EP-4738612-A1 - SYSTEM AND METHOD FOR REAL TIME MULTI-FREQUENCY OPERATION USING METASURFACE-BASED MECHANICALLY CONTROLLED TUNABLE POLARIZATION CONVERSION

EP4738612A1EP 4738612 A1EP4738612 A1EP 4738612A1EP-4738612-A1

Abstract

Polarization is a parameter that plays a pivotal role in communication during transmission and reception of signals. Presence of lumped elements along a signal path or around a region of interaction of incoming waves with surface may trigger distortion in the signals, leading to loss or damage of information. Generally, electronic lumped components are used but their functional abilities are limited during practical operations. The present disclosure addresses the unresolved problems of the conventional system by providing a system and method for real time multi-frequency operation using metasurface-based mechanically controlled tunable polarization conversion. In the present disclosure, a multi-band polarization converter design is provided whose operational parameters including (i) bands of operation, (ii) bandwidth, and (iii) number of bands are controlled together by modulating an air-gap of a reflective unit cell of a two-dimensional array structure of a metasurface using a motorized mechanical arrangement.

Inventors

BANERJEE, AMARTYA
NAVEEN, BHUKYA
CHAKRAVARTY, TAPAS
KUMAR, ACHANNA ANIL
GHATAK, ROWDRA

Assignees

Tata Consultancy Services Limited

Dates

Publication Date: 20260506
Application Date: 20250919

Claims (12)

A mechanically controlled tunable polarization conversion system (100), comprising: a base station (102) in communication with a plurality of user equipment (104), wherein the base station comprises: a signal source (106) that generates a plurality of communication signals; an antenna array (108) comprising a plurality of antennas (108A) coupled to a two-dimensional array structure of a metasurface (110), wherein the two-dimensional array structure of the metasurface (110) comprises a plurality of reflective unit cells (112) arranged in a periodic manner with a predefined periodicity, wherein each of the plurality of reflective unit cells (112) of the two-dimensional array structure of the metasurface (110) comprises a first layer (114) and a second layer (116) separated by a tunable airgap therebetween, and the first layer (114) of each of the plurality of reflective unit cells comprises a square patch (114A) diagonally enclosed by a first set of L-shaped resonators (114B), and a second set of L-shaped resonators (114C) enclosing the first set of L-shaped resonators (114B) placed on a dielectric substrate (114D) at a predefined distance from the first set of L-shaped resonators (114B); a motorized mechanical arrangement (118); and a controller unit (120) that is operably connected to the antenna array (108), the two-dimensional array structure of the metasurface (110) and the motorized mechanical arrangement (118), wherein the controller unit comprises: one or more data storage devices (120A) configured to store instructions; one or more communication interfaces (120B); and one or more hardware processors (120C) operatively coupled to the one or more data storage devices (120A) via the one or more communication interfaces (120B), wherein the one or more hardware processors (120C) are configured by the instructions to: control the motorized mechanical arrangement to translate a back and forth motion of the second layer of each of the plurality of reflective unit cells of the two-dimensional array structure of the metasurface such that the tunable air gap between the first layer and the second layer is modulated to control one or more operational parameters associated with polarization conversion of the plurality of communication signals generated by the signal source.
The mechanically controlled tunable polarization conversion system as claimed in claim 1, wherein the first layer of the metasurface represents a patch-on substrate layer and the second layer of the metasurface represents a ground plane layer.
The mechanically controlled tunable polarization conversion system as claimed in claim 1, wherein the one or more operational parameters associated with polarization conversion comprises at least one of (i) a frequency of operation, (ii) number of frequency regions for operation, and (iii) bandwidth of operation.
The mechanically controlled tunable polarization conversion system as claimed in claim 3, wherein controlling the one or more operational parameters associated with polarization conversion enables tuning and diversifying one or more operational abilities of a polarization converter to multi-frequency and multi-band performance in real time.
A processor implemented method (200), comprising: providing (202), via one more hardware processors, a base station in communication with a plurality of user equipment, wherein the base station comprises a signal source that generates a plurality of communication signals, and an antenna array comprising a plurality of antennas coupled to a two-dimensional array structure of a metasurface; receiving (204), via the one more hardware processors, the plurality of communication signals generated by the signal source on the two-dimensional array structure of a metasurface through the antenna array, wherein the two-dimensional array structure of the metasurface comprises a plurality of reflective unit cells arranged in a periodic manner with a predefined periodicity, and wherein each of the plurality of reflective unit cells of the two-dimensional array structure of the metasurface comprises a first layer and a second layer separated by a tunable airgap there between, and the first layer of each of the plurality of reflective unit cells comprises a square patch diagonally enclosed by a first set of L-shaped resonators, and a second set of L-shaped resonators enclosing the first set of L-shaped resonators placed on a dielectric substrate at a predefined distance from the first set of L-shaped resonator; and controlling (206), via the one more hardware processors, a motorized mechanical arrangement to translate a back and forth motion of the second layer of each of the plurality of reflective unit cells of the two-dimensional array structure of the metasurface such that the tunable air gap between the first layer and the second layer of each of the plurality of reflective unit cells is modulated to control one or more operational parameters associated with polarization conversion of the plurality of communication signals generated by the signal source.
The processor implemented method as claimed in claim 5, wherein the first layer of the metasurface represents a patch-on substrate layer and the second layer of the metasurface represents a ground plane layer.
The processor implemented method as claimed in claim 5, wherein the one or more operational parameters associated with polarization conversion comprises at least one of (i) a frequency of operation, (ii) number of frequency regions for operation, and (iii) bandwidth of operation.
The processor implemented method as claimed in claim 7, wherein controlling the one or more operational parameters associated with polarization conversion enables tuning and diversifying one or more operational abilities of a polarization converter to multi-frequency and multi-band performance in real time.
One or more non-transitory machine-readable information storage mediums comprising one or more instructions which when executed by one or more hardware processors cause: providing, a base station in communication with a plurality of user equipment, wherein the base station comprises a signal source that generates a plurality of communication signals, and an antenna array comprising a plurality of antennas coupled to a two-dimensional array structure of a metasurface; receiving, the plurality of communication signals generated by the signal source on the two-dimensional array structure of a metasurface through the antenna array, wherein the two-dimensional array structure of the metasurface comprises a plurality of reflective unit cells arranged in a periodic manner with a predefined periodicity, and wherein each of the plurality of reflective unit cells of the two-dimensional array structure of the metasurface comprises a first layer and a second layer separated by a tunable airgap there between, and the first layer of each of the plurality of reflective unit cells comprises a square patch diagonally enclosed by a first set of L-shaped resonators, and a second set of L-shaped resonators enclosing the first set of L-shaped resonators placed on a dielectric substrate at a predefined distance from the first set of L-shaped resonator; and controlling, a motorized mechanical arrangement to translate a back and forth motion of the second layer of each of the plurality of reflective unit cells of the two-dimensional array structure of the metasurface such that the tunable air gap between the first layer and the second layer of each of the plurality of reflective unit cells is modulated to control one or more operational parameters associated with polarization conversion of the plurality of communication signals generated by the signal source.
The one or more non-transitory machine-readable information storage mediums as claimed in claim 9, wherein the first layer of the metasurface represents a patch-on substrate layer and the second layer of the metasurface represents a ground plane layer.
The one or more non-transitory machine-readable information storage mediums as claimed in claim 9, wherein the one or more operational parameters associated with polarization conversion comprises at least one of (i) a frequency of operation, (ii) number of frequency regions for operation, and (iii) bandwidth of operation.
The one or more non-transitory machine-readable information storage mediums as claimed in claim 11, wherein controlling the one or more operational parameters associated with polarization conversion enables tuning and diversifying one or more operational abilities of a polarization converter to multi-frequency and multi-band performance in real time.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS AND PRIORITY The present application claims priority from Indian provisional patent application no. 202421083564, filed on October 31, 2024. TECHNICAL FIELD The disclosure herein generally relates to the field of polarization conversion, and, more particularly, to a system and method for real time multi-frequency operation using metasurface-based mechanically controlled tunable polarization conversion. BACKGROUND Polarization is a parameter that plays a pivotal role in communication during transmission and reception of signals. Polarization of a signal is defined by time-varying characteristics of its electric field vector at a fixed point in space. Often it becomes the requirement to effectively control and convert the polarization of electromagnetic (EM) signals for practical system applications. For security enhancement, inference reduction and protection from eavesdropping elements, polarization converters are proposed as effective first-line-of-defence solutions for RF communication. Two dimensional periodic arrays of specially designed unit cell elements, or more specifically metasurface designs are proposed as potential solutions to develop such effective and robust polarization converters for real-world applications. State-of-the-art RF communication systems demand not only multi-band or wideband converters but also such designs which offer real-time control over their performance. Generally, electronic lumped components are used to achieve real-time control over such metasurface designs, however this trend also limits its functional abilities during practical operations. Presence of lumped elements along a signal path or around a region of interaction of incoming waves with surface may trigger distortion in the signals, leading to loss or damage of information. Additionally, the presence of lumped elements indicates a need of meticulously designed biasing circuits which further adds to complexity and cost of the designs concerned. SUMMARY Embodiments of the present disclosure present technological improvements as solutions to one or more of the above-mentioned technical problems recognized by the inventors in conventional systems. For example, in one embodiment, a mechanically controlled tunable polarization conversion system is provided. The mechanically controlled tunable polarization conversion system comprising: a base station in communication with a plurality of user equipment, wherein the base station comprises: a signal source that generates a plurality of communication signals; an antenna array comprising a plurality of antennas coupled to a two-dimensional array structure of a metasurface, wherein the two-dimensional array structure of the metasurface comprises a plurality of reflective unit cells arranged in a periodic manner with a predefined periodicity, wherein each of the plurality of reflective unit cells of the two-dimensional array structure of the metasurface comprises a first layer and a second layer separated by a tunable airgap therebetween, and the first layer of each of the plurality of reflective unit cells comprises a square patch diagonally enclosed by a first set of L-shaped resonators, and a second set of L-shaped resonators enclosing the first set of L-shaped resonators placed on a dielectric substrate at a predefined distance from the first set of L-shaped resonators; a motorized mechanical arrangement; and a controller unit that is operably connected to the antenna array, the two-dimensional array structure of the metasurface and the motorized mechanical arrangement, wherein the controller unit comprises: one or more data storage devices configured to store instructions; one or more communication interfaces; and one or more hardware processors operatively coupled to the one or more data storage devices via the one or more communication interfaces, wherein the one or more hardware processors are configured by the instructions to: control the motorized mechanical arrangement to translate a back and forth motion of the second layer of each of the plurality of reflective unit cells of the two-dimensional array structure of the metasurface such that the tunable air gap between the first layer and the second layer is modulated to control one or more operational parameters associated with polarization conversion of the plurality of communication signals generated by the signal source. In another aspect, a processor implemented method is provided. The processor implemented method comprising: providing, via one more hardware processors, a base station in communication with a plurality of user equipment, wherein the base station comprises a signal source that generates a plurality of communication signals, and an antenna array comprising a plurality of antennas coupled to a two-dimensional array structure of a metasurface; receiving, via the one more hardware processors, the plurality of communication signals generated by the signal sourc