Patent Grant
10680341
Reflector antennas are useful for a wide variety of applications. For example, reflector antennas are used in microwave relay linking, point to point communications, VSAT (very small aperture terminal) applications, and many other types of applications. In some instances, reflector antennas are used to track objects in the earth's orbitals (e.g., satellites) while in other instances dish antennas are used to track earth-side objects (e.g., vehicles or even missile trajectories).
In addition to the above applications, reflector antennas can be augmented to include monopulse tracking functionality. At a high level, monopulse tracking is a high precision target tracking technique. To achieve this high precision tracking, monopulse systems capture an incoming radiation signal and then measure that signal's arrival direction. To capture that signal, a monopulse system uses different quadrants of a feed horn array. The signal is then analyzed by a monopulse comparator network. In particular, the monopulse comparator network processes the return signals to generate a sum signal, two delta signals (Azimuth, Elevation), and a Q channel. These signals are then used to determine the direction of peak signal strength for the target. Accordingly, by using the antenna's feed horn array and the monopulse comparator network, a monopulse tracking system is able to precisely monitor and track a target's location and movement.
The monopulse comparator network discussed above is formed using several radio frequency (RF) building blocks. Some of these RF components include straight and rotational waveguides, hardware filtering components, hardware amplifier components, power splitters, and phase shifters. Notably, these RF building blocks are used to receive and manipulate the incoming radio waves to use for tracking the target. This same network also serves as the transmit path of the antenna via the sum port.
Receiving, transmitting, and manipulating radio waves are core functions of an antenna system (and a monopulse tracking system). Worthwhile to note, when unconfined, a radio wave will propagate in all three spatial dimensions. In other words, radio waves propagate as a spherical wave through space. Waveguides, which were briefly introduced above, have been developed to confine a radio wave's propagation. In particular, a waveguide is a metallic transmission line that restricts a radio wave so that it travels in only one direction. Waveguides are beneficial because even though they restrict a wave's propagation, the waveguide is structured so that the wave will not lose significant power. In order to redirect a radio wave, a waveguide must include walls that are completely reflective. Because of these reflective properties, the radio waves are routed through the waveguide in the desired direction.
Antennas, including monopulse tracking systems, use waveguides. In particular, an antenna uses a waveguide to transfer radio frequency energy between various portions of the antenna system. For instance, a waveguide may be used to connect an antenna to its transmitter or to its receiver. Furthermore, the monopulse comparator network, which was briefly discussed above, also uses waveguides when calculating the sum and delta signals.
While it is known how to design antennas that perform monopulse tracking, current designs are limited because they produce dish antennas that are bulky and difficult to work with. By way of example, current dish antenna designs physically mount the RF components on a rear portion of the dish antenna. As a result, there is not a lot of physical space behind the antenna to mount other hardware components. Furthermore, when hardware is mounted on the rear portion of the dish antenna, the antenna's center of gravity changes. As a result, it is necessary to reinforce and potentially even customize each antenna's mounting framework and direction control mechanisms. Accordingly, there is a substantial need to improve how a dish antenna is designed. Even more particularly, there is a substantial need to improve the design of antennas used for monopulse tracking.
The subject matter claimed herein is not limited to embodiments that solve any disadvantages or that operate only in environments such as those discussed above. Rather, this background is provided to illustrate only one exemplary technology area where some of the embodiments described herein may be practiced.
Disclosed embodiments are directed to improvements in the design and fabrication of a parabolic antenna reflector.
In some embodiments, a parabolic antenna reflector is comprised of an inner reflective face and a structure used to support the reflective front face. Construction of the inner reflective face results in a similarly shaped rear surface (i.e. an outer face), which is offset in nature from the inner reflective face. The inner reflective face is formed in a parabolic shape and includes a first outer circumferential portion. Similarly, the outer face is also formed in a parabolic shape, but its shape is different than the inner reflective face's shape. Also, the outer face includes a second outer circumferential portion. The first outer circumferential portion is coupled to the second outer circumferential portion to form an inner body between the inner reflective face and the outer face. Here, the inner body comprises a monopulse comparator waveguide structure embedded and in the volume between the inner reflective face and the rear surface (i.e. the outer face). Furthermore, this monopulse structure is fabricated as a single continuous body during build of the reflector. As a result, this waveguide is embedded between the inner reflective face and the outer face.
Other embodiments are directed to a parabolic reflector antenna. This antenna includes a feed horn array, one or more mounting struts, a sub-reflector, and a parabolic-shaped main reflector. This parabolic-shaped main reflector is comprised of an inner face that is formed in a parabolic shape and an outer face that is formed in a different parabolic shape. The parabolic-shaped main reflector also includes two monopulse comparator waveguides (resulting in four paths from the horn). Both waveguides are embedded in an inner body that is formed by a union of an outer circumference of the inner face and an outer circumference of the outer face. Notably, the second monopulse comparator waveguide is disposed in the inner body at a position that is opposite to a position of the first monopulse comparator waveguide.
Other embodiments are directed to an antenna system. This antenna system includes one or more hardware processors and one or more computer-readable hardware storage devices. Computer-executable instructions are stored on these hardware devices and, when executed, cause the processors to perform monopulse tracking. Further, the antenna system includes a feedhorn array, one or more mounting struts, a sub-reflector, and a parabolic-shaped main reflector. This parabolic-shaped main reflector is comprised of an inner face that has a parabolic shape and an outer face that has a different parabolic shape. The parabolic-shaped main reflector also includes two monopulse comparator waveguides (resulting in four paths from the horn). These waveguides are both embedded within an inner body formed by a union of an outer circumference of the inner face and an outer circumference of the outer face.
This Summary is provided to introduce a selection of concepts in a simplified form, which concepts are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.
Additional features and advantages will be set forth in the description which follows and, in part, will be obvious from the description, or may be learned by the practice of the teachings herein. Features and advantages of the embodiments may be realized and obtained by means of the instruments and combinations particularly pointed out in the appended claims. Features of the embodiments will become more fully apparent from the following description and appended claims, or may be learned by the practice of the embodiments as set forth hereinafter.
In order to describe the manner in which the above-recited and other advantages and features can be obtained, a more particular description of the subject matter briefly described above will be rendered by reference to specific embodiments which are illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments and are not therefore to be considered to be limiting in scope, embodiments will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:
Disclosed embodiments are directed to improvements in the design and fabrication of a parabolic antenna reflector.
The embodiments may be implemented to overcome many of the technical difficulties involved in the design and fabrication of a parabolic antenna reflector. In particular, the current embodiments cause one or more radio frequency (RF) components to be embedded inside the main reflector itself as opposed to those components being physically mounted to a back portion of the main reflector. In some instances, causing the RF components to be embedded inside the main reflector is achieved through the use of additive manufacturing techniques. As a result, a single 3-dimensional unit may be created, which single unit includes the main reflector's inner and outer face as well as the embedded RF components. In some instances, other portions of the antenna structure are also fabricated using additive manufacturing techniques and are either embedded inside the main reflector or additively built on it. As a result, the single 3-dimensional unit may include many other physical structures as well (e.g., the sub-reflector, the feed horn array, various mounting struts, various hardware amplifiers, various hardware filters, etc.).
The present embodiments directly improve the current technology because they reduce both fabrication time, fabrication costs, and assembly time. Further, the present embodiments eliminate the need to interact with multiple vendors to acquire the needed hardware components. To clarify, the traditional technology requires monopulse tracking system developers to contract with many different vendors to acquire all of the necessary parts. For example, developers previously had to individually contact waveguide manufacturers, dish manufacturers, etc. Using the principles discussed herein, however, developers no longer need to contact different vendors to create a monopulse tracking system because the system can be fabricated using additive manufacturing techniques. As a result, the embodiments significantly reduce the amount of time required to fabricate such a system.
The present embodiments also improve the current technology because they leverage novel three-dimensional fabrication techniques to combine multiple, complex parts into a single printed unit. This process provides many benefits, including but not limited to, the ability to fabricate significantly more complex hardware geometries in a compact space without the need for flanges or other interface points, the ability to significantly reduce assembly time, and the ability to reduce the total number of seams in RF waveguide pieces. Notably, because the number of seams and connections are reduced for the various RF components, the antenna's overall performance is significantly improved.
The present embodiments also improve the current technology by eliminating the need to perform manual tuning. For instance, conventional monopulse tracking systems require extensive manual tuning to ensure that the waveguides do not introduce undesired reflections. By following the principles discussed herein, however, the need to perform manual tuning is eliminated because the waveguides are fabricated as a single unit to meet certain pre-established tolerances. Further, by embedding the waveguides in the main reflector itself, the waveguides are positioned physically closer to the feed horn array than conventional antenna structures. Because of this placement, the embodiments operate to eliminate undesired waveguide losses. To clarify, the closer placement helps reduce waveguide losses.
The embodiments also improve the current technology by freeing up the amount of physical space on the rear portion of the main reflector. As discussed earlier, convention reflectors are required to have all of their hardware components physically mounted to their backside. This positioning not only introduces the possibility of impedance mismatching and undesired waveguide losses but it also significantly changes the antenna's center of gravity. As a result, the traditional technology requires reinforcements to an antenna's mounting struts and positional control mechanisms. The current embodiments provide significant advancements to the art by moving many of the RF components to an internal portion of the reflector itself. As a result, the embodiments improve many of the structural aspects of an antenna.
To achieve these benefits, some of the disclosed embodiments are directed to a parabolic antenna reflector that is comprised of an inner reflective face and an outer face. The inner reflective face is formed in a parabolic shape and includes a first outer circumferential portion. Similarly, the outer face is also formed in a parabolic shape, but its shape is different than the inner reflective face's shape. Also, the outer face includes a second outer circumferential portion. The first outer circumferential portion is coupled to the second outer circumferential portion to form an inner body between the inner reflective face and the outer face. Here, the inner body comprises a monopulse comparator waveguide. As a result, this waveguide is embedded between the inner reflective face and the outer face.
Other embodiments that achieve the above-mentioned benefits are directed to a parabolic reflector antenna. This antenna includes a feed horn array, one or more mounting struts, a sub-reflector, and a parabolic-shaped main reflector. This parabolic-shaped main reflector is comprised of an inner face that is formed in a parabolic shape and an outer face that is formed in a different parabolic shape. The parabolic-shaped main reflector also includes two monopulse comparator waveguides. Both waveguides are embedded in an inner body that is formed by a union of an outer circumference of the inner face and an outer circumference of the outer face. In these embodiments, the second monopulse comparator waveguide is disposed in the inner body at a position that is opposite to a position of the first monopulse comparator waveguide.
Still further, other embodiments that achieve the above-mentioned benefits are directed to an antenna system. This antenna system includes one or more hardware processors and one or more computer-readable hardware storage devices. Computer-executable instructions are stored on these hardware devices and, when executed, cause the processors to perform monopulse tracking. Further, the antenna system includes a feedhorn array, one or more mounting struts, a sub-reflector, and a parabolic-shaped main reflector. This parabolic-shaped main reflector is comprised of an inner face that has a parabolic shape and an outer face that has a different parabolic shape. The parabolic-shaped main reflector also includes two monopulse comparator waveguides. These waveguides are both embedded within an inner body formed by a union of an outer circumference of the inner face and an outer circumference of the outer face.
Having just described various benefits and high-level attributes of the embodiments, the disclosure will now focus on
As illustrated in
The parabolic main reflector 105 has a cross-sectional shape of a parabola. Because of this parabolic shape, the parabolic main reflector 105 is able to direct radio waves in a particular direction. The parabolic main reflector 105 directs radio waves in a particular direction creating a narrow beam of energy.
In addition to receiving radio frequency energy, the parabolic main reflector 105 can also be used to transmit energy. For instance, the parabolic main reflector 105 can be used to transmit a beam of energy to locate and/or track remote objects. As discussed earlier in connection with monopulse tracking, the parabolic main reflector 105 can be used to track a signal being received.
To transmit such a signal, the feed horn array 115 initially emits radio energy. This energy is first reflected off of the sub-reflector 110. After bouncing off of the sub-reflector 110, the radio energy is directed back to the parabolic main reflector 105. After striking the parabolic main reflector 105, the radio energy is again redirected. This time, the radio energy is directed away from the antenna and is directed towards a target object.
The antenna positioner 120 is used to aim the entire unit. The antenna positioner 120 is configured to allow the antenna 100 to be aimed essentially in any direction. As a result, the antenna 100 can be used to both receive and propagate radio energy. Furthermore, the antenna 100 can be used to track remote objects.
In order to perform monopulse tracking, an antenna is required to have various hardware components. Accordingly, attention will now be directed to
As shown, the antenna system 300 includes one or more hardware processors 305, input/output (I/O) devices 310, RF components 315, hardware amplifier components 320, hardware filters 325, reflectors 330, and data storage 335. The ellipses 340 demonstrates that the antenna system 300 is not limited to just the features and components illustrated in
Embodiments of the present invention may be used to perform monopulse tracking. To perform this type of tracking, the embodiments may execute computer-executable instructions which are stored in the data storage 335. Because monopulse tracking is generally known in the art, it is not necessary to further discuss the processes involved. It is worthwhile to note, however, that the embodiments discussed herein are able to utilize a general-purpose computer, special-purpose computer, or special-purpose processing device to perform the various processes involved in monopulse tracking.
Turning now to
Turning now to
Because the plurality of hardware components 605 are physically mounted to the back of the conventional antenna 600, it was necessary to ensure the mounting was structurally sound, ensure the impedances were properly matched between the RF components, and ensure that the supporting struts could properly control the conventional antenna 600. The current embodiments, however, significantly improve an antenna's design because some of the hardware components are embedded into the main parabolic reflector.
Accordingly, attention will now be directed to
The present embodiments leverage additive manufacturing technologies to fabricate a single-piece reflector antenna. By using these additive manufacturing techniques, the single-piece reflector antenna can be constructed in a manner such that the single-piece body includes a parabolic main reflector (e.g., the parabolic main reflector 105 shown in
Further, by using additive manufacturing techniques, the resulting single-unit reflector, which includes the embedded RF components, significantly reduces the total number of transition points (i.e. seams) in the various RF waveguide pieces. As a result, the overall performance of the antenna is significantly improved. Even further, by using precise additive manufacturing processes, the need to perform manual tuning is eliminated.
Accordingly, the embodiments provide for a single body reflector that includes an embedded monopulse comparator. These embodiments may be practiced in a variety of situations and settings. By way of example and not limitation, one application for this novel technology is in the development of tracking solutions using antennas configured to operate in the Ka-band (and above). Due to the narrow beam widths of antennas at the Ka-band and above, tracking is essential for maintaining a link with the target object. However, due to the small wavelengths at higher frequencies (which small wavelengths cause the form factor of the dish antenna to be smaller, e.g., 9.5 inches), the conventional antenna systems are deficient because they fail to provide adequate physical space on the rear portion of the antenna. As a result, the hardware components needed to perform the tracking functions (traditionally) were not placed as close to the received signal as possible. These characteristics led the antennas to not be very efficient. Now, however, the embodiments actually cause the RF components to be embedded within the parabolic main reflector. Furthermore, by introducing other optimizations (e.g., introducing a bend to the monopulse comparator, which will be discussed in more detail later), the embodiments ensure that the hardware components are as close to the incoming signal as possible. Accordingly, the present embodiments significantly improve the current technology.
Attention will now be turned to
In particular,
As shown in
By using an additive manufacturing system (e.g., the additive manufacturing system 700 of
Accordingly,
By way of example and not limitation, a waveguide 910, a hardware amplifier component 915, and a hardware filter component 920 may be embedded inside the parabolic main reflector 900. Furthermore, the ellipses 925 demonstrate that other types of RF components may be embedded inside the parabolic main reflector 900 as well. One example of an additional RF component is a diplexer. Accordingly, the parabolic main reflector 900 may be fabricated using additive manufacturing techniques so that it includes one or more RF components embedded therein.
Previously, it was mentioned that various optimizations may be performed on the RF components to ensure that those RF components operate properly when embedded inside of a main reflector.
In particular,
Previously, the disclosure focused on embedding a monopulse comparator inside of a parabolic main reflector. As indicated earlier, a monopulse comparator is comprised of one or more waveguides. Accordingly,
To improve the operability of these waveguides 1010A and 1010B, the waveguides 1010A and 1010B are fabricated so that they include one or more bends in their structures. For example,
Additional optimizations are performed to determine where to place the bends 1015 on the waveguides 1010A and 1010B and to determine how much to angle the bends 1015. Notably, the placement and angle of the bends 1015 are selected so as to match impedances, which matching eliminates undesirable radio wave reflections. Accordingly, the placement and angle of the bends 1015 on the waveguides 1010A and 1010B are selected to eliminate reflected energy (i.e. to achieve the least amount of loss in the waveguides). Accordingly, the waveguides 1010A and 1010B are bent so as to generally follow the curve of the parabolic shape of the parabolic main reflector 1000. As indicated in
Having just described some of the specific characteristics of some of the embodiments, attention will now be directed to
In some instances, the parabolic dish is part of a parabolic reflector antenna. This parabolic reflector antenna may comprise a feed horn array, one or more mounting struts, a sub-reflector, and the parabolic dish. This parabolic dish includes an inner face being formed in a parabolic shape. It also includes an outer face being formed in a different parabolic shape. Further, it may also include two monopulse comparator waveguides. Both of these waveguides are embedded in an inner body of the parabolic dish. This inner body is formed by a union of an outer circumference of the inner face and an outer circumference of the outer face. A second monopulse comparator waveguide may be disposed in the inner body at a position that is opposite to a position of the first monopulse comparator waveguide (as shown in
In other instances, the parabolic dish might be a part of an antenna system. This antenna system may include one or more hardware processors (e.g., the hardware processors 305 of
In some instances, the parabolic dish is a 9.5-inch antenna dish. Notably, however, the embodiments are not limited solely to a 9.5-inch dish.
In some instances, as discussed earlier, the inner body of the parabolic dish may include filtering hardware components (e.g., a diplexer) and amplifier hardware components.
As discussed in connection with
By embedding some of the RF components inside the parabolic dish, the rear side of the parabolic dish is made available to place other hardware components. As a result, some embodiments include one or more RF hardware components that are physically mounted to an outer portion of the outer face of the parabolic dish (as is generally shown in
In embodiments that include two embedded monopulse comparator waveguides, the first monopulse comparator waveguide may be an azimuth comparator while the second may be an elevation comparator.
While the above discussion focused on the use of additive manufacturing techniques to create a single body dish antenna, other embodiments are also contemplated for embedding hardware components into a dish antenna. By way of example, an inner face of the dish antenna may be constructed. This inner face may have a thickness. Then, various hardware components may be physically mounted to a back side of the inner face. After those components are mounted, then an outer face may be constructed. This outer face may then be physically mounted to the back side of the inner face so as to cause the various hardware component to be enveloped between the inner face and the outer face. Then, additional hardware components may be physically mounted on a back portion of the outer face. As a result, instead of using additive manufacturing techniques, these embodiments are assembled in a piece-by-piece fashion to cause hardware components to be enveloped by the dish's inner and outer face. In these embodiments, additional back-end layers may continually be attached to the back end of the antenna to ensure that adequate space is available to mount all of the necessary hardware components.
Accordingly, having just described the structural aspects of a parabolic dish that has embedded RF components, attention will now be directed to
Initially, method 1200 includes an act (act 1210) in which a first portion of a dish antenna is fabricated using additive manufacturing techniques. This first portion is a part of an outer face of the dish antenna. By outer face, it is meant a rear side, or rather back side, of the dish antenna.
Then, method 1200 includes an act (act 1220) in which a monopulse comparator waveguide is fabricated immediately on top of the first portion. This monopulse comparator waveguide is also fabricated using additive manufacturing techniques. Further, the monopulse comparator waveguide is surrounded by a second portion of the outer face of the dish antenna. In other words, the outer face is continually built up around the monopulse comparator waveguide.
Finally, method 1200 includes an act (act 1230) in which an inner face of the dish antenna is fabricated on top of both the monopulse comparator waveguide and the second portion of the outer face of the dish antenna. As a result, the monopulse comparator waveguide is enveloped between the outer face and the inner face. In other words, the monopulse comparator waveguide is embedded inside of the dish antenna.
As a result, a dish antenna may be fabricated using additive manufacturing techniques. This dish antenna includes an embedded monopulse comparator (e.g., waveguides). The comparator is completely confined within the dish antenna. Furthermore, the comparator's waveguides include one or more bends to allow the waveguides to generally follow the dish antenna's parabolic shape.
Accordingly, the present embodiments provide significant advantages over the current technology by embedding RF components inside of a dish antenna.
The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.
| Number | Name | Date | Kind |
|---|---|---|---|
| 5223850 | Branigan | Jun 1993 | A |
| 5307077 | Branigan | Apr 1994 | A |
| 8736505 | Lambert et al. | May 2014 | B2 |
| 9112255 | Hollenbeck | Aug 2015 | B1 |
| 20150244074 | Pera | Aug 2015 | A1 |
| Entry |
|---|
| Huang et al. “Design of a Wideband and Low-Profile Monopulse Array Fabricated by 3-D Metal Printing Technique” IEEE AP-S, 2015, pp. 322-323. |
| Huang et al. “Fabrication of a High-Efficiency Waveguide Antenna Array via Direct Metal Laser Sintering”, IEEE Antennas and Wireless Propagation Letters, 2015, pp. 1-4. |
| Shelley et al. “X- and Ka-Band low profile antennas for aeronautical and land mobile satcom” The 8th European Conference on Antennas and Propagation (EuCAP 2014), 2014, pp. 2619-2622. |
