Classifications

• • 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
  • H01Q1/22—Supports; Mounting means by structural association with other equipment or articles
  • H01Q1/24—Supports; Mounting means by structural association with other equipment or articles with receiving set
  • H01Q1/241—Supports; Mounting means by structural association with other equipment or articles with receiving set used in mobile communications, e.g. GSM
  • H01Q1/246—Supports; Mounting means by structural association with other equipment or articles with receiving set used in mobile communications, e.g. GSM specially adapted for base stations
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01Q—ANTENNAS, i.e. RADIO AERIALS
  • H01Q21/00—Antenna arrays or systems
  • H01Q21/24—Combinations of antenna units polarised in different directions for transmitting or receiving circularly and elliptically polarised waves or waves linearly polarised in any direction
  • H01Q21/26—Turnstile or like antennas comprising arrangements of three or more elongated elements disposed radially and symmetrically in a horizontal plane about a common centre
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01Q—ANTENNAS, i.e. RADIO AERIALS
  • H01Q5/00—Arrangements for simultaneous operation of antennas on two or more different wavebands, e.g. dual-band or multi-band arrangements
  • H01Q5/40—Imbricated or interleaved structures; Combined or electromagnetically coupled arrangements, e.g. comprising two or more non-connected fed radiating elements
  • H01Q5/48—Combinations of two or more dipole type antennas

Definitions

• the present disclosure relates to an antenna device, for example, for use in a base station.
• the antenna device may be referred to as a multi-layered antenna device, as it includes two radiating elements arranged on a common axis, for example, arranged or stacked above each other.
• the antenna device is designed to have a high radiation directivity.
• the present disclosure relates also to a method for operating the antenna device.
• LTE Long-Term Evolution
• 5G 5th generation
• mMIMO massive multiple input multiple output
• the width of an antenna device also influences its radiation directivity.
• the radiation directivity of the antenna device is limited by its aperture, and therefore, by its width. This effect becomes particularly critical, when several antenna arrays are placed inside the same enclosure of the antenna device. It is well know that when multiple dipoles are placed in a side by side configuration on a small reflector of an antenna device, the horizontal beam width (HBW) of the antenna device increases, which reduces the radiation directivity.
• Some exemplary approaches which address this reduction of the radiation directivity, attempt to conform the HBW using a 90° hybrid. This hybrid provides a small increment in radiation directivity, but does not exploit fully the reduction of the HBW, because it generates side lobes out of the main cuts. Some other exemplary approaches attempting to address the reduction of the radiation directivity result in antenna devices with an increased depth (or thickness), or a reduced gain, or a reduced bandwidth.
• one or more end-fire arrays are arranged in the normal direction perpendicular to a reflector, in order to form an improved radiation directivity antenna device.
• this approach could still be improved, as there are some disadvantages with the implementation of the antenna device, which has a two-layered radiation element: firstly, a long electrical length feeding network leads to resonances, which limit the operating bandwidth of the antenna device; secondly, a 180° phase difference is introduced through a rotating balun feeding structure of an upper and a lower radiating element, which leads to rather large size, high costs, and a difficult production of the baluns; thirdly, the approach is based on a large radiator size.
• a goal of this disclosure is to provide an antenna device that may have a width that complies with regulations and is usable for existing support structures at antenna sites.
• An objective is, in particular, to ensure that the radiation directivity of the antenna device is high and not significantly reduced compared to a conventional antenna device with a larger width. Consequently, the HBW of the antenna device shall not be significantly widened.
• a first aspect of this disclosure provides an antenna device comprising: a first radiating element and a second radiating element being arranged on a common axis, each radiating element being configured to radiate a radio wave in response to a radiofrequency (RF) signal fed to the respective radiating element; and a feed structure configured to feed the RF signal to the first radiating element and the second radiating element; wherein the feed structure comprises a redirecting device for redirecting the power between two or more branches, the redirecting device being configured to distribute the power of the RF signal between the first radiating element and the second radiating element; and wherein the feed structure comprises a phase inverter configured to set a quasi-inverted phase between the RF signal at the first radiating element and the RF signal at the second radiating element as a first phase difference.
• RF radiofrequency
• the result may be a significant increase in the directivity of the combined radiation pattern of the antenna device. This allows either a miniaturization of a reflector or an increase in coverage and/or an increased signal to interference plus noise ratio (SINR) provided by the antenna device.
• SINR signal to interference plus noise ratio
• the first phase difference, and potentially an amplitude difference as a further degree of freedom, between the RF signals at the two radiating elements, may also be used to improve the front to back and cross-polar discrimination of the antenna device.
• the antenna device may have a width that complies with the existing regulations and is usable for existing support structures at antenna sites. This is due to two radiating elements arranged on the common axis, for example, arranged or stacked above each other.
• the first phase difference may be introduced without a rotating balun feeding structure, which enables a smaller size, lower costs, and less production complexity.
• the antenna device of the first aspect has the advantage that a simple feeding of the two radiating elements is provided, while a high radiation directivity is achieved. Further, the antenna device is suitable for wideband, easy to process, and can be of low cost.
• the antenna device of the first aspect is described as a transmission (not reception) device. However, it can also be operated as a reception device.
• the redirecting device is further configured to set a second phase difference, in addition to the first phase difference set by the phase inverter, between the RF signal at the first radiating element and the RF signal at the second radiating element.
• the second phase difference can be used to balance the voltage standing wave ration (VSWR) bandwidth and the directivity of the antenna device.
• VSWR voltage standing wave ration
• the radiating fields of the two radiating elements i.e., the radio waves radiated by the radiating elements
• the radiating fields of the two radiating elements can be made to constructively interfere.
• the redirecting device comprises a first way for providing the RF signal to the first radiating element and a second way for providing the RF signal to the second radiating element, wherein the second phase difference is set by the first way having a different lengths than the second way.
• the redirecting device of the feed structure comprises: a balun connected to the first radiating element and the second radiating element; and a feeding line for feeding the RF signal to the balun, the feeding line being connected to the balun in a single feeding point.
• the feeding of the two radiating elements can be simplified.
• the redirecting device of the feed structure comprises: a balun connected to the first radiating element and the second radiating element; and a feeding line for feeding the RF signal to the balun, the feeding line having a first feeding part and a second feeding part, and the first feeding part being connected to the balun in a different feeding point than the second feeding part.
• the balun comprises two conductive parts separated by a gap, the gap intersecting with the feeding line in one or more feeding points.
• the feeding line may be connected by coupled feeding to the balun.
• each feeding point is arranged either between the first radiating element and the second radiating element, or between a reflector of the antenna device and the two radiating elements, or from the top of the first radiating element.
• the balun is connected to the feeding line in one or more feeding points by either coupled feeding or direct feeding.
• the phase inverter comprises a cross-jumpstructure, the cross-jump- structure being designed such that a positive pole of the feed structure cross-jumps to a side of a negative pole of the feed structure, and the negative pole of the feed structure cross-jumps to a side of the positive pole of the feed structure.
• the phase inverter is arranged either on one of the first radiating element and the second radiating element, or on a balun of the feed structure connected to the first radiating element and the second radiating element.
• the antenna device further comprises a reflector arranged on the common axis and configured to reflect the radio waves from the first radiating element and the second radiating element into a main radiating direction.
• the first radiating element and the second radiating element are arranged in different planes.
• the different planes are parallel to each other.
• the first radiating element and the second radiating element are arranged concentrically on the common axis.
• the feed structure is configured to feed the RF signal in parallel to the first radiating element and the second radiating element.
• At least one of the first radiating element and the second radiating element is a dual-polarized radiating element.
• each radiating element may radiate with a first polarization and a second polarization.
• one of the first radiating element and the second radiating element is arranged closer to a reflector of the antenna device than the other radiating element and has a larger radiating area than the other radiating element.
• the antenna device further comprises a support structure configured to hold the first radiating element and the second radiating element such that both radiating elements are arranged on the common axis.
• the feed structure is at least partly provided on the support structure.
• a second aspect of this disclosure provides a method of operating an antenna device comprising a first radiating element and a second radiating element being arranged on a common axis, each radiating element being configured to radiate a radio wave in response to a RF signal fed to the respective radiating element, wherein the method comprises: feeding the RF signal to the first radiating element and the second radiating element; wherein the power of the RF signal is divided between the first radiating element and the second radiating element; and wherein a phase difference of 180° ⁇ a is set between the RF signal at the first radiating element and the RF signal at the second radiating element, wherein a > 0°.
• the method of the second aspect may operate the antenna device of any implementation form of the first aspect.
• the method of the second aspect achieves the same advantages as described for the antenna device of the first aspect.
• FIG. 1 shows a basic principle of an antenna device according to an embodiment of this disclosure in (a), and an implementation of the device in (b).
• FIG. 2 shows different implementations of an antenna device according to an embodiment of this disclosure, in particular, different examples of the phase inverter.
• FIG. 3 shows different implementations of an antenna device according to an embodiment of this disclosure, in particular, different examples of the redirecting device.
• FIG. 4 shows various exemplary implementations of an antenna device according to an embodiment of this disclosure.
• FIG. 5 shows an antenna device according to an embodiment of this disclosure in a perspective view.
• FIG. 6 shows an antenna device according to an embodiment of this disclosure in a topview.
• FIG. 7 shows further exemplary implementations of an antenna device according to an embodiment of this disclosure.
• FIG. 8 shows a method according to an embodiment of this disclosure for operating an antenna device of this disclosure.
• FIG. 1(a) shows an antenna device 100 according to an embodiment of this disclosure.
• the antenna device 100 may be suitable for a base station of a mobile communication network.
• the antenna device 100 may be suitable for a base station antenna drive system.
• the antenna device 100 comprises a first radiating element 101 and a second radiating element 102, which are arranged on a common axis 103.
• the first radiating element 101 and the second radiating element 102 may be arranged concentrically on the common axis 103.
• the two radiating elements 101 and 102 may be arranged or stacked one above the other along the common axis 103.
• the first radiating element 101 may be arranged above the second radiating element 102.
• the first radiating element 101 and the second radiating element 102 may be arranged in different planes or layers of the antenna device 100. These different planes or layers may be parallel to each other. Accordingly, the antenna device 100 may be referred to as a multi-layered antenna device.
• Each of the radiating elements 101, 102 is configured to radiate a radio wave in response to a RF signal, which is fed to the respective radiating element 101 or 102.
• Each radiating element 101, 102 may be a dipole. Further, each radiating element 101, 102 may be configured to radiate with a first polarization and with a second polarization, wherein the two polarizations may be orthogonal. To this end, each radiating element 101, 102 may have two different dipole arms.
• the antenna device 100 also comprises a feed structure 104, which is configured to feed the RF signal to the first radiating element 101 and the second radiating element 102.
• the feed structure may be configured to feed the RF signal in parallel to the first radiating element 101 and the second radiating element 102.
• the feed structure 104 may comprise multiple components.
• the feed structure thereby comprises a redirecting device 104 for redirecting power between two or more branches, wherein the redirecting device 104 is configured in the antenna device 100 to distribute the power of the RF signal between the first radiating element 101 and the second radiating element 102.
• the redirecting device 104 may be a power divider.
• the feed structure also comprises a phase inverter 105, which is configured to set a quasiinverted phase between the RF signal at the first radiating element 101 and the RF signal at the second radiating element 102 as a first phase difference.
• the phase inverter 105 may be a phase shifter.
• the first phase difference may be ⁇ 180°.
• FIG. 1(b) shows an antenna device 100 according to an embodiment of this disclosure, which builds on the embodiment of the antenna device 100 shown in FIG. 1(a). Same elements in FIG. 1(a) and 1(b) are labelled with the same reference signs, and are implemented likewise.
• the antenna device 100 of FIG. 1(b) accordingly also comprises the two radiating elements 101, 102, the redirecting device 104, and the phase inverter 105.
• the redirecting device 104 is further configured to set a second phase difference 106, in addition to the first phase difference set by the phase inverter 105, between the RF signal at the first radiating element 101 and the RF signal at the second radiating element 102.
• the redirecting device 105 may, for example, comprise a first way or first arm for providing the RF signal to the first radiating element 101, and a second way or second arm for providing the RF signal to the second radiating element 102.
• the second phase difference 106 may be set by the first way or first arm having a different lengths than the second way or second arm.
• the power of the RF signal is divided between the first radiating element 101 and the second radiating element 102.
• it may be divided equally between the two radiating elements 101, 102, but it can also be divided unequally between them.
• a phase difference of 180° ⁇ a may be set between the RF signal at the first radiating element 101 (e.g., having an absolute phase of O - 180°, wherein ⁇ I> is a determined phase value) and the RF signal at the second radiating element 102 (e.g., having an absolute phase of + a).
• the antenna device 100 of FIG. 1(a) a 0°
• a basic principle of the antenna device 100 with the duallayer radiating elements 101, 102 is that the redirecting device 104 connects the first (e.g., upper) and second (e.g., lower) radiating elements 101, 102.
• One of the two radiating elements 101, 102 gets a fixed phase inversion as a first phase difference (shown in FIG. 1(a) and 1(b)).
• the two radiating elements 101, 102 may have a second phase difference 106 of a (shown in FIG. 1(b)).
• the fixed phase inversion may be implemented through a cross-jump structure as the phase inverter 105.
• the cross-jump structure may be designed such that a positive pole of the feed structure cross-jumps to a side of a negative pole of the feed structure, and the negative pole of the feed structure cross-jumps to a side of the positive pole of the feed structure.
• FIG. 2 shows different implementations of an antenna device 100 according to an embodiment of this disclosure, which build on the embodiments shown in FIG. 1(a) and 1(b). Same elements in these figures are labelled with the same reference signs, and are implemented likewise.
• FIG. 2 shows different examples of the phase inverter 105, especially how the phase inverter 105 - for example, implemented as cross-jump structure - can be introduced at different locations of the feed structure.
• the phase inverter 105 may be arranged on the first radiating element 101 (see FIG. 2(a)), or on the second radiating element 102 (see FIG. 2(c)).
• the phase inverter 105 may be arranged on a balun 201 of the feed structure of the antenna device 100 (see Fig. 2(b) or 2(d)).
• the balun 201 may thereby be connected to the first radiating element 101 and the second radiating element 102, and may be used to feed the RF signal to the radiating elements 101, 102.
• FIG. 2 shows also that the antenna device 200 may further comprise a reflector 204, which may be arranged on the common axis 103.
• the reflector 204 is configured to reflect the radio waves from the first radiating element 101 and the second radiating element 102, respectively, into a main radiating direction.
• the second radiating element 102 may be arranged closer to the reflector 204 than the first radiating element 101.
• the second radiating element 102 may further have a larger radiating area than the first radiating element 101, to reduce shadowing.
• FIG. 2 shows also that the antenna device 200, particularly the feed structure, may comprise a feeding line 202 for feeding the RF signal to the balun 201.
• the feeding line 202 may be connected to the balun 201 in one or more feeding points.
• the feed structure of the antenna device 200 may further comprise a support structure, which is configured to hold the first radiating element 101 and the second radiating element 102, such that the radiating elements 101, 102 are arranged on the common axis 103.
• the feed structure may be at least partly provided on the support structure.
• the balun 201 may be provided on the support structure, and/or the feeding line 202 may be at least partly provided on the support structure.
• FIG. 3 shows different implementations of an antenna device 100 according to an embodiment of this disclosure, which build on the embodiments shown in FIG 1(a) and 1(b) and FIG. 2. Same elements in these figures are labelled with the same reference signs, and are implemented likewise.
• FIG. 3 shows different examples of the redirecting device 104.
• the redirecting device 104 may comprise the balun 201, and the feeding line 202 may be connected to the balun 201 in a single feeding point 303 (see FIG. 3(a) and 3(c)).
• the feeding line 202 may have a first feeding part and a second feeding part, wherein the first feeding part is connected to the balun 201 in a different feeding point 303 than the second feeding part (see FIG. 3(b) and (d)). That is, the feeding line 202 may be connected in two or more feeding points 303 to the balun 201.
• Each of the feeding points 303 may be arranged either between the first radiating element 101 and the second radiating element 102 (see FIG. 3(b), 3(c) and 3(d)), or may be arranged between the reflector 204 of the antenna device 100 and the two radiating elements 101, 102 (see FIG. 3(a), 3(b) and 3(c)), or may be arranged from the top of the first radiating element 101.
• the second phase difference a between the two radiating elements 101, 102 may change, and may accordingly be set by choosing the location of the feeding points 303.
• Another possible implementation would be to implement the redirecting device 104 first, and to then feed the two radiating elements 101, 102 through two feeding points 303.
• the feeding can be realized by coupled feeding.
• the balun 201 may comprise two conductive parts, which are separated by a gap, and the gap may intersect with the feeding line 202 in one or more feeding points 303.
• the feeding can be realized by direct feeding (e.g., by a direct metal connection).
• the balun 201 may be connected to the feeding line 202 in one or more feeding points 303 by either coupled feeding or direct feeding.
• the redirecting device 104 of the antenna device 100 can greatly simplify the feeding of the radiating elements 101, 102, may remove resonances to get a broader bandwidth, may reduce size and cost of the antenna device 100, and may reduce its production complexity.
• FIG. 4 shows various exemplary implementations of an antenna device 100 according to an embodiment of this disclosure, which build on the embodiments shown in the previous figures. Same elements in these figures are labelled with the same reference signs, and are implemented likewise.
• FIG. 4(a) shows an antenna device 100, wherein the phase inverter 105 is implemented as a cross-jump structure on the balun 201.
• FIG. 4(b) shows an antenna device 100, wherein the phase inverter 105 is implemented as a cross-jump structure on the first radiating element 101 (the top radiating element).
• FIG. 4(c) shows an antenna device 100, wherein the phase inverter 105 is implemented as a cross-jump structure on the first radiating element 101 with a single-point direct-feeding structure.
• FIG. 4(d) shows an antenna device 100, wherein the phase inverter 105 is implemented as a cross-jump structure on the first radiating element 101 with a die cast balun 201. All the implementations of FIG. 4 have been simulated or measured, and exhibit lower HBW and thus increased directivity than comparable conventional antenna devices.
• FIG. 5 and FIG. 6 show an antenna device 100 according to an embodiment of this disclosure in a perspective view and a top view, respectively.
• the antenna device 100 of FIG. 5 and FIG. 6 builds on the embodiments shown in the previous figures. Same elements in these figures are labelled with the same reference signs, and are implemented likewise.
• FIG. 5 shows the antenna device 100 with its two radiating elements 101, 102 arranged on the common axis 103. Further, FIG. 5 shows the balun 201, which is connected to the first radiating element 101 and the second radiating element 101, and shows the feeding line 202 that is connected to the balun 201. FIG. 5 also shows that the first radiating element 101 and the second radiating element 102 may each comprise a substrate 503, and may each comprise two dipole arms in the substrate 503 or on the substrate 503.
• the first radiating element 101 may specifically comprise a first top dipole arm 501a for a first polarization and a second top dipole arm 501b for a second polarization.
• the two top dipole arms 501a and 501b may be arranged orthogonal to each other.
• the second radiating element 102 may specifically comprise a first bottom dipole arm 502a for the first polarization and a second bottom dipole arm 502b for the second polarization.
• the two bottom dipole arms 502a and 502b may be arranged orthogonal to each other.
• FIG. 7 shows further exemplary implementations of an antenna device 100 according to an embodiment of this disclosure, which build on the embodiments shown in the previous figures. Same elements in these figures are labelled with the same reference signs, and are implemented likewise.
• FIG. 7(a) shows an antenna device 100 with the balun 201 provided on the support structure, and with a cross-jump structure implementing the phase inverter 105 on the first radiating element 101.
• FIG. 7(b) shows an antenna device 100 with a feeding line 201 connected to the balun 201 in one feeding point 303, and a cross-jump structure implementing the phase inverter 105 on the balun 201 near the first radiating element 101.
• FIG. 8 shows a method 800 according to an embodiment of this disclosure.
• the method 800 is suitable for operating an antenna device 100, for instance, the antenna device 100 shown in the previous figures.
• the antenna device 100 comprises a first radiating element 101 and a second radiating element 102 arranged on a common axis 103.
• Each radiating element 101, 102 is configured to radiate a radio wave in response to a RF signal fed to the respective radiating element 101, 102.
• the method 800 comprises feeding (step 801) the RF signal to the first radiating element 101 and the second radiating element 102.
• the power of the RF signal is thereby divided (step 802) between the first radiating element 101 and the second radiating element 102.
• a phase difference of 180° ⁇ a is thereby set (step 803) between the RF signal at the first radiating element 101 and the RF signal at the second radiating element 102, wherein a > 0°.

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• Physics & Mathematics (AREA)
• Electromagnetism (AREA)
• Engineering & Computer Science (AREA)
• Computer Networks & Wireless Communication (AREA)
• Aerials With Secondary Devices (AREA)
• Variable-Direction Aerials And Aerial Arrays (AREA)

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• 2021
  • 2021-11-25 WO PCT/EP2021/082908 patent/WO2023093985A1/en active Application Filing
  • 2021-11-25 CN CN202180104389.2A patent/CN118369820A/zh active Pending
  • 2021-11-25 EP EP21820485.7A patent/EP4427299A1/de active Pending

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