CN102480027A - Offset-feed type satellite television antenna and satellite television receiving system thereof - Google Patents

Abstract

The invention discloses an offset-feed type satellite television antenna, which comprises a metamaterial panel arranged at the rear of a feed source. The metamaterial panel comprises a core layer and a reflection plate arranged on one side surface of the core layer. The core layer comprises at least one core layer sheet layer. The core layer sheet layer comprises a sheet substrate and a plurality of artificial micro-structures arranged on the substrate. Based on a fixed point as a circle centre, the refractive indexes in the same semi-diameter on the core layer sheet layer are same; the refractive index is gradually reduced along with increasing of semi-diameter; a connection line between the circle centre and the feed source is vertical to the core layer sheet layer; and the circle centre is not superposed with the centre of the core layer sheet layer. According to the offset-feed type satellite television antenna disclosed by the invention, the traditional parabolic antenna is replaced by the sheet metamaterial panel; the antenna is easier to manufacture and process and lower in cost; furthermore, the invention also provides a satellite television receiving system with the offset-feed type satellite television antenna.

Description

A kind of offset-feed type satellite tv antenna and satellite television receiving system thereof

Technical field

The present invention relates to the communications field, more particularly, relate to a kind of offset-feed type satellite tv antenna and satellite television receiving system thereof.

Background technology

The satellite earth receiving station that traditional satellite television receiving system is made up of parabolic antenna, feed, tuner, DVB.Parabolic antenna is responsible for satellite-signal is reflexed to feed and the tuner that is positioned at along.Feed is loudspeaker that are used to collect satellite-signal in the along setting of parabolic antenna, claims corrugated horn again.Its major function has two: the one, and the electromagnetic wave signal that antenna is received collects, and is transformed into signal voltage, the supply high frequency head.The 2nd, the electromagnetic wave that receives is carried out polarization conversion.Tuner LNB (also claiming frequency demultiplier) carries out frequency reducing and signal with the satellite-signal that feed is sent here to amplify and be sent to DVB then.Generally can be divided into C-band frequency LNB (3.7GHz-4.2GHz, 18-21V) and Ku audio range frequency LNB (10.7GHz-12.75GHz, 12-14V).The workflow of LNB is exactly to utilize local oscillation circuit that high-frequency signals is converted to intermediate frequency 950MHz-2050MHz again after earlier the satellite high-frequency signals being amplified to hundreds thousand of times, is beneficial to the transmission of coaxial cable and the mediation work of separating of DVB.DVB is that the satellite-signal that tuner transports is carried out demodulation, demodulates satellite television image or digital signal and audio signal.

During receiving satellite signal, parallel electromagnetic wave converges on the feed after reflecting through parabolic antenna.Usually, the feed that parabolic antenna is corresponding is a horn antenna.

But because the Machining of Curved Surface difficulty of the reflecting surface of parabolic antenna is big, required precision is also high, therefore, make trouble, and cost is higher.

Summary of the invention

Technical problem to be solved by this invention is to difficult, the defect of high cost of existing satellite tv antenna processing, a kind of offset-feed type satellite tv antenna simple, low cost of manufacture of processing to be provided.

The technical solution adopted for the present invention to solve the technical problems is: a kind of offset-feed type satellite tv antenna; Said offset-feed type satellite tv antenna comprises the ultra material panel that is arranged on the feed rear; Said ultra material panel comprises core layer and is arranged on the reflecting plate of core layer one side surface; Said core layer comprises at least one core layer lamella, and said core layer lamella comprises the base material of sheet and is arranged on a plurality of artificial micro-structural on the base material, is the center of circle with a fixed point; The refractive index at same radius place is identical on the said core layer lamella; Along with the increase refractive index of radius reduces gradually, the line of this center of circle and feed is perpendicular to the core layer lamella, and this center of circle does not overlap with the center of core layer lamella.

Further, said core layer lamella also comprises the packed layer that covers artificial micro-structural.

Further, said core layer comprises the core layer lamella that a plurality of refraction index profile are identical and be parallel to each other.

Further, said ultra material panel also comprises the matching layer that is arranged on the core layer opposite side, to realize the refractive index match from the air to the core layer.

Further, the refractive index of said core layer lamella is the rounded distribution in the center of circle with its center, and the refractive index n of said core layer lamella (r) distributes and satisfies following formula:

$n\left(r\right)=n_{\max }-\frac{\sqrt{l^2+r^2}-l}{2d};$

Wherein, radius is the refractive index value at r place on n (r) the expression core layer lamella;

L be feed arrive with its near the distance of matching layer, or l is the distance that feed arrives core layer;

D is the thickness of core layer, $d=\frac{\sqrt{l^2+R^2}-l}{2(n_{\mathrm{Max}}-n_{\mathrm{Min}})};$

R representes maximum radius;

n _MaxRefractive index maximum on the expression core layer lamella;

n _MinRefractive index minimum value on the expression core layer lamella.

Further, said matching layer comprises a plurality of matching layer lamellas, and each matching layer lamella has single refractive index, and the refractive index of a plurality of matching layer lamellas of said matching layer all satisfies following formula:

$n\left(i\right)={((n_{\max }+n_{\min })/2)}^{\frac{i}{m}};$

Wherein, m representes total number of plies of matching layer, and i representes the numbering of matching layer lamella, wherein, and near the m that is numbered of the matching layer lamella of core layer.

Further, said each matching layer lamella comprises first substrate and second substrate that material is identical, fills air between said first substrate and second substrate.

Further, the said center of circle is arranged on the lower limb of core layer lamella.

Further, said lower limb is a straight line, and the said center of circle is arranged on the mid point of lower limb.

Further, said lower limb is a curve, and the said center of circle is arranged on the place, summit of lower limb.

Further, a plurality of artificial micro-structural shape of each core layer lamella of said core layer is identical, and a plurality of artificial micro-structural at same radius place has identical physical dimension, and along with the physical dimension of the artificial micro-structural of increase of radius reduces gradually.

According to offset-feed type satellite tv antenna of the present invention, replaced traditional parabolic antenna by the ultra material panel of sheet, to make processing and be more prone to, cost is cheaper.

The present invention also provides a kind of satellite television receiving system, comprises feed, tuner and DVB, and said satellite television receiving system also comprises above-mentioned offset-feed type satellite tv antenna, and said offset-feed type satellite tv antenna is arranged on the rear of feed.

Description of drawings

Fig. 1 is the structural representation of offset-feed type satellite tv antenna of the present invention;

Fig. 2 is the perspective diagram of the ultra material cell of a kind of form of the present invention;

Fig. 3 is the refraction index profile sketch map of square core layer lamella of the present invention;

Fig. 4 is the structural representation of the core layer lamella of a kind of form of the present invention;

Fig. 5 is the structural representation of matching layer of the present invention;

Fig. 6 is the refraction index profile sketch map of semicircular core layer lamella of the present invention;

Fig. 7 is the refraction index profile sketch map of the core layer lamella of circle of the present invention.

Embodiment

Extremely shown in Figure 5 like Fig. 1; The offset-feed type satellite tv antenna comprises the ultra material panel 100 that is arranged on feed 1 rear according to the present invention, and said ultra material panel 100 comprises core layer 10 and be arranged on the reflecting plate 200 on core layer one side surface that said core layer 10 comprises at least one core layer lamella 11; Said core layer lamella comprises the base material 13 of sheet and is arranged on a plurality of artificial micro-structural 12 on the base material 13; With a fixed point is the center of circle, and the refractive index at same radius place is identical on the said core layer lamella, along with the increase refractive index of radius reduces gradually; The line of this center of circle and feed is perpendicular to the core layer lamella; And this center of circle does not overlap with the center of core layer lamella, and promptly feed has been realized the offset-fed of antenna not on the axis of core layer lamella.Feed 1 all has stent support with ultra material panel 100, and among the figure and not shown support, it is not a core of the present invention, adopts traditional supporting way to get final product.Feed is preferably horn antenna in addition.Among the present invention, the said center of circle is arranged on the lower limb of core layer lamella 11, like this, has just avoided the influence of so-called feed shade, at antenna area, and machining accuracy, under the identical prerequisite of receive frequency, the gain that can improve antenna.Core layer lamella 11 among Fig. 2 is square, and the said center of circle is arranged on the lower limb B1 of square core layer lamella, is arranged on or rather on the mid point O1 of lower limb B1.Certainly, core layer lamella 11 also can be other shape, for example the described semicircle of Fig. 6.Fig. 2, Fig. 6 have a common ground, and promptly its lower limb is straight line, and the center of circle is the mid point O1 of straight line lower limb.Certainly, core layer lamella 11 can also be a circle shown in Figure 7; Its lower limb of circle shown in Figure 7 can have been regarded one section circular arc (curve) as, and promptly its lower limb B2 is a curve, and the center of circle is on the summit O2 of curve lower limb B2.The shape of core layer lamella can also have other shape according to different needs.In addition, among the present invention, reflecting plate is the metallic reflection plate with smooth surface, for example can be copper coin, aluminium sheet or the iron plate etc. of polishing.

To shown in Figure 4, said core layer 10 comprises the core layer lamella 11 that a plurality of refraction index profile are identical and be parallel to each other like Fig. 1.A plurality of core layer lamellas 11 fit tightly, each other can be bonding through double faced adhesive tape, and perhaps through fixed connections such as bolts.Adjacent in addition core layer lamella 11 also comprises packed layer 15, and packed layer 15 can air, can be other dielectric-slab also, is preferably the plate-like piece of processing with base material 13 identical materials.The base material 13 of each core layer lamella 11 can be divided into a plurality of identical ultra material cell D; Each ultra material cell D is made up of an artificial micro-structural 12, unit base material V and unit packed layer W, and each core layer lamella 11 has only a ultra material cell D on thickness direction.Each ultra material cell D can be identical square; It can be cube; Also cuboid; The length physical dimension of each ultra material cell D is not more than 1/5th (are generally incident electromagnetic wave wavelength 1/10th) of incident electromagnetic wave wavelength, so that whole core layer has continuous electric field and/or magnetic responsiveness to electromagnetic wave.Under the preferable case, said ultra material cell D is that the length of side is the cube of incident electromagnetic wave wavelength 1/10th.Certainly, the thickness of packed layer can be regulated, and its minimum value can be down to 0; That is to say does not need packed layer, and in such cases, base material and artificial micro-structural are formed ultra material cell; Promptly this moment ultra material cell D the thickness thickness that equals unit base material V add the thickness of artificial micro-structural, but at this moment, the thickness of ultra material cell D also will satisfy the requirement of 1/10th wavelength; Therefore, in fact, be selected under the situation of 1/10th wavelength at the thickness of ultra material cell D; The thickness of unit base material V is big more, and then the thickness of unit packed layer W is more little, under the optimum certainly situation; Promptly be situation as shown in Figure 2, promptly the thickness of unit base material V equals the thickness of unit packed layer W, and the material of first unit base material V and packed layer W's is identical.

Artificial micro-structural 12 of the present invention is preferably metal micro structure, and said metal micro structure is made up of one or more metal wire.Metal wire itself has certain width and thickness.Metal micro structure of the present invention is preferably the metal micro structure with isotropic electromagnetic parameter, like the alabastrine metal micro structure in the described plane of Fig. 2.

For artificial micro-structural with planar structure; Isotropism; Be meant on this two dimensional surface with arbitrary electromagnetic wave of unspecified angle incident, the electric field response of above-mentioned artificial micro-structural on this plane is all identical with magnetic responsiveness, also is that dielectric constant is identical with magnetic permeability; For the artificial micro-structural with three-dimensional structure, isotropism is meant that for incident electromagnetic wave on three-dimensional arbitrary direction, the electric field response of each above-mentioned artificial micro-structural on three dimensions is all identical with magnetic responsiveness.When artificial micro-structural was 90 degree rotational symmetry structures, artificial micro-structural promptly had isotropic characteristic.

For two-dimension plane structure, 90 degree rotation symmetries are meant that it revolves arbitrarily perpendicular to this plane and the rotating shaft of crossing its symmetrical centre around one and turn 90 degrees the back and overlap with original structure on this plane; For three-dimensional structure; If have 3 rotating shafts of vertical in twos and common intersection point (intersection point is a pivot); Make this structure revolve and turn 90 degrees the back and all overlaps perhaps symmetrically with an interface that then this structure is 90 to spend rotational symmetry structures with original structure with original structure around arbitrary rotating shaft.

The alabastrine metal micro structure in plane shown in Figure 2 is a kind of form of isotropic artificial micro-structural; Described alabastrine metal micro structure has first metal wire 121 and second metal wire of vertically dividing equally each other 122; Said first metal wire 121 two ends are connected with two first metal branches 1211 of equal length; Said first metal wire 121 two ends are connected on the mid point of two first metal branches 1211; Said second metal wire 122 two ends are connected with two second metal branches 1221 of equal length, and said second metal wire 122 two ends are connected on the mid point of two second metal branches 1221.

Known refractive index

wherein μ is a relative permeability; ε is a relative dielectric constant, and μ and ε close and be called electromagnetic parameter.Experiment showed, when electromagnetic wave passes through refractive index dielectric material heterogeneous, can be to the big direction deviation of refractive index (to the big ultra material cell deviation of refractive index).Therefore, core layer of the present invention has the effect of converging to electromagnetic wave, and the electromagnetic wave that satellite sends is at first through converging effect the first time of core layer; Through baffle reflection; Again through converging effect the second time of core layer, therefore, the refraction index profile of appropriate design core layer; Can be so that the electromagnetic wave that satellite sends be successively through converging for the first time, after baffle reflection and second converges, can converging on the feed.Under the selected situation of the material of the material of base material and packed layer; The electromagnetic parameter that can obtain ultra material internal through shape, physical dimension and/or artificial micro-structural the arranging on base material of designing artificial micro-structural distributes, thereby designs the refractive index of each ultra material cell.At first calculate the electromagnetic parameter spatial distribution (being the electromagnetic parameter of each ultra material cell) of excess of export material internal from the needed effect of ultra material; Select shape, the physical dimension (having deposited multiple artificial micro-structural data in the computer in advance) of the artificial micro-structural on each ultra material cell according to the spatial distribution of electromagnetic parameter; Design to each ultra material cell can be used the method for exhaustion; For example earlier selected artificial micro-structural with given shape is calculated electromagnetic parameter, the contrast that the result who obtains and we are wanted; Circulation repeatedly; Till the electromagnetic parameter that finds us to want,, then accomplished the parameter choosing of artificial micro-structural if found; If do not find, then change a kind of artificial micro-structural of shape, the circulation above repeating is till the electromagnetic parameter that finds us to want.If still do not find, then said process can not stop yet.That is to say the artificial micro-structural of the electromagnetic parameter that has only found our needs, program just can stop.Because this process is all accomplished by computer, therefore, seem complicated, can accomplish soon in fact.

Among the present invention, the base material of said core layer is made by ceramic material, macromolecular material, ferroelectric material, ferrite material or ferromagnetic material etc.Macromolecular material is available to have polytetrafluoroethylene, epoxy resin, F4B composite material, FR-4 composite material etc.For example, the electrical insulating property of polytetrafluoroethylene is very good, therefore can not produce electromagnetic electric field and disturb, and have excellent chemical stability, corrosion resistance, long service life.

Among the present invention, said metal micro structure is metal wires such as copper cash or silver-colored line.Above-mentioned metal wire can be through etching, plating, brill quarter, photoetching, electronics is carved or ion is carved method attached on the base material.Certainly, also can adopt three-dimensional laser processing technology.

As shown in Figure 1, be the structural representation of the ultra material panel of first embodiment of the invention, in the present embodiment, said ultra material panel also comprises the matching layer 20 that is arranged on the core layer opposite side, to realize from the air to the core layer 10 refractive index match.We know; It is big more that refractive index between the medium differs, and then electromagnetic wave reflects big more when a medium incides another medium; Reflection is big; Mean the loss of energy, at this time just need the coupling of refractive index, known refractive index

wherein μ is a relative permeability; ε is a relative dielectric constant, and μ and ε close and be called electromagnetic parameter.We know that the refractive index of air is 1, therefore, design matching layer like this, and are promptly basic identical near the refractive index and the air of a side of air, basic identical near the core layer lamella refractive index that the refractive index of a side of core layer is joined with it.Like this, just realized the refractive index match from the air to the core layer, reduced reflection, i.e. energy loss can reduce greatly, like this electromagnetic wave can transmit farther.

In the present embodiment, like Fig. 1 and shown in Figure 3, the refractive index refractive index n (r) of said core layer lamella 11 distributes and satisfies following formula:

$n\left(r\right)=n_{\max }-\frac{\sqrt{l^2+r^2}-l}{2d}---\left(1\right);$

Wherein, radius is the refractive index value at r place on n (r) the expression core layer lamella; Also be that radius is the refractive index of the ultra material cell D of r on the core layer lamella; Radius refers to the distance of mid point O1 to the center of circle of each unit base material V here, the mid point of the unit base material V here, refer to unit base material V and center of circle O1 conplane one the surface mid point.

L be feed 1 to its near the distance of matching layer 20;

D is the thickness of core layer, $d=\frac{\sqrt{l^2+R^2}-l}{2(n_{\mathrm{Max}}-n_{\mathrm{Min}})}---\left(2\right);$

R representes maximum radius;

n _MaxRefractive index maximum on the expression core layer lamella 11;

n _MinRefractive index minimum value on the expression core layer lamella 11;

By formula (1), the determined core layer 10 of formula (2), can guarantee that the electromagnetic wave that satellite sends converges to the feed place.This perhaps utilizes optical principle can obtain (promptly utilizing equivalent optical path to calculate) through computer simulation emulation.

In the present embodiment, the thickness of core layer lamella 11 is certain, usually below 1/5th of incident electromagnetic wave wavelength X, and preferably 1/10th of the incident electromagnetic wave wavelength X.Like this, when design, if selected the number of plies of core layer lamella 11, then the thickness d of core layer has just been confirmed, therefore, for the offset-feed type satellite tv antenna (wavelength is different) of different frequency, we know by formula (2), through appropriate design (n _Max-n _Min) value, just can obtain arbitrarily the offset-feed type satellite tv antenna of the frequency that we want.For example, C-band and Ku wave band.The frequency range of C-band is 3400MHz～4200MHz.Frequency 10.7～the 12.75GHz of Ku wave band wherein can be divided into frequency ranges such as 10.7～11.7GHz, 11.7～12.2GHz, 12.2～12.75GHz.

As shown in Figure 1, in the present embodiment, said matching layer 20 comprises a plurality of matching layer lamellas 21, and each matching layer lamella 21 has single refractive index, and the refractive index of a plurality of matching layer lamellas of said matching layer all satisfies following formula:

$n\left(i\right)={((n_{\max }+n_{\min })/2)}^{\frac{i}{m}}---\left(4\right);$

Wherein, m representes total number of plies of matching layer, and i representes the numbering of matching layer lamella, wherein, and near the m that is numbered of the matching layer lamella of core layer.We can find out from formula (4), the largest refractive index n of setting of matching layer (total number of stories m) and core layer _MaxWith minimum refractive index n _MinDirect relation is arranged; When i=1, represent the 1st layer refractive index, because it will equal the refractive index 1 of air basically, therefore, as long as n _MaxWith n _MinConfirm, then can confirm total number of stories m.

Matching layer 20 can be a plurality ofly to be had single refractive index materials and process by what occurring in nature existed; Also with matching layer as shown in Figure 5; It comprises a plurality of matching layer lamellas 21; Each matching layer lamella 21 comprises first substrate 22 and second substrate 23 that material is identical, fills air between said first substrate 21 and second substrate 22.The ratio of the volume through control air and the volume of matching layer lamella 21; Can realize the change of refractive of refractive index from 1 (refractive index of air) to first substrate; Thereby refractive index that can each matching layer lamella of appropriate design realizes the refractive index match from the air to the core layer.

Fig. 4 is a kind of core layer lamella 11 of form; A plurality of artificial micro-structural 12 shapes of each core layer lamella 11 of said core layer are identical; Be the alabastrine metal micro structure in plane; And the central point of metal micro structure overlaps with the mid point of unit base material V, and a plurality of artificial micro-structural at same radius place has identical physical dimension, and along with the physical dimension of the artificial micro-structural 12 of the increase of radius reduces gradually.Reduce and reduce gradually because the refractive index of each ultra material cell is the size along with metal micro structure; Therefore artificial micro-structural physical dimension is big more; Then its corresponding refractive index is big more, therefore, can realize the refraction index profile distribution of (1) by formula of core layer lamella through this mode.

According to different needs (different electromagnetic waves), and different design demand, core layer 10 can comprise the core layer lamella 11 as shown in Figure 4 of the different numbers of plies.

The present invention also has second kind of embodiment, the difference of second embodiment and first embodiment be the l in refractive index n (r) distribution formula of core layer lamella 11 represent feed to the distance of core layer (among first embodiment l represent feed arrive with its near the distance of matching layer).

In addition; The present invention also provides the present invention that a kind of satellite television receiving system also is provided; Comprise feed, tuner and DVB, said satellite television receiving system also comprises above-mentioned offset-feed type satellite tv antenna, and said offset-feed type satellite tv antenna is arranged on the rear of feed.

Feed, tuner and DVB are existing technology, no longer state here.

Combine accompanying drawing that embodiments of the invention are described above; But the present invention is not limited to above-mentioned embodiment, and above-mentioned embodiment only is schematically, rather than restrictive; Those of ordinary skill in the art is under enlightenment of the present invention; Not breaking away under the scope situation that aim of the present invention and claim protect, also can make a lot of forms, these all belong within the protection of the present invention.

Claims (12)

1. an offset-feed type satellite tv antenna is characterized in that, said offset-feed type satellite tv antenna comprises the ultra material panel that is arranged on the feed rear; Said ultra material panel comprises core layer and is arranged on the reflecting plate of core layer one side surface; Said core layer comprises at least one core layer lamella, and said core layer lamella comprises the base material of sheet and is arranged on a plurality of artificial micro-structural on the base material, is the center of circle with a fixed point; The refractive index at same radius place is identical on the said core layer lamella; Along with the increase refractive index of radius reduces gradually, the line of this center of circle and feed is perpendicular to the core layer lamella, and this center of circle does not overlap with the center of core layer lamella.

2. offset-feed type satellite tv antenna according to claim 1 is characterized in that, said core layer lamella also comprises the packed layer that covers artificial micro-structural.

3. offset-feed type satellite tv antenna according to claim 2 is characterized in that, said core layer comprises the core layer lamella that a plurality of refraction index profile are identical and be parallel to each other.

4. offset-feed type satellite tv antenna according to claim 3 is characterized in that, said ultra material panel also comprises the matching layer that is arranged on the core layer opposite side, to realize the refractive index match from the air to the core layer.

5. offset-feed type satellite tv antenna according to claim 4 is characterized in that, the refractive index n of said core layer lamella (r) distributes and satisfies following formula:

$n\left(r\right)=n_{\max }-\frac{\sqrt{l^2+r^2}-l}{2d};$

Wherein, radius is the refractive index value at r place on n (r) the expression core layer lamella;

L be feed arrive with its near the distance of matching layer, or l is the distance that feed arrives core layer;

D is the thickness of core layer, $d=\frac{\sqrt{l^2+R^2}-l}{2(n_{\mathrm{Max}}-n_{\mathrm{Min}})};$

R representes maximum radius;

n _MaxRefractive index maximum on the expression core layer lamella;

n _MinRefractive index minimum value on the expression core layer lamella.

6. offset-feed type satellite tv antenna according to claim 5 is characterized in that, said each matching layer lamella has single refractive index, and the refractive index of a plurality of matching layer lamellas of said matching layer all satisfies following formula:

$n\left(i\right)={((n_{\max }+n_{\min })/2)}^{\frac{i}{m}};$

Wherein, m representes total number of plies of matching layer, and i representes the numbering of matching layer lamella, wherein, and near the m that is numbered of the matching layer lamella of core layer.

7. offset-feed type satellite tv antenna according to claim 6 is characterized in that, said each matching layer lamella comprises first substrate and second substrate that material is identical, fills air between said first substrate and second substrate.

8. offset-feed type satellite tv antenna according to claim 5 is characterized in that the said center of circle is arranged on the lower limb of core layer lamella.

9. offset-feed type satellite tv antenna according to claim 8 is characterized in that, said lower limb is a straight line, and the said center of circle is arranged on the mid point of lower limb.

10. offset-feed type satellite tv antenna according to claim 8 is characterized in that, said lower limb is a curve, and the said center of circle is arranged on the place, summit of lower limb.

11. according to any described offset-feed type satellite tv antenna of claim 2 to 10; It is characterized in that; The a plurality of artificial micro-structural shape of each core layer lamella of said core layer is identical; The a plurality of artificial micro-structural at same radius place has identical physical dimension, and along with the physical dimension of the artificial micro-structural of increase of radius reduces gradually.

12. satellite television receiving system; Comprise feed, tuner and DVB; It is characterized in that said satellite television receiving system comprises that also said offset-feed type satellite tv antenna is arranged on the rear of feed like any described offset-feed type satellite tv antenna of claim 1 to 11.

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