US-12627045-B2 - Advanced antenna system (AAS) subarray splitter with advanced upper sidelobe suppression (AUSS)

US12627045B2US 12627045 B2US12627045 B2US 12627045B2US-12627045-B2

Abstract

Methods and apparatuses are provided for advanced antenna system subarray splitter having advanced upper sidelobe suppression. An antenna system includes a plurality of antenna subarrays. Each of the plurality of antenna subarrays having a subarray input; and at least one subarray splitter in communication with the subarray input. Each of the at least one subarray splitter splits a subarray into a plurality of branches, at least one of the branches including a phase taper function and an amplitude taper function. For each of the plurality of antenna subarrays, the phase taper function and the amplitude taper function includes a plurality of fixed phase values and a plurality of fixed amplitude values, respectively, that are configured to not exceed a predetermined sidelobe suppression target for a plurality of electrical tilt angles across a predetermined angular range for the antenna subarray of the plurality of antenna subarrays.

Inventors

Martin Da Silveira
Neil McGowan

Assignees

TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)

Dates

Publication Date: 20260512
Application Date: 20200415

Claims (20)

1 . An antenna system, the antenna system comprising: a plurality of antenna subarrays, each of the plurality of antenna subarrays having: a subarray input; and at least one subarray splitter in communication with the subarray input, each of the at least one subarray splitter splitting the antenna subarray into a plurality of branches, at least one of the branches comprising a phase only taper function; and for each of the plurality of antenna subarrays, the phase only taper function comprising a plurality of fixed phase values that are configured to not exceed a predetermined sidelobe suppression target for a plurality of electrical tilt angles across a predetermined angular range for the antenna subarray of the plurality of antenna subarrays; each of the plurality of antenna subarrays includes a plurality of antenna elements, a first antenna element of the plurality of antenna elements being separated from a second antenna element of the plurality of antenna elements by a first distance, d; for at least one of the plurality of antenna subarrays, the plurality of antenna elements further comprises a third antenna element that is separated from the second antenna element by a second distance, the second distance being different from the first distance, d; and the first, second and third antenna elements are adjacent to one another.
2 . The antenna system of claim 1 , wherein the phase only taper function comprises a phase progression and a phase taper.
3 . The antenna system of claim 1 , wherein each fixed phase value of the plurality of fixed phase values corresponds to a single frequency.
4 . The antenna system of claim 1 , wherein the predetermined sidelobe suppression target is a maximum sidelobe level threshold in a sidelobe suppression angular region.
5 . The antenna system of claim 4 , wherein the sidelobe suppression angular region is at least one of: according to a specification requirement; and 20 degrees above a peak.
6 . The antenna system of claim 1 , wherein the predetermined angular range is between 2 degrees and 12 degrees relative to a horizon.
7 . The antenna system of claim 1 , wherein the plurality of fixed phase values and a plurality of fixed amplitude values are configured to not exceed the predetermined sidelobe suppression target for the plurality of electrical tilt angles and further for a plurality of frequencies.
8 . The antenna system of claim 1 , wherein the plurality of fixed phase values and a plurality of fixed amplitude values are configured to not exceed the predetermined sidelobe suppression target for the plurality of electrical tilt angles and further for a set of phase and amplitude excitation values corresponding to at least one input signal into the subarray input, the at least one input signal corresponding to at least one cellular signal and the set of phase and amplitude excitation values being for electrically titling a beam of the antenna system in a vertical direction.
9 . The antenna system of claim 1 , wherein each of the plurality of electrical tilt angles are different from one another and the configuration of the plurality of fixed phase values is to not exceed the predetermined sidelobe suppression target for each of the plurality of different, electrical tilt angles across the predetermined angular range.
10 . The antenna system of claim 1 , wherein the configuration is according to an algorithm to minimize a cost function.
11 . The antenna system of claim 10 , wherein the cost function is based at least in part on at least one of: a maximum power of at least one sidelobe in a sidelobe suppression angular region for each of the plurality of electrical tilt angles; a power at a beam peak direction at each of the plurality of electrical tilt angles; a target power of a beam peak at each of the plurality of electrical tilt angles; a target sidelobe power at each of the plurality of electrical tilt angles; and at least one weighting factor associated with a specification requirement for at least one of the plurality of electrical tilt angles.
12 . The antenna system of claim 1 , wherein the at least one subarray splitter comprises: one subarray splitter in communication with the corresponding subarray input.
13 . The antenna system of claim 1 , wherein the at least one subarray splitter comprises: a multi-way splitter in communication with the corresponding subarray input, the multi-way splitter splitting the antenna subarray into at least two antenna subarrays; at least one phase shifter at an output of the multi-way splitter and between the multi-way splitter and at least one antenna subarray of the at least two antenna subarrays; and for each of the at least two antenna subarrays, a second subarray splitter splitting the respective antenna subarray into the plurality of branches.
14 . A method implemented in an antenna system, the method comprising: electrically tilting a beam in a vertical direction using a plurality of antenna subarrays, each of the plurality of antenna subarrays having: a subarray input; and at least one subarray splitter in communication with the subarray input, each of the at least one subarray splitter splitting the antenna subarray into a plurality of branches, at least one of the branches comprising a phase only taper function; and for each of the plurality of antenna subarrays, the phase only taper function comprising a plurality of fixed phase values that are configured to not exceed a predetermined sidelobe suppression target for a plurality of electrical tilt angles across a predetermined angular range for the antenna subarray of the plurality of antenna subarrays; each of the plurality of antenna subarrays includes a plurality of antenna elements, a first antenna element of the plurality of antenna elements being separated from a second antenna element of the plurality of antenna elements by a first distance, d; for at least one of the plurality of antenna subarrays, the plurality of antenna elements further comprises a third antenna element that is separated from the second antenna element by a second distance, the second distance being different from the first distance, d; and the first, second and third antenna elements are adjacent to one another.
15 . The method of claim 14 , wherein the phase only taper function comprises a phase progression and a phase taper.
16 . The method of claim 14 , wherein each fixed phase value of the plurality of fixed phase values corresponds to a single frequency.
17 . The method of claim 14 , wherein the predetermined sidelobe suppression target is a maximum sidelobe level threshold in a sidelobe suppression angular region.
18 . The method of claim 17 , wherein the sidelobe suppression angular region is at least one of: according to a specification requirement; and 20 degrees above a peak.
19 . The method of claim 14 , wherein the predetermined angular range is between 2 degrees and 12 degrees relative to a horizon.
20 . The method of claim 14 , wherein the plurality of fixed phase values and a plurality of fixed amplitude values are configured to not exceed the predetermined sidelobe suppression target for the plurality of electrical tilt angles and further for a plurality of frequencies.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a Submission Under 35 U.S.C. § 371 for U.S. National Stage Patent Application of International Application Number: PCT/IB2020/053574, filed Apr. 15, 2020 entitled “ADVANCED ANTENNA SYSTEM (AAS) SUBARRAY SPLITTER WITH ADVANCED UPPER SIDELOBE SUPPRESSION (AUSS),” the entirety of which is incorporated herein by reference. TECHNICAL FIELD The present disclosure relates wireless communications and, in particular, to an advanced antenna system (AAS) subarray splitter with advanced upper sidelobe suppression (AUSS). BACKGROUND Wireless networks may use advanced antenna systems to support an increasing demand for wireless communications. These advanced antenna systems may be configured to operate over a wide range of frequencies and/or angles. In addition, these antennas may be designed to reduce unwanted signals such as the sidelobes, which may represent energy waste and/or cause interference to other equipment. Arrangements to further improve the performance and efficiency of such antenna systems are still being considered. SUMMARY Some embodiments of the present disclosure advantageously provide methods, apparatuses and systems related to advanced antenna system (AAS) subarray splitter with advanced upper sidelobe suppression (AUSS). According to one aspect of the present disclosure, an antenna system is provided. The antenna system includes a plurality of antenna subarrays. Each of the plurality of antenna subarrays has a subarray input; and at least one subarray splitter in communication with the subarray input. Each of the at least one subarray splitter splitting the antenna subarray into a plurality of branches. At least one of the branches includes a phase taper function and an amplitude taper function. For each of the plurality of antenna subarrays, the phase taper function and the amplitude taper function including a plurality of fixed phase values and a plurality of fixed amplitude values, respectively, that are configured to not exceed a predetermined sidelobe suppression target for a plurality of electrical tilt angles across a predetermined angular range for the antenna subarray of the plurality of antenna subarrays. In some embodiments, the phase taper function comprises a phase progression and a phase taper. In some embodiments, each fixed phase value of the plurality of fixed phase values corresponds to a single frequency, and each fixed amplitude value of the plurality of fixed amplitude values corresponds to a single frequency. In some embodiments of this aspect, the antenna system further includes, for each of the plurality of antenna subarrays, a plurality of antenna elements, a first antenna element of the plurality of antenna elements being separated from a second antenna element of the plurality of antenna elements by a first distance, d, wherein the phase taper function is based in part on the first distance, d. In some embodiments, the antenna system further includes, for at least one of the plurality of antenna subarrays, a third antenna element of the plurality of antenna elements, the third antenna element being separated from the second antenna element by a second distance, the second distance being different from the first distance, d. In some embodiments of this aspect, the predetermined sidelobe suppression target is a maximum sidelobe level threshold in a sidelobe suppression angular region. In some embodiments of this aspect, the sidelobe suppression angular region is at least one of: according to a specification requirement; and 20 degrees above a peak. In some embodiments of this aspect, the predetermined angular range is between 2 degrees and 12 degrees relative to a horizon. In some embodiments of this aspect, the plurality of fixed phase values and the plurality of fixed amplitude values are configured to not exceed the predetermined sidelobe suppression target for the plurality of electrical tilt angles and further for a plurality of frequencies. In some embodiments of this aspect, the plurality of fixed phase values and the plurality of fixed amplitude values are configured to not exceed the predetermined sidelobe suppression target for the plurality of electrical tilt angles and further for a set of phase and amplitude excitation values corresponding to at least one input signal into the subarray input, the at least one input signal corresponding to at least one cellular signal and the set of phase and amplitude excitation values being for electrically titling a beam of the antenna system in a vertical direction. In some embodiments of this aspect, each of the plurality of electrical tilt angles are different from one another and the configuration of the plurality of fixed phase values and the plurality of fixed amplitude values is to not exceed the predetermined sidelobe suppression target for each of the plurality of different, electrical tilt angles across the predetermined angular range. In some embodiments of