Abstract
The present disclosure provides a dual-polarized radiating element comprising a feeding arrangement and four dipole arms. The feeding arrangement comprises four slots, which extend from a periphery towards a center of the feeding arrangement and are arranged at regular angular intervals forming a first angular arrangement. The four dipole arms extend outwards from the feeding arrangement and are arranged at regular angular intervals forming a second angular arrangement. The second angular arrangement of the four dipole arms is rotated with respect to the first angular arrangement of the four slots.
Claims
1. A dual-polarized radiating element, comprising: a feeding arrangement comprising four slots, which extend from a periphery towards a center of the feeding arrangement and are arranged at regular angular intervals forming a first angular arrangement; and four dipole arms, which extend outwards from the feeding arrangement and are arranged at regular angular intervals forming a second angular arrangement, wherein the second angular arrangement of the four dipole arms is rotated with respect to the first angular arrangement of the four slots, wherein an inner end of each slot of the four slots terminates at a symmetrically bent slot.
2. The dual-polarized radiating element according to claim 1, wherein: the four slots and the four dipole arms, respectively, are arranged at 90 degrees (°) intervals; and the second angular arrangement of the four dipole arms is rotated by 45° with respect to the first angular arrangement of the four slots.
3. The dual-polarized radiating element according to claim 1, wherein: adjacently arranged slots extend perpendicular to another; non-adjacently arranged slots extend in-line with another; and the two in-line extending slot pairs define two orthogonal polarizations of the dual-polarized radiating element.
4. The dual-polarized radiating element according to claim 1, wherein at least a part of each dipole arm extends at least one of: upwards, and downwards, with respect to a plane defined by the feeding arrangement.
5. The dual-polarized radiating element according to claim 1, wherein an outer end of each dipole arm of the four dipole arms terminates with a flap, and wherein the flap is bent downwards or upwards with respect to the feeding arrangement plane, and wherein the flap is optionally bent back towards the feeding arrangement.
6. The dual-polarized radiating element according to claim 1, further comprising a parasitic director arranged above the feeding arrangement.
7. The dual-polarized radiating element according to claim 6, wherein at least one of: the parasitic director extends outwards from the feeding arrangement by a distance that is less than a distance by which each of the four dipole arms extends outwards from the feeding arrangement; and each dipole arm comprises an outer part extending upwards with respect to a plane defined by the feeding arrangement, and the parasitic director is arranged in a recess defined within the outer part of each of the four dipole arms.
8. The dual-polarized radiating element according to claim 1, wherein: the feeding arrangement comprises four transmission lines; and each transmission line of the four transmission lines crosses one of the four slots.
9. The dual-polarized radiating element according to claim 8, wherein two transmission lines of the four transmission lines cross non-adjacent slots and are combined into one transmission line.
10. The dual-polarized radiating element according to claim 9, wherein: the feeding arrangement comprises a printed circuit board (PCB), on which PCB the four transmission lines are combined into the two transmission lines; or the radiating element comprises a PCB arrangement extending from a bottom surface of the feeding arrangement, on which PCB arrangement the four transmission lines are combined into the two transmission lines.
11. The dual-polarized radiating element according to claim 1, wherein: the feeding arrangement comprises a PCB; the four slots are arranged on the PCB; and the four dipole arms are connected are connected to the PCB.
12. The dual-polarized radiating element according to claim 1, wherein: the feeding arrangement comprises a metal sheet; the four slots are cut outs in the metal sheet; and the four dipole arms are formed by the metal sheet.
13. The dual-polarized radiating element according to claim 12, wherein the metal sheet comprises four flaps, which are bent upwards or downwards with respect to a plane defined by the feeding arrangement and are arranged in between the four dipole arms, respectively.
14. The dual-polarized radiating element according to claim 1, wherein the symmetrically bent slot is a U-shaped slot.
15. An antenna, comprising at least one dual-polarized radiating element each dual-polarized radiating element, comprising: a feeding arrangement comprising four slots, which extend from a periphery towards a center of the feeding arrangement and are arranged at regular angular intervals forming a first angular arrangement; and four dipole arms, which extend outwards from the feeding arrangement and are arranged at regular angular intervals forming a second angular arrangement, wherein the second angular arrangement of the four dipole arms is rotated with respect to the first angular arrangement of the four slots, wherein an inner end of each slot of the four slots terminates at a symmetrically bent slot, and wherein: two dipole arms of the at least one dual-polarized radiating element extend along a longitudinal axis of the antenna; and two dipole arms of the at least one dual-polarized radiating element extend along a lateral axis of the antenna.
16. The antenna according to claim 15, wherein each slot of the at least one dual-polarized radiating element extends at an angle of 45 degrees (°) with respect to the longitudinal axis of the antenna.
17. The antenna according to claim 15, further comprising: a plurality of dual-polarized radiating elements arranged along the longitudinal axis of the antenna in a first column; and a plurality of other radiating elements arranged along the longitudinal axis of the antenna in two second columns disposed side-by-side the first column.
18. The antenna according to claim 17, wherein: the antenna is configured for multiband operation; the plurality of dual-polarized radiating elements are configured to radiate in a lower frequency band; and the plurality of other radiating elements are configured to radiate in a higher frequency band.
19. The antenna according to claim 17, wherein, for each of the plurality of dual-polarized radiating elements, each of the two dipole arms extending along the lateral axis of the antenna extends between two of the other radiating elements in each of the two second columns.
Description
BRIEF DESCRIPTION OF DRAWINGS
(1) The above-described aspects and implementation forms of the present disclosure will be explained in the following description of specific embodiments in relation to the enclosed drawings in which
(2) FIG. 1 shows a radiating element according to an embodiment of the present disclosure.
(3) FIG. 2 shows a radiating element according to an embodiment of the present disclosure.
(4) FIG. 3 compares current-density plots of a radiating element according to an embodiment of the present disclosure with a conventional square-shaped radiating element.
(5) FIG. 4 shows a device according to an embodiment of the present disclosure.
(6) FIG. 5 shows the device of FIG. 4 in a side view.
(7) FIG. 6 shows a device according to an embodiment of the present disclosure.
(8) FIG. 7 shows a device according to an embodiment of the present disclosure.
(9) FIG. 8 shows a dielectric support structure for a device according to an embodiment of the present disclosure.
(10) FIG. 9 shows a device according to an embodiment of the present disclosure.
(11) FIG. 10 shows a device according to an embodiment of the present disclosure.
(12) FIG. 11 shows a device according to an embodiment of the present disclosure.
(13) FIG. 12 shows a voltage standing wave ratio (VSWR) of a radiating element according to an embodiment of the present disclosure.
(14) FIG. 13 shows a radiation pattern of a radiating element according to an embodiment of the present disclosure.
(15) FIG. 14 shows a radiating element according to an embodiment of the present disclosure working in a multiband antenna architecture.
(16) FIG. 15 shows an antenna according to an embodiment of the present disclosure.
DETAILED DESCRIPTION OF EMBODIMENTS
(17) FIG. 1 shows a dual-polarized radiating element 100 according to an embodiment of the present disclosure. The radiating element 100 comprises a feeding arrangement 101, and four dipole arms 103. It further exhibits a specific angular arrangement of its components.
(18) The feeding arrangement 101 comprises four slots 102, which extend from a periphery towards a center of the feeding arrangement 101, and are arranged at regular angular intervals 104, which forms a first angular arrangement. In particular, two adjacent slots 102 in the first angular arrangement are arranged with an angle α in between. Further, each of the slots 102 extends from the periphery of the feeding arrangement 101 to a center portion of the feeding arrangement 101, preferably in a radial manner.
(19) The four dipole arms 103 extend outwards from the feeding arrangement 101, and are arranged at regular angular intervals 105, which forms a second angular arrangement. In particular, two adjacent dipole arms 103 in the second angular arrangement are arranged with an angle β in between. A dipole arm 103 is a structural element extending from the feeding arrangement 101, with a length in extension direction that is larger than its width. Preferably, each of the dipole arms 103 has further a width that is smaller than the width of the feeding arrangement 101 side, from which it extends.
(20) The second angular arrangement of the four dipole arms 103 is rotated 106 with respect to the first angular arrangement of the four slots 102, particularly by an angle Φ 106.
(21) FIG. 2 shows another radiating element 100 according to an embodiment of the present disclosure, which builds on the radiating element 100 shown in FIG. 1. Identical elements in these two FIGS. 1 and 2 are provided with the same reference signs.
(22) In particular, the radiating element 100 of FIG. 2 has the four slots 102 and four dipole arms 103, which are here respectively arranged at 90° intervals each. Further, the angular arrangements of the dipole arms 103 and the slots 102 are here rotated with respect to each other by 45°. Accordingly, the radiating element 100 extends with its dipole arms 103 mainly in two perpendicular directions (referred to as vertical and horizontal directions, respectively), but the polarizations of the radiating element 100 will lie at ±45° to these horizontal and vertical directions. FIG. 2 specifically shows that adjacently arranged slots 102 extend perpendicular to another, and that non-adjacently arranged slots 102 extend in line with another in this radiating element 100. Thus, two in line extending slot pairs are defined.
(23) The two in line extending slot pairs define the two ±45° orthogonal polarizations of the dual-polarized radiating element 100, when it is operated. To this end, the radiating element 100 is fed in operation preferably like a conventional square dipole, whereby the four slots 102 of the feeding arrangement 101 are particularly fed symmetrically 2-by-2.
(24) FIG. 2 also shows that each of the four slots 102 ends in a symmetrically bent, more or less U-shaped slot 201. The purpose of the four slots 201 is to extend the total length of each of the four slots 102, particularly for impedance matching purposes. Since the length of the four slots 102 cannot be extended further to a center portion of the feeding arrangement 101 (due to a lack of space in the middle), they can only be extended to the sides and backwards. In order to thereby maintain the symmetry, the bent slot 201 preferably have the same pattern at both sides of a slot 102. This leads to the symmetrically bent slots 201, preferably the shown U-shaped ones.
(25) The feeding arrangement 101 shown in FIG. 2 comprises a PCB 205, and the four dipole arms 102 are soldered to the PCB 205 through soldering pins 206. The soldering pins 206 cross the PCB 205 from bottom to top. Capacitive coupling between the four dipole arms 102, and to the PCB 205, is possible. However, in this case the coupling area should be dimensioned accordingly, in order to achieve enough coupling. It should also be ensured that the distance between the dipole arms 102 and the PCB 205 is small and stable.
(26) Preferably, the dipole arms 102 do not extend only horizontally and vertically, but—as shown in FIG. 2—also in the third perpendicular dimension, i.e. along a z-axis. In other words, at least a part 203 of each dipole arm 102 preferably extends upwards and/or downwards with respect to the feeding arrangement plane in which the feeding arrangement is arranged 101. In FIG. 2, each dipole arm 103 extends upwards in a part 203. By extending in the z-axis, the dipole arms 102 can be made longer electrically, without increasing their footprint. Furthermore, also a distance to ground can be increased, which reduces the capacitance to ground, and therefore increases the working bandwidth. Most importantly, all these advantages come for free, because the total height of the radiating element 100 does not need to be increased. This is explained below with respect to FIG. 4.
(27) As further shown in FIG. 2, the dipole arms 102 are preferably terminated with flaps 204, which make the dipole arms 102 again electrically longer, without increasing their footprint. Preferably, as shown in FIG. 2, the flaps 204 are bent downwards. However, it is also possible to have upwards or downwards bent flaps 204, and even a bending of flaps 204 back towards the feeding arrangement 101 is possible. Examples of alternative flaps 204 will be provided with respect to other figures further below. Also described further below is an optional support 800 for the radiating element 100.
(28) FIG. 3 shows a comparison of simulations of a current-density plot in a radiating element 100 (left side) according to FIG. 2, and in a conventional square-shaped radiating element 300 (right side). In the conventional radiating element 300, most of the current is concentrated in slots 302 of a feeding arrangement 301, whereas in the radiating element 100 the dipole is reshaped in such a way, that the current flows horizontally and vertically instead. The horizontal and vertical components of the current are equal, and the combination generates the ±45° polarizations. This advantageously allows to maximize the surface efficiency of the radiating element 100, which means that practically the whole surface of the radiating element 100, i.e. both of the feeding arrangement 101 and the dipole arms 103, contributes to the radiation. The amount of metallic surface is thus optimized. In the conventional square-shaped radiating element 300, there is a big surface amount that practically does not contribute to the radiation. Nevertheless, its presence inside, for instance, a multiband antenna, will create shadows on and interference with other radiating elements working in different, especially in HBs.
(29) For the radiating element 100, the feeding of the slots 102 is, as for a conventional square dipole, but the current distribution corresponds more to a cross dipole. Therefore, advantages of both dipole kinds are combined, and the radiating element 100 has broadband characteristics, but at the same time a very small footprint.
(30) FIG. 4 shows another radiating element 100 according to an embodiment of the present disclosure. The radiating element 100 of FIG. 4 builds on the radiating element 100 shown in FIG. 3. Identical elements in these two FIGS. 3 and 4 are provided with the same reference signs. FIG. 4 shows a radiating element 100 that further comprises a parasitic director 401, which is preferably arranged above the feeding arrangement 101. The parasitic director 401 further helps to achieve the required bandwidth, and at the same time to minimize the dimensions of the radiating element 100.
(31) FIG. 5 shows a side view of the radiating element 100 that is shown in FIG. 4. In FIG. 5, it shows that preferably the parasitic director 401 extends outwards from the feeding arrangement 101 less than each one of the four dipole arms 103. Thus, the parasitic director 401 does not increase the width and length of the radiating element 100 in the horizontal and vertical directions, respectively. Further, additionally or optionally, each dipole arm 103 may comprise, as shown in FIG. 5, an outer part 203 that extends upwards with respect to the feeding arrangement plane. Then, the parasitic director 401 is preferably arranged in a recess 501, which is defined within the four outer parts 203. Thus, the parasitic director 401 does also not increase the height of the radiating element 100. Further, as mentioned above, the dipole arms 103 are extended electrically in length due to the parts 203, however, preferably not above the above plane of the parasitic director 401. The height of the radiating element 100 of FIG. 4 is, for example assuming an operating frequency band of 690-960 megahertz (MHz), about 65 mm. That means, the height of the radiating element 100 is about 0.15λ at 690 MHz, and even below 0.152, at 960 MHz, wherein 2, is the wavelength corresponding to the respective frequencies. That is, it is a low profile radiating element 100.
(32) FIG. 6 shows another radiating element 100 according to an embodiment of the present disclosure in a bottom view. Elements shown in FIG. 6 and identical elements in the previous figures, are provided with the same reference signs. The PCB 205 carrying the feeding arrangement 101 and the slots 102, 201 is visualized transparent in FIG. 6, so that the crossings between the (feeding) transmission lines 601 and the slots 102 can be easily seen.
(33) FIG. 6 shows that the feeding arrangement 101 preferably further comprises four transmission lines 601, wherein each transmission line 601 crosses one of the four slots 102. The transmission lines 601 are preferably short-ended microstrip lines. The transmission lines 601 are particularly used for feeding the four slots 102, and are combined, in order to feed two non-adjacent slots 102 in an identical manner. This leads to the dual polarization of the radiating element 100. In FIG. 6, the combination of the four transmission lines 601 into two transmission lines 602 is carried out on a PCB arrangement 603. In particular, this PCB arrangement 603 extends from a bottom surface of the feeding arrangement 101. The PCB arrangement 603 may specifically extend orthogonally from the feeding arrangement 101. Because the four transmission lines 601 are combined into the two transmission lines 602, firstly a feeding signal can be transmitted from the PCB arrangement 603 to, for example, a PCB 205 of the feeding arrangement 101, and secondly the radiating element 100 can be grounded.
(34) For instance, a ground of the PCB arrangement 603 may be connected (e.g. soldered) to a ground of the feeding arrangement 101. The PCB arrangement 603 may also be connected to an additional PCB, which serves, for instance, as a transition between the radiating element 100 and a feeding network. Other implementations, like a direct connection to a phase shifter, or a direct connection to a coaxial cable, are also possible.
(35) FIG. 7 shows another radiating element 100 according to an embodiment of the present disclosure, in which the transmission lines 601 are combined into transmission lines 702 in a different manner than in FIG. 6. Nevertheless, identical elements in the two FIGS. 6 and 6 are provided with the same reference signs. In particular, in FIG. 7 the combination of the four transmission lines 601 into two transmission lines 702 is carried out on the feeding arrangement 101, particularly, on the PCB 205 of the feeding arrangement 101. Thereby, the number of total soldering points can be reduced, since only two signal paths are present, instead of four. Furthermore, slots in the center of the PCB 205 can be divided into four small slots, which offers advantages in terms of isolation between different frequency bands.
(36) FIG. 8 shows a dielectric support 800, onto which the radiating element 100 according to an embodiment of the present disclosure can be mounted. This is also indicated in the previous figures showing the radiating elements 100. The dielectric support 800 advantageously ensures mechanical stability of the radiating element 100, and ensures that a distance from the radiating element 100 to an antenna reflector, as well as a distance from a parasitic director 401 to the radiating element 100, is stably maintained. The dielectric support 800 may specifically comprise support feet 804, which also define a distance of the radiating element 100 to, for example, a feeding network or to the antenna reflector. Further, the support 800 can include support elements 802, in order to stably support the four dipole arms 102 of the radiating element 100. The support 800 can also comprise attachment means 803, which are configured to hold the feeding arrangement 101, and preferably the parasitic director 401.
(37) FIG. 9 shows a radiating element 100 according to an embodiment of the present disclosure. Elements in FIG. 9 and identical elements in the previous figures, are provided with the same reference signs. In FIG. 9 the feeding arrangement 101 of the radiating element 100 is made out of one single bent metal sheet together with the dipole arms 103, instead of comprising a PCB 205 and the four dipole arms 103 attached thereto. In particular, the feeding arrangement 101 comprises a metal sheet 901, wherein the four slots 102 are preferably cutouts in the metal sheet 901, and also the four dipole arms 103 are formed by the metal sheet 901. This has, for example, the advantage that the metal sheet 901 can be easily designed with four further flaps 902, which may be arranged in between the four dipole arms 102. The further flaps 902 may be bent upwards or downwards with respect to the feeding arrangement plane. Furthermore, the slots 102 may further extend along the flaps 902. In FIG. 9, the flaps 902 are bent downwards, and furthermore slightly back towards the feeding arrangement 101. Further, as shown in FIG. 9, also the dipole arms 103 can have additional bends, for instance, side flaps 903 for increasing the electrical width of the dipole arm 102. The side flaps 903 may be formed by bending the dipole arms 103 along their extension direction. The slots 102 can be fed by transmission lines on a PCB, e.g. arranged below the metal sheet 901. In a further embodiment the slots 102 may be fed using a suitable cable feed, e.g. arranged below the metal sheet 901.
(38) FIG. 10 shows yet another radiating element 100 according to an embodiment of the present disclosure, which builds for instance on the radiating element 100 shown in FIG. 2. Identical elements in these two FIGS. 2 and 10 are provided with the same reference signs. In FIG. 10, the flaps 204 terminating the dipole arms 103 are not only bent downwards, but also back towards the feeding arrangement 101. This provides further electrical length to the dipole arms 103. Further, the optional parasitic capacitor 401 is shown to be arranged above the feeding arrangement 101, and particularly within the extension length of the four dipole arms 103.
(39) FIG. 11 shows another radiating element 100 according to an embodiment of the present disclosure, which builds on the radiating element 100 shown in FIG. 1. Identical elements in these two FIGS. 1 and 11 are provided with the same reference signs. Here, in FIG. 11, the dipole arms 103 extend outwards from the feeding arrangement 101 and are terminated by upward bent flaps 204, respectively, for increasing their electrical length. Also, the optional PCB arrangement 603 extending from the feeding arrangement 101 is shown. The PCB arrangement 603 may serve also as mechanical support, for instance, instead of the support 800.
(40) Notably, with respect to the above-described radiating elements 100, the decision of whether terminating flaps 204 of the dipole arms 103 are bent upwards or downwards can be decided after a detailed optimization process of the radiating element 100. The decision can, for instance, depend on the arrangement of the radiating element 100 on an antenna, particularly together with other radiating elements arranged side-by-side the radiating element 100.
(41) FIGS. 12 and 13 show RF performance of the radiating element 100 according to an embodiment of the present disclosure. Specifically, the VSWR and the radiation pattern of the radiating element 100 are shown. FIG. 12 specifically shows that the VSWR is below 16.5 decibel (dB) (1.35:1) from 690-960 MHz. FIG. 13 shows that the radiation pattern is symmetric, the 3 dB beamwidth is around 65° and the Cross-polar discrimination is above 10 dB in the range from +60° to −60°.
(42) FIG. 14 shows, how the radiating element 100 according to an embodiment of the present disclosure can advantageously be arranged in a multiband antenna architecture. At both sides of the radiating element 100, there are provided other radiating elements 1400, for instance, configured to work in an HB like in HB arrays. Due to the shape of the radiating element 100, a distance between the other radiating elements 1400 on either side of the radiating element 100 can be minimized, namely by arranging the other radiating elements 1400 nested with the dipole arms 103 that extend from the feeding arrangement 101 of the radiating element 100. Therefore, either the dimensions of the multiband antenna architecture can be reduced, or the number of HB arrays within the same dimensions of the architecture can be increased.
(43) FIG. 15 shows in this respect an antenna 1500 according to an embodiment of the present disclosure. The antenna 1500 comprises three columns of radiating elements, each column extending along a longitudinal axis 1501 of the antenna 1500. In particular, the radiating elements 100 are arranged in a first column 1504, which is located in between and side-by-side two second columns 1503 comprising the other radiating elements 1400. Preferably, the second columns 1503 are HB arrays, and the first column 1504 is an LB array. FIG. 15 again shows, how two of the dipole arms 103 of each radiating element 100 extend between two of the other radiating elements 1400 in the HB arrays, i.e. they extend along a lateral axis 1502 of the antenna 1500. The other two dipole arms 103 of each radiating element 100 extend along the longitudinal axis 1501 of the antenna 1500. This allows a very dense packing of the respective HB and LB arrays. However, as also desired, the radiation polarizations defined by the slots 102 of the radiating elements 100 are still ±45° with respect to the longitudinal axis 1501 of the antenna 1500.
(44) In summary, the detailed description and the figures show, that and how the radiating element 100 is made low profile, but is at the same time provided with broadband characteristics. Furthermore, that and how the radiating element 100 has a shape that minimizes interference with other radiating elements 1400 arranged side-by-side in a multiband antenna 1500, and minimizes the width of the antenna 1500.
(45) The present disclosure has been described in conjunction with various embodiments as examples as well as implementations. However, other variations can be understood and effected by those persons skilled in the art and practicing the claimed disclosure, from the studies of the drawings, this disclosure and the independent claims. In the claims as well as in the description the word “comprising” does not exclude other elements or steps and the indefinite article “a” or “an” does not exclude a plurality. A single element or other unit may fulfill the functions of several entities or items recited in the claims. The mere fact that certain measures are recited in the mutual different dependent claims does not indicate that a combination of these measures cannot be used in an advantageous implementation.
