INCORPORATION BY REFERENCE TO ANY PRIORITY APPLICATIONS [0001] This application claims the priority benefit of U.S. Provisional Application No. 63/152248, filed on February 22, 2021, titled ARTICULATED WAVEGUIDE, of U.S. Provisional Application No. 63/152294, filed on February 22, 2021, titled APPLICATION OF MICROWAVE ENERGY DIRECTLY TO A ROCK FACE UNDERGROUND, and of U.S. Provisional Application No. 63/152253, filed on February 22, 2021, titled MICROWAVE ENERGY APPLICATOR, the entire content of each of which is incorporated by reference herein for all purposes and forms a part of this specification.

BACKGROUND

Field

[0002] The development relates generally to waveguides, in particular to articulated waveguide systems, which may be used in microwave-based systems for mining rock, among other applications.

Description of the Related Art

[0003] Waveguides are used for guiding electromagnetic energy, such as microwaves. Having rotatable joints in the waveguide may allow for movement of the waveguide, which may allow for enhanced capabilities in certain applications. Conventional rotary waveguide joints suffer from high signal and/or energy loss. Therefore, there is a need for an improved articulated waveguide to address these and other drawbacks of existing solutions.

SUMMARY

[0004] The embodiments disclosed herein each have several aspects no single one of which is solely responsible for the disclosure’s desirable attributes. Without limiting the scope of this disclosure, its more prominent features will now be briefly discussed. After considering this discussion, and particularly after ready the section entitled “Detailed Description,” one will understand how the features of the embodiments described herein provide advantages over existing systems, devices, and methods relating to rotational joints in waveguides and to microwave-based approaches for mining rock.

[0005] The following disclosure describes non-limiting examples of some embodiments. For instance, other embodiments of the disclosed device, systems and methods may or may not include the features described herein. Moreover, disclosed advantages and benefits may apply only to certain embodiments of the invention and should not be used to limit the disclosure. Systems, devices and methods are described for an articulated waveguide.

[0006] In one aspect, a microwave-based system for mining rock includes a microwave generator, a robotic arm, and an antenna. The robotic arm is connected with the generator and comprises a plurality of waveguide segments. The waveguide segments are rigid and configured to guide therethrough microwaves generated by the microwave generator for application to the rock. First and second waveguide segments of the plurality of waveguide segments are rotatably attached together at a joint. The antenna is positioned at least partially within the joint. The antenna comprises a first elongated antenna second and a second elongated antenna segment attached to and extending from the first antenna segment. The first antenna segment is configured to receive microwaves from the first waveguide segment, and the second antenna segment is configured to transmit microwaves into the second waveguide segment.

[0007] Various embodiments of the various aspects may be implemented. In some embodiments, the antenna is T-shaped;

[0008] In some embodiments, the joint comprises a rotatable connector that rotatably attaches the first and second waveguide segments together, and wherein the antenna does not contact the rotatable connector;

[0009] In some embodiments, the joint defines a rotational axis about which the first waveguide segment is configured to rotate relative to the second waveguide segment, and wherein the first antenna segment is oriented perpendicular to the rotation axis;

[0010] In some embodiments, the second antenna segment is oriented parallel to the rotation axis; [0011] In some embodiments, the joint defines a rotational axis about which the first waveguide segment is configured to rotate relative to the second waveguide segment, and wherein the second antenna segment is oriented parallel to the rotation axis;

[0012] in some embodiments, the first and second waveguide segments have four-sided cross-sectional profiles;

[0013] in some embodiments, the cross-sectional profiles are rectangular.

[0014] In some embodiments, the joint defines a rotational axis about which the first waveguide segment is configured to rotate relative to the second waveguide segment, and wherein the first waveguide segment defines a central axis that intersects the rotational axis;

[0015] In some embodiments, the central axis intersects the first antenna segment;

[0016] In some embodiments, the joint defines a rotational axis about which the first waveguide segment is configured to rotate relative to the second waveguide segment, and wherein the second waveguide segment defines a central axis that intersects the rotational axis;

[0017] In some embodiments, the central axis intersects or abuts the second antenna segment;

[0018] In some embodiments, the system further comprises two or more of the joints; and/or

[0019] In some embodiments, the system further comprises an applicator at an end of the robotic arm configured to focus the microwaves to a beam.

[0020] In another aspect, a waveguide system for transmitting microwaves includes a plurality of waveguide segments and an antenna. The waveguide segments are rigid and configured to guide therethrough microwaves. First and second segments of the plurality of waveguide segments are rotatably attached at a joint. The antenna is positioned at least partially within the joint. The antenna comprises a first elongated antenna segment and a second elongated antenna segment attached to and extending from the first antenna segment. The first antenna segment is configured to receive microwaves from the first waveguide segment, and the second antenna segment is configured to transmit microwaves into the second waveguide segment. [0021] Various embodiments of the various aspects may be implemented. In some embodiments, the joint comprises a rotatable connector that rotatably attaches the first and second waveguide segments together, and wherein the antenna does not contact the rotatable connector;

[0022] In some embodiments, the joint defines a rotational axis about which the first waveguide segment is configured to rotate relative to the second waveguide segment, and wherein the first antenna segment is oriented perpendicular to the rotation axis;

[0023] In some embodiments, the joint defines a rotational axis about which the first waveguide segment is configured to rotate relative to the second waveguide segment, and wherein the second antenna segment is oriented parallel to the rotation axis;

[0024] In some embodiments, the first and second waveguide segments have four-sided cross-sectional profiles;

[0025] In some embodiments, the joint defines a rotational axis about which the first waveguide segment is configured to rotate relative to the second waveguide segment, and wherein the first waveguide segment defines a central axis that intersects the rotational axis;

[0026] In some embodiments, the central axis intersects the first antenna segment;

[0027] In some embodiments, the joint defines a rotational axis about which the first waveguide segment is configured to rotate relative to the second waveguide segment, and wherein the second waveguide segment defines a central axis that intersects the rotational axis; and/or

[0028] In some embodiments, the central axis intersects the second antenna segment.

BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The foregoing and other features of the present disclosure will become more fully apparent from the following description and appended claims, taken in conjunction with the accompanying drawings. Understanding that these drawings depict only several embodiments in accordance with the disclosure and not to be considered limiting of its scope, the disclosure will be described with additional specificity and detail through use of the accompanying drawings. In the following detailed description, reference is made to the accompanying drawings, winch form a part hereof. In the drawings, similar symbols typicalSy identify similar components, unless context dictates otherwise. The illustrative embodiments described in the detailed description, drawings, and claims are not meant to be limiting. Other embodiments may be utilized, and other changes may be made, without departing from the spirit or scope of the subject matter presented here. It will be readily understood that the aspects of the present disclosure, as generally described herein, and illustrated in the drawings, may be arranged, substituted, combined, and designed m a wide variety of different configurations, all of which are explicitly contemplated and made part of this disclosure.

[0030] FIG. lA is a perspective view- of an embodiment of a microwave-based system for mining rock having an articulated waveguide.

[0031] FIG. IB is a perspective view- of the articulated waveguide of the system of FIG. 1A.

[0032] FIG. 2 is a perspective view ^’ of an embodiment of a waveguide joint for rotatably connecting first and second waveguide segments, and that may be used in the systems of FIGS. 1 A and IB.

[0033] FIGS, 3A and 3B are perspective views of the waveguide joint of FIG. 2 illustrating various rotational orientations of the waveguide segments.

[0034] FIG. 4A is a side view of the waveguide joint of FIG. 2,

[0035] FIG. 4B is a cross-sectional view of the waveguide joint, as taken along a plane that includes the axes Al, Wi and W2 as shown in FIG. 4A, showing a vertical segment (as oriented in the figure) of an embodiment of an internal antenna of the joint.

[0036] FIG. 5 is a front view' of the waveguide joint of FIG. 2 showing portions of horizontal and vertical segments (as oriented in the figure) of the internal antenna.

[0037] FIG. 6A is a front view of the internal antenna and rotatable connector of FIGS. 4A and 5, shown in isolation from the waveguide segments for clarity.

[0038] FIG. 6B is a cross-sectional view of the internal antenna and rotatable connector, as taken along a plane that includes the axes Al and A2 as shown in FIG. 6A, showing various features of the antenna and connector. [0039] The following detailed description is directed to certain specific embodiments of the thermal conditioning systems, devices, and methods. In this description, reference is made to the drawings wherein like parts or steps may be designated with like numerals throughout for clarity. Reference in this specification to “one embodiment,” “an embodiment,” or “in some embodiments” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. The appearances of the phrases “one embodiment,” “an embodiment,” or “in some embodiments” in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments necessarily mutually exclusive of other embodiments. Moreover, various features are described which may be exhibited by some embodiments and not by others. Similarly, various requirements are described which may be requirements for some embodiments but may not be requirements for other embodiments. Reference will now be made in detail to embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will he used throughout the drawings to refer to the same or like parts.

[0040] FIG. I A is a perspective view of an embodiment of a microwave-based system 100 for mining rock having an articulated waveguide system 200. Using a microwave-based system for mining rock requires controlled and flexible movement of an applicator while minimizing losses to the microwave energy travelling through the waveguide. The systems, devices and methods described herein allow for six degrees of freedom for orienting the applicator using a robotic arm formed of waveguide segments, and with minimal energy loss at one or more rotatable joints. The joints include an antenna that allows for minimal losses of energy at the joints while providing full three hundred sixty- degree rotation at the joints. By including a plurality of these joints in the robotic waveguide arm, the arm can be articulated to position the applicator at the end of the arm in any desired position, any desired orientation, at any speed, and in any direction, all while ensuring maximum transmission of microwa ve energy through the waveguide.

[0041] As shown in FIG. 1A, the system 100 may include a microwave generator 103, an applicator skid 105, and/or a treatment room 107. The applicator skid 105 may be positioned to face a layer of rock 109 for mining the rock 109, e.g. pre-conditioning and/or breaking the rock 109. The treatment room 107 may include walls and/or shields configured to contain any leaks. The microwave generator 103, applicator skid 105, and/or treatment room 107 may include a control system 110 for controlling the generation of microwaves and articulation of the waveguide system 200, to control application of microwaves to the rock 109. “Articulation” as used herein has its usual and customary meaning, and includes without limitation rotation, translation, and three-dimensional orientation in space. The rock 109 may be in a mountain, a cave, a quarry, or other locations, in some embodiments, the microwave generator 103, applicator skid 105, and/or treatment room 107 may be mobile and configured to travel throughout a mine site.

[0042] FIG. IB is a close up perspective view of the applicator skid 105 showing articulating portions of the waveguide system 200. The applicator skid 105 may include the waveguide system 200 or portions thereof. The waveguide system 200 may include an articulable robotic arm 104. The robotic arm 104 may be formed by a plurality of rigid waveguide segments 204, 208, or more segments, as described herein. There may be any number of the waveguide segments forming a single arm 104, such as two, three, four, five, six, seven, eight, nine, ten or more segments. The robotic arm 104 may be in communication with, e,g. connected to, the microwave generator 103. The microwave generator 103 may generate microwaves that travel through an internal channel defined by the connected waveguide segments of the robotic arm 104. The robotic arm 104 may be articulated by rotating one or more of the waveguide segments at one or more joints 210 thereof. One or more actuators at each joint 210 may cause rotation of the respective joint 210. Non-limiting examples of actuators include an external motor having a lever connecting each waveguide segment 204, 208, a pancake motor structure, and an extensible strut. The actuators may be controlled, either autonomously and/or by an operator. There may be any number of the robotic arms 104. There may be one, two, three, four, five, six, seven, eight, nine, ten or more of the robotic arms 104. Each robotic arm 104 may have any number of rotatable joints 210. There may be one, two, three, four, five, size, seven, eight, nine, ten or more of the rotatable joints 210 in each robotic arm 104.

[0043] The microwave-based system 100 may include one or more microwave applicators 108. The applicator 108 may be connected to the waveguide system 200. For example, the applicator 108 may be positioned at a distal end of the robotic arm 104. The applicator 108 may be connected to a terminal waveguide segment of the robotic arm 104. The applicator 108 may be configured to focus and/or concentrate the microwaves exiting the applicator, for example to a beam, for application to the rock 109. The position and/or movement of the applicator relative to the rock 109 may be controlled by articulation of the robotic arm 104. The control system 110 may control the robotic arm 104 in order to position and/or move the applicator 108 in a desired manner. The robotic arm 104 may be controlled such that the applicator 108 has a desired orientation relative to the rock 109, distance from the rock 109, speed of travel along the rock 109, and/or direction of travel along the rock 109, etc. The use of the robotic arm 104 with the waveguide segments may provide the benefit of a multi-jointed robotic arm 104 having many degrees of freedom.

[0044] FIG. 2 is a perspective view of an example embodiment of the joint 210 of the waveguide system 200. As described herein, one or more of the joints 210 may be included in the robotic arm 104 of the microwave-based system 100. The waveguide system 200 may include a plurality' of rigid waveguide segments, for example, a first waveguide segment 204 and a second waveguide segment 208. The waveguide segments 204, 208 may be configured to atach to longer waveguide segments of the robotic arm 104. The waveguide segments 204, 208 as shown may be connectors or base members configured to attach to other waveguide segments of the robotic arm 104. The waveguide segments 204, 208 may be rigid, for example formed of metal or other suitable materials. The waveguide segments 204, 208 may not be flexible. The waveguide segments 204, 208 may have a relatively high stiffness along their length. Any longer waveguide segments connected thereto may have similar properties as the waveguide segments 204, 208, e.g. rigid, metallic, rectangular, etc.

[0045] The waveguide segments 204, 208 may have the same or different cross- sectional profiles, in some embodiments, the waveguide segments 204, 208 may have foursided cross-sectional profiles. In some embodiments, the waveguide segments 204, 208 may have rectangular cross-sectional profiles, with two opposing longer sides of the same longer length being perpendicular to two opposing shorter sides of the same shorter length. This cross sectional profile is designed to allow the mono-modal wave to propagate. In some embodiments, the waveguide segments may have other cross-sectional profiles, for example, three-sided, five-sided, six-sided, seven-sided, eight-sided or more. In some embodiments. the waveguide segments 204, 208 may have rounded or circular cross-sectional profiles, for example, including but not limited to, circular or oval cross-sectional profiles.

[0046] The waveguide segments 204, 208 may have a number of sidewalls 219 corresponding to the cross-sectional profile and a rear wall or cap 225. For example, the waveguide segments 204, 208 having a four-sided cross-sectional profile may have four longitudinal sidewalls 219 and a rear wall or cap 225. The waveguide segments 204, 208 may have at least one open end defining an opening 220 to a longitudinal channel 221 formed therein. The channel 221 may have the cross-sectional profiles described herein. Microwave energy may travel through the channel 221. The channel 221 may be continuous from the microwave generator 103 to the applicator 108. The channel 221 may extend along a tortuous route due to articulation of the robotic arm 104. The channel 221 path may change as the arm 104 is articulated. The channel 221 may extend into the first waveguide segment 204, through the joint 210 such as through a connecting portion of the channel, which may at a rotational connector portion, and into the second waveguide segment 208. The opening 220 may have a shape corresponding to the cross-sectional profile of the waveguide segments 204, 208. Energy may be received into one of the openings 220 and then exit the other of the openings 220.

[0047] The waveguide segments 204, 208 may include a flange 222 that extends radially outward from the sidewalls 219 at the opening 220. The opening 220 may have a size corresponding to the cross-sectional profile of the waveguide segment 204, 208 defined by the channel 221. The flange 222 may extend beyond an outer surface of the sidewalls 219 of the waveguide segments 204, 208. The flange 222 may have one or more openings 223 that extend through the flange 222, The openings 223 may have a circular shape. The border may have any number of openings 223, for example, one, five, ten, fifteen, twenty, or more openings 223. The openings 223 may receive fasteners such as bolts to connect the rigid waveguide segments together to form the channel 221. The channel 221 may be straight or linear between adjacent joints 210 of the robotic arm 104. The channel 221 may extend linearly along a first direction through the first waveguide segment 204, linearly along a second direction that is perpendicular to the first direction at the joint 210 and toward the second waveguide segment 208, and then linearly along a third direction that is perpendicular to the second direction and along the second waveguide segment 208. [0048] The joint 210 may comprise a rotational connector 212. The first waveguide segment 204 and the second waveguide segment 208 may be rotatably attached or connected with each other at the joint 210 via the rotational connector 212. The rotational connector 212 may rotatably connect respecti ve ends of the waveguide segments 204, 208. In some embodiments, the waveguide system 200 may include more than two waveguide segments and a corresponding number of joints 210 and rotational connectors 212. The rotational connector 212 may be made of metal or other suitable materials. The rotational connector 212 may include rotatable portions. The waveguide segments and/or rotatable rotational connector 212 may be configured to be rotated by an actuator 211, which may be controlled by the control system 110, in order to rotate the waveguide segments 204, 208 to which respective portions of the rotational connector 212 are attached. In some embodiments, the rotational connector 212 may be in other locations, for example on the side, top, or bottom of the joint 210. There may be one or more rotational connectors at each joint 210.

[0049] The joint 210 may include one or more of the actuators 211 configured to cause and/or control the articulation of the robotic arm 104 and corresponding movement of the applicator 108. The actuator 211 may be, for example, an electromechanical actuator, a hydraulic actuator, an electrothermal actuator, or other suitable actuator. The actuator 211 may include a motor that can be commanded to cause and/or control movement of the rotational connector 212 and/or waveguide segments 204, 208. The actuator 211 may be located at or near the rotational connector 212, for example between opposing ends of rotatably connected waveguide segments. The actuator 211 may directly rotate or indirectly rotate, e.g. via a transmission, the rotational connector 212 and/or waveguide segments 204, 208. In some embodiments, the actuator 211 may not be located at the joint 210. The actuator 211 may control rotation of the waveguide segments 204, 208, thereby causing the waveguide segments 204, 208 to rotate about the rotational connector 212. For example, the actuator 211 may control movement of struts connected to the waveguide segments 204, 208. The actuator 211 may be connected to one of the waveguide segments, e.g. near one of the joints 210 that the actuator 211 is rotating.

[0050] The rotational connector 212 and/or actuator 211 may be positioned on the outside of the joint 210, for example external to the microwave channel 221. The positioning of the rotational connector 212 and other components related to movement of the joint 210 on the outside of the joint 210 may provide the benefit of preventing an interaction or interference between those components and the electromagnetic microwave energy within the channel 221 of the waveguide system 200. The rotational connector 212 and/or actuator 211 may include one or more sensors to assist in the control and/or rotation of the robotic arm 104. The control of rotation may be dependent on position, force, or other parameters.

[0051] The waveguide system 200 may include an antenna system or antenna 216. The antenna 216 may be located within the channel 221. The antenna 216 may be internal to the joint 210. The antenna 216 may be comprised of an electromagnetic transmission capable material, such as copper metal. The antenna 216 may allow for transmission of the microwave energy from the first waveguide segment 204 to the second waveguide segment 208 while mitigating losses of the microwave energy at the joints 210. The antenna 216 is further described herein, for example with respect to FIGS. 3A-6B.

[0052] As shown in FIGS. 3A and 3B, the rotational connector 212 may be configured to allow for three hundred sixty degree rotation of the first and second waveguide segments 204, 208 relative to each other. Regardless of the angular speed of rotation of the waveguide segments 204, 208 relative to each other, the joint 210 may preserve the efficiency and performance of the transmission of microwave energy therethrough with minimal losses. The joint 210 and/or rotational connector 212 may define a rotational axis Al. The rotational axis A1 may be perpendicular to longitudinal axes defined by the first and second waveguide segments 204, 208, as further described herein, e.g. with respect to FIGS. 4A-5. The rotational axis Al may intersect ends of the first and second waveguide segments 204, 208. The rotational axis Al may be concentric to the rotational connector 212.

[0053] The first waveguide segment 204 and second waveguide segment 208 may ^¬ be configured to rotate relative to each other about the rotational axis Al. For example, the first waveguide segment 204 may be stationary while the second waveguide segment 208 rotates, or the first waveguide segment 204 may rotate while the second waveguide segment 208 is stationary', or the first waveguide segment 204 and the second waveguide segment 208 may simultaneously rotate. In some embodiments, the first waveguide segment 204 may rotate while the second waveguide segment 208 is stationary and then the first waveguide segment 204 may be stationary while the second waveguide segment 208 rotates, or vice versa. “Stationary” may be m reference to a local or moving reference frame, for example if other joints 210 of the system are being articulated and causing the joint 210 to translate through space. “Stationary” may be in reference to a fixed reference frame, for example relative to the rock 109. Stationary may thus mean the particular waveguide segment is not rotating relative to the axis A1.

[0054] In some embodiments, the waveguide segments 204, 208 may rotate in an H-plane, here defined as the longest side of the waveguide, around the rotational connector 212. The H-plane may refer to a plane including a direction of the magnetic component or field vector of the electromagnetic microwave energy travelling through the channel 221. An E-plane may refer to a plane including a direction of the electric component or field vector of the electromagnetic microwave energy travelling through the channel 221. The H-Plane and E-plane may be oriented ninety degrees relative to each other. In some embodiments, the antenna segments may project m the E-plane direction into each waveguide segment 204, 208. The antenna geometry' inside each waveguide segment 204, 208 may remain identical as seen by the electromagnetic field in each waveguide. Rotational orientation only needs to maintain this constant projecting geometry _'· .

[0055] As shown in FIGS. 3A and 3B, the first and second waveguide segments 204, 208 may rotate to face and extend along different, non-parallel, and/or unaligned directions. The first and second waveguide segments 204, 208 may rotate to face the same direction, as shown in FIG. 2. The first and second waveguide segments 204, 208 may rotate to be positioned relative to one another at any angle. The waveguide segments 204, 208 may rotate around the rotational connector 212, The rotational connector 212 may remain translationally stationary while each respective waveguide segment 204, 208 rotates about the joint 210.

[0056] The rotation of the waveguide system 200 allows for microwave energy to be applied to precise locations. The rotation further allows for this application to occur at an increased speed by reducing the time it takes to position the waveguide segments 204, 208, and thus the applicator 108. Precision is necessary to treat, precondition, and/or alter only the intended portions of the rock 109, while leaving all adjacent portions of the rock 109 unaffected. [0057] The position and location of the wa veguide system 200 and applicator 108 may be determined by the surface relief and/or orientation of the rock 109. The direction of the waveguide segments 204, 208 may be determined by a scanning pattern. The scanning pattern may he created by a raster scan or a created regular pattern, for example with the control system 110. The pattern may be created by applying energy unevenly or in a random pattern to the rock 109. An intelligent pattern may he applied by the control system 110. An intelligent pattern may be based on how the rock responds to the energy applied. Predictive modeling may be used to determine the scanning pattern. In some embodiments, sensors may be used to track how the material is responding and indicate the need for changes in the positioning of the waveguide system 200. Various control techniques may be employed, and the overall microwave system or applicator may have various features, for example those described in U.S. application no. titled “Microwave-Based Mining Systems and Methods with Robotic Arm Waveguide,” (Attorney Docket No.: OFFW.006A) filed on the same date as the instant application, in U.S. application no. titled

“Microwave Energy Applicator,” (Attorney Docket No,: OFFW.008A) filed on the same date as the instant application, and in U.S. Provisional Application No, 63/152,294 titled “Application of Microwave Energy Directly to a Rock Face Underground” and filed February _' 22, 2021, the entirety of each of which is incorporated by reference herein for all purposes and forms a part of this specification.

[0058] FIG. 4A is a side view' of the joint 210 of the waveguide system 200 showing the rotational connector 212 connecting the first and second waveguide segments 204, 208. FIG. 4B is a cross-sectional view of the joint 210, as taken along a plane that includes the axes A I, W1 and W2 as shown in FIG. 4 A. FIG. 4B shows a horizontal segment (as oriented in the figure) of an embodiment of the internal antenna of the joint 210.

[0059] The rotational connector 212 may have a circular cross-sectional profile. The rotational connector 212 may align with a first opening 224 of the first waveguide segment 204 and a second opening 228 of the second waveguide segment 208. The rotational connector 212 may be hollow' to allow' for the antenna 216 to be positioned at least partially within the rotational connector 212.

[0060] The first waveguide segment 204 defines and extends along a first waveguide axis Wl. The axis W1 may be located at the geometric center of the cross- sectional profile of the first waveguide segment 204, for example at the geometric center of a rectangular profile, which may be defined by inner surfaces of the waveguide segment. Similarly, the second waveguide segment 208 defines and extends along a second waveguide axis W2, which may have the same respective properties described as the first waveguide axis W1 but with respect to the second wave guide segment 208. The axes W1 and/or W2 may intersect the rotational axis Al, as further described. The perpendicular distance between the axes W1 and W2 may be determined by the particular application of use of the system, such as mining or other contexts, or type of mine, type of rock, etc. The perpendicular distance between the axes W1 and W2 may be determined by factors such as the need for the first and second waveguide segments to rotate without impeding each other, and to be able to install an actuator to control precisely the relative motion between the two segments. For the robot arm application, the distance may be as short as possible to maintain a high level of rigidity across many segments, although additional external stiffening structures may be incorporated without affecting the electromagnetic performance of the design.

[0061] The rotational connector 212 may be a coaxial tube. One or more bearings 235 may be used at the contact points between the rotational connector 212 and the waveguide segments 204, 208. The bearing 235 may be sized according to the expected force and therefore allow the rotational connector 212 to function as intended. The waveguide segments 204, 208 may rotate relative to the rotational connector 212 via the bearings 235. The bearings 235 may each have a stationary side and a rotational side to allow' for relative movement. The bearings may be radial bearings, thrust bearings, or other suitable types. There may be one or more bushings 237 extending between the waveguide segments and located radially inwardly of the bearings 235. The bearings 235 may contact or rotate relative to the bushing 237. In some embodiments, the waveguide segments 204 and/or 208 may include protrusions, which may be cylindrical, extending from a sidewall 219 of the respective segment and into or forming part of the rotational connector 212. For example, the protrusion may replace, or extend into, the bushing 237.

[0062] The antenna 216 may include a first antenna segment 216A and second antenna segment 216B. The segments 216A, 216B may extend away from each other, as further described. As shown in FIG. 4B, the second antenna segment 216B may extend through a portion of the channel 221 along the rotational axis Al. The second antenna segment 216B may extend from a first portion of the channel 221 within the first waveguide segment 204 to a second portion of the channel 221 within the second waveguide segment 208. The second antenna segment 216B may be concentric to the rotational connector 210, and/or to the potion of the channel 221 defined therein. The second antenna segment 216B may have ends that intersect or abut the axes W1 and VV2, for example at the geometric centers of the first and second waveguide segments 204, 208. The second antenna segment 216B may transmit microwave energy from the first antenna segment 216A into the second waveguide segment 208, as further described.

[0063] The antenna segments 216A, 216B may be cylindrical, tapered, conical, or other shapes. The antenna segments 216A, 216B may be elongated. The internal geometry of the antenna may not be electromagnetically important and may have a design necessary' to reduce mass, such as hollowing out, or the incorporation of passages for cooling fluid flow. The connections between the antenna segments 216A, 216B may be fastened or brazed or welded. Non-permanent attachments may allow disassembly for maintenance and repair. Wall thicknesses may be determined for skin effects to be sufficiently covered.

[0064] FIG. 5 is a front view of the joint 210 of the waveguide system 200. As described herein, the waveguide system 200 may include the antenna 216. FIGS. 6A and 6B show the antenna 216 and rotational connector 212, and with the first and second waveguide segments 204, 208 removed for clarity,

[0065] The antenna 216 may be positioned within or internal to the joint 210. The antenna 216 may be located in or near the center of rotation. The antenna 216 may be positioned closer to the rear walls 225 of the waveguide segments 204, 208 than to the openings 220. The positioning of the antenna 216 may avoid contact with any surrounding structures, such as the rotational connector 212 and the wails of the waveguide segments 204, 208. This “no contact” configuration may prevent wear and tear of the antenna 216 and the surrounding structures. The lack of contact may further allow _'' for the surrounding structures to be made of thin and low' mass material. Further, the separation between the structural elements of the waveguide system 200 and the antenna 216 improves efficiency as it allows for more compact articulation. Additionally, the embodiments described herein provide the benefit of low reflection losses. For example, the reflection losses may be better than -40dB depending on the frequency.

[0066] The antenna 216 may include the first antenna segment 216A. The antenna 216 may include the second antenna segment 216B. The first and second antenna segments 216A, 216B may be elongated. The antenna segments 216A, 216B may have a tube like shape. The antenna segments 216A, 216B may be at least partially hollow.

[0067] The antenna segments 216 A, 216B may have various locations and orientations. The antenna segments 216A, 216B may be entirely internal to the waveguide segments 204, 208. Thus, no portion of the antenna 216 may be located external to the channel 221 or external to the waveguide segments 204, 208. As shown, the first antenna segment 216A may define and extend along a central longitudinal antenna axis A2. The antenna axis A2 may be concentric to or located a geometric center of a cross-sectional profile of the first antenna segment 216A. The antenna axis A2 may be located at the geometric center of the waveguide channel 221. The antenna axis A2 may be perpendicular to the waveguide axis W1 , The antenna axis A2 may be perpendicular to the rotational axis Al. The antenna axis A2 may intersect the waveguide axis W1 and/or the rotational axis A I.

[0068] Further, the antenna segments 216A, 216B may be at least partially, or entirely, located on one or the other sides of the joint. The first antenna segment 216A may be entirely on one side, and the second antenna segment 216B may traverse the joint. For example, the waveguide axis W1 may intersect the rotational axis Al and the antenna axis A2 on a first side of the joint 210. The waveguide axis W2 may intersect the rotational axis Al and intersect, abut, or extend near the second antenna segment 216B on a second side of the joint 210 that is opposite the first side. Additionally, a transverse axis A3 may be defined by and extend through a geometric center of the profile of the second waveguide segment 208, as shown in FIG. 5. The transverse axis A3 may intersect the waveguide axis W2 and/or the rotational axis Al within the channel 221 of the second waveguide segment 208. The second antenna segment 216B may extend to and terminate at the axis A3, as shown.

[0069] The first antenna segment 216A may extend to inner surfaces of the sidewalls 219 of the first waveguide segment 204. The first antenna segment 216A may contact and/or be supported by the sidewalls 219, or intermediate structures such as fittings, brackets, etc. The second antenna segment 216B may extend from the first antenna segment 216A and not contact any other structures. The second antenna segment 216B may thus float within the microwave channel 221 and only contact the first antenna segment 216A. There may be a termination point of each antenna segment at a connection between the first antenna segment 216A and the second antenna segment 216B. Although two antenna segments 216 A, 216B are described, the antenna 216 may he made up of one, two, or more than two segments, such as three, four, five, six, seven, eight, nine, ten or more segments. The various configurations may facilitate manufacture and assembly into the structure. This may done to preserve an external surface geometry of the antenna 216. The antenna 216 may thus be stationary' with respect to, and rotate with, the first waveguide segment 204. The second antenna segment 216B may rotate relative to the second waveguide segment 208. The second antenna segment 216B may be omnidirectional such that microwave energy is transmitted three hundred sixty degrees, allowing for full relative rotation of the two waveguide segments 204, 208, as described.

[0070] The second antenna segment 216B may be positioned at least partially within the first waveguide segment 204, the rotational connector 212, and/or the second waveguide segment 208, The second antenna segment 216B may extend from the first antenna segment 216A. The second antenna segment 216B may extend from a centrally located point on the first antenna segment 216A. The second antenna segment 216B may be oriented parallel to the rotational axis Ai. The second antenna segment 216B may be positioned along the rotational axis Al. The second antenna segment 216B may define and extend along a central longitudinal axis that is coincident with the rotational axis Al . The first and second antenna segments 216 A, 216B may form a T-Shape. The second antenna segment 216B may be positioned vertically within the waveguide system 200, and/or the first antenna segment 216 A may be oriented horizontally, as oriented in the figure. The first antenna segment 216A may be oriented along a long dimension of the channel 221, for example parallel to a long dimension of a, rectangular profile. The second antenna segment 216B may be oriented along a short dimension of the channel 221, for example parallel to a short dimension of a rectangular profile. A first end of the second antenna segment 216B may be connected to the first antenna segment 216 A, for example at a midpoint or other location along the first antenna segment 216A. The first and second antenna segments 216A, 216B may be separate parts connected together, or they may be single, integral piece. The first antenna segment 216A may extend away from the second antenna segment 216B, in one or more directions, for example two opposing directions as shown. A second end of the second antenna segment 216B may extend into the rotational connector 212. The second end of the second antenna segment 216B may extend into the second waveguide segment 208. The second free end of the second antenna segment 216B may be located at an intersection of the rotational axis A1 and the transverse axis A3. The antenna 216 may thus have the “T” shape with perpendicular segments, as shown.

[0071] In some embodiments, the antenna 216 may be fixed solely to the first waveguide segment 204. The antenna 216 may be fixed to first waveguide segment 204 via the first antenna segment 216A. A first end of the first antenna segment 216A may be connected to a first wall of the first waveguide segment 204. A second end of the first antenna segment 216A may be connected to a second wall of the first waveguide segment 204. The second antenna segment 216B may be solely coupled to the first antenna segment 216A.

[0072] In some embodiments, the first and/or second antenna segments 216A, 216B may be in other locations and/or orientations. For example, the orientation of the antenna 216 may be flipped, such that the first antenna segment 216A is located within the second waveguide segment 208, and the second antenna segment 216B extends into and terminates within the first waveguide segment 204, etc. The antenna 216 may be bidirectional and configured to transmit energy in both directions through the channel 221, even with the antenna 216 in a single orientation within the joint 210 (e.g. without needing to flip the antenna 216). As a further example, the axis A2 may be offset from the geometric center of the waveguide channel 221, for example from the waveguide axis Wl, either vertically up or down as oriented in the figure. The lower end of the second antenna segment 216B may extend farther than the transverse axis A3, or not extend to the transverse axis A3. In some embodiments, the antenna segments 216A and/or 216B may be linear, non-linear, curved, other contours, or combinations thereof. The antenna 216 may not have a T-shape. The antenna 216 may have other shapes, such as an L-shape. For example, the first segment 216A may be half the length shown, with the second segment 216B extending from an end of the first segments 216A. Thus various suitable shapes of the antenna 216 according to the reception and transmission principles described herein may be implemented. The various structures may allow the antenna 216 to be rigidly affixed to the structure of the stationary waveguide. This precisely positions the antenna 216 geometrically for maximum transmission of the energy across the articulation joint. The result is that energy transmission will not vary according to rotational orientation, and be less sensitive to the mechanical environment such as vibrations. The antenna diameter may also be optimized for better transmission and cooling.

[0073] The waveguide system 200 may receive and guide therethrough microwave energy or signals generated by the microwave generator 103. The energy may be received into and through the first waveguide segment 204 and transmitted to the second waveguide segment 208 via the antenna 216. The antenna 216 may act as a double conductor. Energy may contact the first segment 216A, the energy may be transferred into current which passes through the first and second segments 216 A, 216B. and microwave energy may exit the second segment 216B and enter the waveguide segment. The antenna 216 may thus serve as a transmitter of the energy from the first waveguide segment 216A, through the joint 210 such as through the rotational connector 212, and into the second waveguide segment 216B, and with minimal reflection. The first waveguide segment 204 may function as an entry. The second waveguide segment 208 may function as an exit. The antenna 216 may thus receive and transmit the energy. The antenna 216 bridges or connects the first and second waveguide segments 204, 208. The first antenna segment 2i6A may absorb the electromagnetic waves. The electromagnetic waves may then transmit or travel down the second antenna segment 216B. The second waveguide segment 208 may then guide the energy therethrough. The waveguide system 200 is bi-directional as it may emit energy in two directions corresponding to the angle of rotation. The waveguide system 200 as described herein may maintain the polarization of the energy travelling therethrough. The antenna 216 may be an electrical conductor which can be made of any suitable material. Copper may be used due to its very low resistive losses. The material may also be a combination of materials such as an internal metallic or non-conductive substrate with a highly conductive external coating. The design and location of the antenna 216 is placed withm the waveguide such that it resonates at a precise frequency or frequency band with maximum effectiveness for absorbing and emitting the power from one end to the other. [0074] The energy being transmitted by the waveguide system 200 may be measured in real time by one or more sensors. The one or more sensors may be attached to the waveguide system 200. One or more sensors may be attached to the waveguide segments 204, 208. The energy being emitted from the microwave generator 103 may be measured. The energy being transmitted through the applicator 108 into the rock 109 may be measured. The energy may be measured in both directions in the waveguide system 200, for example the entry energy and the exit energy. The transmitted and/or reflected power may also be measured. The power entering the surrounding environment may be measured. By tracking and/or measuring the energy and/or power, the user may see what power and/or energy is actually being applied to the rock and/or material. Further, the energy transmission and reflection measurements may be used to determine temperature. This may be beneficial as rock electromagnetic characteristics may change with temperature. Such measurements may indicate how lossy the one or more joints 210 may be.

[0075] In some embodiments, the one or more sensors may also be configured to track audible and/or visual indications of cracking at the surface and/or within the rock or material. Ground penetrating radar may also be used for real time and/or post degradation determination.

[0076] Various modifications to the implementations described in this disclosure will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other implementations without departing from the spirit or scope of this disclosure. Thus, the disclosure is not intended to be limited to the implementations shown herein, but is to be accorded the widest scope consistent with the claims, the principles and the novel features disclosed herein. The word “example” is used exclusively herein to mean “serving as an example, instance, or illustration.” Any implementation described herein as “example” is not necessarily to be construed as preferred or advantageous over other implementations, unless otherwise stated.

[0077] Certain features that are described in this specification in the context of separate implementations also may be implemented in combination m a single implementation. Conversely, various features that are described in the context of a single implementation also may be implemented m multiple implementations separately or in any suitable sub-combination. Moreover, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination may in some cases be excised from the combination, and the claimed combination may be directed to a sub-combination or variation of a sub-combination.

[0078] Similarly, while operations are depicted m the drawings in a particular order, this should not be understood as requiring that such operations be performed m the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. Additionally, other implementations are within the scope of the following claims. In some cases, the actions recited in the claims may be performed in a different order and still achieve desirable results.

[0079] It will be understood by those within the art that, in general, terms used herein are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory' phrases “at least one” and “one or more” to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles “a” or “an” limits any particular claim containing such introduced claim recitation to embodiments containing only one such recitation, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an” (e.g., “a” and/or “an” should typically be interpreted to mean “at least one” or “one or more”), the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically he interpreted to mean at least the recited number (e.g., the bare recitation of “two recitations,” without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to “at least one of A, B, and C, etc.” is used, m general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, and C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances where a convention analogous to “at least one of A, B, or C, etc.” is used, m general such a construction is intended in the sense one having skill m the art would understand the convention fe.g., “a system having at least one of A, B, or C” would include hut not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase “A or B” will be understood to include the possibilities of “A” or “B” or “A and B.”