Generating surface electromagnetic waves with underwater horn antennas

Abstract

Systems for gradient surface electromagnetic wave generation and related methods are described. In some implementations, a first horn antenna may be configured to disrupt momentum conservation parallel to an interface between water and another material, enabling the generation of gradient surface electromagnetic waves. A second horn antenna, positioned in proximity to the first, may be adapted to generate anti-resonances in response to the gradient surface electromagnetic waves initiated by the first horn antenna. The presence of an object, which may be composed of metal or dielectric materials, near the interface may alter the anti-resonances generated by the horn antennas. This alteration in anti-resonances may indicate the presence of the object, thereby facilitating the detection of metallic and dielectric objects in close proximity to the water surface. This system and method may enhance biosensing and bioimaging applications by supplementing traditional x-ray and ultrasound techniques with gradient surface electromagnetic wave-based detection.

Description

Docket No. 0045-920595GENERATING SURFACE ELECTROMAGNETIC WAVES WITH UNDERWATER HORN ANTENNASFIELD OF TECHNOLOGY

[0001] The present disclosure relates generally to gradient surface electromagnetic wave generation systems, and more specifically to generating surface electromagnetic waves with underwater horn antennas.BACKGROUND

[0002] In the field of underwater communications and imaging, various technologies may be employed to facilitate the transmission of information and the capture of visual data. These technologies may operate based on different principles, such as the propagation of acoustic waves or radio frequency waves, each with its own set of characteristics suitable for specific applications.SUMMARY

[0003] The described implementations relate to improved gradient surface electromagnetic wave generation systems and associated methods for generating surface electromagnetic waves with underwater horn antennas. The interface between water and air presents a unique medium where certain types of electromagnetic waves may propagate along the surface, potentially offering alternative methods for communication and imaging. The dielectric properties of water and air may create conditions that support the existence of surface waves with distinct propagation behaviors. Specialized antennas may be used to interact with these surface waves, aiming to enhance the efficiency and effectiveness of underwater communication systems and imaging techniques.

[0004] In some examples, a method for the generation and propagation of gradient surface electromagnetic waves (GSEWs) at the water-air interface may be introduced. This method may employ specialized horn antennas that are submerged in water and filled with the same medium. By breaking the conservation of momentum parallel to the interface, these hom antennas may enable the efficient excitation of GSEWs. The antennas may be designed to operate at specific frequencies where the dielectric permittivity gradient at the interface is conducive to the formation of GSEWs. This approach may allow for enhanced underwater communication and imaging capabilities due to the improved propagation characteristics of GSEWs compared to conventional radio frequency waves in water.Docket No. 0045-920595

[0005] The horn antennas may be strategically oriented to achieve phase matching conditions, which may facilitate the direct coupling of radio waves emitted by the antennas with the GSEWs. This configuration may significantly improve the coupling efficiency and may enable the GSEWs to propagate along the water surface with reduced attenuation. Some implementations may further capitalize on the sensitivity of GSEWs to changes in the dielectric properties of the adjacent media, making it possible to detect the presence of objects or variations in the medium’s composition. This capability may be particularly advantageous for communications and imaging applications. The use of GSEWs, therefore, may present a significant advancement in underwater communication and imaging technologies, offering higher resolution, greater sensitivity, and extended range compared to existing methods.

[0006] A gradient surface electromagnetic wave generation system is described. The system may include a first horn antenna, which may be configured to break momentum conservation parallel to an interface of water and another material. The system may include a second horn antenna positioned in proximity to the first hom antenna and may be adapted to generate antiresonances in response to the first horn antenna. The system may include an object positioned near the interface, the object comprising at least one of a metal or a dielectric, the presence of the object altering the anti -resonances generated by the second horn antenna.

[0007] A method for generating gradient surface electromagnetic waves is described. The method may include breaking momentum conservation parallel to an interface of water and another material using a first horn antenna. The method may include positioning a second hom antenna in proximity to the first horn antenna to generate anti-resonances in response to the first hom antenna. The method may include altering the anti-resonances generated by the second horn antenna by positioning an object comprising at least one of a metal or a dielectric near the interface.

[0008] Some examples of the technologies and related methods described herein may further include a vector network analyzer connected to the first hom antenna and the second horn antenna. The vector network analyzer may be configured to measure the alteration of the antiresonances in response to the presence of the test object.

[0009] In some examples of the technologies and related methods described herein, the first hom antenna and the second horn antenna may be filled with water. The water may be used as a prism to facilitate the generation of the gradient surface electromagnetic waves.Docket No. 0045-920595

[0010] In some examples of the technologies and related methods described herein, the interface between the first horn antenna and the second horn antenna may support the propagation of the gradient surface electromagnetic waves.

[0011] In some examples of the technologies and related methods described herein, the object may be a metal object near the interface. The system may be configured to detect the presence of the metal object near the interface based on the alteration of the anti-resonances.

[0012] In some examples of the technologies and related methods described herein, the object may be a dielectric object near the surface. The system may be configured to detect the presence of the dielectric object near the interface based on the alteration of the anti-resonances.

[0013] In some examples of the technologies and related methods described herein, the first horn antenna and the second horn antenna may be configured to operate in a plasmonic- plasmonic mode. This configuration may enhance the sensitivity to the object.

[0014] In some examples of the technologies and related methods described herein, the object may comprise a metal rod. The system may be configured to detect changes in the antiresonances indicative of the metal rod’s presence.

[0015] In some examples of the technologies and related methods described herein, the first horn antenna and the second horn antenna may be positioned at a water level. The system may be configured to detect fluctuations in the water level based on the anti-resonances.

[0016] In some examples of the technologies and related methods described herein, the first horn antenna and the second horn antenna may be aligned in a vertical orientation. This alignment may enhance the detection of vertical surface states.

[0017] In some examples of the technologies and related methods described herein, the first horn antenna and the second horn antenna may be aligned in a horizontal orientation. This alignment may enhance the detection of horizontal surface states.

[0018] In some examples of the technologies and related methods described herein, the object may be characterized as a reference. The system may be configured to calibrate the antiresonances based on the reference.

[0019] In some examples of the technologies and related methods described herein, the first horn antenna and the second horn antenna may be adapted for use with water / tissue interfaces. This adaptation may expand the applications to biological sensing.Docket No. 0045-920595BRIEF DESCRIPTION OF THE DRA WINGS

[0020] FIG. 1 shows a system which supports techniques for generating surface electromagnetic waves with underwater horn antennas in accordance with various aspects of the present disclosure.

[0021] FIG. 2 shows antenna signal measurements which supports techniques for generating surface electromagnetic waves with underwater horn antennas in accordance with various aspects of the present disclosure.

[0022] FIG. 3 shows signal attenuation comparison which supports techniques for generating surface electromagnetic waves with underwater horn antennas in accordance with various aspects of the present disclosure.

[0023] FIG. 4 shows an underwater detection experiment which supports techniques for generating surface electromagnetic waves with underwater horn antennas in accordance with various aspects of the present disclosure.

[0024] FIG. 5 shows experimental data comparison which supports techniques for generating surface electromagnetic waves with underwater horn antennas in accordance with various aspects of the present disclosure.

[0025] FIG. 6 shows a flowchart illustrating a method of using gradient surface electromagnetic wave generation systems for generating surface electromagnetic waves with underwater horn antennas in accordance with various aspects of the present disclosure.DETAILED DESCRIPTION

[0026] The described implementations relate to improved gradient surface electromagnetic wave generation systems and associated methods for generating surface electromagnetic waves with underwater horn antennas. In some examples, the efficient generation and propagation of surface electromagnetic waves in underwater environments may remain a significant challenge in the realm of underwater communications and imaging. Conventional antennas used for radio frequency transmission may not be optimized for operation in aquatic settings, leading to rapid attenuation of signals and poor communication range. Furthermore, the mismatch in momentum between free-space radio waves and surface electromagnetic waves at the water-air interface may present a barrier to the direct excitation of these waves. This momentum mismatch may result in inefficient energy transfer and may limit the practical applications of surface electromagnetic waves for underwater use. Additionally, existing technologies may struggle to provide high- resolution imaging and sensitive detection capabilities in underwater environments, which mayDocket No. 0045-920595 be crucial for various applications including underwater navigation, exploration, and biological sensing.

[0027] According to some implementations, some systems may include horn antennas that are filled with water and operated underwater. These horn antennas, which are typically used in open air, may be adapted for use in a submerged environment, resulting in a shift in their operating frequency band. In these systems, a modified Otto configuration may be employed, which traditionally involves the use of high refractive index prisms for phase matching in the excitation of surface waves. However, in this context, the horn antennas underwater serve a similar purpose without the need for prisms.

[0028] The systems may allow for phase matching conditions to be achieved by adjusting the angular orientation of the horn antennas underwater. This adjustment may facilitate the generation of gradient surface electromagnetic waves, as it overcomes the mismatch in momentum that typically prevents their excitation from free space sources. When operated underwater, the horn antennas experience a downward shift in their operating frequency band due to the change in the environment from air to water, which has different electromagnetic properties.

[0029] The systems may specifically target the generation of gradient surface electromagnetic waves over a water-air interface. This may open up potential applications in underwater communications and imaging, where traditional electromagnetic waves are heavily attenuated. The systems may take advantage of dielectric permittivity gradients at the water interface to support the existence and propagation of gradient surface electromagnetic waves. These gradients provide the necessary conditions for these waves to exist.

[0030] Some implementations may promise improved underwater communication capabilities by generating gradient surface electromagnetic waves, which may propagate with less attenuation compared to conventional electromagnetic waves in water, thus enhancing communication range and signal clarity. The systems may have implications for underwater imaging, as the properties of gradient surface electromagnetic waves, such as their sensitivity to the dielectric properties of materials, enabling new imaging methods that provide different contrast mechanisms compared to existing technologies.

[0031] The systems may have been experimentally validated, demonstrating the ability to excite and propagate gradient surface electromagnetic waves using the described horn antennas and configuration. This includes the observation of gradient surface electromagnetic waves in various water environments and the detection of objects placed in the water. The systems mayDocket No. 0045-920595 have been compared with conventional dipole antennas in similar experimental configurations, with the horn antennas used for gradient surface electromagnetic wave generation showing superior performance.

[0032] The systems may include the measurement of attenuation characteristics of gradient surface electromagnetic waves, comparing them with conventional signal propagation in water. The gradient surface electromagnetic waves exhibit considerably larger attenuation constants, indicating their potential for longer-range propagation in underwater environments. The systems may demonstrate the capability to detect the presence of objects in water, as shown through experiments where the presence of metallic and dielectric objects affects the measured signals.

[0033] Aspects of the subject matter described in this disclosure can be implemented to realize one or more of the following potential advantages. The described configurations may be adapted for remote sensing applications, where the ability to detect objects through conductive barriers may be beneficial. The techniques may be utilized to improve the accuracy of surface wave-based communication systems, particularly in challenging underwater environments where traditional methods face significant signal degradation. The approaches may be scaled to different frequencies and environments, suggesting versatility in the application of the underlying principles.

[0034] Aspects of the disclosure are initially described in the context of gradient surface electromagnetic wave generation systems. Aspects of the disclosure are additionally illustrated by and described with reference to example implementations. Aspects of the disclosure are further illustrated by and described with reference to a flowchart that relates to methods of using gradient surface electromagnetic wave generation systems for generating surface electromagnetic waves with underwater horn antennas.

[0035] FIG. 1 shows system 100 which supports techniques for generating surface electromagnetic waves with underwater horn antennas in accordance with various aspects of the present disclosure. As depicted in FIG. 1, the system 100 may a first horn antenna 102, a second horn antenna 104, an object 106, water 108, an air gap 110, and / or other components.

[0036] The first horn antenna 102 may serve as an initial point for GSEW excitation in the experiment. In some implementations, the first horn antenna 102 may be designed to emit radio frequency signals that initiate the generation of gradient surface electromagnetic waves (GSEWs). The first horn antenna 102 may be positioned at a specific orientation to achieve phase matching conditions that facilitate the excitation of GSEWs. The first horn antenna 102 may be filled with a medium, such as water, to adjust its operating frequency when submerged.Docket No. 0045-920595

[0037] The second horn antenna 104 may act as a receiver for the GSEWs generated by the first horn antenna 102. In some implementations, the second horn antenna 104 may be tuned to detect the specific frequency range of the GSEWs produced during the experiment. The second horn antenna 104 may be placed at a certain distance from the first horn antenna 102 to capture the GSEWs after they have propagated through the experiment medium. The second horn antenna 104 may be oriented at an angle that aligns with the expected direction of the GSEWs to maximize reception.

[0038] The object 106 may be positioned within the water 108 to interact with the GSEWs during the experiment. In some implementations, the object 106 may be composed of materials that have distinct dielectric properties to influence the interaction with GSEWs. The object 106 may be placed at varying depths within the water 108 to study the effect of object placement on GSEW propagation. The object 106 may be of various shapes and sizes to simulate different scenarios in which GSEWs may be used for detection or imaging.

[0039] The water 108 may provide a medium for the propagation of GSEWs in the experiment. In some implementations, the water 108 may be chosen for its dielectric properties that are similar to human tissue, making it a suitable medium for biosensing and bioimaging applications. The water 108 may be contained within a specific area of the experiment setup to ensure controlled propagation of GSEWs. The water 108 may be of varying purity levels, such as tap water or pool water, to study the effect of water composition on GSEW propagation.

[0040] The air gap 110 may separate the first horn antenna 102 and the water 108, allowing for the generation of GSEWs across this interface. In some implementations, the air gap 110 may be adjusted in width to optimize the phase matching conditions for GSEW excitation. The air gap 110 may be an integral part of the modified Otto configuration used in the experiment to facilitate GSEW generation. The air gap 110 may be maintained at a consistent width throughout the experiment to ensure reproducibility of results.

[0041] In some implementations, the first horn antenna 102 may be positioned at one end of the air gap 110, with the second horn antenna 104 placed at the opposite end. The object 106 may be situated within the water 108, directly beneath the air gap 110, to interact with the GSEWs as they propagate. The water 108 may fill the space below the air gap 110, creating a medium for the GSEWs to travel through. The air gap 110 may be configured to maintain a specific distance between the first horn antenna 102 and the water 108, as well as between the second horn antenna 104 and the water 108, to achieve the desired phase matching conditions.Docket No. 0045-920595

[0042] FIG. 2 shows antenna signal measurements 200 which support techniques for generating surface electromagnetic waves with underwater horn antennas in accordance with various aspects of the present disclosure. The antenna signal measurements 200 illustrates the results of two measurement runs, depicted in black and grey, to demonstrate the reproducibility of the S21 signal measurements when a pair of horn antennas are placed underwater in the Otto configuration. The S21 signal, which represents the transmission coefficient between the two antennas, is measured at an angle of 55 degrees with respect to the water surface, as per the system 100 shown in FIG. 1. This angle is critical for achieving phase matching conditions that allow for the efficient coupling of the emitted radio waves from the horn antennas with the gradient surface electromagnetic waves (GSEWs) propagating along the water-air interface.

[0043] The data presented in FIG. 2 are indicative of the successful excitation and detection of GSEWs using the described underwater horn antennas. The consistency between the two measurement runs underscores the reliability of the system and method for generating GSEWs, which is a key consideration for practical underwater communication and imaging applications. The antenna signal measurements 200 further substantiates the underlying principles of the modified Otto configuration, which leverages the dielectric properties of water to facilitate the generation of GSEWs without the need for traditional high refractive index prisms.

[0044] Moreover, the measurements captured in FIG. 2 provide empirical evidence supporting the theoretical considerations discussed in the patent application. These considerations include the role of dielectric permittivity gradients at the water-air interface in supporting the existence of GSEWs and the ability of specialized underwater horn antennas to overcome the momentum mismatch typically encountered at this interface. The results depicted in the antenna signal measurements 200 are instrumental in validating the proposed method for generating GSEWs and may serve as a foundation for further development and optimization of the system for enhanced underwater biosensing and bioimaging capabilities.

[0045] FIG. 3 shows signal attenuation comparison 300 which supports techniques for generating surface electromagnetic waves with underwater horn antennas in accordance with various aspects of the present disclosure. The comparison 300 illustrates the attenuation characteristics of gradient surface electromagnetic waves (GSEWs) as they propagate through a water medium, providing insights into the potential for enhanced underwater communication and imaging applications. The comparison 300 presents two distinct attenuation profiles: one for GSEWs and another for conventionally propagated signals, both measured at a frequency of 674 MHz.Docket No. 0045-920595

[0046] The first profile, indicated by a black line, represents the attenuation of GSEWs as a function of distance between the horn antennas when oriented at an angle 0=30 degrees relative to the water surface. This orientation may facilitate achieving phase matching conditions that allow for the efficient coupling of radio waves emitted by the horn antennas with the GSEWs propagating along the water-air interface. The observed attenuation constant 6SEW=16 cm for the GSEW signal is considerably larger than that of the conventional signal, suggesting that GSEWs may offer superior propagation characteristics in underwater environments.

[0047] The second profile, depicted by a grey line, corresponds to the attenuation of conventionally propagated signals measured between the horn antennas pointed directly at each other at an angle 0=90 degrees. The attenuation constant 6=4 cm for this conventional signal matches the known skin depth in water at the measured frequency, serving as a benchmark for comparison with the GSEW signal.

[0048] The signal attenuation comparison 300 further includes local maxima around 0=35 degrees for the S21(0) dependencies, as measured in both fresh and pool water environments. These maxima, which are indicative of enhanced coupling under phase matching conditions, underscore the importance of angular orientation in the excitation and detection of GSEWs. The comparison 300 thus provides empirical evidence supporting the theoretical considerations discussed in the present disclosure, demonstrating the practical feasibility of GSEW-based techniques for underwater applications. The results captured in FIG. 3 validate the proposed method and system for generating and utilizing GSEWs, highlighting their potential to significantly improve underwater communication and imaging by overcoming the limitations of conventional radio frequency wave propagation in such environments.

[0049] FIG. 4 shows an underwater detection experiment 400 which supports techniques for generating surface electromagnetic waves with underwater horn antennas in accordance with various aspects of the present disclosure. As depicted in FIG. 4, the underwater detection experiment 400 may include one or more of a first hom antenna 402, a second horn antenna 404, a metal object 406, a water interface 408, a plastic container 410, and / or other components.

[0050] The first hom antenna 402 may serve as an initial point of emission for surface electromagnetic waves in the underwater detection experiment. In some implementations, the first hom antenna 402 may be positioned to direct the emitted waves towards the water interface 408. The first horn antenna 402 may be designed to operate at specific frequencies suitable for underwater communication.Docket No. 0045-920595

[0051] The second horn antenna 404 may act as a receiver for the surface electromagnetic waves emitted by the first horn antenna 402 in the underwater detection experiment. In some implementations, the second horn antenna 404 may be strategically placed to capture the waves after they have interacted with the water interface 408. The second horn antenna 404 may be tuned to the same frequency range as the first horn antenna 402 to ensure coherent signal reception.

[0052] The metal object 406 may be used as a test subject to assess the detection capabilities of the surface electromagnetic waves in the underwater detection experiment. In some implementations, the metal object 406 may introduce a detectable disturbance in the propagation of the surface electromagnetic waves. The metal object 406 may vary in size and composition to simulate different detection scenarios.

[0053] The water interface 408 may provide a medium through which the surface electromagnetic waves propagate in the underwater detection experiment. In some implementations, the water interface 408 may influence the behavior of the waves, such as their speed and attenuation. The water interface 408 may be characterized by its dielectric properties, which may affect the interaction with the surface electromagnetic waves.

[0054] The plastic container 410 may house the water that forms the water interface 408 in the underwater detection experiment. In some implementations, the plastic container 410 may be constructed from materials that minimally interfere with the propagation of the surface electromagnetic waves. The plastic container 410 may be of various shapes and sizes to accommodate different volumes of water for the water interface 408.

[0055] In some implementations, the first horn antenna 402 and the second horn antenna 404 may be submerged in the water contained within the plastic container 410. The metal object 406 may be placed at a specific location within the water interface 408 to create a detectable disturbance. The plastic container 410 may be transparent to allow visual monitoring of the experiment.

[0056] FIG. 5 shows experimental data comparison 500 which supports techniques for generating surface electromagnetic waves with underwater horn antennas in accordance with various aspects of the present disclosure. The comparison 500 illustrates the sensitivity of gradient surface electromagnetic wave (GSEW) systems to the presence of objects near the water-air interface, which is critical for the detection capabilities in biosensing and bioimaging applications. In the depicted experiments, the alteration of anti-resonances in the S21 signal is measured by a vector network analyzer connected to a pair of horn antennas, demonstrating theDocket No. 0045-920595 system’s response to the introduction of a metal or dielectric object in the vicinity of the interface.

[0057] The upper part of FIG. 5 compares the S21 signal measured with and without a metal object placed inside the water layer. The presence of the metal object is indicated by the blue curve, while the yellow curve represents the baseline measurement without the object. The comparison reveals a discernible change in the anti-resonance pattern when the metal object is introduced, confirming the system’s capability to detect metallic objects through alterations in the electromagnetic wave characteristics at the interface.

[0058] The lower part of FIG. 5 presents a similar experiment conducted with the horn antennas operating at 670 MHz, focusing on the detection of a dielectric object near the water surface. The results demonstrate that the system is equally adept at sensing dielectric materials, as evidenced by the changes in the S21 signal. This part of the comparison 500 underscores the versatility of the GSEW system in detecting various types of objects, which is essential for diverse applications ranging from underwater exploration to medical diagnostics.

[0059] Overall, FIG. 5 provides empirical evidence supporting the efficacy of GSEW-based techniques in object detection. The comparison 500 exemplifies the system’s potential to enhance current biosensing and bioimaging methods by offering a non-invasive, high-resolution alternative that leverages the unique properties of surface electromagnetic waves at the water- air interface. The data presented in FIG. 5 is integral to the understanding of the system’s operational principles and its practical applications in real-world scenarios.

[0060] FIG. 6 shows a flowchart illustrating a method 600 of using gradient surface electromagnetic wave generation systems for generating surface electromagnetic waves with underwater horn antennas in accordance with various aspects of the present disclosure.

[0061] At 602, the method 600 may include breaking momentum conservation parallel to an interface of water and another material using a first horn antenna. The operations of 602 may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of 602 may be performed using one or more components of the system 100 as described with reference to FIG. 1.

[0062] At 604, the method 600 may include positioning a second horn antenna in proximity to the first horn antenna to generate anti-resonances in response to the first horn antenna. The operations of 604 may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of 604 may be performed using one or more components of the system 100 as described with reference to FIG. 1.Docket No. 0045-920595

[0063] At 606, the method 600 may include altering the anti-resonances generated by the second horn antenna by positioning an object comprising at least one of a metal or a dielectric near the interface. The operations of 606 may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of 606 may be performed using one or more components of the system 100 as described with reference to FIG. 1.

[0064] It should be noted that the methods described herein describe possible implementations, and that the operations and the steps may be rearranged or otherwise modified and that other implementations are possible. Furthermore, aspects from two or more of the methods may be combined.

[0065] The description set forth herein, in connection with the appended drawings, describes example configurations and does not represent all the examples that may be implemented or that are within the scope of the claims. The term “exemplary” used herein means “serving as an example, instance, or illustration,” and not “preferred” or “advantageous over other examples.” The detailed description includes specific details for the purpose of providing an understanding of the described techniques. These techniques, however, may be practiced without these specific details. In some instances, well-known structures and devices are shown in block diagram form in order to avoid obscuring the concepts of the described examples.

[0066] In the appended figures, similar components or features may have the same reference label. Further, various components of the same type may be distinguished by following the reference label by a dash and a second label that distinguishes among the similar components. If just the first reference label is used in the specification, the description is applicable to any one of the similar components having the same first reference label irrespective of the second reference label.

[0067] Information and signals described herein may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0068] The various illustrative blocks and modules described in connection with the disclosure herein may be implemented or performed with a general-purpose processor, a DSP, an ASIC, an FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but in the alternative, theDocket No. 0045-920595 processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration).

[0069] The description herein is provided to enable a person skilled in the art to make or use the disclosure. Various modifications to the disclosure will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other variations without departing from the scope of the disclosure. Thus, the disclosure is not limited to the examples and designs described herein, but is to be accorded the broadest scope consistent with the principles and novel features disclosed herein.

Claims

Docket No. 0045-920595What is claimed is:

1. A gradient surface electromagnetic wave generation system, comprising: a first horn antenna configured to break momentum conservation parallel to an interface of water and another material; a second horn antenna positioned in proximity to the first horn antenna and adapted to generate anti-resonances in response to the first horn antenna; and an object positioned near the interface, the object comprising at least one of a metal or a dielectric, the presence of object altering the anti-resonances generated by the horn antenna.

2. The system of claim 1 , further comprising a vector network analyzer connected to the first horn antenna and the second horn antenna, wherein the vector network analyzer is configured to measure the alteration of the anti-resonances in response to the presence of the object.

3. The system of claim 1 , wherein the first horn antenna and the second horn antenna are filled with water, and the water may be used as a prism to facilitate the generation of the gradient surface electromagnetic waves.

4. The system of claim 1 , wherein the interface between the first horn antenna and the second horn antenna supports the propagation of the gradient surface electromagnetic waves.

5. The system of claim 1 , wherein the object is a metal object near the interface, and the system is configured to detect the presence of the metal object near the interface based on the alteration of the anti-resonances.

6. The system of claim 1, wherein the object is a dielectric object near the surface, and the system is configured to detect the presence of the dielectric object near the interface based on the alteration of the anti-resonances.

7. The system of claim 1 , wherein the first horn antenna and the second horn antenna are configured to operate in a plasmonic-plasmonic mode, enhancing the sensitivity to the object.Docket No. 0045-9205958. The system of claim 1 , wherein the object comprises a metal rod, and the system is configured to detect changes in the anti-resonances indicative of the metal rod’s presence.

9. The system of claim 1 , wherein the first horn antenna and the second horn antenna are positioned at a water level, and the system is configured to detect fluctuations in the water level based on the anti-resonances.

10. The system of claim 1, wherein the first horn antenna and the second horn antenna are aligned in a vertical orientation, enhancing the detection of vertical surface states.1 1 . The system of claim 1 , wherein the first horn antenna and the second horn antenna are aligned in a horizontal orientation, enhancing the detection of horizontal surface states.

12. The system of claim 1 , wherein the object is characterized as a reference, and the system is configured to calibrate the anti-resonances based on the reference.

13. The system of claim 1 , wherein the first horn antenna and the second horn antenna are adapted for use with water / tissue interfaces, expanding the applications to biological sensing.

14. A method for generating gradient surface electromagnetic waves, comprising: breaking momentum conservation parallel to an interface of water and another material using a first horn antenna; positioning a second horn antenna in proximity to the first horn antenna to generate anti-resonances in response to the first horn antenna; and altering the anti-resonances generated by the second horn antenna by positioning an object comprising at least one of a metal or a dielectric near the interface.

15. The method of claim 14, further comprising measuring the alteration of the antiresonances in response to the presence of the object with a vector network analyzer connected to the first hom antenna and the second horn antenna.

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