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EP-4480039-B1 - END-FED ANTENNA

EP4480039B1EP 4480039 B1EP4480039 B1EP 4480039B1EP-4480039-B1

Inventors

  • ARNOLD, MATTHIAS
  • GENTNER, Philipp Karl
  • PONN, PHILIPP

Dates

Publication Date
20260513
Application Date
20220215

Claims (15)

  1. An antenna system (200, 300, 400, 600) comprising: a reflector (406); a radiating element (202, 302, 402) configured to emit an electromagnetic wave having a first polarization; and a feeding structure (210, 316) comprising a first splitter (218, 604) for splitting an electrical signal into a first electrical signal and a second electrical signal, wherein the feeding structure (210, 316) is coupled to the radiating element (202, 302, 402), and wherein the feeding structure (210, 316) is configured to: provide, via a first electrical coupling (214, 308) of the feeding structure (210, 316), the first electrical signal to a first end portion of the radiating element (202, 302, 402), provide, via a second electrical coupling (216, 310) of the feeding structure (210, 316), the second electrical signal to a second end portion of the radiating element (202, 302, 402), wherein the first end portion is different from the second end portion, and wherein the second electrical coupling (216, 310) is arranged in the antenna system (200, 300, 400, 600) at least partially on a side of the radiating element (202, 302, 402) which faces towards the reflector (406) of the antenna system (200, 300, 400, 600), and shift a phase of the second electrical signal relative to the first electrical signal prior to said providing of the second electrical signal to the second end portion of the radiating element (202, 302, 402); and wherein the radiating element comprises a third winding structure (313) which couples the first splitter (218, 604) with the first end portion of the radiating element (202, 302, 402).
  2. An antenna system (200, 300, 400, 600) as claimed in claim 1, wherein the radiating element (202, 302, 402) comprises a dual-polarized cross dipole comprising two dipole arms (204, 206, 304, 306) which are arranged orthogonal with respect to each other, wherein the feeding structure (210, 316) is coupled to a first dipole arm (204, 304) of the two dipole arms, wherein the first end portion of the radiating element (202, 302, 402) comprises a first end portion of the first dipole arm (204, 304) and the second end portion of the radiating element (202, 302, 402) comprises a second end portion of the first dipole arm (204, 304), and wherein the first end portion of the first dipole arm (204, 304) is opposite to the second end portion of the first dipole arm (204, 304).
  3. An antenna system (200, 300, 400, 600) as claimed in claim 1 or 2, wherein the feeding structure (210, 316) is configured to shift the phase of the second electrical signal relative to the first electrical signal by 180 degrees or approximately 180 degrees prior to said providing of the second electrical signal to the second end portion of the radiating element (202, 302, 402).
  4. An antenna system (200, 300, 400, 600) as claimed in any preceding claim, wherein the feeding structure (210, 316) comprises one or more of an analogue phase-shifter and a delay line (610) for shifting the phase of the second electrical signal relative to the first electrical signal prior to said providing of the second electrical signal to the second end portion of the radiating element (202, 302, 402).
  5. An antenna system (200, 300, 400, 600) as claimed in any preceding claim, further comprising: a first capacitive coupling element (608a), arranged between the first splitter (604) and the first end portion of the radiating element (202, 302, 402), for providing the first electrical signal from the first splitter (604) to the first end portion of the radiating element (202, 302, 402), and a second capacitive coupling element (608b), arranged between the first splitter (604) and the second end portion of the radiating element, for providing the second electrical signal from the first splitter (604) to the second end portion of the radiating element (202, 302, 402).
  6. An antenna system (200, 300, 400, 600) as claimed in any preceding claim, wherein the first splitter (218, 604) is a T-splitter.
  7. An antenna system (200, 300, 400, 600) as claimed in any preceding claim, wherein the feeding structure (210, 316) comprises a first feeding line (212, 318a) which is arranged in the feeding structure (210, 316) to provide the electrical signal to the first splitter (218, 604), and wherein the first feeding line (212, 318a) comprises a first winding structure; and/or wherein the second electrical coupling (216, 310) comprises a second feeding line (311) which couples an output of the first splitter (218, 604) with the second end portion of the radiating element, and wherein the second feeding line (311) comprises a second winding structure.
  8. An antenna system (200, 300, 400, 600) as claimed in claim 2, or any one of claims 3 to 7 when dependent from claim 2, wherein the first dipole arm (204, 304) is configured to emit the electromagnetic wave having the first polarization and a second dipole arm (206, 306) of the two dipole arms is configured to emit an electromagnetic wave having a second polarization, wherein the first polarization is orthogonal to the second polarization; and wherein, optionally, the feeding structure (210, 316) comprises a second splitter (315) for splitting an electrical signal into a third electrical signal and a fourth electrical signal, wherein the feeding structure (210, 316) is coupled to the second dipole arm (206, 306), and wherein the feeding structure (210, 316) is configured to: provide, via a third electrical coupling (312) of the feeding structure (210, 316), the third electrical signal to a first end portion of the second dipole arm (206, 306), provide, via a fourth electrical coupling (314) of the feeding structure (210, 316), the fourth electrical signal to a second end portion of the second dipole arm (206, 306), wherein the first end portion of the second dipole arm (206, 306) is opposite to the second end portion of the second dipole arm (206, 306), and wherein the fourth electrical coupling (314) is arranged in the antenna system at least partially on the side of the dual-polarized cross dipole which faces towards the reflector (406) of the antenna system, and shift a phase of the fourth electrical signal relative to the third electrical signal prior to said providing of the fourth electrical signal to the second end portion of the second dipole arm (206, 306).
  9. An antenna system (200, 300, 400, 600) as claimed in claim 2, or any one of claims 3 to 7 when dependent from claim 2, or claim 8, further comprising a decoupling device (408) arranged at least partially between a first portion of the first dipole arm (204, 304) and a second portion of the second dipole arm (206, 306); and wherein, optionally, a height of the decoupling device (408) is between 0.1 λ and 0.5 λ, wherein λ is a wavelength of the electromagnetic waves having the first and second polarizations, respectively.
  10. An antenna system (200, 300, 400, 600) as claimed in any preceding claim, wherein the feeding structure (210, 316) is coupled to respective side contacts of the radiating element (202, 302, 402) for one or both of the first electrical signal and the second electrical signal being feedable to the radiating element (202, 302, 402) from the respective side contacts.
  11. An antenna system (200, 300, 400, 600) as claimed in any preceding claim, wherein the second electrical coupling (216, 310) is sandwiched between a ground structure and the radiating element (202, 302, 402); and wherein, optionally, a shape of the ground structure mates with a shape of the radiating element (202, 302, 402).
  12. An antenna system (200, 300, 400, 600) as claimed in claim 7, further comprising two shielding structures (320a/b, 320c/d), wherein a feeding line (212, 318a, 318b), in particular the first feeding line (212, 318a) as claimed in claim 7, for providing the electrical signal to the first splitter (218, 604) is sandwiched between the two shielding structures (320a/b, 320c/d).
  13. An antenna system (200, 300, 400, 600) as claimed in claim 12, wherein the feeding line (212, 318a, 318b), in particular the first feeding line (212, 318a), extends generally perpendicularly to a direction in which the radiating element (202, 302, 402) extends.
  14. An antenna system (200, 300, 400, 600) as claimed in claim 12 or 13, when dependent on claim 2, wherein the feeding line (212, 318a, 318b), in particular the first feeding line (212, 318a), extends generally perpendicularly to a plane in which the two dipole arms (204, 206, 304, 306) extend.
  15. An antenna system (200, 300, 400, 600) as claimed in any preceding claim, {i} wherein the radiating element (202, 302, 402) comprises a triangularly or generally triangularly shaped portion; and/or {ii} wherein one or more of a feeding line (212, 318a, 318b), in particular the first feeding line (212, 318a) as claimed in claim 7, for providing the electrical signal to the first splitter (218, 604), the first electrical coupling (214, 308), and the second electrical coupling (216, 310) comprise a low-pass filter (322a-c); and/or {iii} wherein the radiating element (202, 302, 402) comprises one or more resonance structures (324); and/or {iv} further comprising one or more second radiators (404) arranged between the reflector (406) of the antenna system (200, 300, 400, 600) and the radiating element (202, 302, 402), wherein the one or more second radiators (404) are configured to emit electromagnetic waves having frequencies which are higher than a frequency of the electromagnetic wave emittable by the radiating element (202, 302, 402); and/or {v} wherein the second electrical coupling (216, 310) is arranged between the radiating element (202, 302, 402) and the reflector (406) in a distance of less than 0.1 of a wavelength of the electromagnetic wave to the radiating element (202, 302, 402) to form a microstrip structure with the radiating element (202, 302, 402).

Description

TECHNICAL FIELD This invention generally relates to an antenna system, in which a first electrical signal is side-fed to a first end portion of a radiating element and a second electrical signal, which is phase-shifted relative to the first electrical signal, is side-fed to a second end portion of the radiating element. The present invention may in particular be incorporated in a base station array antenna radiator element. BACKGROUND Base station antennas according to the state of the art are provided as multiband array antennas. Different antenna elements may hereby be arranged in a multitude of band-individual array columns. Different bands in which multiband antenna arrays according to the state of the art typically operate are low-band (600 MHz - 960 MHz), mid-band (1400 MHz - 2700 MHz) and high-band (3200 MHz - 4200 MHz). Figures 1a and 1b show top-views of schematic illustrations of multiband systems according to the state of the art. In figure 1a, the multiband array antenna 100 comprises low-band antenna elements 102 and high-band antenna elements 104. In this example, the low-band antenna elements 102 and high-band antenna elements 104 are arranged in an interleaving manner. In figure 1b, the multiband array antenna 150 also comprises low-band antenna elements 152 and high-band antenna elements 154, whereby the interleaving arrangement of the low-band and high-band antenna elements 152 and 154 is implemented by some of the high-band antenna elements 154 being surrounded by parts of low-band antenna elements 152. Interleaving designs according to the state of the art are based on a central feeding structure for the antenna elements or a split version in which the cross-polarized low-band antenna elements and the high-band antenna elements cannot be collocated. A drawback according to the interleaving concept of the multiband systems of the state of the art is that the position of the low-band antenna elements needs to be adjusted to the underlying high-band antenna elements. It may be necessary to adjust the position of the antenna elements in order to maintain performance of the individual array. The feeding structure of the low-band antenna element results in performance degradation of the (underlying) high-band antenna elements and their radiation pattern. Prior art can be found, for example, in D.A. Buhtiyarov, Novosibirsk State Technical University, Novosibirsk, Russia, 2014 12TH INTERNATIONAL CONFERENCE - APEIE - 34006, "Input Impedance of Ends-Fed Dipole Radiator with Prescribed Phase Difference Between Excitation Currents". In this paper, a complex multiple-arm balun balance unit is used in order to end-feed a dipole radiator. CN113036432A relates to the technical field of antennas, and provides a pilot frequency filter antenna, a manufacturing method and application of the pilot frequency filter antenna, wherein the pilot frequency filter antenna comprises an antenna floor, and the pilot frequency filter antenna also comprises: a transmission network arranged on one side of the antenna floor; an antenna radiator arranged on one side of the transmission network, which is far away from the antenna floor, and is used for generating a radiation zero point at a low-frequency sideband of a working frequency band. CN112768929A discloses a 5G metal plate forming dual-band filtering antenna which comprises a reflecting plate, a power distribution network component and a radiating sheet clamped at the top of the power distribution network component, wherein the power distribution network component is assembled and arranged on the reflecting plate through a clamping and supporting component, the power distribution network component comprises a first power distribution unit and a second power distribution unit which are assembled and arranged oppositely and a signal isolation cavity formed by surrounding, and wherein the first power distribution unit and the second power distribution unit are respectively provided with at least two groups of first opening resonance rings and second opening resonance rings. US20170179610A1 discloses a 2×2 MIMO array antenna which includes two separate radiating elements mounted to an antenna reflector. Each element is linear polarized with two orthogonal polarizations, one polarization excited by a transmit port and the other polarization receiving radiated signals destined for a receive port. The two elements are aligned that the polarizations excited by the transmit ports of the two elements are along a common axis, or the polarizations received by the receive ports of the two elements are along a common axis. US2011/134008A1 discloses a circularly-polarized antenna including a conductive backplane with a plurality of panels, a vertical array of patch radiators disposed on one of the backplane panels, and a feed stripline disposed on the backplane panel, wherein the backplane panels are vertical, planar, rectangular and form a right prism. US20110199279A1 discloses a