Invention for Methods, apparatus and methods for inducing fundamental wave modes on a transmission medium

Invented by Paul Shala Henry, Robert Bennett, Farhad Barzegar, Irwin Gerszberg, Donald J. Barnickel, Thomas M. Willis, III, AT&T Intellectual Property I LP

The AT&T Intellectual Property I LP invention works as follows

Aspects of this disclosure could include, for instance, a system to generate electromagnetic waves with a fundamental wave mode and directing the electromagneticwaves to an interface of transmission medium for guiding propagation. There are other embodiments.

Background for Methods, apparatus and methods for inducing fundamental wave modes on a transmission medium

Smart phones and other mobile devices are becoming more ubiquitous and data usage is increasing, so macrocell base stations devices and the existing wireless infrastructure will need to have higher bandwidth capabilities in order to meet increased demand.” Small cell deployment is being explored to provide more mobile bandwidth. Picocells and microcells offer coverage in smaller areas than traditional macrocells.

In addition, most households and businesses have come to rely upon broadband data access for services like voice, video, and Internet browsing. Broadband access networks can be used for satellite, 4G, 5G wireless, powerline communication, fiber, cable and telephone networks.

One or more embodiments will now be described using reference to the drawings. Like reference numerals can be used throughout to refer to similar elements. The following description will provide an explanation of each embodiment. However, it is clear that many embodiments can be used without these details and without applying to any particular standard or networked environment.

In one embodiment, a guided-wave communication system is shown for sending and receiving communication signals like data or other signaling via guided magnetic waves. Guided electromagnetic waves can include surface waves and other electromagnetic waves that have been bound to or guided through a transmission medium. You will see that guided wave communications can be used with a wide range of transmission media without departing from the examples. You can choose from one or more of these transmission media, single-stranded, multi-stranded, or insulated; conductors in other shapes and configurations such as wire bundles or cables; conductors with other shapes and configurations such as wire rods or rails; non-conductors like dielectric pipes, rods or rails or other dielectric members; and combinations of conductors or dielectric materials.

The induction of guided electromagnetic waves can occur independently of any charge, current, or electrical potential that is injected into the transmission medium. If the transmission medium is a metal wire, for example, it should be understood that although a small current may form in response to the propagation and propagation electromagnetic waves along the wire’s surface, this is due to the propagation and propagation of the wave along the wire’s surface. It is not formed by an electrical potential, charge, or current that is injected in to the wire. To propagate along the wire’s surface, the electromagnetic waves travelling on the wire do not need to be part of a circuit. Therefore, the wire is a single wire transmission link that is not part a circuit. In some embodiments, a wire may not be necessary. The electromagnetic waves can propagate along one line transmission medium, which is not a cable.

More generally, ‘guided electromagnetic waves?” Or?guided electromagnetic waves? The subject disclosure describes how guided waves are affected by the presence a physical object. This could be a wire, conductor, dielectric, insulated wire, conduit, or hollow element. It can also be a wire bundle or dielectric that is covered, covered, or surrounded by an insulator, dielectric, or other wire bundle. This physical object may be used as a guide through a transmission medium (e.g. an outer, inner, or other boundary between elements) to propagate guided electromagnetic waves. These waves can then carry energy, data, and/or other signals along a transmission path from a sender device to a receiver device.

Guided electromagnetic waves are not restricted to free space propagation, such as unguided or unbounded wireless signals. Their intensity decreases in proportion to the distance traveled. However, guided electromagnetic wave propagation can occur along a transmission medium with a lower loss of magnitude per unit distance than unguided electromagnetic radiation.

Guided electromagnetic waves, unlike electrical signals, can propagate between a sending device and a receiver device without the need for an additional electrical return path. Guided electromagnetic waves can travel from a sending device through a transmission medium without conductive components, such as a dielectric strip, or via a transmission media with only one conductor (e.g. a single wire or insulated cable). Even if the transmission medium contains one or more conductors, the guided electromagnetic wave propagating along it generates currents that flow in the direction of the guided waves. These guided electromagnetic waves can travel along the transmission media from a sending device or receiving device without the need for opposing currents along an electrical return path.

Imagine electrical systems that transmit and/or receive electrical signals via conductive media between sending and receiving devices. This is a non-limiting example. These systems rely on separate electrical forward and return paths. Consider a coaxial cable with a ground shield and a center conductor. The insulator separates the two. In an electrical system, a first terminal can be connected directly to the center conductor. A second terminal can then be connected to ground shield. The sending device can inject an electrical signal into the center conductor through the first terminal. This will cause forward currents to flow along the center conductor and ground shield currents to return. For a two-terminal receiving device, the same conditions apply.

Consider, however, a guided wave communications system, such as the one described in this disclosure, that can use different types of transmission mediums (including a coaxial cable among others) to transmit and receive guided electromagnetic waves with no electrical return path. One embodiment of the subject disclosure allows for guided electromagnetic waves to propagate along the outer surface of a coaxial cables. The guided electromagnetic wave will create forward currents on a ground shield but the guided waves don’t require return currents to allow the guided waves to propagate along an outer surface of a coaxial cable. This is true for all other transmission media that are used in a guided wave communication network to transmit and receive guided electromagnetic waves. Guided electromagnetic waves can be induced by the guide wave communication system on the outer surface of bare wires, or an insulated wire. They can propagate along the wire or the wire insulated without any electrical return path.

Electrical systems that require two or more conductors to carry forward and reverse currents on separate conductors in order to propagate electrical signals injected from a sending device are different from guided wave systems that induce guided magnetic waves on the interface of a transmission media without the need for an electrical return path to allow the propagation guided electromagnetic waves along that interface.

It should be noted that guided electromagnetic wave described in the subject disclosure may have an electromagnetic field structure that is primarily or substantially outside a transmission medium to be bound or guided by it and to propagate non-trivial lengths along or along its outer surface. Other embodiments of guided electromagnetic waves may have an electromagnetic field structure that is primarily or substantially within a transmission medium in order to be bound or guided by it and to propagate nontrivial distances within that medium. Other embodiments allow guided electromagnetic waves to have an electromagnetic field structure which lies both inside and outside of a transmission medium, so that it can be bound to or guided along the transmission media. The desired electronic field structure in an embodiment may vary based upon a variety of factors, including the desired transmission distance, the characteristics of the transmission medium itself, and environmental conditions/characteristics outside of the transmission medium (e.g., presence of rain, fog, atmospheric conditions, etc.).

Various embodiments herein relate to coupling device, which can be referred as?waveguide couples?, or?waveguide coupling?. Or, more simply as ‘couplers? or?coupling device? or ?launchers? For launching and/or extracting directed electromagnetic waves to and fro a transmission medium at millimeter wave frequencies (e.g. 30 to 300 Ghz), wherein the wavelength may be smaller than one or more dimensions the coupling device or the transmission medium, such as the diameter of a wire or any other cross sectional dimension, and lower microwave frequencies like 300 MHz to 30 Ghz. A coupling device can generate transmissions that propagate as waves, such as a strip, an arc, or any other length of dielectric material, a horn or monopole or rod, or another antenna; a magnetic coupler or other resonant coupler; coil, strip line, waveguide, or any other coupling device. The coupling device receives the electromagnetic wave from either a transmitter or transmission medium. The electromagnetic field structure that makes up the electromagnetic wave can be carried within the coupling apparatus, outside it or a combination of both. The coupling device can be located in close proximity of a transmission medium so at least some portion of the electromagnetic wave is bound or couples to it and propagates as guided electromagnetic waves. A coupling device can take guided waves from a transmission medium, and then transfer them to a receiver in a reciprocal manner.

A surface wave, according to an example embodiment, is a type or guided wave that is guided through a surface of an transmission medium. This could be an exterior or outer surface of wires or any other surface that is adjacent or exposed to another medium with different properties (e.g. dielectric properties). In an example embodiment, the surface of the wire that guides surface waves can be a transitional surface between different media types. In the case of uninsulated or bare wires, the wire’s surface can be either the exterior or interior conductive surface that is exposed to air, or free space. Another example is that of an insulated wire. The surface of the wiring can be the conductive section of the wire which meets the insulation portion. Or it can be the insulator area of wire that is exposed. Depending on the relative properties of the conductor, air and insulator (e.g. dielectric properties), the material region between the insulator and conductive surfaces of wires can also be considered the surface.

According an example embodiment, the term “about?” “About” refers to a wire or transmission medium that is used with a guidedwave. It can also include fundamental guided wave propagation modes, such as a circular or substantially circular distribution of the field or a symmetrical distribution of the electromagnetic field (e.g. electric field, magnetic fields, etc.). or any other fundamental mode pattern that is at least partially around a wire, or another transmission medium. A guided wave can also propagate?about? A guided wave can propagate?about? a wire or another transmission medium if it uses a guided propagation mode. This includes the fundamental wave propagation models (e.g. zero order modes), as well as additional or alternative non-fundamental modes like higher-order guided waves modes (e.g. 1st order modes and 2nd order modes). Asymmetrical modes, and/or other guided waves (e.g. surface), that have non-circular fields around a wire. The term “guided wave mode” is used herein. Refers to the guided wave propagation mode for a transmission medium, coupling devices or other component of a guided-wave communication system.

For example, non-circular field distributions may be unilateral or multilateral and have one or more axiallobes that are characterized with relatively higher field strength and/or one/more nulls, or null regions, which are characterized as relatively low-field strength. According to one example embodiment, the field distribution may also vary depending on azimuthal orientation. This means that one or more angular areas around the wire can have an electric, magnetic, or combination thereof, that is greater than one or several other regions. As the guided waves travel along the wire, it will become apparent that the relative positions or orientations of the guidedwave higher order modes and asymmetrical modes may change.

Millimeter-wave” is used herein. Can refer to electromagnetic waves/signals falling within the?millimeter wave frequency band? between 30 GHz and 300 GHz. Microwave is a term that refers to electromagnetic waves/signals. Microwaves can be used to refer to electromagnetic signals/signals falling within a “microwave frequency band”. From 300 MHz up to 300 GHz. The term “radio frequency” is used. The term?radio frequency? oder?RF? can be used to refer to electromagnetic waves/signals that fall within the?radio frequency band. The term?RF? can be used to refer to electromagnetic signals/waves that fall within the ‘radio frequency band? between 10 kHz and 1 THz. Wireless signals, electrical signals and guided electromagnetic waves, as described in this disclosure, can operate at any frequency, including frequencies within the millimeter-wave or microwave frequency bands. Particularly, if a transmission medium or coupling device includes a conductor element, the frequency at which the guided electromagnetic waves are carried and/or propagate along that transmission medium can be lower than the mean collision frequency for the electrons within the conductor element. The frequency of guided electromagnetic waves propagated along the transmission medium and carried by the coupling devices can also be non-optical. A radio frequency that is below the range of optical frequencies which begins at 1 THz.

As used in this document, the term “antenna” means: An antenna is a device that transmits/radiates or receives wireless signals.

In accordance to one or more embodiments, a process includes creating instances of first electromagnetic radiation that combine to form combined electromagneticwaves having a fundamental mode and non-optical operating frequencies, and directing the combined electromagnetic waves through the waveguide to an interface of a transmission media for guiding propagation without the use of an electrical return path.

According to one or more embodiments, the system can include a plurality transmitters for launching instances for first electromagnetic waves that combine into combined electromagnetic wave waves with a substantially fundamental mode and non-optical operating frequencies, and a waveguide to direct the combined electromagnetic wave to an interface of an transmission medium for guiding propagation without the use of an electrical return path.

In accordance to one or more embodiments, the machine-readable storage media includes executable instructions. These instructions, when executed by the processor of a Waveguide System, facilitate the performance of operations. This includes obtaining operational parameters for configuring a plurality launchers of the waveguide, and configuring those launchers according the operational parameters to generate electromagnetic waves. The waveguide system also comprises a waveguide structure that directs the combined electromagnetic wave to an interface of an transmission medium for guiding propagation without the use of an electrical return path.

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