Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01Q—ANTENNAS, i.e. RADIO AERIALS
  • H01Q1/00—Details of, or arrangements associated with, antennas
  • H01Q1/52—Means for reducing coupling between antennas; Means for reducing coupling between an antenna and another structure
  • H01Q1/528—Means for reducing coupling between antennas; Means for reducing coupling between an antenna and another structure reducing the re-radiation of a support structure
• • E—FIXED CONSTRUCTIONS
  • E04—BUILDING
  • E04H—BUILDINGS OR LIKE STRUCTURES FOR PARTICULAR PURPOSES; SWIMMING OR SPLASH BATHS OR POOLS; MASTS; FENCING; TENTS OR CANOPIES, IN GENERAL
  • E04H12/00—Towers; Masts or poles; Chimney stacks; Water-towers; Methods of erecting such structures
  • E04H12/02—Structures made of specified materials
  • E04H12/08—Structures made of specified materials of metal
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01Q—ANTENNAS, i.e. RADIO AERIALS
  • H01Q1/00—Details of, or arrangements associated with, antennas
  • H01Q1/12—Supports; Mounting means
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01Q—ANTENNAS, i.e. RADIO AERIALS
  • H01Q1/00—Details of, or arrangements associated with, antennas
  • H01Q1/12—Supports; Mounting means
  • H01Q1/1242—Rigid masts specially adapted for supporting an aerial
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01Q—ANTENNAS, i.e. RADIO AERIALS
  • H01Q1/00—Details of, or arrangements associated with, antennas
  • H01Q1/27—Adaptation for use in or on movable bodies
  • H01Q1/34—Adaptation for use in or on ships, submarines, buoys or torpedoes
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01Q—ANTENNAS, i.e. RADIO AERIALS
  • H01Q23/00—Antennas with active circuits or circuit elements integrated within them or attached to them

Definitions

• the invention relates to an antenna arrangement according to the preamble of patent claim 1.
• the antenna comprises a mast section which serves as a UHF antenna and a further mast section which serves as a VHF antenna.
• Such an antenna arrangement is often used in DF antenna systems, such as those used on naval ships.
• a known requirement for such ships is known to be the invisibility of the respective ship to the opposing radar. Since the DF antennas are always located at the top of a ship's mast, they first protrude above the horizon and can thus be easily detected.
• the decisive factor for the detection of an object using radar is the respective monostatic radar backscatter cross section of the respective object.
• the application results in a threat sector to be optimized which corresponds to the angular range of the possible incident radar radiation from the opposing radar.
• the object of the invention is to provide a generic antenna arrangement with an optimized, low monostatic radar backscatter cross section for the threat sector.
• the antenna arrangement according to the invention comprises a mast and antenna elements arranged on the mast, the mast being constructed from a plurality of frustoconical elements and a surface normal of the antenna elements forming an angle l ⁇ l of between 5 ° and 35 ° with the perpendicular to the mast axis z.
• the mast axis z coincides with the symmetrical axis of each frustoconical element.
• the individual frustoconical elements of the mast are advantageously connected to one another alternately on the base surfaces and on the ceiling surfaces.
• the surface areas of the base and ceiling surfaces lying on top of one another are expediently the same in each case.
• the base area is the area perpendicular to the symmetrical axis of the truncated cone, which results from the largest diameter of the truncated cone.
• the ceiling surface accordingly designates that surface of the truncated cone which results from the smallest diameter of the truncated cone.
• the mast therefore essentially consists of several double truncated cones.
• the transitions between the individual truncated cones are expediently carried out homogeneously, i.e. no flanges are used.
• the surface normals on the lateral surfaces of two adjacent, frustoconical mast elements connected to one another on the ceiling surfaces have an angle of less than 90 °. This prevents the two lateral surfaces from serving as an ideal reflector.
• the mast is expediently mounted on a base plate.
• the mast is advantageously applied to the base plate in such a way that a normal is on the top the base plate forms an obtuse angle with a normal to the outer surface of the first frustoconical element applied to the base plate. This ensures that the mast stands securely.
• FIG. 1 schematically shows a mast section of an antenna arrangement according to the prior art
• FIG. 3 shows, for a mast section of an antenna arrangement according to FIG. 1, an exemplary course of the monostatic radar backscatter as a function of the angle Wink and the radar frequency f,
• FIG. 4 for a mast section of an antenna arrangement according to the invention in accordance with FIG. 2 shows an exemplary course of the monostatic radar backscatter as a function of the angle ⁇ and the radar frequency f,
• FIG. 5 shows an exemplary representation of a mast optimized with regard to monostatic radar backscattering
• FIG. 6 shows the course of the monostatic radar backscattering for a cylindrical mast of the exemplary length of 1 m and an exemplary diameter of 125 mm as a function of the angle ⁇ and the radar frequency f.
• FIG. 7 shows the course of the monostatic radar backscattering for a mast of an antenna arrangement according to the invention of the exemplary length of 1 m and an exemplary maximum diameter of 125 mm depending on the angle ⁇ and the radar frequency f.
• 8 shows an exemplary antenna arrangement according to the invention with a mast section for a UHF antenna and a further section for a VHF antenna.
• Fig. 1 shows a section of a known antenna arrangement, such as e.g. is known from [1].
• the arrangement is characterized by an essentially cylindrical mast 1, on which radially symmetrical antenna elements 2 are arranged.
• the antenna elements are expediently designed as dipole elements.
• the mounting (not shown) of the antenna elements 2 on the mast takes place via known measures, e.g. non-conductive connections.
• FIG. 2a schematically shows an exemplary section of an antenna arrangement according to the invention.
• the section comprises two truncated cones 3 which are connected to one another at their base surfaces.
• the two truncated cones thus form a kind of double truncated cone.
• the truncated cones 3 expediently have a concentric through hole (not shown) with a diameter smaller than the smallest diameter of a top surface of a truncated cone. This hole is used for the passage of measuring cables etc. (not shown).
• the truncated cones 3 are connected by means of screw connections (not shown) made inside the truncated cones 3. These screw connections are expediently accessible through the hole for cable routing.
• the 2a shows a plurality of antenna elements 2, which are advantageously arranged on a circular line, the circle lying in a plane perpendicular to the mast axis with a diameter larger than the maximum diameter of a frustoconical element.
• the antenna elements 2 are expediently arranged uniformly on the circular line, the antenna elements 2 being positioned on the circular line at a fixed angle to one another.
• the antenna elements 2 are aligned parallel to the radially spaced lateral surface 4 of the frustoconical element 3.
• the antenna elements 2 are aligned as dipoles D.
• the center of gravity S of a dipole D is expediently in the plane of
• the angle term is additionally defined as the mathematical angle between the direction a of the incident and backscattered radar radiation and the mast axis z. This results in an elevation angle (not shown) of 90 ° - ⁇ .
• 2b shows the definition of the angle ⁇ and the definition of the azimuth angle ⁇ .
• FIGS. 6 and 7 assume that radar radiation is incident on the respective body along the direction a (FIG. 2a) to the mast axis z.
• the angle ⁇ thus indicates the angle of incidence and backscatter of the incident radar radiation in relation to the mast axis z.
• the azimuth angle ⁇ is 0 ° in all diagrams for the sake of simplicity.
• FIG. 3 shows, for a known antenna arrangement according to FIG. 1, an exemplary course of the monostatic radar backscatter as a function of the angle des and the radar frequency f.
• FIG. 4 shows an exemplary course of the monostatic radar backscatter as a function of the angle ⁇ and the radar frequency f for an antenna arrangement according to FIG. 2a according to the invention.
• the monostatic radar backscatter for the antenna arrangement according to the invention has been significantly reduced at the respective radar frequencies in the angular range near the vertical of the mast.
• the monostatic radar backscattering of a mast section of a known antenna arrangement at 2.5 GHz, at an angle ⁇ of 87.5 °, approximately -5 dB (cf. FIG. 3).
• the monostatic radar backscattering at 2.5 GHz at an angle ⁇ of 87.5 ° is approximately -22.5 dB.
• FIG. 7 shows the course of the monostatic radar backscattering for a mast of an antenna arrangement according to the invention, as shown in FIG. 5, with an exemplary length L of 1 m and an exemplary maximum diameter DM of 125 mm depending on the angle ⁇ and Radar frequency f shown.
• 6 shows the course of the monostatic radar backscattering of a cylindrical mast with an exemplary length of 1 m and an exemplary diameter of 125 mm depending on the angle in and the radar frequency f. It is clear from the comparison of FIG. 6 with FIG. 7 that the monostatic radar backscattering for a mast of the antenna arrangement according to the invention was significantly reduced at the respective radar frequencies.
• the monostatic radar backscattering of a mast of a known antenna arrangement at 2.5 GHz is approximately -13 dB at an elevation angle of 87.5 ° (cf. FIG. 3).
• the monostatic radar backscattering at 2.5 GHz at an angle ⁇ of 87.5 ° is approximately -22.5 dB.
• the antenna arrangement according to the invention it is thus possible to reduce the monostatic backscatter in the azimuth range 0 ° ⁇ ⁇ ⁇ 360 ° and in the range 60 ° ⁇ ⁇ 90 °, the latter corresponding to an elevation range of 0 ° to 30 °.
• This antenna arrangement comprises an arrangement for a UHF antenna in an upper section A of the mast 1 and an arrangement for a VHF antenna in a lower section B.
• the antenna elements 2 are in several Planes arranged perpendicular to the mast axis z, which makes it possible to operate individual sections A, B of the antenna arrangement, each with different frequency ranges.
• the antenna arrangement is divided into several sections, each section being assigned to a different frequency range from the UHF and / or VHF range.
• the length of the surface line s1, s2 of a truncated cone-shaped element 3 is advantageously greater than the wavelength of the radar wavelength incident on the antenna arrangement. Furthermore, the circumference of the frustoconical element 3 with the largest diameter DM is larger than the wavelength of the radar wavelength incident on the antenna arrangement. It is possible that the length of the surface line s2 of a frustoconical element 3 differs from the length of the surface line s1 of another frustoconical element 3.
• the antenna elements are advantageously connected to the mast 1 via non-conductive brackets H.
• the antenna elements 2 expediently have a flat surface.
• the antenna elements 2 are expediently aligned parallel to the lateral surface 4 of the frustoconical element 3.
• the mast 1, which is optimized with regard to radar backscattering, serves as a reflector for the antenna elements 2.
• the antenna elements 2 are expediently not aligned parallel to the lateral surface 4 of the frustoconical element 3.
• the antenna elements 2 can expediently be arranged as five-element interferometer antennas.
• the antenna elements 2 can also advantageously be made of be made of a circuit board material, in particular components such as resistors, capacitors or coils being integrated into the antenna elements 2 (not shown). These components serve as damping elements and influence the antenna properties. This can, for example, increase the bandwidth of the antenna. Furthermore, the radiation coupling between the individual antenna elements 2 can thereby be reduced.
• different antenna elements 2 can be used in the upper section A than in the lower section B.
• the surface normal S_E of the antenna elements 2 forms an angle
• the individual frustoconical elements 3 of the mast 1 are advantageously connected to one another alternately on the base surfaces and on the ceiling surfaces, and the base and ceiling surfaces lying on top of one another are in each case identical.
• the mast 1 thus essentially consists of several double truncated cones.
• the transitions between the individual truncated cones are expediently carried out homogeneously, i.e. no flanges are used.
• the surface normals L1, L2 on the lateral surfaces 4 of two adjacent frustoconical mast elements 3 have an angle ⁇ less than 90 °. This prevents the two adjacent lateral surfaces 4 from serving as an ideal reflector.
• the mast 1 is expediently applied to a base plate P.
• the mast 1 is advantageously applied to the base plate P such that a normal L3 on the top of the base plate P with a normal L4 on the lateral surface 4 of the first frustoconical element 3 applied to the base plate P forms an obtuse angle ⁇ .
• the proposed antenna arrangement can be used with transmitting and / or receiving antennas and with direction finding antennas.
• the frequency range in which the antenna arrangement can be operated lies in the HF range between 1.0 MHz and 30 MHz, in the VHF range between 20 MHz and 200 MHz, in the UHF range between 200 MHz and 3000 MHz.
• the antenna arrangement can also be operated at lower or higher frequencies.

Landscapes

• Engineering & Computer Science (AREA)
• Architecture (AREA)
• Civil Engineering (AREA)
• Materials Engineering (AREA)
• Wood Science & Technology (AREA)
• Chemical & Material Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Structural Engineering (AREA)
• Variable-Direction Aerials And Aerial Arrays (AREA)
• Aerials With Secondary Devices (AREA)
• Support Of Aerials (AREA)
• Details Of Aerials (AREA)
• Waveguide Aerials (AREA)

Priority Applications (3)

Applications Claiming Priority (2)

Publications (1)

Family

ID=36658895

Family Applications (1)

Country Status (7)

Cited By (1)

Families Citing this family (1)

Citations (5)

Family Cites Families (3)

• 2005
  • 2005-06-23 DE DE102005029090A patent/DE102005029090A1/de not_active Withdrawn
• 2006
  • 2006-05-09 KR KR1020077028611A patent/KR100983406B1/ko not_active IP Right Cessation
  • 2006-05-09 DE DE502006001851T patent/DE502006001851D1/de active Active
  • 2006-05-09 ES ES06742315T patent/ES2317534T3/es active Active
  • 2006-05-09 WO PCT/DE2006/000793 patent/WO2006136127A1/de active Application Filing
  • 2006-05-09 AT AT06742315T patent/ATE411632T1/de not_active IP Right Cessation
  • 2006-05-09 EP EP06742315A patent/EP1894269B1/de not_active Not-in-force
• 2007
  • 2007-12-06 ZA ZA200710627A patent/ZA200710627B/xx unknown

Patent Citations (5)

Also Published As

Similar Documents

Legal Events