Antenna module and massive MIMO antenna

Abstract

The present invention provides an antenna module for a massive MIMO antenna, the antenna module comprising a plurality of first signal ports, a number of first antenna elements arranged in a first matrix arrangement, wherein a number of rows of the first matrix arrangement and/or a number of columns of the first matrix arrangement equals the number of first signal ports, and a switching matrix that is configured to controllably couple each of the first signal ports either with all first antenna elements of a respective row of the first matrix arrangement or all first antenna elements of a respective column of the first matrix arrangement. Further, the present invention provides a respective massive MIMO antenna.

Claims

1. An antenna module for a massive MIMO antenna, the antenna module comprising: a plurality of first signal ports, a number of first antenna elements arranged in a first matrix arrangement, wherein a number of rows of the first matrix arrangement and/or a number of columns of the first matrix arrangement equals the number of first signal ports, and a switching matrix that is configured to controllably couple each of the first signal ports either with all first antenna elements of a respective row of the first matrix arrangement or all first antenna elements of a respective column of the first matrix arrangement.

2. The antenna module according to claim 1, comprising: a plurality of second signal ports, a number of second antenna elements arranged in a second matrix arrangement, wherein a number of rows of the second matrix arrangement and/or a number of columns of the second matrix arrangement equals the number of second signal ports, and wherein each one of the second antenna elements is arranged as a cross polarized pair with a respective one of the first antenna elements, and wherein the switching matrix is further configured to controllably couple each of the second signal ports either with all second antenna elements of a respective row of the second matrix arrangement or all second antenna elements of a respective column of the second matrix arrangement.

3. The antenna module according to claim 1, wherein each of the first signal ports and/or the second signal ports comprises a signal splitter/combiner that is configured to split a single source upstream signal into split upstream signals for the respective antenna elements that the respective first signal port or second signal port (is coupled to via the switching matrix, and that is configured to combine two source downstream signals received via the respective antenna elements that the respective first signal port or second signal port is coupled to into a single combined downstream signal.

4. The antenna module according to claim 3, comprising for each signal splitter/combiner at least one phase shifter in at least one signal line between the signal splitter/combiner and the respective first antenna element or second antenna element.

5. The antenna module according to claim 1, wherein the first antenna elements are positioned half a wavelength of an operating frequency of the antenna module away from each other; and/or wherein the second antenna elements are positioned half the wavelength of the operating frequency of the antenna module away from each other.

6. The antenna module according to claim 2, wherein the switching matrix is further configured to controllably couple each of the first signal ports and each of the second signal ports to the first antenna element and to the second antenna element of a respective one of the cross polarized pairs of antenna elements.

7. The antenna module according to claim 1, wherein the switching matrix comprises a plurality of controllable RF switches and a switch controller that is coupled to control inputs of the RF switches and that is configured to control the RF switches based on a control input signal.

8. The antenna module according to claim 1, wherein the switching matrix comprises a plurality of one-time switching elements.

9. The antenna module according to claim 1, wherein a length of the signal lines between the first signal ports and/or the second signal ports through the switching matrix to the respective first antenna elements and/or second antenna elements is equal for all signal lines.

10. A massive MIMO antenna, comprising a plurality of antenna modules comprising: plurality of first signal ports, a number of first antenna elements arranged in a first matrix arrangement, wherein a number of rows of the first matrix arrangement and/or a number of columns of the first matrix arrangement equals the number of first signal ports, and a switching matrix that is configured to controllably couple each of the first signal ports either with all first antenna elements of a respective row of the first matrix arrangement or all first antenna elements of a respective column of the first matrix arrangement, and a transceiver for every first input port and/or second input port of the antenna modules.

11. The massive MIMO antenna according to claim 10, comprising 16 antenna modules, wherein the antenna modules are arranged in a matrix arrangement comprising four rows and four columns.

12. The massive MIMO antenna according to claim 10, wherein each of the first signal ports and/or the second signal ports comprises a signal splitter/combiner that is configured to split a single source upstream signal into split upstream signals for the respective antenna elements that the respective first signal port or second signal port is coupled to via the switching matrix, and that is configured to combine two source downstream signals received via the respective antenna elements that the respective first signal port or second signal port is coupled to into a single combined downstream signal.

13. The massive MIMO antenna according to claim 12, comprising for each signal splitter/combiner at least one phase shifter in at least one signal line between the signal splitter/combiner and the respective first antenna element or second antenna element.

14. The massive MIMO antenna according to claim 10, wherein the first antenna elements are positioned half a wavelength of an operating frequency of the antenna module away from each other; and/or wherein the second antenna elements are positioned half the wavelength of the operating frequency of the antenna module away from each other.

15. The massive MIMO antenna according to claim 12, wherein the switching matrix is further configured to controllably couple each of the first signal ports and each of the second signal ports to the first antenna element and to the second antenna element of a respective one of cross polarized pairs of antenna elements.

16. The massive MIMO antenna according to claim 10, wherein the switching matrix comprises a plurality of controllable RF switches and a switch controller that is coupled to control inputs of the RF switches and that is configured to control the RF switches based on a control input signal.

17. The massive MIMO antenna according to claim 10, wherein the switching matrix comprises a plurality of one-time switching elements.

18. The massive MIMO antenna according to claim 10, wherein a length of the signal lines between the first signal ports and/or the second signal ports through the switching matrix to the respective first antenna elements and/or second antenna elements is equal for all signal lines.

19. The antenna module according to claim 4, wherein the first antenna elements are positioned half a wavelength of an operating frequency of the antenna module away from each other; and/or wherein the second antenna elements are positioned half the wavelength of the operating frequency of the antenna module away from each other.

20. The antenna module according to claim 6, wherein the switching matrix comprises a plurality of one-time switching elements, the plurality of one-time switching elements comprising trace fuses.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) For a more complete understanding of the present invention and advantages thereof, reference is now made to the following description taken in conjunction with the accompanying drawings. The invention is explained in more detail below using exemplary embodiments which are specified in the schematic figures of the drawings, in which:

(2) FIG. 1 shows a block diagram of an embodiment of an antenna module according to the present invention;

(3) FIG. 2 shows a block diagram of another embodiment of an antenna module according to the present invention;

(4) FIG. 3 shows another block diagram of the embodiment of an antenna module according to the present invention of FIG. 1;

(5) FIG. 4 shows another block diagram of the embodiment of an antenna module according to the present invention of FIG. 2;

(6) FIG. 5 shows a diagram of a beamforming area of an embodiment of an antenna module according to the present invention;

(7) FIG. 6 shows another diagram of a beamforming area of an embodiment of an antenna module according to the present invention;

(8) FIG. 7 shows a block diagram of another embodiment of an antenna module according to the present invention;

(9) FIG. 8 shows a block diagram of another configuration of the embodiment of an antenna module according to the present invention of FIG. 7;

(10) FIG. 9 shows a block diagram of another configuration of the embodiment of an antenna module according to the present invention of FIG. 7;

(11) FIG. 10 shows a block diagram of another configuration of the embodiment of an antenna module according to the present invention of FIG. 7; and

(12) FIG. 11 shows a block diagram of an embodiment of a massive MIMO antenna according to the present invention.

(13) In the figures like reference signs denote like elements unless stated otherwise.

DETAILED DESCRIPTION OF THE DRAWINGS

(14) The antenna modules 100, 200 described below only comprise antenna elements of the same polarization. It is however understood, that the descriptions of antenna modules 100, 200 also apply mutatis mutandis to an embodiment of an antenna module with cross polarized pairs of antenna elements and respective massive MIMO antennas. In this context it is understood, that the first signal ports and the first antenna elements refer to a first polarization and the second signal ports and the second antenna elements refer to a second polarization.

(15) FIG. 1 shows a block diagram of an antenna module 100. The antenna module 100 comprises two first signal ports 101, 102 and four first antenna elements 103, 104, 105, 106. The first antenna elements 103, 104, 105, 106 are coupled to the first signal ports 101, 102 via a switching matrix 107. It is understood, that the number of four first antenna elements 103, 104, 105, 106 and two first signal ports 101, 102 is just exemplarily chosen and that other embodiments of an antenna module may comprise other numbers of first signal ports and antenna elements. Such an embodiment may for example comprise three first signal ports and nine first antenna elements.

(16) The switching matrix 107 is capable of controllably interconnecting the antenna elements 103, 104, 105, 106 with the first signal ports 101, 102 in different configurations. In FIG. 1 a configuration is shown, in which the first antenna elements 103, 105 are coupled to the first signal port 101, and in which the first antenna elements 104, 106 are coupled to the second signal port 102.

(17) This means, that the first antenna elements 103, 104, 105, 106 are vertically coupled pair-wise. Consequently, the first antenna elements 103, 105 will receive the same upstream signals via first signal port 101 and will provide the received downstream signals both to the first signal port 101. The same applies to first antenna elements 104, 106, which will receive the same upstream signals via first signal port 102 and will provide the received downstream signals both to the first signal port 102.

(18) A massive MIMO antenna may comprise a plurality of antenna modules 100. If all the antenna modules 100 in such an antenna are configured as shown in FIG. 1, every column of first antenna elements 103, 104, 105, 106 may be individually provided with a RF signal. Therefore, beamforming in the horizontal direction may be performed within a large beamforming area of about +/−50°.

(19) The configuration of the switching matrix 107 as shown in FIG. 1 may therefore e.g. be advantageously used in rural areas, where low buildings are distributed over the landscape (see e.g. FIG. 5).

(20) Although not explicitly shown, it is understood, that the switching matrix 107 may comprise any number of necessary RF switches or other elements that are required to perform the coupling between the first signal ports 101, 102 and the first antenna elements 103, 104, 105, 106. Such RF switches may e.g. be conventional RF switches, transistors or the like. As alternative, the switching matrix 107 may also comprise one-time controllable switches, like e.g. fuse-traces or the like.

(21) FIG. 2 shows a block diagram of an antenna module 200. The antenna module 200 is based on the antenna module 100. Therefore, the antenna module 200 comprises two first signal ports 201, 202 that are connected to four first antenna elements 203, 204, 205, 206 via a switching matrix 207. Below the diagram of the antenna module 200, an amplified version of the switches 208, 209 in the switching matrix 207 is shown.

(22) It can be seen in FIG. 2 that only one of the signal lines between the first signal port 201 and the first antenna elements 203, 205 comprises switch 208, i.e. the signal line between first signal port 201 and first antenna element 205. The same applies to first signal port 202 and the first antenna elements 204, 206, where only the signal line between first signal port 202 and the first antenna element 204 comprises switch 209.

(23) As will be seen in FIG. 4, the switch 208 may either couple first antenna element 205 or first antenna element 204 to first signal port. Switch 209 may either couple first antenna element 204 or first antenna element 205 to the first signal port 202.

(24) It can be seen, that the switching matrix 207 of FIG. 2 is in the same configuration as the switching matrix 107 in FIG. 1. This means, that in the shown state of the switching matrix 207, the first antenna element 203 is fixedly coupled to the first signal port 201, and that the first antenna element 205 is coupled to the first signal port 201 via switch 208. In addition, the first antenna element 206 is fixedly coupled to the first signal port 202, and the first antenna element 204 is coupled to the first signal port 202 via switch 208.

(25) FIG. 3 shows another block diagram of the antenna module 100. In FIG. 3, the switching matrix 107 is configured such that the first antenna elements 103, 104 are both coupled to the first signal port 101. The first antenna elements 105, 106 are both coupled to the first signal port 102.

(26) This means, that the first antenna elements 103, 104, 105, 106 are horizontally coupled pair-wise. Consequently, the first antenna elements 103, 104 will receive the same upstream signals via first signal port 101 and will provide the received downstream signals both to the first signal port 101. The same applies to first antenna elements 105, 106, which will receive the same upstream signals via first signal port 102 and will provide the received downstream signals both to the first signal port 102.

(27) A massive MIMO antenna may comprise a plurality of antenna modules 100. If all the antenna modules 100 in such an antenna are configured as shown in FIG. 3, every row of first antenna elements 103, 104, 105, 106 may be individually provided with a RF signal. Therefore, beamforming in the horizontal direction may be performed within a large beamforming area of about +/−50°.

(28) FIG. 4 shows another block diagram of the antenna module 200. For the antenna module 200 the switching matrix 207 is in the same state as the switching matrix 107 of FIG. 3.

(29) Therefore, in the shown state of the switching matrix 207, the first antenna element 203 is fixedly coupled to the first signal port 201, and that the first antenna element 204 is coupled to the first signal port 201 via switch 208. In addition, the first antenna element 206 is fixedly coupled to the first signal port 202, and the first antenna element 205 is coupled to the first signal port 202 via switch 208.

(30) For sake of simplicity, in the description of the beamforming areas 310, 410 of FIGS. 5 and 6 the reference signs used in the other figures will be used.

(31) FIG. 5 shows a diagram of a possible beamforming area 310 of an antenna module 100, 200, 500.

(32) The beamforming area 310 shows a rather rural landscape with a plurality of buildings (not separately referenced) that are distributed in the landscape in a rather flat fashion.

(33) It is obvious that such a landscape may be adequately provided with wireless communication capabilities by a massive MIMO antenna 620 that provides a horizontally broad coverage area while providing a vertically rather limited coverage area.

(34) In FIG. 5 the coverage area of a massive MIMO antenna 620 is shown, where the switching matrix 107, 207, 507 is configured such that vertically neighboring first antenna elements 103, 104, 105, 106, 203, 204, 205, 206, 503, 504, 505, 506 or second antenna elements 514, 515, 516, 517 are paired. Such a massive MIMO antenna 620 may e.g. provide beam 311 with a width of about 30° and may cover an area of 120° horizontally and 30° vertically.

(35) The configuration of the massive MIMO antenna 620 for this situation may be as shown in FIGS. 1 and 2.

(36) FIG. 6 shows another diagram of a beamforming area 410 of an antenna module 100, 200, 500.

(37) The beamforming area 410 in contrast to the beamforming area 310 shows an urban area. It can be seen, that rather tall buildings (not separately referenced) are present. For ease of understanding, the beamforming area 310 is also shown in FIG. 6. It can be seen, that the beamforming area 310 would not suffice to provide all parts of the shown buildings with adequate coverage.

(38) In the shown example, to supply the tall buildings in the beamforming area 410 a vertical coverage of about 80° would be required. This may be achieved by configuring a massive MIMO antenna 620 to provide a rather large coverage in vertical direction.

(39) The configuration of the massive MIMO antenna 620 for this situation may be as shown in FIGS. 3 and 4.

(40) FIG. 7 shows a block diagram of an antenna module 500. The antenna module 500 is based on the antenna module 100. Therefore, the antenna module 500 comprises first antenna elements 503, 504, 505, 506 that are coupled to first signal input ports 501, 502 via switching matrix 507. In addition to the elements in common with the antenna module 100, the antenna module 500 further comprises second signal ports 512, 513 that are coupled to the switching matrix 507, and second antenna elements 514, 515, 516, 517 that are also coupled to the switching matrix 507.

(41) The second antenna elements 514, 515, 516, 517 are each arranged pair-wise with one of the first antenna elements 503, 504, 505, 506. In these pair-wise arrangements, the single antenna elements 503, 514; 504, 515; 505, 516; 506; 517 are in each case arranged cross polarized to each other.

(42) In an embodiment, all of the first antenna elements 503, 504, 505, 506 may comprise the same polarization, and all of the second antenna elements 514, 515, 516, 517 may comprise the same polarization.

(43) The switching network 507 allows performing different types of interconnections between the first signal input ports 501, 502 and the second signal ports 512, 513. In the following FIGS. 8, 9 and 10, different configurations of the switching network 507 will be shown.

(44) FIG. 8 shows the antenna module 500. The switching matrix 507 in FIG. 8 is configured such that the first signal input port 501 is coupled to the first antenna elements 503, 505. The first signal input port 502 is coupled to the first antenna elements 504, 506. The second signal port 512 is coupled to the second antenna elements 514, 516, and the second signal port 513 is coupled to the second antenna elements 515, 517.

(45) This arrangement configures the antenna module 500 such that vertically neighboring first antenna elements 503, 505 are coupled to the same first signal input port 501, and first antenna elements 504, 506 are coupled to the same first signal input port 502.

(46) Therefore, a rather broad horizontal coverage may be achieved.

(47) FIG. 9 also shows the antenna module 500. The switching matrix 507 in FIG. 9 is configured such that the first signal input port 501 is coupled to the first antenna elements 503, 504. The first signal input port 502 is coupled to the first antenna elements 505, 506. The second signal port 512 is coupled to the second antenna elements 514, 515, and the second signal port 513 is coupled to the second antenna elements 516, 517.

(48) This arrangement configures the antenna module 500 such that horizontally neighboring first antenna elements 503, 504 are coupled to the same first signal input port 501, and first antenna elements 5045 506 are coupled to the same first signal input port 502.

(49) Therefore, a rather broad vertical coverage may be achieved.

(50) FIG. 10 also shows the antenna module 500. The switching matrix 507 in FIG. 10 is configured such that the first signal input port 501 is coupled to the first antenna elements 503 and the second antenna element 514. The first signal input port 502 is coupled to the first antenna elements 505 and the second antenna element 516. The second signal port 512 is coupled to the first antenna elements 504 and the second antenna element 515, and the second signal port 513 is coupled to the first antenna elements 506 and the second antenna element 517.

(51) This arrangement configures the antenna module 500 such that the pairs of cross-polarized antenna elements are each coupled to a single one of the signal ports 501, 502, 512, 513.

(52) In this configuration the advantages of cross-polarization will be lost. However, other advantages, i.e. regarding signal strength, may be provided.

(53) FIG. 11 shows a block diagram of a massive MIMO antenna 620. The massive MIMO antenna 620 comprises an array of 4×4 =16 antenna modules 621 (only the first one is referenced for sake of simplicity). In addition, the massive MIMO antenna 620 comprises for every antenna module 621 transceivers 622. In FIG. 11 the transceivers for antenna module 621 are shown as a single block 622. This block 622 may therefore represent any number, i.e. one or more, of transceivers. The transceivers for the other antenna elements are omitted for sake of clarity.

(54) If for example the antenna modules 621 each comprise four first antenna elements and two first signal ports, two transceivers may be provided for every antenna module 621. The block 622 may therefore represent two transceivers.

(55) If the antenna modules 621 each comprise four first antenna elements, four second antenna elements, two first signal ports, and two second signal ports, four transceivers may be provided for every antenna module 621. The block 622 may therefore represent four transceivers.

(56) It is understood, that any other configuration of the antenna modules 621 may also be supported by the respective number of transceivers.

(57) Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that a variety of alternate and/or equivalent implementations exist. It should be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration in any way. Rather, the foregoing summary and detailed description will provide those skilled in the art with a convenient road map for implementing at least one exemplary embodiment, it being understood that various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope as set forth in the appended claims and their legal equivalents. Generally, this application is intended to cover any adaptations or variations of the specific embodiments discussed herein.

(58) The present invention provides an antenna module 100, 200, 500 for a massive MIMO antenna, the antenna module 100, 200, 500 comprising a plurality of first signal ports 101, 102, 201, 202, 501, 502, a number of first antenna elements 103, 104, 105, 106, 203, 204, 205, 206, 503, 504, 505, 506 arranged in a first matrix arrangement, wherein a number of rows of the first matrix arrangement and/or a number of columns of the first matrix arrangement equals the number of first signal ports 101, 102, 201, 202, 501, 502, and a switching matrix 107, 207, 507 that is configured to controllably couple each of the first signal ports 101, 102, 201, 202, 501, 502 either with all first antenna elements 103, 104, 105, 106, 203, 204, 205, 206, 503, 504, 505, 506 of a respective row of the first matrix arrangement or all first antenna elements 103, 104, 105, 106, 203, 204, 205, 206, 503, 504, 505, 506 of a respective column of the first matrix arrangement. Further, the present invention provides a respective massive MIMO antenna.

LIST OF REFERENCE SIGNS

(59) 100, 200, 500 antenna module 621 antenna module 101, 102, 201, 202, 501, 502 first signal port 103, 104, 105, 106, 203, 204, 205, 206 first antenna element 503, 504, 505, 506 first antenna element 107, 207, 507 switching matrix 208, 209 switch 310, 410 beamforming area 311, 411 beam 512, 513 second signal port 514, 515, 516, 517 second antenna element 620 massive MIMO antenna 622 transceivers