The present disclosure relates to circuits, devices, systems and methods for providing phase shifting for antenna tilt in radio-frequency (RF) applications.
In radio-frequency (RF) applications, beam steering can be achieved by mechanical tilting of an antenna tilt. Beam steering can also be achieved by a non-mechanical technique where an antenna maintains a fixed orientation, and beam steering is provided by an electrical control of a plurality of antenna-elements.
In accordance with some implementations, the present disclosure relates to an antenna architecture that includes a common node and a plurality of signal paths each having first and second ends, with the first end coupled to the common node, such that a common signal provided at the common node splits into respective signals in the signal paths. The antenna architecture further includes a phase shifter block implemented along each of at least some of the signal paths, with the phase shifter block including a phase shifting line configured to provide a phase shift for the signal passing through the respective signal path, such that the signals emerging from the signal paths are provided with incremental phase shifts. The antenna architecture further includes an antenna unit coupled to the second end of each signal path, such that the signals provided to the antenna units result in a transmitted signal being directed at a tilt angle with respect to the antenna units.
In some embodiments, the common node can be configured to be coupled to a transceiver through a power amplifier. In some embodiments, the antenna unit can include an antenna pair.
In some embodiments, each incremental phase shift can have a value of Δφ. The plurality of signal paths can include N signal paths, with the quantity N being an integer greater than 1.
In some embodiments, the quantity N can be an even number. The signal paths can include a first signal path providing a phase shift of zero for a first antenna unit, and a second signal path providing a phase shift of −Δφ with a respective phase shifter block for a second antenna unit on one side of the first antenna unit. The signal paths can further include a third signal path providing a phase shift of +Δφ with a respective phase shifter block for a third antenna unit on the other side of the first antenna unit, and a fourth signal path providing a phase shift of −2Δφ with a respective phase shifter block for a fourth antenna unit next to the second antenna unit.
In some embodiments, the quantity N cam be an odd number. The signal paths can include a first signal path providing a phase shift of zero for a first antenna unit, a second signal path providing a phase shift of −Δφ with a respective phase shifter block for a second antenna unit on one side of the first antenna unit, and a third signal path providing a phase shift of +Δφ with a respective phase shifter block for a third antenna unit on the other side of the first antenna unit. The signal paths can further include a fourth signal path providing a phase shift of −2Δφ with a respective phase shifter block for a fourth antenna unit next to the second antenna unit, and a fifth signal path providing a phase shift of +2Δφ with a respective phase shifter block for a fifth antenna unit next to the third antenna unit.
In some embodiments, N-1 of the signal paths can be provided with a respective phase shifter block, and the remaining one signal path not include a phase shifter block. The phase shifting line of each of the N-1 phase shifter blocks for supporting the tilt angle of the transmitted signal can be one of M phase shifting lines corresponding to M tilt angles of the transmitted signal, with the quantity M being an integer greater than 1, such that the phase shifter block is configured to switchably introduce a selected phase shifting line for the phase shifter block to support a selected tilt angle of the transmitted signal.
In some embodiments, each phase shifter block can include a first SPMT switch with the single pole coupled to the common node and the M throws coupled to first ends of the M phase shifting lines, and a second SPMT switch with the M throws coupled to second ends of the M phase shifting lines and the single pole coupled to the respective antenna unit.
In some embodiments, the N-1 phase shifter blocks can include a phase shifter block for providing a phase shift of +Δφ and another phase shifter block for providing a phase shift of −Δφ. In some embodiments, each of the M switchable phase shifting lines of the phase shifter block can be dimensioned to provide the phase shift of +Δφ in a positive direction from zero degree, and each of the M switchable phase shifting lines of the other phase shifter block can be dimensioned to provide the phase shift of −Δφ in a negative direction from zero degree. In some embodiments, each of the M switchable phase shifting lines of the phase shifter block can be dimensioned to provide the phase shift of +Δφ in a positive direction from zero degree, and the other phase shifter block can include M switchable phase shifting lines that are dimensioned the same as the M switchable phase shifting lines of the phase shifter block. The other phase shifter block can further include a static phase shifting line in line with the M switchable phase shifting lines, such that the other phase shifter block provides the phase shift of −Δφ.
In some embodiments, at least the phase shifting line can be implemented on a substrate having a dielectric constant greater than 20, 30, or 40. The substrate can have a dielectric constant of, for example, approximately 50. The substrate can include, for example, a ceramic substrate.
In some embodiments, the architecture can be configured to be capable of supporting cellular functionality. In some embodiments, the cellular functionality can include 5G cellular functionality.
In some implementations, the present disclosure relates to a method for operating a plurality of antenna units. The method includes providing a common signal to a common node and splitting the common signal into a plurality of signal paths each having first and second ends, with the first end coupled to the common node, such that the common signal splits into respective signals in the signal paths. The method further includes providing a phase shift along each of at least some of the signal paths, with the phase shift being provided at least in part by a phase shifting line along the respective signal path, such that the signals emerging from the signal paths are provided with incremental phase shifts. The method further includes transmitting a signal through an antenna unit coupled to the second end of each signal path, such that the transmitted signal from the antenna units is directed at a tilt angle with respect to the antenna units.
In some implementations, the present disclosure relates to a wireless system that includes a transceiver and an antenna architecture operatively coupled to the transceiver. The antenna architecture includes a common node and a plurality of signal paths each having first and second ends, with the first end coupled to the common node, such that a common signal provided at the common node splits into respective signals in the signal paths. The antenna architecture further includes a phase shifter block implemented along each of at least some of the signal paths, with the phase shifter block including a phase shifting line configured to provide a phase shift for the signal passing through the respective signal path, such that the signals emerging from the signal paths are provided with incremental phase shifts. The antenna architecture further includes an antenna unit coupled to the second end of each signal path, such that the signals provided to the antenna units result in a transmitted signal being directed at a tilt angle with respect to the antenna units.
In some embodiments, the wireless system can be part of a base station. In some embodiments, the base station can be configured to provide cellular functionality. In some embodiments, the cellular functionality can include 5G functionality.
For purposes of summarizing the disclosure, certain aspects, advantages and novel features of the inventions have been described herein. It is to be understood that not necessarily all such advantages may be achieved in accordance with any particular embodiment of the invention. Thus, the invention may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other advantages as may be taught or suggested herein.
The headings provided herein, if any, are for convenience only and do not necessarily affect the scope or meaning of the claimed invention.
In radio-frequency (RF) applications, such as in 5G macro basestations, mechanical antenna tilt is utilized to provide coarse beam steering. For example, an antenna may have a 5 to 15 degree downtilt applied so that the beam covers a target area on the ground.
Described herein are examples related to architectures, circuits, devices and methods related to electrical tilting of antennas. While such examples are described in the example context of 5G basestations, it will be understood that one or more features of the present disclosure can also be utilized in other RF frequency ranges and/or other settings.
Electrical beam tilt can be implemented by applying a linear phase shift across a number of antennas. In many RF applications, such phase shifters typically need to handle high powers, as they are placed between power amplification and the antennas. Size and insertion loss associated with the phase shifters is also an important design consideration.
As shown in the upper portion of
As shown in the lower portion of
In the example of
In the example of
In some embodiments, such an architecture of
It is noted that in the example of
It is also noted that the example antenna architecture 100 of
In the example of
In the example of
In the example of
In the example of
In the example architecture of
In another example, an antenna architecture 112 is shown to include three antenna pairs coupled to a common node through respective paths, with each path providing a respective phase shift. For such a configuration having three antenna pairs, a phase shifter can be provided along each of two of the three paths, with the remaining path providing no phase shift or a desired phase shift by the path itself. Accordingly, two phase shifters are implemented for the antenna architecture 112.
In yet another example, an antenna architecture 114 is shown to include four antenna pairs coupled to a common node through respective paths, with each path providing a respective phase shift. For such a configuration having four antenna pairs, a phase shifter can be provided along each of three of the four paths, with the remaining path providing no phase shift or a desired phase shift by the path itself. Accordingly, three phase shifters are implemented for the antenna architecture 114.
In yet another example, an antenna architecture 116 is shown to include five antenna pairs coupled to a common node through respective paths, with each path providing a respective phase shift. For such a configuration having five antenna pairs, a phase shifter can be provided along each of four of the five paths, with the remaining path providing no phase shift or a desired phase shift by the path itself. Accordingly, four phase shifters are implemented for the antenna architecture 116.
By way of examples, and referring to
In some embodiments, phase shifts of ±1φ and ±2φ may be sufficient for desired beam tilts for up to five antenna pairs. However, it will be understood that one or more features of the present disclosure can also be implemented to provide beam tilts utilizing greater numbers of antenna pairs.
In the context of an antenna architecture having five antenna pairs with four phase shifter blocks (as depicted in
It is noted that in some embodiments, electrical downtilt is independent of frequency if transmit (Tx) line phase shifters are utilized. Electrical length of a Tx line may change, but the desired phase shift can change accordingly.
Referring to
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Referring to
Configured in the foregoing manner, a desired tilt angle can be provided by closing appropriate switches and opening the remaining switches based on selected lines of the four phase shifter blocks. For example, and as shown in the tables on the right side of
Similarly, a 8 degree tilt angle can be achieved by closing the switches associated with the 140 degree line and opening the remaining switches of the first phase shifter block (+2Δφ); closing the switches associated with the 70 degree line and opening the remaining switches of the second phase shifter block (+1Δφ); closing the switches associated with the 290 degree line and opening the remaining switches of the third phase shifter block (−1Δφ); and closing the switches associated with the 220 degree line and opening the remaining switches of the fourth phase shifter block (−2Δφ).
Similarly, a 12 degree tilt angle can be achieved by closing the switches associated with the 210 degree line and opening the remaining switches of the first phase shifter block (+2Δφ); closing the switches associated with the 105 degree line and opening the remaining switches of the second phase shifter block (+1Δφ); closing the switches associated with the 255 degree line and opening the remaining switches of the third phase shifter block (−1Δφ); and closing the switches associated with the 150 degree line and opening the remaining switches of the fourth phase shifter block (−2Δφ).
In
In some embodiments, each substrate (140) of the modules 130, 132, 134, 136 can include a material with high dielectric constant. For example, a high dielectric constant (e.g., about 50) ceramic can be utilized as the substrate 140 of the modules 130, 132, 134, 126. Use of such a high dielectric constant material can significantly reduce sizes of the modules, and also significantly reduce losses of the phase shifting lines, when compared to, for example, an FR4 substrate.
In some embodiments, a given module (e.g., 130, 132, 134 or 136) can include the substrate 140 (e.g., ceramic substrate) and the switches associated with the phase shifting lines. For example, for the three-tilt angle configuration of
It is noted that if a module is configured to provide different numbers of tilt angles, switches associated with the phase shifting lines can be configured accordingly. For example, SP4T switches can be utilized for four-tilt angles, and SP6T switches can be utilized for six-tilt angles.
More particularly, the phase shifter block 122′ can be configured to be capable of providing a phase shift of −1Δφ for each of 4, 8 and 12 degrees of tilts by utilizing phase shifting lines similar to those of the phase shifter block 122. For example, the foregoing −1Δφ phase shift for the three example tilt angles can be provided by a static phase shifting line 123′ (220 degree line) in line with a switchable assembly of a 105 degree line, a 70 degree line, and a 35 degree line. It is noted that such a switchable assembly of three lines has the same structure as the three lines of the phase shifting block 122.
Similarly, the −2Δφ phase shift for the three example tilt angles can be provided by a static phase shifting line 121′ (80 degree line) in line with a switchable assembly of a 210 degree line, a 140 degree line, and a 70 degree line. It is noted that such a switchable assembly of three lines has the same structure as the three lines of the phase shifting block 120.
It is noted that in some implementations, the configuration of
In the example of
As described herein, modules with phase shifter blocks can be based on a substrate such as FR4 or ceramic material. As also described herein, use of a high dielectric constant ceramic material can provide reduced module sizes as well as related benefits.
For example,
In the foregoing size comparison, each lateral dimension of the first assembly (high dielectric constant ceramic substrate) is about 3.5 times less than the respective lateral dimension of the second assembly (FR4 substrate), and the area of the first assembly is about 12.25 times less than the area of the second assembly.
It is also noted that shorter physical length of the phase shifting lines and lower dielectric losses result in lower losses in the modules of the first assembly (high dielectric constant ceramic substrate). For example, in the first assembly (ceramic substrate with dielectric constant of 50), the longest phase shifting line corresponds to the 325 degree line; and such a line is shown to provide a loss of about 0.14 dB. In the second assembly (FR4 substrate with dielectric constant of 4), the longest phase shifting line also corresponds to the 325 degree line; and such a line is shown to provide a loss of 0.76 dB. Simulations show that overall, losses are lower in the modules of the first assembly by about 0.6 dB when compared to the modules of the second assembly (FR4 substrate).
Referring to
In some embodiments, an antenna architecture having one or more features as described herein can be implemented in a device, a facility, and/or a system that utilizes beam tilting functionality. In some embodiments, such a device, facility and/or system can be configured to provide 5G functionality.
For example,
Unless the context clearly requires otherwise, throughout the description and the claims, the words “comprise,” “comprising,” and the like are to be construed in an inclusive sense, as opposed to an exclusive or exhaustive sense; that is to say, in the sense of “including, but not limited to.” The word “coupled”, as generally used herein, refers to two or more elements that may be either directly connected, or connected by way of one or more intermediate elements. Additionally, the words “herein,” “above,” “below,” and words of similar import, when used in this application, shall refer to this application as a whole and not to any particular portions of this application. Where the context permits, words in the above Description using the singular or plural number may also include the plural or singular number respectively. The word “or” in reference to a list of two or more items, that word covers all of the following interpretations of the word: any of the items in the list, all of the items in the list, and any combination of the items in the list.
The above detailed description of embodiments of the invention is not intended to be exhaustive or to limit the invention to the precise form disclosed above. While specific embodiments of, and examples for, the invention are described above for illustrative purposes, various equivalent modifications are possible within the scope of the invention, as those skilled in the relevant art will recognize. For example, while processes or blocks are presented in a given order, alternative embodiments may perform routines having steps, or employ systems having blocks, in a different order, and some processes or blocks may be deleted, moved, added, subdivided, combined, and/or modified. Each of these processes or blocks may be implemented in a variety of different ways. Also, while processes or blocks are at times shown as being performed in series, these processes or blocks may instead be performed in parallel, or may be performed at different times.
The teachings of the invention provided herein can be applied to other systems, not necessarily the system described above. The elements and acts of the various embodiments described above can be combined to provide further embodiments.
While some embodiments of the inventions have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the disclosure. Indeed, the novel methods and systems described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the methods and systems described herein may be made without departing from the spirit of the disclosure. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the disclosure.
This application claims priority to U.S. Provisional Application No. 63/295,527 filed Dec. 31, 2021, entitled PHASE SHIFTERS FOR ANTENNA TILT, the disclosure of which is hereby expressly incorporated by reference herein in its respective entirety.
Number | Date | Country | |
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63295527 | Dec 2021 | US |