SE544567C2 - An antenna with reduced back-lobe radiation - Google Patents
An antenna with reduced back-lobe radiationInfo
- Publication number
- SE544567C2 SE544567C2 SE1930225A SE1930225A SE544567C2 SE 544567 C2 SE544567 C2 SE 544567C2 SE 1930225 A SE1930225 A SE 1930225A SE 1930225 A SE1930225 A SE 1930225A SE 544567 C2 SE544567 C2 SE 544567C2
- Authority
- SE
- Sweden
- Prior art keywords
- profile sections
- type
- dish antenna
- profile
- antenna
- Prior art date
Links
Classifications
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q19/00—Combinations of primary active antenna elements and units with secondary devices, e.g. with quasi-optical devices, for giving the antenna a desired directional characteristic
- H01Q19/02—Details
- H01Q19/021—Means for reducing undesirable effects
- H01Q19/022—Means for reducing undesirable effects for reducing the edge scattering of reflectors
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q15/00—Devices for reflection, refraction, diffraction or polarisation of waves radiated from an antenna, e.g. quasi-optical devices
- H01Q15/14—Reflecting surfaces; Equivalent structures
- H01Q15/16—Reflecting surfaces; Equivalent structures curved in two dimensions, e.g. paraboloidal
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q17/00—Devices for absorbing waves radiated from an antenna; Combinations of such devices with active antenna elements or systems
- H01Q17/001—Devices for absorbing waves radiated from an antenna; Combinations of such devices with active antenna elements or systems for modifying the directional characteristic of an aerial
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q17/00—Devices for absorbing waves radiated from an antenna; Combinations of such devices with active antenna elements or systems
- H01Q17/008—Devices for absorbing waves radiated from an antenna; Combinations of such devices with active antenna elements or systems with a particular shape
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q19/00—Combinations of primary active antenna elements and units with secondary devices, e.g. with quasi-optical devices, for giving the antenna a desired directional characteristic
- H01Q19/10—Combinations of primary active antenna elements and units with secondary devices, e.g. with quasi-optical devices, for giving the antenna a desired directional characteristic using reflecting surfaces
- H01Q19/12—Combinations of primary active antenna elements and units with secondary devices, e.g. with quasi-optical devices, for giving the antenna a desired directional characteristic using reflecting surfaces wherein the surfaces are concave
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q1/00—Details of, or arrangements associated with, antennas
- H01Q1/42—Housings not intimately mechanically associated with radiating elements, e.g. radome
Abstract
A parabolic dish antenna (100) configured to radiate electromagnetic energy in a main axial direction (D), the dish antenna having a rim portion (110) extending circumferentially around a periphery of the dish antenna (100), wherein the rim portion (110) comprises a plurality of profile sections (120, 130), the profile sections being of at least a first and a second type, wherein a profile section of the first type has a crosssectional shape different from a profile section of the second type, to cause a phase difference of an electromagnetic field propagating past the rim via the profile sections (120, 130), thereby suppressing a back-lobe radiation (B) of the parabolic dish antenna (100).
Description
TITLE AN ANTENNA WITH REDUCED BACK-LOBE RADIATION TECHNICAL FIELD The present disclosure relates to directive antennas, and in particular to parabolic dish antennas.
BACKGROUND Parabolic dish antennas are configured to radiate electromagnetic energy in a forwardaxiai direction. The direction of maximum radiation is often referred to as the main lobedirection of the antenna. The radiation pattern of most antennas is a pattern of lobesat various angles where the radiated signal power reaches a local maximum,separated by nulls at angles where the radiated signal power falls to some small value.A side lobe in the opposite direction from the main lobe, i.e., the reverse axiai direction,is called the back lobe of the antenna. lt is often desired to reduce radiation in directions other than the main lobe direction,since energy radiated in these directions may cause interference to other systems anddecrease antenna efficiency. Also, energy received from directions other than the mainlobe direction may comprise unwanted signals which can interfere with the operationof the antenna system. The relationship between antenna gain in the main axiaidirection and gain in the reverse axiai direction is referred to as the front-to-back ratio.lt is desired to maximize this front-to-back ratio.
US 3,599,219 shows a dual-polarized antenna which employs a polygonal rimsurrounding a round reflector, whereby an increase in front-to back ratio is obtained.
However, there is a continuing need for further improvements of parabolic dish antennas.
SUMMARY lt is an object of the present disclosure to provide an improved parabolic reflector antenna arrangement having a reduced front-to-back ratio. This object is obtained by a parabolic dish antenna configured to radiate electromagnetic energy in a main axialdirection. The dish antenna has a rim portion extending circumferentially around aperiphery of the dish antenna. The rim portion comprises a plurality of profile sections.The profile sections are of at least a first and a second type, wherein a profile sectionof the first type has a cross-sectional shape different from a profile section of thesecond type, to cause a phase difference of an electromagnetic field propagating pastthe rim via the profile sections, thereby suppressing a back-lobe radiation of theparabolic dish antenna.
The object is also obtained by a parabolic dish antenna configured to radiateelectromagnetic energy in a main axial direction. The dish antenna has a rim portionextending circumferentially around a periphery of the dish antenna. The rim portioncomprises a plurality of profile sections. The profile sections are of at least a first anda second type, wherein collection of profile sections of at least the first and the secondtype arranged adjacent to each other around the rim portion is modularly selectable tocause a phase difference of an electromagnetic field propagating past the rim via theprofile sections, thereby suppressing a back-lobe radiation of the parabolic dish antenna.
The object is furthermore obtained by a parabolic dish antenna configured to radiateelectromagnetic energy in a main axial direction. The dish antenna has a rim portionextending circumferentially around a periphery of the dish antenna. The rim portioncomprises a plurality of profile sections. The profile sections are of at least a first anda second type, wherein a profile section of the first type comprises a material having adielectric constant value different from a dielectric constant value of a profile section ofthe second type. A collection of profile sections of at least the first and the second typearranged circumferentially adjacent to each other around the rim portion is selectableto cause a phase difference of an electromagnetic field propagating past the rim viathe profile sections, thereby suppressing a back-lobe radiation of the parabolic dish antenna.
Thus, there is disclosed herein a plurality of different ways in which a rim portion of adisc antenna can be fitted with modular system of profile sections having differentproperties in terms of cross-sectional shape and/or dielectric properties. Anelectromagnetic field propagating past the rim will have different phases depending onif the field propagates past a profile section of the first type or the second type. There may also be further types arranged along the rim portion, i.e., a third type of profilesection and/or a fourth type. When the electromagnetic field components are summedat the back of the disc antenna, the components add destructively due to the phase difference, resulting in a reduced back-lobe radiation from the antenna.
Preferably, the phase relationship between electromagnetic field componentsassociated with the first type of profile sections along the rim portion and associatedwith the second type of profile section is about 180 degrees and the amplitude, power,or energy of the different components is approximately equal.
According to aspects, the first and the second type of profile sections are configuredto extend different distances in the axial direction. By extending different distances inthe axial direction the path lengths for propagating past the first type profile sectionscompared to propagating past the second type profile sections become different,thereby causing a suppressed back-lobe radiation from the antenna. The cross-sectional shapes can be configured such that the phase difference of the differentelectromagnetic components have phase differences greater than 90 degrees to causedestructive interference. Preferably the phase difference is about 180 degrees to cause maximum destructive interference, i.e., cancellation in case of similar amplitudes.
According to aspects, the first and the second type of profile sections are configuredto extend different lengths along the rim portion. By extending different lengths alongthe rim portion the relative percentages of the different electromagnetic fieldcomponents at the back of the antenna can be adjusted. This way the amplituderelationship between different phase components of the electromagnetic field can bemade more even, resulting in improved suppression of the back-lobe radiation.
According to aspects, the first and the second type of profile sections are arrangedalternating around the rim portion. This means that a profile section of the first type isconfigured adjacent to profile sections of the second type. This configuration providesfor an even phase distribution and therefore improved back-lobe radiation suppression.
According to aspects, the profile sections are selected in dependence of a frequencyband of operation associated with the antenna. By configuring the profile sections independence of frequency, the phase relationship between the electromagnetic fieldcomponents at the back of the antenna can be further fine-tuned in order to enable further reductions in back-lobe radiation from the antenna.
According to aspects, adjacent profile sections are arranged to be releasably fastenedto each other by fastening elements. Thus, a modular system is provided which canbe adapted to different types of antennas and to different types of frequency bands.
According to other aspects, adjacent profile sections are arranged to be fastened to each other by an adhesive such as a glue.
According to aspects, the profile sections comprise a groove configured to hold aradome, i.e., a protective enclosure used to protect the antenna from external factorssuch as rain and debris. This way the rim portion also functions as a radome holding means, which is an advantage.
According to aspects, one or more of the profile sections are at least partly hollow. Thisreduces weight of the antenna, which is an advantage.
To summarize, it has been realized that the rim portion of a disc antenna can be fittedwith different profile sections arranged circumferentially to cause a reduction in back-lobe radiation in an efficient manner. The differentiating factor of the different profileshapes may, e.g., be an extension in the axial direction of the different sections. Thedifferentiating factor may also be different types of material having different dielectric properties, and/or different extensions in the radial direction.
A rim portion having alternating profile section shapes around the periphery can bemanufactured in an efficient manner, which is an advantage. The rim portion geometrycan also be adapted to different types of antennas and to different operating frequencybands in a modular manner, which is an advantage. Also, the rim portion providesstructural integrity to the overall antenna design and can be designed for a relativelylow weight-addition to the overall antenna system.
According to aspects, the profile sections are at least partly made in an electrically non-conductive material or in an electromagnetically absorbing material. This is anadvantage since electrically conductive materials are often heavier and may also bemore costly. Electrically non-conductive materials such as plastics, nylon, orpolytetrafluoroethylene (PTFE), can often be accurately molded into shape in a cost- efficient manner.
Optional material for use in the proposed profile sections comprise Polycarbonate(PC), Acrylonitrile Styrene Acrylate (ASA), Acrylonitrile Butadiene Styrene (ABS).
Regarding the material of the alternating profile sections, one material that may beused is a stainless-steel compound plastic referred to as Beki-Shield® (trademarkname), produced by Bekaert Fibre Technologies. This materiel has RF shieldingproperties, i.e. it is non-transmitting. lt cannot be readily classified as beinghomogenous conductive nor being an absorbing material. Generally, all terms used inthe claims are to be interpreted according to their ordinary meaning in the technicalfield, unless explicitly defined otherwise herein. All references to "a/an/the element,apparatus, component, means, step, etc." are to be interpreted openly as referring toat least one instance of the element, apparatus, component, means, step, etc., unlessexplicitly stated otherwise. The steps of any method disclosed herein do not have tobe performed in the exact order disclosed, unless explicitly stated. Further features of,and advantages with, the present invention will become apparent when studying theappended claims and the following description. The skilled person realize that differentfeatures of the present invention may be combined to create embodiments other thanthose described in the following, without departing from the scope of the present invenüon.
BRIEF DESCRIPTION OF THE DRAWINGS The present disclosure will now be described more in detail with reference to the appended drawings, where: Figure 1 schematically shows an antenna arrangement; Figure 2 illustrates an example antenna radiation pattern; Figures 3-5 show example rim profile cross-sectional shapes; and Figure 6 illustrates an example communication system.
DETAILED DESCRIPTION The invention will now be described more fully hereinafter with reference to theaccompanying drawings, in which certain aspects of the invention are shown. Thisinvention may, however, be embodied in many different forms and should not beconstrued as limited to the embodiments and aspects set forth herein; rather, these embodiments are provided by way of example so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in theart. Like numbers refer to like elements throughout the description.
Figures 1a and 1b show different views of a parabolic dish antenna 100 configured toradiate electromagnetic energy in a main axial direction D. The antenna 100 comprisesa feed arrangement (not shown in Figures 1a and 1b) and a parabolic reflector 101.Parabolic dish antennas are known in general and will therefore not be discussed in more detail herein.
The parabolic dish antenna 100 is associated with a radiation pattern diagram. Anexample 200 of such a pattern is illustrated in Figure 2. A main lobe 210 extends in afon/vard axial direction D at zero degrees. This is the direction of communication, i.e.,a far end receiver is often located in this direction. The antenna is not perfect, whichmeans that there are side-lobes 220 extending at angles other than the forward axialdirection D. As is commonly the case with parabolic reflector antennas, there is arelatively strong back-lobe 230 extending in the reverse axial direction B, i.e., indirection opposite to the main lobe direction D. This relatively strong back-lobe appearsdue to symmetry effects associated with the parabolic reflector antenna.
The dish antenna 100 has a rim portion 110 extending circumferentially around aperiphery of the dish antenna 100. Here, the periphery is the extreme point of the dishantenna in a radial direction R perpendicular to the axial direction D. The rim portion110 of the antenna 100 is 'crenelated', i.e., it comprises high profile sectionsinterleaved by low profile sections distributed evenly around the periphery. ln otherwords, the rim portion 110 comprises a plurality of profile sections. The profile sectionsare of at least a first and a second type. A profile section of the first type has a cross-sectional shape different from a profile section of the second type. The difference incross-sectional shapes causes a phase difference of an electromagnetic fieldpropagating past the rim via the different profile sections, thereby suppressing a back-lobe radiation (B) of the parabolic dish antenna.
Some example cross sectional shapes will be described below in connection to Figures3A-3C, 4A-4C, and 5A-5C.
Due to the different profile shapes, the electromagnetic field travelling along a surfaceof the reflector antenna travels further as it propagates or diffracts via the profile sectionof the first type to the back-side of the antenna than it does when it propagates or diffracts via the second type profile sections. Now, if the geometry of the differentsections is configured in dependence of a wavelength of the electromagnetic field, i.e.,in dependence of a wavelength of a frequency band of operation associated with theantenna 100, then two types of field components will be generated. One type of fieldcomponent will have one phase value and the other type of field component will haveanother phase value since the two components will have traveled along differentgeometry paths. ln particular, when the two types of field components are summed atthe back of the antenna 140, the two types of field component will add destructively, orat least not constructively, causing attenuation of the total electromagnetic fieldradiated from the back of the antenna, i.e., effectively reducing the power in the back-lobe. This way the front-to-back ratio of the antenna is increased, which is anadvantage.
The same effect can also be obtained by using profile sections having differentdielectric properties.
Maximum attenuation is of course obtained if two waveforms at the same delay arephase shifted by 180 degrees. lt is also appreciated that, in order to obtain totalcancellation of two waveforms, they need to be of the same amplitude value in additionto being shifted 180 degrees in phase. ln essence, the antenna rim is divided into sections, where each section spans anumber of degrees along the rim of the disc antenna. Profile sections having differentcross-sectional shapes are arranged along the antenna rim in a modular patterncausing phase differences in the electromagnetic field components at the back of theantenna. These phase differences reduce antenna back lobe power.
The example illustrated in Figures 1a and 1b shows 12 sections with a 'high' profile(an example first type), and 12 sections with a 'low' profile (an example second type).lt is not necessary that there is an even number of first and second type profilesections. Also, there can be more than two types of elements, i.e., there may be a thirdtype of element, a fourth type, a fifth type, and so on.
According to an example, the first and the second type profile sections cover 15degrees each of the rim portion 110. However, another division in terms of degreesper profile section can be used to adjust or fine-tune waveform componentrelationships at the back of the antenna. For instance, the profile sections may alternate between being 16 degrees wide and 14 degrees wide. Other divisions arealso possible depending on antenna design. An uneven circumferential length of thedifferent types of profile sections can be used to modify field strength associated withthe different phases at the back of the antenna. lf the circumferential length of a giventype of segment is increased then the relative percentage of electromagnetic fieldcomponents associated with a given phase increases, and vice versa.
The number of antenna sections can be freely varied; more sections provide a finerresolution in terms of design options, but the section dimensions should be kept suchthat the periodicity does not come too close to the operating wavelength of the antenna.lf too few sections are used, i.e., too large sections spanning over large segments ofthe antenna rim, then the location relative to the electric field direction will have animpact which may be undesired.
The profile sections 120, 130 are optionally arranged to be releasably fastened to eachother by fastening elements. This way the rim portion can be assembled from thedifferent profile sections. As will be shown below, the arrangement can also be usedto securely hold a circular shape radome to protect the dish antenna. The profile sections can also be glued together or attached by other methods.
According to some aspects, different types of rim portion sections can be assembledto calibrate the antenna radiation pattern according to some requirement orspecification. Thus, there is provided herein a modular system where a selection ofdifferent type profile sections can be selected from in order to compose a collection ofprofile sections along the rim portion with the required properties. For instance, thecollection can be selected in dependence of a frequency band of operation of theantenna, or in dependence of some external factor such as antenna mounting bracketgeometry of objects in the near field of the antenna.
The profile sections may have different cross-sectional shapes. Some examples ofvarious cross-sectional shapes will now be discussed in connection to Figures 3-5.Some example 'first type' profile sections 310, 320, 330 are exemplified in Figures 3A,3B, and 3C, while some 'second type' profile sections 410, 420, 430 are shown inFigures 4A, 4B, and 4C. lt is noted that the example first type profile shapes extendfurther in the axial direction D compared to the second type profile shapes.
Figures 5A, 5B, and 5C illustrate some example 'third type' profile sections 510, 520,530 which extend further in the axial direction compared to the second type profileshapes 410, 420, but which have a smaller extension in the axial direction D comparedto the first type profile sections 310, 320,lt is appreciated that any selection of the example profile sections in Figures 3-5 canbe combined along the rim portion 110, i.e., some profile sections along the rim portionmay be those shown in Figure 3 or in Figure 4 and some others may be those shownin FigureThe parabolic dish antenna may comprise alternating first and second type profilesections or alternating first and third type profile sections, or alternating second andthird type profile sections, or a mix of different profile sections selected from the first,second, and third types. Other cross-sectional shapes are also possible; the disclosureis not limited to the examples given in Figures 3-5. The profile sections are, accordingto some aspects, designed with fixed cross-sectional shapes, which cross-sectionalshapes alternate in a periodical manner along the rim portion 110 of the disc antenna.
According to aspects, the profile sections 310, 320, 330 comprise an angled portion350 configured angled outwards in a radial direction R of the parabolic dish antennaThe profile sections 310, 330, 530 may be hollow 360 , i.e., may comprise cavities to,e.g., reduce a weight of the rim portion 110. lt has been found that these cavities maybe present while still maintaining the back-lobe suppressing function of the rim portion110. Thus, according to some aspects, one or more of the profile sections 120, 130,500 are at least partly hollowExamples 310, 430, 510 comprise protrusions 370, 440 extending radially outwardsfrom the rim portion. These protrusions 370, 440 have an effect on the diffractiveproperties of the rim portionThe example profile sections 310, 320, 330, 410, 420, 430, 510, 520, 530 comprise anoptional groove configured to hold a radome 340 of the parabolic dish antenna. Thisway the rim portion section not only reduces back-lobe radiation but also providestructural integrity to the antenna and serve as radome mounting means as well. lnother words, the profile sections 120, 130, 500 optionally comprise a groove configuredto hold a radome 340. The radome 340 may for example have a disc shape.
According to some aspects, the profile sections 120, 130, 500 are at least partly madein an electrically non-conductive material or electromagnetically absorbing material.
According to some other aspects, the profile sections 120, 130, 500 are at least partlymade in an electrically conductive material.
Figure 6 illustrates an example communication system 600 comprising at least oneparabolic dish antenna 100 according to the above discussion.
The dielectric properties of the profile sections also affect the phase relationshipbetween the electromagnetic field components associated with propagation past the different type profile sections.
Another alternative or complementary method to reduce the back-lobe radiation of theantenna is to achieve the phase difference of the electromagnetic field over the rim byletting parts of the radiation that contributes to the back-lobe pass through materials with different dielectric properties and hence have an extended optical path length.
To summarize the discussion above, there has been disclosed herein a parabolic dishantenna 100 configured to radiate electromagnetic energy in a main axial direction D,the dish antenna having a rim portion 110 extending circumferentially around aperiphery of the dish antenna 100, wherein the rim portion 110 comprises a plurality ofprofile sections 120, 130, 500, the profile sections being of at least a first and a secondtype, wherein a profile section of the first type has a cross-sectional shape differentfrom a profile section of the second type, to cause a phase difference of anelectromagnetic field propagating past the rim via the profile sections 120, 130, 500,thereby suppressing a back-lobe radiation B of the parabolic dish antennaAccording to aspects, the first and the second type of profile sections 120, 130, 500are configured to extend different distances in the axial direction D.
According to aspects, the first and the second type of profile sections 120, 130,are configured to extend different lengths along the rim portionAccording to aspects, the first and the second type of profile sections are arrangedalternating around the rim portionAccording to aspects, the profile sections are selected in dependence of a frequency band of operation associated with the antenna.According to aspects, the profile sections 120, 130, 500 are at least partly made in anelectrically non-conductive material and/or or electromagnetically absorbing material.
According to aspects, the profile sections 120, 130, 500 are at least partly made in anelectrically conductive material and/or an electromagnetically shielding material.
According to aspects, adjacent profile sections 120, 130, 500 are arranged to bereleasably fastened to each other by fastening elements.
According to aspects, the profile sections 120, 130, 500 comprise a groove configuredto hold a radomeAccording to aspects, one or more of the profile sections 120, 130, 500 are at leastpartly hollowThere was also disclosed a parabolic dish antenna 100 configured to radiateelectromagnetic energy in a main axial direction D, the dish antenna having a rimportion 110 extending circumferentially around a periphery of the dish antenna 100,wherein the rim portion 110 comprises a plurality of profile sections 120, 130, 500, theprofile sections being of at least a first and a second type, wherein a profile section ofthe first type has a cross-sectional shape different from a profile section of the secondtype, wherein a collection of profile sections of at least the first and the second typearranged adjacent to each other around the rim portion 110 is selectable to cause aphase difference of an electromagnetic field propagating past the rim via the profilesections 120, 130, 500, thereby suppressing a back-lobe radiation B of the parabolicdish antennaThere was furthermore disclosed a parabolic dish antenna 100 configured to radiateelectromagnetic energy in a main axial direction D, the dish antenna having a rimportion 110 extending circumferentially around a periphery of the dish antenna 100,wherein the rim portion 110 comprises a plurality of profile sections 120, 130, 500, theprofile sections being of at least a first and a second type, wherein a profile section ofthe first type comprises a material having a dielectric constant value different from adielectric constant value of a profile section of the second type, wherein a collection ofprofile sections of at least the first and the second type arranged circumferentiallyadjacent to each other around the rim portion 110 is selectable to cause a phasedifference of an electromagnetic field propagating past the rim via the profile sections120, 130, 500, thereby suppressing a back-Iobe radiation B of the parabolic dishantenna 100.
Claims (12)
1. A parabolic dish antenna (100) configured to radiate electromagneticenergy in a main axial direction (D), the dish antenna having a rim portion (110)extending circumferentially around a periphery ofthe dish antenna (100), characterizedin that the rim portion (110) comprises a plurality of profile sections (120, 130, 500),the profile sections being of at least a first and a second type, wherein a profile sectionof the first type has a cross-sectional shape different from a profile section of thesecond type, and wherein the first and the second type of profile sections (120, 130,500) are made at least partly in materials having different dielectric constant values, tocause a phase difference of an electromagnetic field propagating past the rim via theprofile sections (120, 130, 500), thereby suppressing a back-lobe radiation (B) of theparabolic dish antenna (100).
2. The parabolic dish antenna (100) according to claim 1, wherein the firstand the second type of profile sections (120, 130, 500) are configured to extenddifferent distances in the axial direction (D).
3. The parabolic dish antenna (100) according to any previous claim, whereinthe first and the second type of profile sections (120, 130, 500) are configured to extenddifferent lengths along the rim portion (110).
4. The parabolic dish antenna (100) according to any previous claim, whereinthe first and the second type of profile sections are arranged alternating around the rimportion (110).
5. The parabolic dish antenna (100) according to any previous claim, whereinthe profile sections arranged circumferentially along the rim portion (110) are selectedin dependence of a frequency band of operation, or a center frequency of operation,associated with the antenna.
6. The parabolic dish antenna (100) according to any previous claim, whereinthe profile sections (120, 130, 500) are at least partly made in an electrically non-conductive material and/or in an electromagnetically absorbing material.
7. The parabolic dish antenna (100) according to any previous claim, whereinthe profile sections (120, 130, 500) are at least partly made in an electrically conductivematerial and/or in an electromagnetically shielding material.
8. The parabolic dish antenna (100) according to any previous claim, whereinadjacent profile sections (120, 130, 500) along the rim portion (110) are arranged tobe releasably fastened to each other by fastening elements.
9. The parabolic dish antenna (100) according to any previous claim, whereinthe profile sections (120, 130, 500) comprise a groove configured to hold a radome(340).
10. The parabolic dish antenna (100) according to any previous claim, whereinone or more of the profile sections (120, 130, 500) are at least partly hollow (360).
11. . The parabolic dish antenna (100) according to any previous claim, wherein the phase difference is larger than 90 degrees, and preferably around 180 degrees.
12. A parabolic dish antenna (100) configured to radiate electromagneticenergy in a main axial direction (D), the dish antenna having a rim portion (110)extending circumferentially around a periphery ofthe dish antenna (100), characterizedin that the rim portion (110) comprises a plurality of profile sections (120, 130, 500),the profile sections being of at least a first and a second type, wherein a profile sectionof the first type comprises a material having a dielectric constant value different from adielectric constant value of a profile section of the second type, wherein a collection ofprofile sections of at least the first and the second type arranged circumferentiallyadjacent to each other around the rim portion (110) is selectable to cause a phasedifference of an electromagnetic field propagating past the rim via the profile sections(120, 130, 500), thereby suppressing a back-lobe radiation (B) of the parabolic dishantenna (100).
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| SE1930225A SE544567C2 (en) | 2019-06-26 | 2019-06-26 | An antenna with reduced back-lobe radiation |
| PCT/EP2020/066421 WO2020260045A1 (en) | 2019-06-26 | 2020-06-15 | An antenna with reduced back-lobe radiation |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| SE1930225A SE544567C2 (en) | 2019-06-26 | 2019-06-26 | An antenna with reduced back-lobe radiation |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| SE1930225A1 SE1930225A1 (en) | 2020-12-27 |
| SE544567C2 true SE544567C2 (en) | 2022-07-19 |
Family
ID=71103370
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| SE1930225A SE544567C2 (en) | 2019-06-26 | 2019-06-26 | An antenna with reduced back-lobe radiation |
Country Status (2)
| Country | Link |
|---|---|
| SE (1) | SE544567C2 (en) |
| WO (1) | WO2020260045A1 (en) |
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| GB1205014A (en) * | 1966-10-04 | 1970-09-09 | Gen Electric & English Elect | Improvements in or relating to directional aerial systems |
| US3599219A (en) * | 1969-01-29 | 1971-08-10 | Andrew Corp | Backlobe reduction in reflector-type antennas |
| JPS5637703A (en) * | 1979-09-04 | 1981-04-11 | Nippon Telegr & Teleph Corp <Ntt> | Reflector antenna |
| WO1999010950A2 (en) * | 1997-08-21 | 1999-03-04 | Kildal Antenna Consulting Ab | Improved reflector antenna with a self-supported feed |
| EP2416449A1 (en) * | 2010-08-02 | 2012-02-08 | Alcatel Lucent | Parabolic-reflector antenna |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3140491A (en) * | 1963-01-24 | 1964-07-07 | Boeing Co | Diffraction shield consisting of notched ring which frames passive reflector |
| US9634373B2 (en) * | 2009-06-04 | 2017-04-25 | Ubiquiti Networks, Inc. | Antenna isolation shrouds and reflectors |
| WO2011099183A1 (en) * | 2010-02-15 | 2011-08-18 | 日本電気株式会社 | Radiowave absorber and parabolic antenna |
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2019
- 2019-06-26 SE SE1930225A patent/SE544567C2/en unknown
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2020
- 2020-06-15 WO PCT/EP2020/066421 patent/WO2020260045A1/en active Application Filing
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1205014A (en) * | 1966-10-04 | 1970-09-09 | Gen Electric & English Elect | Improvements in or relating to directional aerial systems |
| US3599219A (en) * | 1969-01-29 | 1971-08-10 | Andrew Corp | Backlobe reduction in reflector-type antennas |
| JPS5637703A (en) * | 1979-09-04 | 1981-04-11 | Nippon Telegr & Teleph Corp <Ntt> | Reflector antenna |
| WO1999010950A2 (en) * | 1997-08-21 | 1999-03-04 | Kildal Antenna Consulting Ab | Improved reflector antenna with a self-supported feed |
| EP2416449A1 (en) * | 2010-08-02 | 2012-02-08 | Alcatel Lucent | Parabolic-reflector antenna |
Non-Patent Citations (1)
| Title |
|---|
| G. James et al., "Selective reduction in back radiation from paraboloidal reflector antennas" in: IEEE Transactions on Antennas and Propagation, Vol. 21, No. 6, Nov 1973, pp. 886-887, ISSN 0018-926X, DOI: 10.1109/TAP.1973.1140618 * |
Also Published As
| Publication number | Publication date |
|---|---|
| WO2020260045A1 (en) | 2020-12-30 |
| SE1930225A1 (en) | 2020-12-27 |
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