Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01Q—ANTENNAS, i.e. RADIO AERIALS
  • H01Q11/00—Electrically-long antennas having dimensions more than twice the shortest operating wavelength and consisting of conductive active radiating elements
  • H01Q11/02—Non-resonant antennas, e.g. travelling-wave antenna
  • H01Q11/08—Helical antennas
• • 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
  • H01Q19/06—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 refracting or diffracting devices, e.g. lens
• • 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
  • H01Q19/06—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 refracting or diffracting devices, e.g. lens
  • H01Q19/062—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 refracting or diffracting devices, e.g. lens for focusing
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01Q—ANTENNAS, i.e. RADIO AERIALS
  • H01Q25/00—Antennas or antenna systems providing at least two radiating patterns
  • H01Q25/007—Antennas or antenna systems providing at least two radiating patterns using two or more primary active elements in the focal region of a focusing device
  • H01Q25/008—Antennas or antenna systems providing at least two radiating patterns using two or more primary active elements in the focal region of a focusing device lens fed multibeam arrays

Definitions

• the invention relates to an antenna system including a l e n s and means for feeding elctromagnetic waves, which can preferably be used for receiving microwave signals.
• Antenna systems including a Luneburg lens and appropriate feeds are known, e.g. from US 4 531 129. Such systems can be used as part of a satellite broadcasting receiver system to receive microwave signals. But they can also be used as part of a transmitter system.
• plane reflecting surfaces may be placed through its center and the ray paths may be traced by the use of images.
• the addition of such reflectors produces virtual sources whose positions depend on the orientation of the real feed source and the reflector.
• antenna systems which include a parabolic reflector and a feeder horn provided in the focal point of the parabolic reflector, for receiving microwave signals.
• said feeder horn can be replaced by a helical antenna with two ends whereby the first end is linked to a feeder line.
• a helical antenna may be built as a so-called endfire helical antenna, where under maximum received power conditions the direction of the signal power flow at the said first end is in the same direction as the received radiation.
• a helical antenna can also be built as a so-called backfire helical antenna, where under maximum received power conditions the direction of the signal power flow at the said first end is in the opposite direction to the received radiation.
• an antenna system which comprises a reflector, a primary helical antenna having a coil with a pair of ends, said coil located at the focal point of said reflector so that the axis of the helical antanna coincides essentially with the axis of said reflector.
• a feeder line couples the antenna system with an external circuit, so that said primary helical antenna represents a backfire helical antenna coupled with said feeder line at the nearer end from said reflector and the other end of the helical antenna is free standing, and said feeder line is a coaxial cable.
• the antenna system according to the invention includes a lens, preferably a Luneburg-type lens, with feed means shaped as a helical coil.
• said feed means which are also named means for feeding, can be used for receiving and transmitting electromagnetic waves.
• the inventive antenna system can also be used as transmitter antenna system.
• Figs. 1a, 1b show known antenna systems including a
• Fig. 2 shows a first preferred embodiment of the
• Fig. 3 shows a second preferred embodiment of the
• Fig 1a shows a known antenna system in which a wave 10 is refracted by a spherical Luneburg lens 11 such that it is focussed in a focal point 12a. Near the focal point 12a a feeder horn 13a is provided, which receives the focussed wave and leads appropriate signals by a coaxial cable 14a to a receiver 15.
• waves may be focussed in focal points 12b, 12c respectively, received by feeder horns 13b, 13c and appropriate signals may be led by coaxial cables 14b, 14c to the receiver 15.
• the receiver 15 is prefera bly built as a low noise receiver, which might contain appropriate converting and receiving means.
• Fig. 1b shows another known antenna system with a virtual- source Luneburg lens. Details with the same function as in fig. 1a have got the same reference numbers.
• the wave 10 is focussed by a construction of a hemispherical Luneburg lens 21 and a plane reflector 16 at a focal point 22a.
• the not shown waves may be focussed at focal points 22b, 22c respectively and the according signals are led to the receiver 15.
• the antenna aperture is blocked by the feeder horns 13a, 13b, 13c and by the coaxial cables 14a, 14b, 14c.
• fig. 2 shows the wave 10 only outside of the spherical Luneburg lens 11. But it is to be kept in mind that said wave 10 propagates also inside said lens 11.
• an endfire helical antenna 23a is provided, which is connected with the coaxial cable 14a.
• endfire helical antennas 23b, 23c are provided and connected with the coaxial cables 14b, 14c respectively.
• the signals received by the endfire helical antennas 23a, 23b, 23c are led by the coaxial cables 14a, 14b, 14c to the receiver 15.
• Fig. 3 shows another preferred embodiment of the invention, the wave 10 again for clearness being shown only outside of the hemispherical Luneburg lens 21.
• the signals received by the backfire helical antennas 22a, 22b, 22c are led by the feeder lines 24a, 24b, 24c respectively to the receiver 15.
• the helical antennas 23, 33 and the feeder lines 24 are integrated in the respective lenses 11, 21. This can be realized by an appropriate production process, where openings may be provided for cable paths and/or the helical antennas 23, 33.
• the refraction index of said lenses may be corrected appropriately, which may be achieved by using a production process, where dielectric material, e.g. shaped as a thread, with a variable refraction index is wrapped. Appropriate corrections of the refraction index are also possible, if dielectric material is formed as a series of hemispherical shells or other suitable shapes. It is still another possibility to create the cable paths after the manufacture of said lenses by drilling.
• the coaxial cables 14 may be substituted by any other suitable feeder lines, which might be integrated in the lens used;
• the refraction index of the lenses used may have a variation such that the focal points 12, 22 are located inside or outside of the surface of the respective lens 11, 21, whereby the location of the respective feeders 23, 33 may vary appropriately;
• additional feeders may be arranged outside of the surface of said lens;
• Luneburg-type lenses instead of full- or hemi-spherical Luneburg-type lenses, other lenses, e.g. cylindrical Luneburg-type lenses, may be used, whereby an easier arrangement of the feeders 23, 33 and/or a different beamshape may be achieved;
• the shape of the reflector 16 which may be metallic, is varied in such a manner, that it covers at least one of those sides of the lens which are not penetrated by the waves 10 to be received;
• the refraction index of the used lens may vary in such a manner that the receiving of several waves with different frequencies is optimized
• a homogeneous-type lens may be used, which means that
• the refraction index may be constant throughout the lens; - the inventive antenna system may also be used as transmitter antenna system, if the feeder lines 14, 24 are connected to suitable transmitting means.
• the antenna system according to the invention includes a lens, which focusses incoming waves at respective focal points.
• Helical feeders which are provided near said focal points and preferably integrated in said lens, receive the waves and appropriate signals are led by feeder lines to a suitable receiver or amplifier, or pre-amplifier, or the like.
• the antenna system is less bulky and especially in this case the length of required feeder lines can be reduced and the receiving efficiency can be increased compared to known systems.
• the system according to the invention is preferably used as part of a system for receiving Direct Broadcasting Satellite microwaves from different satellites.

Landscapes

• Aerials With Secondary Devices (AREA)
• Variable-Direction Aerials And Aerial Arrays (AREA)

Priority Applications (5)

Applications Claiming Priority (2)

Publications (1)

Family

ID=8208533

Family Applications (1)

Country Status (14)

Cited By (13)

Families Citing this family (6)

Citations (6)

• 1992
  • 1992-01-18 JP JP4502758A patent/JPH06504659A/ja active Pending
  • 1992-01-18 WO PCT/EP1992/000090 patent/WO1992013373A1/en active IP Right Grant
  • 1992-01-18 ES ES92902722T patent/ES2090604T3/es not_active Expired - Lifetime
  • 1992-01-18 EP EP92902722A patent/EP0569390B1/de not_active Expired - Lifetime
  • 1992-01-18 AU AU11629/92A patent/AU1162992A/en not_active Abandoned
  • 1992-01-18 RU RU9293052689A patent/RU2067342C1/ru active
  • 1992-01-18 DE DE69212807T patent/DE69212807T2/de not_active Expired - Fee Related
  • 1992-01-18 KR KR1019930702241A patent/KR930703718A/ko active IP Right Grant
  • 1992-01-27 NZ NZ24141292A patent/NZ241412A/xx unknown
  • 1992-01-27 ZA ZA92539A patent/ZA92539B/xx unknown
  • 1992-01-27 TR TR00102/92A patent/TR27907A/xx unknown
  • 1992-01-27 MX MX9200323A patent/MX9200323A/es unknown
  • 1992-01-28 MY MYPI92000134A patent/MY108658A/en unknown
  • 1992-01-28 CN CN92100676A patent/CN1027476C/zh not_active Expired - Fee Related

Patent Citations (6)

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