Tunable phase shifting system, and a method for operating thereof

Abstract

Disclosed examples generally relate to a tunable phase shifting system and a method for operating thereof. In some examples, the tunable phase shifting system, includes: (i) a surface-confined electromagnetic field waveguide assembly comprising a signal transmission pathway extending between an input interface and an output interface, the signal transmission pathway supporting a surface‑guided electromagnetic mode and comprising two or more cells, each cell comprising a conductive segment and an adjacent gap segment arranged along the pathway; and (ii) at least one disturber positioned to interact with a field of the mode, wherein when an input signal is applied at the input interface, the system generates, at the output interface, a corresponding phase-shifted signal.

Description

TUNABLE PHASE SHIFTING SYSTEM, AND A METHOD FOR OPERATING THEREOFCROSS-REFERENCE TO RELATED APPLICATION(S)

[0001] This application claims priority to, and the benefit of, United States Provisional Patent Application No. 63 / 756,369, filed on February 10, 2025, the entire contents of which are hereby incorporated by reference.FIELD

[0002] The present disclosure generally relates to phase shifters, and more particularly, to a tunable phase shifting system and a method for operating thereof.BACKGROUND

[0003] Phase shifters are essential components of various microwave, millimeter-wave (mm-wave), and optical systems. These include phased arrays and RF front ends, smart antennas, modulators, spectrometer and radiometer instruments, satellite communications, sensors and material detection, and the like.

[0004] To that end, applications of the mentioned systems include, (i) providing measured information in space mission for new science objectives using spectrometer and radiometer instruments, (ii) electronic beam scanning in order to remove large and heavy motors for beam steering or to avoid mechanical movements of spacecrafts, and (iii) next generations of communication system (5G and beyond) circuits such as delay circuits, signal processing, and antenna directivity control, to name a few.

[0005] At a broad level, a phase shifter functions to change the phase of an input signal to a desired level. According to the desired application, phase shifters operate at various frequency ranges requiring different fabrication technologies and configurations appropriate for their implementations. Phase shifter performances are compared according to the factors: level and variation of insertion loss with respect to frequency, linearity of phase shift response versus bandwidth, switching time in tunable phase shifters, weigh and complexity of configuration, figure of merit (FOM) which is level of phase shift per 1 dB insertion loss, amount and resolution of phase shift, and cost of implementation.-1-WSLEGAL\055326\00509\43335578v5

[0006] According to a specific application, an appropriate phase shifter can be designed using different technologies. Generally, at microwave and mm-wave frequencies, phase shifters are grouped in different categories including PIN diodes, FET switches, MMIC switches, radio frequency microelectromechanical systems (RF MEMS), liquid crystal, liquid metals, ferrite materials, dielectric loaded transmission lines.SUMMARY

[0007] In at least one broad aspect, there is provided a tunable phase shifting system, comprising: a surface-confined electromagnetic field waveguide assembly comprising a signal transmission pathway extending between an input interface and an output interface, the signal transmission pathway supporting a surface-guided electromagnetic mode and comprising two or more cells, each cell comprising a conductive segment and an adjacent gap segment arranged along the pathway; and at least one disturber positioned to interact with a field of the mode, wherein when an input signal is applied at the input interface, the system generates, at the output interface, a corresponding phase-shifted signal.

[0008] In some examples, the input signal is at a lower frequency, such as microwave or terahertz frequency.

[0009] In some examples, the assembly further comprises a substrate, and each conductive segment is disposed over the substrate.

[0010] In some examples, the conductive segments in the two or more cells are coupled along a continuous longitudinal portion to form a corrugated pattern.

[0011] In some examples, the at least one disturber is associated with a gap segment and, in a higher-coupling state, is positioned over or overlapping the gap segment.

[0012] In some examples, the at least one disturber is physically movable relative to the gap segment to achieve different degrees of phase shifting.

[0013] In some examples, the system further comprises a micro-actuator for effecting the physical movement.-2-WSLEGAL\055326\00509\43335578v5

[0014] In some examples, the at least one disturber is tunable, with dielectric properties adjustable by an external energy source to provide a controllable phase shift.

[0015] In some examples, the input and output interfaces comprise coplanar waveguide (CPW) transitions, or the surface-confined field assembly is integrated with a substrate-integrated waveguide (SIW).

[0016] In some examples, the surface-guided electromagnetic mode comprises a spoof surface wave.

[0017] In some examples, the at least one disturber comprises two or more disturbers that are independently or concurrently controllable to provide combined or separate phase shift contributions.

[0018] In another broad aspect, there is provided a tunable phase shifting system, comprising: surface-confined field assembly having an input interface and an output interface, and comprising a metal layer disposed over a substrate to form a metal-dielectric interface, wherein the metal-dielectric interface is configured to support a surface-guided electromagnetic mode at an input signal at optical near-IR frequencies; and at least one disturber positioned to interact with a field of the mode, wherein when the input signal is applied at the input interface, the system generates, at the output interface, a corresponding phase-shifted signal.

[0019] In some examples, the at least one disturber is physically movable relative to the metal layer to achieve different degrees of phase shifting.

[0020] In some examples, the at least one disturber is tunable, with dielectric properties adjustable by an external energy source to provide a controllable phase shift.

[0021] In some examples, the surface-guided electromagnetic mode comprises a surface plasmon polariton supported by the metal-dielectric interface.

[0022] In some examples, the at least one disturber comprises two or more disturbers that are independently or concurrently controllable to provide combined or separate phase contributions.

[0023] In some examples, the system further comprising an antenna element coupled to the output interface.-3-WSLEGAL\055326\00509\43335578v5

[0024] In another broad aspect, there is provided a phased antenna array comprising a plurality of the tunable phase shifting systems, as defined in any one of claims 1 to 16, wherein each tunable phase shifting system is coupled to an antenna element at a respective output interface.

[0025] In another broad aspect, there is provided a method of operating the tunable phase shifting system of any one of claims 1 to 17, comprising: identifying a target phase shift for the phase-shifted output signal; determining a configuration state for the at least one disturber to effect the target phase shift; and operating a control mechanism to achieve the configuration state.

[0026] In some examples, the configuration state comprises one or more of (i) a positioning the at least one disturber, or (ii) a tuning factor of the at least one disturber.

[0027] Other features and advantages of the present application will become apparent from the following detailed description taken together with the accompanying drawings. It should be understood, however, that the detailed description and the specific examples, while indicating preferred embodiments of the application, are given by way of illustration only, since various changes and modifications within the spirit and scope of the application will become apparent to those skilled in the art from this detailed description.BRIEF DESCRIPTION OF THE DRAWINGS

[0028] For a better understanding of the various embodiments described herein, and to show more clearly how these various embodiments may be carried into effect, reference will be made, by way of example, to the accompanying drawings which show at least one example embodiment, and which are now described. The drawings are not intended to limit the scope of the teachings described herein.

[0029] FIG. 1 A is schematic illustration of a tunable phase shifting system.

[0030] FIG. IB is a schematic illustration of the tunable phase shifting system feeding an antenna element.

[0031] FIG. 2A is a simplified block diagram showing the tunable phase shifting system feeding an antenna element.-4-WSLEGAL\055326\00509\43335578v5

[0032] FIG. 2B is a simplified block diagram showing multiple tunable phase shifting systems feeding antenna elements, in a phased array antenna assembly.

[0033] FIGs. 3A - 3B show a metal corrugation approach for producing a localized field at microwave and / or THz frequencies (FIG. 3A), and field confinement in the corrugated metals (FIG.3B).

[0034] FIGs. 4A - 4D show horizontal (FIG. 4A) and vertical (FIG. 4B) movement of one disturber relative to an I-shaped corrugated metal, and a side view of the horizontal movement of one disturber in FIG. 4A (FIG. 4C) and of the vertical movement of one disturber in FIG. 4B (FIG. 4D).

[0035] FIGs. 5A - 5D show horizontal (FIG. 5A) and vertical (FIG. 5B) movement of two disturbers relative to an I-shaped corrugated metal, and a side view of the horizontal movement of the disturbers in FIG. 5A (FIG. 5C) and of the vertical movement of the disturbers in FIG. 5B (FIG. 5D).

[0036] FIGs. 6A - 6D show horizontal movement of (i) one disturber (FIG. 6A) and two disturbers (FIG. 6B) from a metal section to a gap section, between two connected I-shaped corrugated metals, (ii) a top view of the horizontal movement of two disturbers in FIG. 6B (FIG. 6C); and (iii) a top view of the horizontal movement of two disturbers in a further example embodiment (FIG. 6D).

[0037] FIGs. 7A - 7C show (i) horizontal movement of one disturber (FIG. 7A), two disturbers (FIG. 7B), and multiple independently movable disturbers as part of a bit concept (FIG. 7C) from a metal section to a gap section between connected I-shaped cells, and (ii) a top view of the configuration of FIG. 7C (FIG. 7D).

[0038] FIG. 8 shows two disturbers used with L-shaped cells.

[0039] FIGs. 9A - 9D show corrugated L-shaped metals connected to two co-planar waveguides (CPW) through transitions, and illustrating: (i) a single disturber in vertical movement (FIG. 9A) and horizontal movement (FIG. 9B), and (ii) two disturbers in vertical movement (FIG. 9C) and horizontal movement (FIG. 9D).

[0040] FIGs. 10A - 10B illustrate an example where a substrate beneath the signal line is exposed to air in certain areas, allowing for the movement of a single movable disturber (FIG. 10A) and more than one movable disturber (FIG. 10B).-5-WSLEGAL\055326\00509\43335578v5

[0041] FIGs. 11 A - 11C illustrate (i) vertical movement (FIG. 11 A) and horizonal movement (FIG. 1 IB), of a disturber in a tunable phase shifting system used with a substrate integrated waveguide (SIW) structure, as well (ii) the SIW structure from a top view in the case of horizontal disturber movement (FIG. 11C).

[0042] FIGs. 12A - 12B show a bulky U-shaped corrugated metal for cases of vertical and horizontal movable disturbers (FIG. 12A), and for localized field transmission (FIG. 12B).

[0043] FIGs. 13A - 13B show (i) electromagnetic field arrows on the connected U-shaped corrugations, and the generated polaritons (FIG. 13 A), and (ii) the corresponding localized field transmission (FIG. 13B).

[0044] FIG. 14 shows a tunable phase shifting system comprising of U-shaped metals with a horizontally movable disturber.

[0045] FIGs. 15A - 15B show a tunable phase shifting system comprising of U-shaped metals with a vertically movable disturber (FIG. 15 A), and a side view thereof (FIG. 15B).

[0046] FIGs. 16A - 16B show (i) a tunable phase shifting system based on movement of the disturber from a metallic part to a gap between two cells in a U-shaped metal (FIG. 16A), and (ii) a side view of the phase shifter in FIG. 16 A, with a demonstration of the electric field by arrows (FIG.16B).

[0047] FIGs. 17A - 17B show (i) a metal (grey color) and dielectric interference appropriate for intrinsic localized surface wave excitation, at optical frequencies (FIG. 17 A), and (ii) confined surface waves at the metal (grey color) and dielectric interference, at optical frequencies (FIG. 17B).

[0048] FIGs. 18A - 18B show a tunable phase shifting system implemented at optical frequencies using a metal (grey area) and dielectric interference, with a horizontally movable disturber or disturbers (FIG. 18 A), and (ii) a side view thereof (FIG. 18B).

[0049] FIG. 19 is a heater (black cylinder) inserted into a material forming the disturber, and being used for changing its material properties.

[0050] FIGs. 20A - 20B show a tunable phase shifting system based on changing material properties of a disturber using a heater, including with a single disturber (FIG. 20A) and two disturbers (FIG. 20B).-6-WSLEGAL\055326\00509\43335578v5

[0051] FIG. 21 is an illustration of a U-shaped corrugated metal loaded by a disturber.

[0052] FIGs. 22A - 22B show an optical tunable phase shifting system, tuned by changing material properties of the disturber using heating (FIG. 22A), and a side view thereof (FIG. 22B).

[0053] FIGs. 23A - 23C is an example of, (i) connecting a phase shifter to a single antenna (FIG. 23 A), and (ii) a phased array antenna comprising of more than two antennas (FIGs. 23B, 23C).

[0054] FIG. 24 shows an example method for operating a tunable phasing shifting system.

[0055] FIG. 25A shows simulated results of the achieved phase shift from the disclosed phase shifter, in FIG. 9B and FIG. 9D, by loading three metal corrugations with a dielectric disturber made of TMM3 (dielectric constant er=3.54) on one side and two sides.

[0056] FIG. 25B shows simulated results of amplitude of the phase shifted signal from the proposed phase shifter, in FIG. 9B and FIG. 9D, by loading three metal corrugations with a dielectric disturber made of TMM3 (dielectric constant er=3.54) on one side and two sides.

[0057] FIG. 25C shows simulated results of the achieved phase shift from the proposed phase shifter, in FIG. 9D, by loading three metal corrugations with a dielectric disturber made of different materials, TMM3 (dielectric constant er=3.27), TMM6 (dielectric constant er=6.08), TMM10 (dielectric constant cr=9.2), TMM13 (dielectric constant er=12.85) two sides.

[0058] FIG. 25D shows simulated amplitude results of the phase shifted signal from the proposed phase shifter, in FIG. 9D, by loading three metal corrugations with a dielectric disturber made of different materials, TMM3 (dielectric constant er=3.27), TMM6 (dielectric constant er=6.08), TMM10 (dielectric constant cr=9.2), TMM13 (dielectric constant er=12.85) two sides.

[0059] FIG. 25E shows simulated results of the achieved phase shift from the proposed phase shifter, in FIG. 9D, in three cases of five, seven, and nine loaded metal corrugations by a dielectric disturber made of TMM6 (dielectric constant er=6.08) two sides.

[0060] FIG. 26 shows an example hardware configuration for a system for controlling a configuration of the tunable phase shifting system.-7-WSLEGAL\055326\00509\43335578v5DETAILED DESCRIPTION

[0061] Disclosed examples relate to a tunable phase shifting system using a localized electromagnetic field, and a method for operating thereofI. DEFINITIONS

[0062] Any term or expression not expressly defined herein shall have its commonly accepted definition understood by a person skilled in the art. As used herein, the following terms have the following meanings.

[0063] “Corrugation” means a structuring of connected or coupled conductive surfaces or segments that include intervening gaps (e.g., grooves, slots, holes, or ribs), and which gaps may in some examples be arranged periodically or quasi-periodically. In some examples, the gaps in the corrugation pattern are arranged with a subwavelength pitch (with reference to an input signal), and defined depth / width. As provided herein, and without limitation to theory, the corrugation may be used to modify local boundary conditions to support and confine a surface-guided electromagnetic mode (e.g., spoof surface plasmon polaritons), thereby controlling its dispersion, effective index, and propagation along a structured path.

[0064] “Electromagnetic field” refers to a physical field produced by moving electric charges, comprising of electric and magnetic components, and influencing the behavior of charged particles. It spans the electromagnetic spectrum, including waves such as radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays, each characterized by different frequencies and wavelengths.

[0065] "Evanescent decay" refers to the rapid exponential drop in field amplitude moving away from a surface or interface where a wave is bound. For surface-guided modes, the energy is typically concentrated near the surface and decreases quickly along the perpendicular (vertical) direction, often over a short decay length.-8-WSLEGAL\055326\00509\43335578v5

[0066] "Evanescent wave" refers to a non-propagating field component that is bound to an interface and decays exponentially away from that interface, carrying energy locally without radiating into the far field.

[0067] "Memory" refers to a non-transitory tangible computer-readable medium for storing information in a format readable by a processor, and / or instructions readable by a processor to implement an algorithm. The term "memory" includes a plurality of physically discrete, operatively connected devices despite use of the term in the singular. Non-limiting types of memory include solid-state, optical, and magnetic computer readable media. Memory may be non-volatile or volatile. Instructions stored by a memory may be based on a plurality of programming languages known in the art, with non-limiting examples including the C, C++, Python ™, MATLAB ™, and Java ™ programming languages.

[0068] "Microwave frequencies" refer to electromagnetic waves with wavelengths from about 1 m to 1 mm and frequencies approximately from about 300 MHz to 300 GHz.

[0069] "Near-IR frequencies" refer to electromagnetic waves spanning bands typically from about 700-2500 nm in wavelength (near-infrared), which generally correspond to frequencies on the order of about 120-400 THz (near-IR).

[0070] "Optical frequencies" refer to electromagnetic waves in the visible band, typically spanning wavelengths of about 400-700 nm, corresponding to frequencies on the order of about 430-750 THz.

[0071] “Phase shifting” refers to the process of changing the phase of a wave (e.g., in signals or electromagnetic waves), relative to a reference.

[0072] "Processor" refers to one or more electronic devices that is / are capable of reading and executing instructions stored on a memory to perform operations on data, which may be stored on a memory or provided in a data signal. The term "processor" includes a plurality of physically discrete, operatively connected devices despite use of the term in the singular. Non-limiting examples of processors include devices referred to as microprocessors, microcontrollers, central processing units (CPU), and digital signal processors.

[0073] "Spoof surface wave" (e.g., spoof SPP) refers to an engineered surface-guided mode on a structured conductor (e.g., corrugated conductor), such as at microwave / THz frequencies.-9-WSLEGAL\055326\00509\43335578v5

[0074] "Surface-guided electromagnetic wave" refers to any electromagnetic mode that is bound to and propagates along an interface or structured surface, with its field strongly confined near that surface and decaying evanescently into the adjacent media, including SPPs, spoof SPPs, and other interface-supported surface waves.

[0075] "Surface plasmon polariton (SPP)" refers to a tightly bound electromagnetic mode that propagates along, e.g., a metal-dielectric interface, at optical / near-IR frequencies.

[0076] "Terahertz (THz) frequencies" refer to electromagnetic waves spanning approximately 0.1-10 THz (wavelengths ~3 mm to 30 pm).

[0077] “Waveguide” refers to a physical structure that directs and confines the propagation of electromagnetic waves along a defined path, by shaping boundary conditions and material properties to support one or more guided modes.II. GENERAL OVERVIEW

[0078] FIG. 1 A exemplifies a tunable phase shifting system 150, according to examples herein.

[0079] As shown, system 150 generally includes: (i) a surface-confined electromagnetic field waveguide assembly 102 (or a surface-confined field assembly 102, for short), and (ii) at least one external field disturber 104.

[0080] In some examples, the surface-confined assembly 102 includes at least one input interface (or port) and at least one output interface (or port). In use, an input signal 106a - having an input phase (cp) - is fed into the input interface 106a. The phase shifting system 150 acts on the input signal to generate, at the output interface, a corresponding phase-shifted output signal 106b. Particularly, the output phase represents a phase shifted version of the input phase (cp+Acp). The signals can be lower frequency signals (e.g., microwave to terahertz frequency, and in some examples, frequencies between about 300 MHz and 10 THz), or a higher frequency signals (e.g., near-infrared optical signals).

[0081] In more detail, as exemplified in FIG. 3B, when a signal is fed through the assembly 102 - the assembly 102 converts the signal into a localized electromagnetic (EM) surface field mode.-10-WSLEGAL\055326\00509\43335578v5Since the surface field mode confinement is high, the field amplitude decays (e.g., evanescently decays) in a direction perpendicular to the surface of assembly 102.

[0082] The external field disturber 104 is provided to effect a phase shift by interrupting the localized EM field, around assembly 102. As provided herein, the desired phase shifting is based on controlling the interaction between the field disturber 104, and the localized EM field.

[0083] To this effect, and as discussed in greater detail below, the field disturber 104 can control phase shifting through various techniques.

[0084] In some examples, phase shifting is effected through physical movement of the disturber 104, relative to the assembly 102. The intensity of interaction is controlled by calibrating the degree of physical (or spatial) proximity of the disturber 104 relative to assembly 102.

[0085] In other examples, phase shifting is effected by changing or tuning material dielectric properties of the disturber 104. For example, increasing the disturber's dielectric constant may increase the total effected phase shift. The dielectric properties are varied by various means, including using an external energy source. The energy source may apply, for instance, heating, external electric currents or magnetic fields, to induce a change in material dielectric properties.

[0086] Each of the assembly 102 and disturber unit 104 are now described in greater detail.III. SURFACE-CONFINED FIELD ASSEMBLY

[0087] The following is a description of the surface-confined field assembly 102, which can be used by itself or in combination with any other component disclosed herein, e.g., the field disturber 104.

[0088] To this effect, assembly 102 can have various configurations, which can vary based on the operating frequency and / or signal type of the input and output signals 106a, 106b.(i.) Lower Frequency Signals

[0089] As best shown in FIGs. 3 and 6 - 8, to accommodate for input signals at lower frequencies (e.g., microwave to terahertz frequencies, and in some examples, frequencies between -11-WSLEGAL\055326\00509\43335578v5about 300 MHz and 10 THz), the assembly 102 may include: (i) an electrically conductive layer 112 (e.g., a metal layer), and in some cases, overlaid over (ii) a substrate layer 114 (e.g., a dielectric substrate).

[0090] In some examples, the conductive layer 112 comprises metals, such as copper, gold, and / or aluminum. The material composition of the substrate or dielectric layer 114 can vary depending on the targeted electromagnetic performance, and the selected corrugation geometry (as discussed below). In at least some examples, the substrate 114 may be air (with a relative permittivity close to 1) or substrates with higher permittivity. For example, the substrate 114 may comprise a dielectric material with a relative permittivity of approximately 3.5, such as a Rogers R04003 substrate. More generally, the choice of dielectric constant is selected based on the design dimensions, dispersion characteristics, and overall performance of the structure, and with a view to the intended operating requirements and fabrication technology.

[0091] In cases where a substrate 114 is provided, the conductive layer 112 may cover any portion of the substrate 114. While any suitable electrically conductive layer 112 can be used, for ease of discussion, it is assumed that layer 112 is a metal layer.

[0092] FIGs. 3A - 3B exemplify various configurations for a single unit 302 of the assembly 102. As shown, the metal layer 112 can have one of a number of design or shape configurations, which are used to form a corrugated pattern. For example, in FIG. 3A(a) and 3B(a), the metal layer 112 is configured with an I-shaped design. In FIGs. 6A - 6C, it is observed that the I-design is repeatable and connectable to define a signal transmission path 116 with connected (or coupled) I-shapes forming a corrugated pattern.

[0093] In other examples, as shown in FIGs. 3A(b) and 3(B)(b), each unit 302 has a metal layer 112 configured with an L-shaped design. As shown in FIG. 8, this design is also repeatable and connectable to define a signal transmission path 116 with connected (or coupled) L-shapes, also forming a corrugated pattern.

[0094] In other cases, the assembly 102 is formed of any other repeated shape forming a corrugated pattern, and which repeats at any uniform or non-uniform interval. It is also possible that the design includes any combination of shapes (e.g., a mix of I- and L-shapes). The exact design-12-WSLEGAL\055326\00509\43335578v5configuration may vary based on the specific application, with the shapes varying based - for example - on phase shift performance and dimensions determined based on desired operating frequency ranges.

[0095] As used herein throughout, a "signal transmission path (or pathway)" 116 defines the guided flow path (along a guiding direction) for the signal between an input port 120 and an output port 122 of the assembly 102. For example, the path is formed by the corrugated metal geometry, which carries the accompanying surface currents and supports the surface-confined electromagnetic mode. The signal path 116 can have any desired shape (e.g., linear or non-linear). The input and output ports 120, 122 are generally defined on the assembly 102 and may interface with the metal layer 112.

[0096] As exemplified in FIGs. 6A and 8, the corrugated pattern formed by the metal layer 112 generally includes, along the signal pathway 116: (i) a continuous portion 124 extending between the input and output interfaces 120, 122, and (ii) one or more corrugated portions 126 located, for example, on one or both lateral sides of the continuous portion 124.

[0097] In some examples, the continuous portion 124 forms a waveguide portion, which extends longitudinally between the input and output interfaces 120, 122.

[0098] In some examples, only a single lateral side of the continuous portion 124 includes a corrugated portion 126. In other cases, both lateral sides of the continuous portion 124 include corrugated portions 126.

[0099] To that end, each corrugated portion 126 may include a series of "cells" 118 arranged along, for example, the transmission path 116 (FIGs. 6A and 6C). Each cell 118 can include a conductive segment (e.g., a metal segment) 128 and an adjacent gap segment 130. The conductive segments 128 may be coupled together along the continuous portion 124. The cells may have an I- or L-shaped design.

[0100] The corrugated portion 126 can include any number of cells, and in some cases, two or more cells. The selected cell count varies with design targets such as operating frequency, interaction length, desired phase-shift range and resolution, bandwidth, and permissible insertion loss.

[0101] As used herein, “gap segment" 130 refers to the non-metallic opening adjacent to a metal segment within a cell, disposed - for instance - along the guiding direction (or signal path 116).-13-WSLEGAL\055326\00509\43335578v5

[0102] As used herein, “lateral plane” or “lateral axis” refers to a direction parallel to the substrate and generally in same or parallel plane to the transmission path direction 116 (e.g., lateral axis 132 in FIGs. 6A and 8). “Vertical plane” or “vertical axis” refers to a direction perpendicular to the substrate or transmission path direction (out of plane) (e.g., vertical axis 134 in FIGs. 6A and 8). It is understood that the embodiments herein are not limited to a particular orientation, and orientational references are only provided for clarity of description.

[0103] In at least one example, the longitudinal spacing 132 of the gap segments 130 (along the direction of pathway 116) are configured to be subwavelength with reference to the input signal. The longitudinal spacing 132 defines the spacing between adjacent metal segments 128. The spacing is selectable to tailor confinement, dispersion, and phase-per-length, and may be increased or decreased to balance various factors (e.g., bandwidth, insertion loss, and sensitivity to a nearby disturber).

[0104] To that effect, and without limitation to theory, the gap segments 130 - forming part of the corrugated portion 126 - enable the formation of a surface-guided electromagnetic (EM) field mode that concentrates fringe electric fields (see e.g., dotted arrows in FIGs. 6C, 8 and 13A). This geometric feature therefore provides localization of the electromagnetic field, and contributes to surface-mode confinement.

[0105] In more details, the gaps act as distributed resonators that lower the mode’s phase velocity and trap energy near the surface, creating a “spoof’ surface plasmon-like mode with strong evanescent decay away from the metal layer 112. By tailoring the groove depth, width, and period (as well as the longitudinal width of each metal cell 128) the structure supports a surface-confined guided mode that carries the input signal with high field concentration at the corrugated interface.

[0106] To that end, in some examples, the continuous portion 124 is not necessarily provided at all, or at least not provided continuously from the input to output interface 120, 122. For example, as exemplified in FIG. 6D, it is possible that a series or plurality (e.g., two or more) disconnected or decoupled "cells" 118 are provided and aligned consecutively (or adjacently) along the signal transmission path 116. For instance, a series of disconnected metal segments 128 - aligned along the signal transmission path 116 - may be separated by associated gap segments 130 with variable or fixed longitudinal spacing 132. In this case, a waveguide is formed along the signal transmission path 116, with the surface-guided electromagnetic (EM) field mode concentrating fringe electric fields along the -14-WSLEGAL\055326\00509\43335578v5sequential gap segments 130. In other cases, some of the metal segments 128 may be coupled together along a longitudinal portion 124 to form corrugated portions, while others metal segments are decoupled (see also FIG. 6D). In these examples, the metal segments 128 can have any desired shape or dimension, based on the design parameters (as discussed previously).

[0107] A unique aspect of the disclosed design is that the confined EM fields are produced along a vertical axis 134. This, as discussed below, allows a vertically positioned disturber 104 to interact and couple with the field, to affect a desired phase change. This is contrasted to other transmission configurations (e.g., coplanar waveguides) where the field may be localized in a horizontal or lateral plane, i.e., as between the transmission line and grounding plates. In these cases, the field is more inaccessible for manipulation.

[0108] More specifically, and without limitation to specific theory, the above-noted differences compared to other transmission structures arises from the propagation mode supported by the presently disclosed structure. In the disclosed design, the confined electromagnetic field supports a TM (Transverse Magnetic)-like mode, in which the electric field has a significant component along the vertical axis, enabling effective interaction with a vertically positioned disturber. In contrast, coplanar waveguides support a quasi-TEM (Transverse Electromagnetic) mode, where the electric field is primarily distributed laterally between the signal conductor and the ground planes. These mode characteristics describe the orientation of the electric-field components relative to the direction of propagation, and further clarify why the field in the disclosed structure is more accessible for vertical coupling and phase manipulation.

[0109] By extension, it will also be appreciated that, in disclosed examples, a separate ground plane or plate is not strictly required. This is because the corrugated geometry (or separated cells, as shown in FIG. 6D), itself supports a bound surface mode without a return ground reference. The metal features and adjacent gaps provide the distributed inductive and capacitive loading needed to confine and guide the wave. In some embodiments a ground is optionally added (e.g., CPW launches, SIW variants) for matching or integration, but the surface-mode section operates without it.

[0110] As further exemplified in FIGs. 10A - 10B, it is possible that some implementations include an air gap provided below the metal layer 112 (e.g., or a portion thereof). This may be produced by as a disconnected portion of the substrate 114, and may accommodate more than one disturber 104 disposed vertically below the transmission signal path 116.-15-WSLEGAL\055326\00509\43335578v5

[0111] In some examples, the configuration for the surface-confined field assembly 102 is used or merged with other conventional signal guiding configurations, including: (i) coplanar waveguides (CPWs) (e.g., FIGs 7 and 9- 10); and / or (ii) substrate integrated waveguides (SIWs) (e.g., FIG. 11).

[0112] FIGs 7 and 9 - 10 provide a design configuration where the assembly 102 is merged with a CPW architecture. As shown in FIG. 7 A, the end proximal the input and output interfaces 120, 124 can define a CPW transition. The continuous portion 124 is then used as the transmission line to interface with the CPW architecture, and is laterally flanked by grounding plates 702 (as commonly used in CPW designs). Accordingly, the tunable phase shifting system 150 can be inserted into a conventional CPW signal path via launch and extraction transitions, thereby providing phase-shifting capability within a standard CPW configuration.

[0113] FIGs. 11 A - 11C exemplify the tunable phase shifting system 150 used, integrated and merged into an SIW structure. The SIW includes a top plate defining the metal layer 112, and a bottom conductive plate. On a first lateral side of the continuous path 124, vias 1102 extend through the substrate 114 to couple the top and bottom plates. On a second lateral side of the continuous path 124, a corrugated portion 126 is provided.

[0114] While the disclosed examples primarily exemplify corrugation in a lateral plane, the corrugation can alternatively (or additionally) be provided in a vertical plane. In this embodiment, best exemplified in FIGs. 12-16, a conductive material (e.g., metal) is corrugated along the vertical axis (out of plane) (e.g., a bulky U-shape corrugation). This, in turn, forms grooves or ribs that extend into the thickness of the conductor 112. This vertical corrugation concentrates the field within the out-of-plane gaps, supporting a spoof SPP-like surface mode with enhanced confinement. In these cases, a substrate layer 114 may not be necessary.(ii.) Higher Frequency Signals

[0115] FIGs. 20A - 20B exemplify a configuration for the assembly 102, operating at higher frequency signals (e.g., optical near-IR frequencies).

[0116] At higher frequencies, a metal-dielectric interface (e.g., conductive layer 112 and substrate 114) is used to intrinsically support surface wave propagation. In particular, the metal- -16-WSLEGAL\055326\00509\43335578v5dielectric interference at these frequencies supports generation of surface charges at the interface in response to an external electromagnetic field that is propagating along the structure. In these embodiments, the metal layer 112 defines the signal transmission path, and the input and output ports 120, 122.

[0117] Without limitation to theory, in an optical mode, the phase shifter leverages a surface plasmon polariton (SPP). The SPP is a surface-hugging electromagnetic wave bound to the metaldielectric interface. The metal’s negative permittivity at optical / near-IR frequencies enables strong confinement and evanescent decay away from the interface, along the vertical axis away from that surface. This vertical confinement allows a disturber placed above or below the interface to effectively modulate the local environment and thus the SPP’s phase.

[0118] Suitable metals, that may be included in the metal-dielectric interface, include various noble metals (e.g., gold and silver) for low loss and stable SPPs in the visible / telecom bands; aluminum can be used in the blue / UV but with higher loss.IV. EXTERNAL FIELD DISTURBER UNIT

[0119] The following is a description of external field disturber units 104, which can be used alone or in combination with any other component disclosed herein, e.g., the surface-confined field assembly 102.

[0120] As provided herein, the tunable phase shifting system 150 can include any number of field disturber units 104, including one unit (e.g., FIG. 4 and 6A), two units (e.g., FIGs. 5 and 6b), or more than two units (FIG. 7C). In some examples, the number of disturbers 104 is increased in order to achieve a specific phase shift.

[0121] Each disturber 104 can be made of a material selected to functionally alter the local electromagnetic environment, and thereby change the propagation constant of the surface-guided mode (e.g., within the gap segments 130).

[0122] In some examples, each disturber 104 is formed of a dielectric material. Representative materials used to form the disturber 104 include low-loss RF laminates (e.g., Rogers / Taconic),-17-WSLEGAL\055326\00509\43335578v5high-index dielectrics (e.g., Si, TiO2), polymers, and ceramics, machined or molded to the desired shape and size. The disturber 104 can be monolithic or a composite.

[0123] Particularly, the dielectric disturber interacts with the localized electromagnetic field, as described above (e.g., in gap segments 130). This interaction alters the propagation constant of the propagating field, thereby changing the phase velocity and, consequently, the accumulated phase along the transmission signal pathway 116. For instance, as explained below, as the dielectric disturber is positioned closer to the region of strongest field confinement, the resulting phase shift increases.

[0124] The disturber 104 can be designed in different shapes and dimensions according to the amount of phase shift required for desired applications.

[0125] As provided above, the disturber 104 can variably interrupt the localized field around the surface-confined field assembly 102 using various techniques, including (i) physical movement, and / or (ii) changing material properties of the disturber 104.

[0126] More generally, each disturber 104 may be positioned or configured between a lower-coupling state (disengaged) and a higher-coupling state (engaged), wherein the higher-coupling state can include intermediate degrees of engagement. In the disengaged state, the disturber does not (or does not substantially) affect the localized field. In the engaged state, it interacts with the field to alter the propagation constant and produce a phase shift. Intermediate degrees provide partial coupling and proportional phase tuning. This transition can be achieved by changing the disturber’s position (e.g., standoff or lateral placement) or by modifying its material properties.

[0127] In some embodiments, the disturber 104 is always in an engaged or coupled state, without accommodating a disengaged state. For example, it may be fixed in a proximal engaged position with constant dielectric properties. It may also be variably engaged, such as by: (i) adjusting its position within the engaged range, or (ii) tunably engaged at a fixed position by changing its dielectric properties to set different coupling levels.

[0128] As noted above, a unique aspect of the disclosed examples is that the disturbers 104 can be disposed a within a vertical plane relative to the surface-confined field. This out-of-plane positioning targets the evanescent decay along the vertical axis.-18-WSLEGAL\055326\00509\43335578v5(i.) Physical Movement

[0129] In at least one example, phase shifting is effected through physical movement of the disturber 104 relative to the assembly 102.

[0130] When the disturber 104 is subject to physical movement, it can be moved in any direction relative to the surface-confined field.

[0131] In cases where the assembly 102 is configured with a corrugated portion 126 (or gap portions 130) - a lower-coupling state (e.g., inactive or unengaged state) is obtained when the disturber 104 is positioned distally from a gap segment 130 of the corrugated portion. Further, a higher-coupling state (e.g., active or engaged state) is obtained when the disturber 104 is positioned more proximally to a gap segment 130, depending on the desired degree of phase shift. For example, the disturber 104 can be placed above or below or within a gap segment 130, with varying degrees of overlap.

[0132] Disclosed examples provide for both horizontal movement (e.g., FIG. 4A and 4C, 1 IB, 14, 16, and 18) and vertical movement (e.g., FIGs. 4B and 4D, 11 A 15B) of the disturber 104, relative to the corrugated portion 126 on an assembly 102.

[0133] In the horizontal movement case, the disturber 104 is in a lower-coupling state when positioned over a metal segment 128 of the corrugated portion 126, or moved laterally away from the corrugated portion 126. In contrast, it is in a high-coupling state when positioned over or overlapping a gap segment 130.

[0134] In the vertical movement case, the disturber is in a lower-coupling state when retracted to a large standoff from the surface-confined field. Further, it is in a higher-coupling state when positioned more proximally a gap segment 130.

[0135] In other cases, it is possible to move the disturber 104 in any other direction (aside from horizontally or vertically) to bring it farther away and closer to a gap segment 130, including movement in a diagonal direction.

[0136] In some examples, the disturber 104 can interact with more than one gap segment 130 in a corrugated design (FIG. 8)

[0137] FIGs. 7 provides for movement of a disturber 104 when the tunable system 150 is integrated with a CPW structure. FIG. 10 provides movement of a disturber 104 when an open-air -19-WSLEGAL\055326\00509\43335578v5region is provided in the substrate 114. This allows for the further movement of a movable disturber 104, thereby influencing the phase shifting performance. FIG. 11 provides movement of a disturber 104 when the tunable system 150 is integrated with an SIW structure.

[0138] FIG. 18 provides for movement of the disturber 104 with a surface-confined field assembly 102 adapted in an optical mode configuration. In this case, the disturber 104 is moved generally closer and further away from the metal layer 112.

[0139] In some examples, the tunable system 150 can also include two or more disturbers 104 moving in either a horizontal plane (FIGs. 5B-5C, 6B-6C, 7B-7D, 8, 9D), or a vertical plane (FIGs.5B, 5D, 9C, 10B). The multiple disturbers may be independently movable, or may be moved concurrently or partially concurrently. The disturbers may also be positioned on opposing sides of the signal path 116.

[0140] FIGs. 7C-7D exemplify a “bit” tuning concept in which multiple movable disturbers 104 provide discrete, repeatable phase increments. Each disturber contributes a defined phase step when engaged, and combinations of engaged disturbers sum to produce a desired total phase. In this concept, each disturber 104 can be associated with a specific gap segment 130, and in the engaged (coupled) state it is positioned over or overlapping that gap to contribute its defined phase step.(ii.) Changing Material Properties

[0141] In other examples, field confinement is effected by changing material properties of the disturber 104 (also termed herein, a "tunable" disturber).

[0142] For example, as shown in FIG. 19, changing material properties of a disturber is effected using a heater 1902. Representative heater types include resistive microheaters (thin-film metal serpentine traces), Joule-heated wires embedded in the disturber, polysilicon heaters in IC processes, and plasmonic nanoheaters for optical embodiments. Heaters may be driven by DC or-20-WSLEGAL\055326\00509\43335578v5pulsed currents, with optional integrated temperature sensing (e.g., RTDs, diodes) for closed-loop control.

[0143] In some examples, the temperature of disturber is controlled by applying an external voltage to the heater. The external voltage is applied by an energy source 1904 (e.g., a DC and / or AC source).

[0144] In at least one example, the tunable disturber 104 is formed of phase changing materials with the capability of changing phase from high resistive amorphous state to lower resistive crystalline, owing to the application of heat. Examples of phase-change materials include, for example, vanadium dioxide (VO2), germanium-antimony-telluride (Ge2Sb2Tes or GST), which undergo reversible phase transitions that alter their electrical, optical, or thermal properties.

[0145] FIG. 20A provides changing material properties of a disturber 104 using an inserted heater 1902 for achieving different effects on the localized field of L-shaped corrugations. FIG. 20B provides changing material properties of two or more disturbers 104.

[0146] In cases where a corrugated portion 126 is provided on the assembly 102, the tunable disturber 104 may be fixed in position and overlapping a gap segment 130 (e.g., above or below, or within the gap segment 130). Further, the degree of overlap and the applied energy / temperature jointly set the coupling level.

[0147] Further, multiple disturbers can be provided and associated with different gap segments 130 (or more than one gap segment). They may be driven concurrently or independently to realize combined or separate phase contributions. They can also be used to implement a “bit” concept in which each disturber provides a defined phase increment when thermally engaged, as discussed previously.

[0148] FIGs. 22 A - 22B provide the proposed optical tunable phase shifter tuned by changing material properties of the disturber 104 using heating.

[0149] In other examples, the material properties of the disturber 104 can also be changed by different approaches, beyond heating. For example, the disturber’s dielectric properties can be tuned by electric fields using, for instance, ferroelectric or electro-optic materials (e.g., BST (barium strontium titanate) or LiNbCh with integrated electrodes). Further, magnetic fields can tune, for instance, ferrites or YIG (yttrium iron garnet) and magneto-optic crystals driven by micro-coils.-21-WSLEGAL\055326\00509\43335578v5Optical excitation can also generate carriers in semiconductors or actuate photo-chromic polymers using compact laser or LED sources. Each method, more generally, adjusts the local permittivity or permeability in the localized EM field region to change the propagation constant and accumulated phase.

[0150] In cases where a tunable disturber is provided, the engaged and disengaged states are defined by the intensity of the applied tuning (e.g., thermal tuning), e.g., the tunable factor. For example, lower temperatures or no heating places the disturber in a lower-coupling (disengaged) state with negligible effect on the localized field. In contrast, increasing temperature moves the material through intermediate states to a higher-coupling (engaged) state that alters the propagation constant and produces a phase shift in the localized field.(iii.) Combination

[0151] In some examples, a configuration of one or more of the disturbers 104 can be modified using a combination of physical movement and / or material configuration change.V. EXAMPLE ANTENNA APPLICATION

[0152] FIG. IB illustrates an example use application ofthe tunable phase shifting system 150. As shown, the output of the tunable phase shifting system 150 is fed and coupled to an antenna element 110. This allows the antenna 110 to transmit the phase shifted output.

[0153] As shown in FIG. 2A, the tunable phase shifting system 150 may couple to a single antenna element 110. FIG. 2B exemplifies use of a phased antenna array system 200 that includes multiple tunable phase shifting systems 150a - 150n, each coupled to a corresponding antenna element 110a - 1 lOn. The external disturbers 104 in each system 150 are configurable such that each antenna element 110 transmits a signal with the same or different phase shift. In other examples, the same disturber(s) 104 is used for all systems 150.

[0154] FIG. 23A provides an example of coupling a tunable phase shifting system 150 to an antenna 110. The antenna part is based on the simple concept of matching the corrugated metal portion 126 to the free environment for radiation. FIG. 23B provides an example of application of a phased -22-WSLEGAL\055326\00509\43335578v5array antenna system employing two antennas 110. FIG. 23C provides an example of a phased array antenna system employing more than two antennas.

[0155] More broadly, the phased antenna arrays can be used in various applications known in the art (as discussed in the background), including space communications for beam steering and link optimization. The phased antenna array, more generally, enables for electronic beamforming, and rapid scanning without mechanical motion.VI. EXAMPLE METHOD(S)

[0156] The following describe various methods for using and / or assembling the tunable phase shifting system 150.(i.) Method of Using (or Operating) Tunable Phase Shifting System

[0157] FIG. 24 shows an example method 2400 for using (or operating) the tunable phase shifting system 150. In some examples, the method is executed by at least one processor 2602 of the control system 2600 (FIG. 26).

[0158] At 2402, a target desired phase shift amount is determined for the output signal.

[0159] At 2404, a configuration state for at least one disturber 104, in the system 150, is selected to achieve the desired phase shift. The configuration includes choosing a coupling state (or a degree thereof), such as a disengaged state, an engaged state, or an intermediate state. Where multiple disturbers 104 are present, the selection may further include determining which one or more disturbers to actuate, and the degree of coupling, to produce the desired phase shift.

[0160] At 2406, a control mechanism (e.g., control mechanism 2606 in FIG. 26) is operated to effect the selected configuration. In some examples, the control mechanism positions the disturber 104 via physical movement relative to a gap segment 130 in a corrugated portion 126 of the surface-confined field assembly 102. In other examples, the control mechanism changes material properties of the disturber (e.g., dielectric properties). For example, this occurs through heating, applied electric or magnetic fields, optical excitation, or carrier injection.-23-WSLEGAL\055326\00509\43335578v5

[0161] An input signal (e.g., microwave, terahertz, or optical) may then be fed into the input interface 120 of the surface-confined field assembly 102, and a corresponding phase-shifted output signal is obtained at the output interface.

[0162] In the case of a phased array configuration, method 2400 may be independently or concurrently applied to each tunable system 150 in the phased array. In this case, each tunable system may have a different target signal phase shift, e.g., to effect the desired collective beam steering angle of the array.(ii.) Method of Assembling or Fabricating Tunable Phase Shifting System

[0163] A tunable phase shifting system 150 can be fabricated by first defining design parameters for the surface-confined guiding assembly 102 and at least one disturber 104. For example, this includes corrugation period, groove depth / width, metal thickness, substrate dielectric properties, transition geometries to CPW / microstrip, and target interaction length.

[0164] A substrate 114 is prepared (if required), and a conductive layer 112 is formed. Where applicable, the corrugated pattern and transitions are then patterned and etched or milled to define the continuous transmission path, adjacent corrugated portions, and any air gaps to accommodate disturber motion.

[0165] The disturber 104 is also fabricated (e.g., as a discrete block) from a selected dielectric or tunable material with integrated heaters or electrodes.

[0166] Actuation and control elements (e.g., MEMS, piezo, micromotor, or microheaters) are further integrated.

[0167] More generally, the localized phase shifter paves the way for potential integration of microwave and optical circuits, e.g. MEMS and CMOS technologies for implementing electro-optical chips. The mentioned electrooptic chip changes the phase of a signal based on a high field confinement phase shifter at optical frequencies. As an example, a very small mechanical actuation of a disturber affecting phase of highly localized electromagnetic field at optical frequencies all in one optoelectronic IC.-24-WSLEGAL\055326\00509\43335578v5VII. EXAMPLE SIMULATION RESULTS

[0168] FIGs. 25A - 25D provide various simulation results for the tunable phase shifting system 150 in FIGs. 9B and / or 9D.

[0169] FIG. 25 A provides simulated results of the achieved phase shift (A(|)) from the proposed tunable phase shifter, in FIGs. 9B and 9D, by loading three metal corrugations with a dielectric disturber made of TMM3 (dielectric constant er=3.54) on one side and two sides according to an embodiment of the invention.

[0170] FIG. 25B provides simulated results of amplitude of the phase shifted signal (S21) from the proposed tunable phase shifter, in FIGs. 9B and 9D, by loading three metal corrugations with a dielectric disturber made of TMM3 (dielectric constant er=3.54) on one side and two sides according to an embodiment of the invention.

[0171] FIG. 25C provides simulated results of the achieved phase shift (A(|)) from the proposed tunable phase shifter, in FIG. 9D, by loading three metal corrugations with a dielectric disturber made of different materials, TMM3 (dielectric constant er=3.27), TMM6 (dielectric constant er=6.08), TMM10 (dielectric constant cr=9.2), TMM13 (dielectric constant er=12.85) two sides according to an embodiment of the invention.

[0172] FIG. 25D provides simulated amplitude results of the phase shifted signal (S21) from the proposed tunable phase shifter, in FIG. 9D, by loading three metal corrugations with a dielectric disturber made of different materials, TMM3 (dielectric constant er=3.27), TMM6 (dielectric constant er=6.08), TMM10 (dielectric constant cr=9.2), TMM13 (dielectric constant er=12.85) two sides according to an embodiment of the invention.

[0173] FIG. 25E provides simulated results of the achieved phase shift (A(|)) from the proposed tunable phase shifter, in FIG. 9D, min three cases of five, seven, and nine loaded metal corrugations by a dielectric disturber made of TMM6 (dielectric constant er=6.08) two sides according to an embodiment of the invention.-25-WSLEGAL\055326\00509\43335578v5VIII. CONTROL SYSTEM

[0174] FIG. 26 shows an example hardware configuration for a system 2600 for controlling a configuration of the tunable phase shift system 150, and particularly, the one or more disturbers 104.

[0175] As shown, the user device 2600 can include a processor 2602 coupled to a memory 2604 and one or more of a control mechanism 2606 and a communication interface 2608.

[0176] Control mechanism 2606 may be any system component that is used to control the one or more disturber 104 between the active state and the inactive state (or any state in between). To that end, the control mechanism 2606 may itself couple to the disturber 104.

[0177] In at least one example, the control mechanism 2606 is a motion control mechanism, that effects physical movement of disturber 104 (as previously discussed). Various motion control mechanisms known in the art may be used. These include MEMS actuator, micromotor, and piezoelectric actuators. Each of these mechanisms is compatible with standard chip fabrication technologies, e.g. employing MEMS compatible with MMIC (Monolithic Microwave Integrated Circuit) / CMOS (Complementary Metal-Oxide-Semiconductor) technologies, making the proposed phase shifter low-cost and simple for fabrication.

[0178] In other examples, the control mechanism 2606 is the external energy source, or controls the external energy source, in the case of a tunable disturber. In such examples, the control mechanism 2606 includes, or controls operation of, external energy sources. By way of non-limiting example, the external energy source may include one or more heating elements for thermal tuning (see examples above), one or more magnetic field sources for magnetic biasing or modulation (e.g., micro-coils, adjustable permanent magnets, or external electromagnets), or one or more optical exciters for optically induced tuning (e.g., compact laser diodes, LEDs, or integrated waveguides configured to deliver controlled optical illumination).

[0179] Communication interface 2608 may comprise an antenna for wireless reception and / or transmission of data to a communications network. More generally, interface 2608 may receive data instructions for control (e.g., remote control) of the control mechanism 2606.-26-WSLEGAL\055326\00509\43335578v5

[0180] While not shown, the system may also include an input interface for directly receiving user inputs (e.g., a keyboard, mouse, touchscreen, etc.). This can also be used for manipulation of the control mechanism 2606.

[0181] To that end, it will be understood by those of skill in the art that references herein to tunable system 150 as carrying out a function or acting in a particular way may imply that processor 1502 is executing instructions (e.g., a software program) stored in memory 1504 and possibly transmitting or receiving inputs and outputs via one or more interfaces.

[0182] Memory 2604 can store various of the methods described herein, including the method 2400 (FIG. 24) as a computer-executable method.IX. INTERPRETATION

[0183] Various systems or methods have been described to provide an example of an embodiment of the claimed subject matter. No embodiment described limits any claimed subject matter and any claimed subject matter may cover methods or systems that differ from those described below. The claimed subject matter is not limited to systems or methods having all of the features of any one system or method described below or to features common to multiple or all of the apparatuses or methods described below. It is possible that a system or method described is not an embodiment that is recited in any claimed subject matter. Any subject matter disclosed in a system or method described that is not claimed in this document may be the subject matter of another protective instrument, for example, a continuing patent application, and the applicants, inventors or owners do not intend to abandon, disclaim or dedicate to the public any such subject matter by its disclosure in this document.

[0184] Furthermore, it will be appreciated that for simplicity and clarity of illustration, where considered appropriate, reference numerals may be repeated among the figures to indicate corresponding or analogous elements. In addition, numerous specific details are set forth in order to provide a thorough understanding of the embodiments described herein. However, it will be understood by those of ordinary skill in the art that the embodiments described herein may be practiced without these specific details. In other instances, well-known methods, procedures and components-27-WSLEGAL\055326\00509\43335578v5have not been described in detail so as not to obscure the embodiments described herein. Also, the description is not to be considered as limiting the scope of the embodiments described herein.

[0185] It should also be noted that the terms “coupled” or “coupling” as used herein can have several different meanings depending in the context in which these terms are used. For example, the terms coupled or coupling may be used to indicate that an element or device can electrically, optically, or wirelessly send data to another element or device as well as receive data from another element or device. As used herein, two or more components are said to be “coupled”, or “connected” where the parts are joined or operate together either directly or indirectly (i.e., through one or more intermediate components), so long as a link occurs. As used herein and in the claims, two or more parts are said to be “directly coupled”, or “directly connected”, where the parts are joined or operate together without intervening intermediate components.

[0186] It should be noted that terms of degree such as "substantially", "about" and "approximately" as used herein mean a reasonable amount of deviation of the modified term such that the end result is not significantly changed. These terms of degree may also be construed as including a deviation of the modified term if this deviation would not negate the meaning of the term it modifies.

[0187] Furthermore, any recitation of numerical ranges by endpoints herein includes all numbers and fractions subsumed within that range (e.g. 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.90, 4, and 5). It is also to be understood that all numbers and fractions thereof are presumed to be modified by the term "about" which means a variation of up to a certain amount of the number to which reference is being made if the end result is not significantly changed.

[0188] The present invention has been described here by way of example only, while numerous specific details are set forth herein in order to provide a thorough understanding of the exemplary embodiments described herein. However, it will be understood by those of ordinary skill in the art that these embodiments may, in some cases, be practiced without these specific details. In other instances, well-known methods, procedures and components have not been described in detail so as not to obscure the description of the embodiments. Various modification and variations may be made to these exemplary embodiments without departing from the spirit and scope of the invention, which is limited only by the appended claims.-28-WSLEGAL\055326\00509\43335578v5

Claims

CLAIMS:

1. A tunable phase shifting system, comprising:a surface-confined electromagnetic field waveguide assembly comprising a signal transmission pathway extending between an input interface and an output interface, the signal transmission pathway supporting a surface-guided electromagnetic mode and comprising two or more cells, each cell comprising a conductive segment and an adjacent gap segment arranged along the pathway; andat least one disturber positioned to interact with a field of the mode,wherein when an input signal is applied at the input interface, the system generates, at the output interface, a corresponding phase-shifted signal.

2. The system of claim 1, wherein the input signal is at a lower frequency, such as microwave or terahertz frequency.

3. The system of any one of claims 1 or 2, wherein the assembly further comprises a substrate, and each conductive segment is disposed over the substrate.

4. The system of any one of claims 1 to 3, wherein the conductive segments in the two or more cells are coupled along a continuous longitudinal portion to form a corrugated pattern.

5. The system of any one of claims 1 to 4, wherein the at least one disturber is associated with a gap segment and, in a higher-coupling state, is positioned over or overlapping the gap segment.

6. The system of claim 5, wherein the at least one disturber is physically movable relative to the gap segment to achieve different degrees of phase shifting.

7. The system of claim 6, further comprising a micro-actuator for effecting the physical movement.-29-WSLEGAL\055326\00509\43335578v58. The system of any one of claims 1 to 7, wherein the at least one disturber is tunable, with dielectric properties adjustable by an external energy source to provide a controllable phase shift.

9. The system of any one of claims 1 to 8, wherein the input and output interfaces comprise coplanar waveguide (CPW) transitions, or the surface-confined field assembly is integrated with a substrate-integrated waveguide (SIW).

10. The system of any one of claims 1 to 9, wherein the surface-guided electromagnetic mode comprises a spoof surface wave.

11. The system of any one of claims 1 to 10, wherein the at least one disturber comprises two or more disturbers that are independently or concurrently controllable to provide combined or separate phase shift contributions.

12. A tunable phase shifting system, comprising:surface-confined field assembly having an input interface and an output interface, and comprising a metal layer disposed over a substrate to form a metal-dielectric interface,wherein the metal-dielectric interface is configured to support a surface-guided electromagnetic mode at an input signal at optical near-IR frequencies; andat least one disturber positioned to interact with a field of the mode,wherein when the input signal is applied at the input interface, the system generates, at the output interface, a corresponding phase-shifted signal.

13. The system of claim 12, wherein the at least one disturber is physically movable relative to the metal layer to achieve different degrees of phase shifting.

14. The system of any one of claims 12 or 13, wherein the at least one disturber is tunable, with dielectric properties adjustable by an external energy source to provide a controllable phase shift.-30-WSLEGAL\055326\00509\43335578v515. The system of any one of claims 12 to 14, wherein the surface-guided electromagnetic mode comprises a surface plasmon polariton supported by the metal-dielectric interface.

16. The system of any one of claims 12 to 15, wherein the at least one disturber comprises two or more disturbers that are independently or concurrently controllable to provide combined or separate phase contributions.

17. The system of any one of claims 1 to 16, further comprising an antenna element coupled to the output interface.

18. A phased antenna array comprising a plurality of the tunable phase shifting systems, as defined in any one of claims 1 to 16, wherein each tunable phase shifting system is coupled to an antenna element at a respective output interface.

19. A method of operating the tunable phase shifting system of any one of claims 1 to 17, comprising:identifying a target phase shift for the phase-shifted output signal;determining a configuration state for the at least one disturber to effect the target phase shift; andoperating a control mechanism to achieve the configuration state.

20. The method of claim 19, wherein the configuration state comprises one or more of (i) a positioning the at least one disturber, or (ii) a tuning factor of the at least one disturber.-31-WSLEGAL\055326\00509\43335578v5

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