the main reflector and subreflector of a high frequency reflector antenna provide useable results for sturdy mechanical placement and comparatively low sensitivity of the electronically switchable interferers over increased transmission power at a low level unwanted misalignment. However, the midfield between main reflector and subreflector is inadequate with respect to the placement of electronically switchable interfering elements to accommodate equally electronically switchable interfering elements for different polarizations of the signal source.

In the German Offenlegungsschrift DE 10 2007 007 707 A1 discloses the use of immovably arranged, controllable radiator elements for influencing the directional characteristic of reflector antennas. The radiator elements are arranged in the mid-field region of the horn in the beam path between sub-reflector and main reflector. The possibilities of a direction-dependent influencing of the receiving characteristic of the reflector antenna in the also very sensitive to minor disturbances near field area are greatly limited.

After the apprenticeship of US 4,387,378 A. can be arranged in an antenna with main reflector and horn to influence the directional receiving characteristic rod-like elements with adjustable reactance in the horn. A polarization-specific influence is not possible with these elements.

The object of the invention is to provide a high-frequency reflector antenna with electronically switchable interference elements for the electronic tracking of a target or a signal source that are insensitive to minor misalignment and at the same time to provide a very specific interaction with differently polarized transmitter signal radiation.

The object underlying the invention is achieved in that the elements protrude into the aperture surface of the horn and are thus arranged in the near field region of the horn. Further advantageous embodiments of the invention are specified in the subclaims. A corresponding method for electronically tracking the high-frequency reflector antenna is specified in claims 5 to 9.

According to the invention, it is provided to arrange electronically switchable elements for influencing the direction-dependent receiving characteristic such that they protrude into the free aperture surface of the horn and are thus arranged in the near field region of the horn. According to the invention, it is further provided that the elements for influencing the direction-dependent receiving characteristic are switchable dipole elements, which are arranged to influence the receiving characteristic of elliptically to circularly polarized high-frequency radiation with its dipole axis along a tangent of a helix coaxial to the horn axis, or for influencing the receiving characteristic of linearly polarized high frequency radiation with its dipole axis are arranged alternately parallel to a tangent of a lateral surface of the horn and parallel to the horn axis, or for influencing the reception characteristic of linearly polarized high frequency radiation with its dipole axis alternately aligned parallel to a tangent of a lateral surface of the horn and radially to the horn axis and protrude into the free aperture surface of the horn with only part of their length.

Surprisingly, it has been shown that a direction-dependent influencing of the reception characteristic of the high-frequency reflector antenna is possible, especially in the near-field region which is sensitive to minor disturbances, and in this region even a polarization-specific disturbance of the direction-dependent receiving characteristic is possible.

By choosing the arrangement of switchable electronic dipoles, which are arranged with their dipole axis on a tangent to a horn coaxial helix, whose interaction in the high-frequency reflector antenna with the field of circularly polarized transmitter signal radiation on the one hand so low that destruction or a unwanted feedback of the transmission signal in the electronics for generating a tracking signal and in the receiving electronics coupled thereto Radio frequency reflector antenna excluded or at least suppressible with minor means. On the other hand, the aforementioned interaction is strong enough to directionally influence the received signal of the high-frequency reflector antenna so as to be able to derive the correct direction of a target or signal source that has migrated out of the focus of the high-frequency reflector antenna.

By choosing the arrangement of switchable electronic dipoles, which are arranged with their dipole axis alternately either on a parallel to a tangent to the lateral surface of the horn or parallel to the horn axis, their interaction in the high-frequency reflector antenna with the field of an optionally vertically or horizontally polarized Transmitter signal radiation on the one hand so low that a destruction or unwanted feedback of the transmission signal in the electronics for generating a tracking signal and in the coupled thereto receiving electronics of the high-frequency reflector antenna is excluded or at least suppressible by small means. On the other hand, the aforementioned interaction is strong enough to directionally disturb the received signal of the high-frequency reflector antenna so as to be able to derive the correct direction of a target or signal source that has migrated out of the focus of the high-frequency reflector antenna.

In order to influence the directional receiving characteristic in the antenna pattern, it has proved to be particularly advantageous if the dipole length for the K _u band between 11 mm and 15 mm, preferably about 13 mm and for the K _a band between 6 mm and 10 mm , preferably about 8 mm. In order to switch these short dipole lengths electronically, it has therefore proved to be advantageous if the individual dipoles consist of two short, collinear electrical conductor surfaces which are interconnected by switchable PIN diodes produced in SMD construction. In order to prevent energy from the high-frequency field from being received by conductor tracks arranged in the immediate vicinity of the PIN diode, or derived by these conductor tracks, it is provided in an advantageous embodiment of the invention that the electrical supply lines for the electronic components are perpendicular to the horn axis, ie radially thereto be guided and only significantly outside the free aperture surface of the horn have an axial direction component to provide there electrical connection with other electronic switching elements available, such as resistors, capacitors, coils or trained as geometric figures conductor surfaces, referred to as Stubs form a high frequency wave trap within which unwanted wave energy runs dead and therefore transformed into heat or resistors and capacitors to form a low-pass filter to block the transmission of high-frequency energy in the electronic components of the other electronics.

In order to influence the direction-dependent receiving characteristic targeted, it is provided according to an embodiment of the invention that the elements for influencing the directional receiving characteristic individually and / or in groups can be activated, preferably by a high-frequency electronic switching element on and off or are tuned. So it should be the individual interfering elements either individually and / or in groups activatable or tunable.

If a PIN diode is used to activate a dipole, an activation by turning on the PIN diode is provided. But it is also possible, for example with the aid of tunnel diodes to place a tunable element in the near field region of the horn.

It is known to provide the horn with an attachment for improving the directional characteristic of the entire antenna when transmitting with respect to the radiated power. This article usually has various axial or radial circumferential grooves to the inside, in order to use these as shaft traps. In the wave traps of the essay, stray radiation components are lost to the outside, which would produce radiation maxima outside a prescribed small angular range without the use of the English-language corrugated horn and thus possibly disturb adjacent satellites to the targeted satellite. As such an attachment displaces the aperture surface of the horn by its own length and enlarges the aperture area, it is meant in the sense of the invention that, when using the above-described attachment, the free aperture surface of the attachment occurs instead of the "free aperture surface of the horn".

Fig. 1

eine Ansicht auf eine erfindungsgemäße Hochfrequenz-Reflektorantenne vom Cassegrain- oder Gregory-Typ,

Fig. 2

eine Ausschnittsvergrößerung aus Figur 1 mit Darstellung der Elemente zur Beeinflussung der richtungsabhängigen Empfangscharakteristik,

Fig. 3

eine Seitenansicht der Aperturöffnung des Horns mit darüber angeordneten Elementen zur Beeinflussung der richtungsabhängigen Empfangscharakteristik,

Fig. 4...

eine Draufsicht auf die Hornöffnung mit zwei Gruppen ringförmig angeordneter Elemente zur Beeinflussung der richtungsabhängigen Empfangscharakteristik, darin

Fig. 4.1

für zirkular polarisierte Sendestrahlung, und

Fig. 4.2

für linear polarisierte Sendestrahlung,

Fig. 5...

zwei Skizzen einer relativen Anordnung von Signalquelle und Hochfrequenz-Reflektorantenne mit eingezeichnetem, dreidimensionalen Antennendiagramm, darin

Fig. 5.1

für ein unverändertes Antennendiagramm,

Fig. 5.2

für ein verändertes Antennendiagramm,

Fig. 6

eine Skizze einer Abfolge unterschiedlich aktivierter Elemente zur Beeinflussung der richtungsabhängigen Empfangscharakteristik mit dazu eingezeichneter Signalempfangsstärke und Richtungsinformation am Beispiel für die Elemente, die zirkular polarisierte Sendestrahlung beeinflussen,

Fig. 7

eine Skizze eines Aufsatzes auf dem Horn als Wellenfalle zur Verdeutlichung der freien Aperturfläche, wenn ein solcher Aufsatz verwendet wird.

The invention will be explained in more detail with reference to the following figures. It shows:

Fig. 1

a view of a Cassegrain or Gregory-type high-frequency reflector antenna according to the invention,

Fig. 2

an excerpt from FIG. 1 with representation of the elements for influencing the direction-dependent reception characteristic,

Fig. 3

a side view of the aperture opening of the horn with overlying elements for influencing the directional receiving characteristic,

Fig. 4 ...

a plan view of the horn opening with two groups of annularly arranged elements for influencing the directional receiving characteristic, therein

Fig. 4.1

for circularly polarized transmit radiation, and

Fig. 4.2

for linearly polarized transmission radiation,

Fig. 5 ...

two sketches of a relative arrangement of signal source and high-frequency reflector antenna with drawn, three-dimensional antenna diagram, therein

Fig. 5.1

for an unchanged antenna diagram,

Fig. 5.2

for a modified antenna diagram,

Fig. 6

a sketch of a sequence of differently activated elements for influencing the direction-dependent reception characteristic with signal reception strength and direction information shown on the example of the elements which influence circularly polarized transmission radiation,

Fig. 7

a sketch of an essay on the horn as a wave trap to illustrate the free aperture area when such an essay is used.

In FIG. 1 a generic high-frequency reflector antenna 1 of the Cassegrain or Gregory type is shown, comprising a main reflector 2, a sub-reflector 3 and a horn 4 for converting the directional electromagnetic radiation to be received. In the high-frequency reflector antenna 1 shown here are arranged according to the idea of the invention arranged elements 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7 and 5.8 for influencing the directional receiving characteristic of the high-frequency reflector antenna 1, which in the free aperture surface. 6 protrude into the horn 4 and thus in the near field region 7 of the horn 4 are arranged. The circled area A around the sub-reflector 3 and the horn 4 is shown in the following figure, FIG. 2 , shown enlarged.

In FIG. 2 are located on the edge of the horn 4 a total of eight elements 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7 and 5.8 for influencing the directional receiving characteristic of the high-frequency reflector antenna 1, wherein four of the eight elements 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7 and 5.8, namely a first group G1 consisting of elements 5.1, 5.3, 5.5 and 5.7 and a second group G2, consisting of elements 5.2, 5.4, 5.6 and 5.8 each have a common group of elements for influencing counter-circularly polarized Form radiofrequency radiation. These elements 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7 and 5.8, which are divided into two groups G1 and G2, protrude into the free aperture surface 6 of the horn 4 so far that they just protrude into the near-field region 7, which is very susceptible to interference. In order to exclude the interaction of the elements 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7 and 5.8 in the transmission mode of the high-frequency reflector antenna 1 with the high-frequency field of the transmission radiation, have on the elements 5.1, 5.2, 5.3, 5.4, 5.5, 5.6 , 5.7 and 5.8 existing dipoles 5.1.1, 5.2.1, 5.3.1, 5.4.1, 5.5.1, 5.6.1, 5.7.1 and 5.8.1 a specific length for the frequency of the transmitter to be received, the show at the transmission frequency a significantly lower interaction with the high frequency field of the transmission radiation. Nevertheless, any positioning of metallic conductors in the near field region 7 of the horn 4 of a high-frequency reflector antenna 1 means a disturbance to the prevailing high-frequency field which is difficult or impossible to predict, and which should be avoided if possible. Surprisingly, however, remains an influence on the high-frequency field in the near field region 7 in the transmission mode of the high-frequency reflector antenna 1, but at least the interaction between the elements 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7 and 5.8 and the high-frequency radiation in the near field region 7 so low, that the high power of the high-frequency reflector antenna 1 in the transmission mode is not in a control electronics not shown here 10, which is the horn 4 and the elements 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7 and 5.8 coupled back , The surprising behavior of the elements 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7 and 5.8 is presumably attributed to the fact that the near field 11 of the horn 4 is structured differently during the transmission mode of the high-frequency reflector antenna than in the reception mode of the high-frequency reflector antenna 1. The different structuring of the near field 11 may still be comprehensible since the radiation source 12, which is not shown here for the transmission mode, terminates at the end of the waveguide 13, which is connected to the horn 4 and is not shown here slightly different near field 11 'builds up, as is present in the receiving operation of the high-frequency reflector antenna 1 there. However, the exact structuring of the near field 11 and 11 'is insufficiently possible even with computer-assisted means for the theoretical simulation of the wave properties in the near field 11 and 11' of a Cassegrain or a Gregory antenna.

In order to enable a signal source tracking specific to a circular polarization of the high-frequency radiation, the elements 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7 and 5.8 in the two groups G1, consisting of the here odd-numbered elements 5.1, 5.3, 5.5 and 5.7, and G2 with the just numbered elements 5.2, 5.4, 5.6 and 5.8, arranged so that on these elements 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7 and 5.8 arranged, electronically switchable dipole 5.1.1 , 5.3.1, 5.5.1, 5.7.1 and 5.2.1, 5.4.1, 5.6.1 and 5.8.1 with their dipole axis 15 (FIG. Figure 4.1 ) are arranged tangentially to a coaxial to the horn axis 16 helix 17.

In order to enable a signal source tracking specific to a linear polarization of the high-frequency radiation, the elements 5.1 ', 5.2', 5.3 ', 5.4', 5.5 ', 5.6', 5.7 'and 5.8' in the two groups G1 ', consisting of the here odd numbered elements 5.1 ', 5.3', 5.5 'and 5.7', and G2 'with the just numbered elements 5.2', 5.4 ', 5.6' and 5.8 ', arranged so that on these elements 5.1', 5.2 ' , 5.3 ', 5.5', 5.6 ', 5.7' and 5.8 ', electronically switchable dipole arrangements 5.1.1', 5.3.1 ', 5.5.1', 5.7.1 'and 5.2.1', 5.4. 1 ', 5.6.1' and 5.8.1 'alternately with their dipole axis 15' ( Figure 4.2 ) are arranged once parallel to a tangent 4.2 of the lateral surface 4.1 and once parallel to the horn axis 16.

In FIG. 3 is a side view of the horn 4 together with the sub-reflector 3, here the subreflector of a Cassegrain antenna shown. In FIG. 3 To illustrate the tangentially oriented helix 17, electronically switchable dipole arrangements 5.1.1, 5.3.1, 5.5.1, 5.7.1 and 5.2.1, 5.4.1, 5.6.1 and 5.8.1, an imaginary helix 17 is shown , wherein the slope of the helix 17 does not necessarily correspond to the slope of the electrical, circularly polarized field to be received. At a wavelength of the high frequency field of a few millimeters, this is in FIG. 3 sketched slope clearly too shallow. Rather, the slope corresponds to the imaginary helix 17, on which the switchable dipole arrangements 5.1.1, 5.3.1, 5.5.1, 5.7.1 and 5.2.1, 5.4.1, 5.6.1 and 5.8.1 are tangentially arranged, presumably the orientation of the locally extended electric field in the near field region 7 of the horn 4th

The switchable dipole arrangements mentioned in the introduction are in the two FIGS. 4 , 1 and 4.2 represented by a view of the open horn 4.

It is clear FIG. 4 , 1 to derive that for the circular polarization on the elements 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7 and 5.8 switchable dipole arrangements 5.1.1, 5.3.1, 5.5.1, 5.7.1 and 5.2.1, 5.4.1 , 5.6.1 and 5.8.1, which are aligned with their dipole axis 15 along a tangential direction of a right-handed and a left-handed helix 17 and 17 '. The switchable dipole arrangements 5.1.1, 5.3.1, 5.5.1, 5.7.1 and 5.2.1, 5.4.1, 5.6.1 and 5.8.1 in each case consist of conductor track elements 18 and 18 'applied to a dielectric support coaxially opposed to each other and in the present circuit via an electronic switching element 19, such as a PIN diode, are electrically connected to each other. In the electrically conductive state of the electronic switching element 19, the printed circuit board elements 18 and 18 'together with the conductive electronic switching element 19 a very small dipole antenna, which cause their activation a ramp-like, spatially locally limited impedance change of the near field region 7 over time. If the electronic switching element 19 is brought into a non-conductive state between two printed conductor elements 18 and 18 ', with PIN diodes by switching off a DC voltage across the two printed circuit board elements 18 and 18', the resonance condition is interrupted, but at least the impedance change of the near field region 7 is reduced , which depends inter alia on the length of the electrically conductive dipole. Since the individual dipole arrangement after switching off the electronic switching element 19 is no longer in resonance with the local high-frequency field, but at least slightly changed the impedance of the near field region 7, it absorbs no, but at least less radiation and therefore does not influence or at least to a much lesser extent the electromagnetic high frequency field in the near field region 7. According to the idea of the invention is not necessarily provided, about a part of the received power in the spatial area, by the switchable dipole arrangements 5.1.1, 5.3.1, 5.5.1, 5.7.1 and 5.2.1 , 5.4.1, 5.6.1 and 5.8.1, the total received power is to be taken by electrical discharge, but it is rather idea of the invention to position 7 nodes in the near field area, which the training of im Near field area 7 standing wave changed. This change in the boundary conditions for forming a complex structured near field wave differs significantly from, for example, laterally attached to the horn 4 waveguide with a switchable element for proper short circuit of a preselected, unwanted mode, such as a TEM ₀₀ , TEM ₀₁ or other modes, for selective frequency reception a not short closed fashion.

In order to minimize the interaction of the electrical supply lines 20 for the electronic switching element 19 with the local high frequency field, is provided according to an advantageous embodiment of the invention that these configured as traces supply lines 20 extend radially to the horn axis 16 and only significantly outside the free aperture surface 6 of the horn 4 have a direction parallel to the horn axis 16 directional component. This arrangement of the supply lines 20 prevents electromagnetic radiation in the transmission mode is undesirably fed back into the control electronics 10, not shown here.

FIG. 4 , 2 It can be seen that for the linear polarization on the elements 5.1 ', 5.2', 5.3 ', 5.4', 5.5 ', 5.6', 5.7 'and 5.8' switchable dipole arrangements 5.1.1 ', 5.3.1', 5.5.1 ', 5.7.1' as well as 5.2.1 ', 5.4.1', 5.6.1 'and 5.8.1' which with their dipole axis 15 'alternate with their dipole axis 15' once parallel to a tangent 4.2 of the lateral surface 4.1 and are arranged once parallel to the horn axis 16. The elements 5.1 ', 5.2', 5.3 ', 5.4', 5.5 ', 5.6', 5.7 'and 5.8' act in principle identical to those described for the circular polarization elements 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7 and 5.8, however, their spatial orientation to the spatial orientation of the elements for the circular polarization is changed. Like the elements for circular polarization, the elements 5.1 ', 5.2', 5.3 ', 5.4', 5.5 ', 5.6', 5.7 'and 5.8' for the mutually perpendicular horizontal and vertical polarization are divided into two groups, namely group G1 'consisting from the elements 5.1 ', 5.3', 5.5 ', and 5.7' and group G2 'consisting of the elements 5.2', 5.4 ', 5.6', and 5.8 '. The first group G1 'thus has an element 5.1' and 5.5 ', approximately in the 12:00 position and approximately in the 06:00 position, respectively, with the dipoles 5.1.1' and 5.5.1 'positioned thereon in parallel to the Horn axis 16 is axially aligned. In the approx. 09: 00 position and the approx. 03:00 position, on the other hand, elements 5.3 'and 5.7' are arranged whose dipoles 5.3.1 'and 5.7.1' are aligned parallel to a tangent 4.2 of the lateral surface 4.1 of the horn 4 are.

This first group G1 'exhibits an interaction with a linear polarization, which is vertical in this view, of the wavefront to be moved on the aperture surface 6 of the horn 4. Based on the vertically oriented electrical vector of the vertical polarization, the two dipoles 5.3.1 'and 5.7.1' are correspondingly aligned vertically and the two dipoles 5.1.1 'and 5.5.1' of the elements 5.1 'and 5.5' are aligned axially, in accordance with the spatial phase difference of the high-frequency field in the propagation direction of the wavefront to be moved onto the aperture surface 6. The spatial orientation of the dipoles 5.1.1 'and 5.5.1', namely the axial direction of the horn 4, which is accompanied by the propagation direction of the wave front to be moved to the aperture surface 6, is responsible for the fact that these dipoles are both of horizontally polarized Wave fronts as well as with vertically polarized wavefronts interact. Each group of G1 'and G2' thus has two polarization-specific elements and two polarization-unspecific elements. In order to make the interaction of all dipoles polarization-specific, it is provided that the dipoles extend on the elements 5.1 'and 5.5' in the radial direction and thereby protrude with a small part of the dipole length into the free aperture surface 6 of the horn 4.

The second group G2 'shows an interaction with a horizontal linear polarization in this view of the wave front to be moved on the aperture surface 6 of the horn 4. Based on the horizontally oriented electrical vector of the horizontal polarization, the two dipoles 5.8.1 'and 5.4.1' corresponding to approximately horizontally aligned and the two dipoles 5.2.1 'and 5.6.1' of the elements 5.2 'and 5.6' are axially aligned , corresponding to the spatial phase difference of the high-frequency field in the propagation direction of the wavefront to be moved on the aperture surface 6. The spatial orientation of the dipoles 5.2.1 'and 5.6.1', namely the axial direction of the horn 4, which is accompanied by the propagation direction of the wave front to be moved to the aperture surface 6, is responsible for the fact that these dipoles are both of horizontally polarized Wave fronts as well as with vertically polarized wavefronts interact. In order to make the interaction of all dipoles polarization-specific, it is provided that the dipoles on the elements 5.2 'and 5.6' extend in the radial direction and thereby protrude with a small part of the dipole length into the free aperture surface 6 of the horn 4.

The effect of influencing the receiving characteristic of a high-frequency reflector antenna is in FIG. 5 shown. In FIG. 5 a reflector 30 is shown with a reception lobe 31 projected thereon. Receiving lobe 31 is a three-dimensional graph depicting the spatially dependent antenna gain, as an improvement of the received signal strength compared to an antenna without a reflector as a contiguous area of a plot shown in polar coordinates. Receiving lobe 31 thus has no spatial extent or any kind of spatial structure. Rather, it forms the function of two solid angles, namely azimuth, which corresponds to the earth's surface at mid-latitudes substantially the cardinal direction, and elevation, which corresponds to the earth's surface at average latitudes substantially the angle above the horizon, the above improvement as linear or logarithmic factor. In the direction of the symmetry axis 32 of the reflector 30, the high-frequency reflector antenna has the highest antenna gain. For as strong a signal as possible reception of a signal source, such as a satellite signal sketched here from satellite 33, the symmetry axis 32 is aligned exactly to the position of the targeted satellite 33. This ideal situation is in the left subfigure 5.1 of FIG. 5 shown. Satellites that are due to their age on a so-called in-orbit, a no longer exactly geostationary orbit around the earth with respect to the ideal eclipse angled eclipses with mostly elliptical orbit, describe to the moving observer on the earth's surface an eight-shaped path 34. Um Trace this track 34 with a small high-frequency reflector antenna is provided that the orientation of the high-frequency reflector antenna, for example, a mobile transmission car of a broadcaster or the alignment of a communication antenna of a commercial, passenger or warship, and finally the communication antenna of an aircraft or a rocket always follows the variable, relative position of the satellite 33. For this purpose, the switchable dipole arrangements 5.1.1, 5.3.1, 5.5.1, 5.7.1 and 5.2.1, 5.4.1, 5.6.1 and 5.8.1 are activated in variable patterns, but usually in sequence, and during the Activation is the signal reception strength 41 of the signal source measured. If the signal reception strength 41 becomes significantly weaker in the case of a predetermined transient activation pattern or even stronger because the reception lobe 31 is modified in terms of its structure, this is an indicator for a signal source outside the alignment By the correlation axis of the electronically switchable dipole arrangements 5.1.1, 5.3.1, 5.5.1, 5.7.1 and 5.2.1, 5.4.1, 5.6.1 and 5.8.1 with the Signal reception strength 41, which correlates with the antenna diagram 40, can be derived directional information in which direction the high-frequency reflector antenna 1 can be moved by electromechanical or hydraulic actuators to the symmetry axis 32 of the high-frequency reflector antenna 1, depending on the position of the receiving unit the high-frequency reflector antenna 1 is predetermined by the symmetry axis 32 of the receiving lobe 31, to align again with the symmetry axis 32 of the receiving lobe 31.

In the right subfigure 5.2 of FIG. 5 is shown how the reception lobe 31 'by deliberately changing the spatial reception characteristic has a recess, which is accompanied by a reduction of the received signal strength 41 in this spatial area. In order to display the reception lobe in two dimensions, a two-dimensional, perspective distorted antenna diagram 40 is drawn over the indented reception lobe 31 '.

The variability of the reception lobe 31 with different activation patterns of the electronically switchable dipole arrangements is shown in the next figure, FIG. 6 represented.

In FIG. 6 is a view into the open horn 4 along the axis of symmetry 32 of the receiving lobe 31 'with eight different activation patterns of electronically switchable dipole arrangements 5.1.1, 5.3.1, 5.5.1, 5.7.1 and 5.2.1, 5.4.1, 5.6. 1 and 5.8.1 are shown. In this diagram, a black-filled area of the respectively marked element 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7 and 5.8 means the activation of the respectively on the respective element 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7 and 5.8 Activated dipole 5.1.1, 5.3.1, 5.5.1, 5.7.1 and 5.2.1, 5.4.1, 5.6.1 and 5.8.1. To the sketched opening of the horn 4 with the elements 5.1.1, 5.3.1, 5.5.1, 5.7.1 and 5.2.1, 5.4.1, 5.6.1 and 5.8.1 is the profile of the receiving lobe 31 ', the shown only for the azimuth, two-dimensional antenna pattern 40, as shown in Figure 5.2 from the point of view of the target or the signal source. At the upper left corner in FIG. 6 started, an electronically switchable dipole 5.1.1 is activated on the blackened element 5.1 in 09: 00 position. As a result this is assumed by way of example, the received signal strength 41 in the signal intensity-time diagram 42, which represents signal intensity I compared to the time t, of a signal source which has migrated with respect to this direction, as shown in the nearly circular antenna diagram 40 with a recess in FIG 09: 00 position is shown. In this example, the electronically switchable dipole arrangements 5.1.1, 5.3.1, 5.5.1, 5.7.1 are successively and each other in the switching times t = 1, t = 2, t = 3, t = 4, t = 5 , t = 6, t = 7 and t = 8 are activated overlapping, which correlates with a reduction in the received signal strength 41 of a signal source which has migrated in the respective direction. If a signal source - here by way of example - has migrated in about 11: 00 direction, the received signal strength 41 will be reduced over a cycle at exactly this activation pattern, in this example at t = 2, which is represented by the received signal strength 41 plotted in time. The high-frequency reflector antenna 1 would have to be tracked for tracking so in the approximately 11: 00 direction to the signal reception strength 41 for all activation patterns at t = 1, t = 2, t = 3, t = 4, t = 5, t = 6, t = 7 and t = 8 to unify. It is important to emphasize at this point that the formation of the near field 11 in the high-frequency reflector antenna 1 is changed by the electronically switchable dipoles. Thus, the correlation of the activation pattern at t = 1, t = 2, t = 3, t = 4, t = 5, t = 6, t = 7 and t = 8 with a change in the signal reception strength 41 is dependent on the exact formation of the High frequency wave in the near field 11. The in FIG. 5 , Sub figure 5.2 shown, eingedellte reception lobe 31 'is shown here only by way of example. The actual change in the three-dimensional antenna pattern is far more complex and involves distortion as well as twisting of the lobe shape. To measure the migration of a target or signal source, the in FIG. 6 By way of example, eight patterns shown are activated in sequence, and simultaneously with the activation, the signal intensity 41 is measured. The measurement runs through a cycle of t = 1 over t = 2, t = 3, t = 4, t = 5, t = 6, t = 7 to t = 8 and starts there again with another cycle, which runs identically as at the start at t = 1. This cycle is traversed at a frequency of 10 Hz to 100 Hz, 100 Hz to 1,000 Hz or 1,000 Hz to 1 MHz, and if an attenuation of the signal reception strength is detected, direction information is generated in accordance with the known activation pattern, in which the high frequency Reflector antenna must be tracked. It is not necessary for tracking that the signal disturbance constantly performed becomes. Rather, it is also possible to perform the measurement of the target or signal source drift also intermittently.

Thus, the method according to the invention is characterized by individual or group-wise activation and / or tuning of the elements for influencing the direction-dependent receiving characteristic, correlating at least one signal strength of at least one receiving unit with the activation and / or tuning pattern of the elements for influencing the receiving characteristic and the provision of Control signals for the mechanical change in direction of the high-frequency reflector antenna as a function of the measured correlation. It is provided that the control signals for the mechanical change in direction of the high-frequency reflector antenna from the correlation of a groupwise activation and / or tuning of the elements for influencing the directional receiving characteristic associated change in the signal strength of at least one receiving unit are generated. In this case, the elements for influencing the direction-dependent receiving characteristic with respect to their spatial arrangement point-symmetric, rotating or randomly activated and / or tuned with a constant or randomly variable frequency. The activation pattern sequence is of subordinate importance if the pattern sequence is fast enough, for example 10 Hz to 100 Hz, 100 Hz to 1000 Hz or even 1000 Hz to 1 MHz to ensure uninterrupted reception.

Since the received signal strength 41 can vary greatly and may depend on atmospheric disturbances, unwanted beats with adjacent frequencies or other disturbing influences, it is provided in an embodiment of the invention that the received signal strength 41 is not static with the activation of a specific activation pattern at times t = 1, t = 2, t = 3, t = 4, t = 5, t = 6, t = 7 and t = 8 to correlate, but to let the individual activation patterns with a predetermined frequency in sequence in a loop, so that the in Figure 5.2 shown indentation in the antenna diagram runs in a circle. The thus modulated received signal strength 41 is supplied via a lock-in amplifier of a further stage for phase correlation, said stage for phase correlation, the phase of the activation pattern, which runs circularly correlated with the phase of the signal from the lock-in amplifier. From the phase correlation it is thus also possible to derive a directional information which, in contrast to the static correlation between activation pattern and direction The advantage is that interfering and undesirably suppressed on the radio frequency signal to be received modulated frequencies and direction information can be derived safer.

In order to change the direction of the high-frequency reflector antenna 1, an electromechanical adjusting device may be provided or a hydraulic adjusting device. Finally, for high-precision alignment of the high-frequency reflector antenna 1, a peristaltic piezo motor can also change the position of the degrees of freedom of the alignable high-frequency reflector antenna. In order to prevent mechanical resonance frequencies of the high-frequency reflector antenna 1 with dimensions of 40 cm mirror diameter up to moving high-frequency reflector antennas, such as a moving broadcasting car of a broadcaster, a ship at sea, a moving aircraft or a rocket in flight 3 m mirror diameter and the carrier system are excited, is provided according to an advantageous embodiment of the invention that the activation pattern away from a measured, mechanical resonance frequency or randomly be varied with randomly varying frequency. This ensures that fasteners and support elements are not released by resonant vibrations over the period of use.

In FIG. 7 Finally, an attachment to a horn is shown, a so-called Rillenhornstrahler 50, which serves as a wave trap to avoid unwanted secondary maxima of a directed beam. If a groove horn is used as a wave trap and for better focusing of the transmission beam, then the free aperture surface 51 of the groove horn radiator 50 takes the place of the free aperture surface 6 of the horn 4, for the placement of the elements. <B><i> LIST OF REFERENCES </ i></b> 1 RF reflector antenna 5.5 element 5.5 ' element 2 main reflector 5.5.1 dipole 3 subreflector 5.5.1 ' dipole 4 horn 5.6 element 4.1 lateral surface 5.6 ' element 4.2 tangent 5.6.1 dipole 5.1 element 5.6.1 ' dipole 5.1 ' element 5.7 element 5.1.1 dipole 5.7 ' element 5.1.1 ' dipole 5.7.1 dipole 5.2 element 5.7.1 ' dipole 5.2 ' element 5.8 element 5.2.1 dipole 5.8 ' element 5.2.1 ' dipole 5.8.1 dipole 5.3 element 5.8.1 ' dipole 5.3 ' element 6 aperture 5.3.1 dipole 7 near field 5.3.1 ' dipole 10 control electronics 5.4 element 11 near field 5.4 ' element 11 ' near field 5.4.1 dipole 12 radiation source 5.4.1 ' dipole 13 hollow conductor 15 dipole 33 satellite 15 ' dipole 34 train 16 Horn axis 17 helix 41 Signal reception strength 17 ' helix 42 Signal intensity-time diagram 18 PCB element 18 ' PCB element 50 Grooved horn 19 switching element 51 aperture 30 reflector 31 reception lobe I signal intensity 31 ' reception lobe t Time 32 axis of symmetry

Claims (9)

1. High-frequency reflector antenna (1), including:

   - a main reflector (2),

   - at least one sub-reflector (3) and

   - at least one horn (4), wherein stationary elements (5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7, 5.8) for influencing the direction-dependent reception characteristic are present in the beam path between main reflector (2) and horn (4),

   characterized in that
   the elements (5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7, 5.8) protrude into the free aperture area (6) of the horn (4) and are thus arranged in the near-field area (7) of the horn (4), wherein
   the elements (5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7, 5.8) for influencing the direction-dependent reception characteristic are dipole elements (5.1.1, 5.2.1, 5.3.1, 5.4.1, 5.5.1, 5.6.1, 5.7.1, 5.8.1), which
   are arranged with their dipole axis (15) along a tangent of a helix (17, 17') which extends coaxially to the horn axis (16) in order to influence the direction-dependent reception characteristic of elliptically to circularly polarised high-frequency radiation, or
   are arranged with their dipole axis (15) alternately parallel to a tangent (4.2) of an outer surface (4.1) of the horn (4) and parallel to the horn axis (16) in order to influence the reception characteristic of linearly polarised high-frequency radiation, or
   are aligned with their dipole axis (15) alternately parallel to a tangent (4.2) of an outer surface (4.1) of the horn (4) and radially to the horn axis (16), protruding with only a part of their length into the free aperture area (6) of the horn in order to influence the reception characteristic of linearly polarised high-frequency radiation.
2. High-frequency reflector antenna according to Claim 1,
   characterized in that
   the dipole length of the elements (5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7, 5.8) in the direction of the dipole axis (15) is between 11 mm and 15 mm, more preferably about 13 mm for the K_u-band, and between 6 mm and 10 mm, more preferably about 8 mm for the K_a-band.
3. High-frequency reflector antenna according to either of Claims 1 or 2,
   characterized in that
   the elements (5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7, 5.8) for influencing the direction-dependent reception characteristic can be activated individually and/or in groups, and can be switched on and off or tuned preferably by a high-frequency capable electronic switching element (19).
4. High-frequency reflector antenna according to any one of Claims 1 to 3,
   characterized in that
   at least one control unit (10) is present, which

   a) activates and/or tunes the elements (5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7, 5.8) for influencing the direction-dependent reception characteristic individually and/or in groups, and

   b) correlates at least one signal strength (41) of at least one receiving unit with the activation and/or tuning pattern of the elements (5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7, 5.8) for influencing the direction-dependent reception characteristic, and

   c) makes control signals available for a mechanical change in direction of the high-frequency reflector antenna depending on the correlation pattern.
5. Method for electronic tracking of high-frequency reflector antennas (1), including:

   - a main reflector (2),

   - at least one sub-reflector (3) and

   - at least one horn (4), wherein elements (5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7, 5.8) for influencing the direction-dependent reception characteristic are present in the beam path between main reflector (2) and horn (4),

   characterized by

   - arranging the elements (5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7, 5.8) such that they protrude into the free aperture area (6) of the horn (4) and are thus arranged in the near-field area (7) of the horn (4), wherein
   the elements (5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7, 5.8) for influencing the direction-dependent reception characteristic are dipole elements (5.1.1, 5.2.1, 5.3.1, 5.4.1, 5.5.1, 5.6.1, 5.7.1, 5.8.1), which
   are arranged with their dipole axis (15) along a tangent of a helix (17, 17') which extends coaxially to the horn axis (16) in order to influence the direction-dependent reception characteristic of elliptically to circularly polarised high-frequency radiation, or
   are arranged with their dipole axis (15) alternately parallel to a tangent (4.2) of an outer surface (4.1) of the horn (4) and parallel to the horn axis (16) in order to influence the reception characteristic of linearly polarised high-frequency radiation, or
   are aligned with their dipole axis (15) alternately parallel to a tangent (4.2) of an outer surface (4.1) of the horn (4) and radially to the horn axis (16), and protrude with only a part of their length into the free aperture area (6) of the horn in order to influence the reception characteristic of linearly polarised high-frequency radiation,

   - activating and/or tuning the elements (5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7, 5.8) for influencing the direction-dependent reception characteristic individually or in groups,

   - correlating at least one signal strength (41) of at least one receiving unit with the activation and/or tuning pattern of the elements (5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7, 5.8) for influencing the direction-dependent reception characteristic,

   - providing control signals for the mechanical change of direction of the high-frequency reflector antenna depending on the measure correlation.
6. Method according to Claim 5,
   characterized in that
   the control signals for the mechanical change in direction of the high-frequency reflector antenna are generated by at least one receiving unit from the correlation of a change in the reception signal strength (41) associated with the group activation and/or tuning of the elements (5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7, 5.8) for influencing the direction-dependent reception characteristic.
7. Method according to either of Claims 5 or 6,
   characterized in that
   elements (5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7, 5.8) for influencing the direction-dependent reception characteristic are activated and/or tuned symmetrically about a point, rotationally or randomly with constant or randomly variable frequency depending on their spatial arrangement.
8. Method according to Claim 6,
   characterized in that
   the change in the activation and/or tuning pattern is made remotely by a mechanical natural resonance frequency of the high-frequency reflector antenna (1).
9. Method according to any one of Claims 5 to 8,
   characterized in that
   the activation of elements (5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7, 5.8) for influencing the direction-dependent reception characteristic is performed intermittently.

Images