Active antenna system
The present invention relates to an active antenna system, AAS, for controlling coverage in a telecommunication network, and the AAS comprising a plurality of subarrays each having multiple radiating elements. The AAS is configured to provide coverage in a coverage angular range and the plurality of subarrays comprising at least two types of subarrays. The at least two types of subarrays comprises: a first type of subarray with a first radiation pattern having at least a first angular region with gain below a first threshold value, and a second type of subarray with a second radiation pattern having at least a second angular region with gain below a second threshold value, wherein the second radiation pattern deviates from the first radiation pattern and the first angular region in the first radiation pattern differs from the second angular region in the second radiation pattern.
1 . A node in a telecommunication system comprising an active antenna system, AAS, for controlling coverage in the telecommunication network, the AAS comprising a plurality of subarrays each having multiple radiating elements, the plurality of subarrays comprising at least two types of subarrays comprising:
a first type of subarray with a first radiation pattern having at least a first angular region with gain below a first threshold value, and
a second type of subarray with a second radiation pattern having at least a second angular region with gain below a second threshold value,
wherein the second radiation pattern deviates from the first radiation pattern and the first angular region in the first radiation pattern differs from the second angular region in the second radiation pattern.
2 . The node according to claim 1 , wherein the first radiation pattern has a gain above the first threshold value in the second angular region.
3 . The node according to claim 1 , wherein the second radiation pattern has a gain above the second threshold value in the first angular region.
4 . The node according to claim 1 , wherein the first type of subarray has a different phase taper and/or a different amplitude taper compared to the second type of subarray.
5 . The node according to claim 1 , wherein each angular region is in a direction including a null in the respective radiation pattern.
6 . The node according to claim 1 , wherein each threshold value is less than one hundredths of maximal gain of each radiation pattern.
7 . The node according to claim 1 , wherein the first threshold value and the second threshold value are substantially identical.
8 . The node according to claim 1 , wherein a combined radiation pattern created by the at least two types of subarrays has a maximal gain envelope pattern above a gain threshold value for all angles within a coverage angular range of the AAS.
9 . The node according to claim 1 , wherein each type of subarray has a height, within which height the multiple radiating elements are arranged, wherein the first type of subarray has a first height and the second type of subarray has a second height, and the first height differs compared to the second height.
10 . The node according to claim 1 , wherein adjacently arranged radiating elements within a subarray have an element separation, and the element separation of the first type of subarray differs compared to the element separation of the second type of subarray.
11 . The node according to claim 1 , wherein the first type of subarray comprises a first number (N1) of radiating elements, and the second type of subarray comprises a second number (N2) of radiating elements.
12 . The node according to claim 11 , wherein the first number
(N1) of radiating elements is equal to the second number (N2) of radiating elements.
13 . The node according to claim 11 , wherein the first number (N1) of radiating elements differs compared to the second number (N2) of radiating elements.
14 . The node according to claim 1 , wherein each radiating element is a dual polarized radiating element.
15 . The node according to claim 1 , wherein the plurality of subarrays are arranged on an antenna surface, and the first type of subarray and/or the second type of subarray are non-symmetrically arranged over the antenna surface in relation to a symmetry line (L).
16 . The node according to claim 1 , wherein the plurality of subarrays are arranged on an antenna surface, and the first type of subarray and/or the second type of subarray are symmetrically arranged over the antenna surface in relation to a symmetry line (L).
17 . A method for controlling coverage in a telecommunication network with an active antenna system, AAS, the AAS comprising a plurality of subarrays each having multiple radiating elements, the AAS being configured to provide coverage in a coverage angular range and the plurality of subarrays comprising at least two types of subarrays, the method comprising:
configuring a first type of subarray with a first radiation pattern having at least a first angular region with gain below a first threshold value,
configuring a second type of subarray with a second radiation pattern having at least a second angular region with gain below a second threshold value, and
configuring the second radiation pattern to deviate from the first radiation pattern such that the first angular region in the first radiation pattern differs from the second angular region in the second radiation pattern.
18 . The method for controlling coverage according to claim 17 , further comprising selecting the first radiation pattern to have a gain above the first threshold value in the second angular region.
19 . The method for controlling coverage according to claim 17 , further comprising selecting the second radiation pattern to have a gain above the second threshold value in the first angular region.
20 . The method for controlling coverage according to claim 17 , further comprising selecting the first type of subarray to have different phase taper and/or amplitude taper compared to the second type of subarray to create different radiation patterns.