Low band crossed-dipole antenna with meandered arms

Abstract

A low band (LB) crossed-dipole antenna. The LB crossed-dipole antenna includes a cross-shaped radiator and a feed line. The cross-shaped radiator includes a first pair of dipole arms and a second pair of dipole arms. The first pair includes a first dipole arm and a second dipole arm. The first dipole arm and the second dipole arm are aligned along a first horizontal axis. The second pair includes a third dipole arm and a fourth dipole arm. The third dipole arm and the fourth dipole arm are aligned along a second horizontal axis that is perpendicular to the first horizontal axis. Each respective dipole arm includes a respective plurality of slotted meander-shaped segments. The plurality of slotted meander-shaped segments are distributed along each respective arm. The feed line electrically feeds the cross-shaped radiator by being electrically coupled to the cross-shaped radiator.

Description

LOW BAND CROSSED-DIPOLE ANTENNA WITH MEANDERED ARMS TECHNICAL FIELD

[0001] The present disclosure generally relates to base station antennas, and particularly, to low band crossed-dipole antennas. BACKGROUND ART

[0002] The telecommunications industry has made significant advancements in communication technology with the introduction of 5G and the upcoming 6G. In order to fully utilize benefits of these new generations, telecom companies have had to incorporate old and new technologies simultaneously. This approach may necessitate addition of new equipment to support the new generation alongside existing infrastructure. However, this integration comes with a high cost in terms of maintenance and equipment expenses. As a result, there has been a growing trend towards the use of multiband base station antennas (BSAs) in recent years to optimize the efficiency of these systems [US Patent no. 11,777,229 B2]. The use of multiband BSAs has been increased in recent years in order to restore available sites to add a new generation of mobile network to older generations. By using such antennas, a BSA might be miniaturized to reduce the wind load and plurality of antennas in BSA towers.

[0003] However, in multi-band BSAs there are several arrays that operate in different frequency bands which are normally low band (LB) arrays operating in 0.698 to 0.96 GHz for GSM and high band arrays (HB) operating from 1.4 to 2.7 GHz for 3G and 4G. Integrating antenna arrays from various bands in a limited area of a BSA is a complicated yet challenging task. Particularly, since LB elements have approximately two times larger dimensions than higher band elements due to their relative wavelength, they may be relatively large scatterers in a BSA compared with, for example, HB elements. When an HB array is excited, HB currents are induced on an LB antenna’s arms. These currents contribute to the radiation pattern of the HB antenna and may distort its intended shape.

[0004] There is, therefore, a need for an LB antenna that may be integrated with higher band antennas in multiband BSAs without causing distortion in radiation patterns of higher band antennas. There is also a need for an LB antenna with a relatively simple structure that may be efficiently integrated in multiband BSAs in terms of design and manufacturing costs.SUMMARY OF THE DISCLOSURE

[0005] This summary is intended to provide an overview of the subject matter of this patent, and is not intended to identify essential elements or key elements of the subject matter, nor is it intended to be used to determine the scope of the claimed implementations. The proper scope of this patent may be ascertained from the claims set forth below in view of the detailed description below and the drawings.

[0006] In one general aspect, the present disclosure describes an exemplary low band (LB) crossed-dipole antenna. An exemplary LB crossed-dipole antenna may include a cross-shaped radiator and a feed line. An exemplary cross-shaped radiator may include a first pair of dipole arms and a second pair of dipole arms. An exemplary first pair of dipole arms may include a first dipole arm and a second dipole arm. In an exemplary embodiment, the first dipole arm and the second dipole arm may be aligned along a first horizontal axis. An exemplary second pair of dipole arms may include a third dipole arm and a fourth dipole arm. In an exemplary embodiment, the third dipole arm and the fourth dipole arm may be aligned along a second horizontal axis that may be perpendicular to the first horizontal axis. An exemplary cross- shaped radiator may further include a square-shaped air gap between the first dipole arm, the second dipole arm, the third dipole arm, and the fourth dipole arm.

[0007] In an exemplary embodiment, each respective dipole arm of the first pair and the second pair may include a respective plurality of slotted meander-shaped segments. An exemplary plurality of slotted meander-shaped segments may be distributed along each respective dipole arm. An exemplary feed line may electrically feed the cross-shaped radiator by being electrically coupled to the cross-shaped radiator.

[0008] In an exemplary embodiment, each respective dipole arm may include a rectangular shape. In an exemplary embodiment, each respective slotted meander-shaped segment of the respective plurality of slotted meander-shaped segments may include a meander-shaped path that may pass through two or more adjacent slots that are positioned in each respective arm along the width of the rectangular shape. In an exemplary embodiment, every two successive slots of the two or more adjacent slots may be vertically extended from opposing horizontal sides of the rectangular shape through inside the rectangular shape.

[0009] An exemplary LB crossed-dipole antenna may further include a cross-shaped director that may be positioned above the cross-shaped radiator. An exemplary cross-shaped director may include a first pair of director arms, a second pair of director arms, and a solid plate. Anexemplary first pair of director arms may include a first director arm and a second director arm that may be aligned along the first horizontal axis. An exemplary second pair of director arms may include a third director arm and a fourth director arm that may be aligned along the second horizontal axis. In an exemplary embodiment, the solid plate may be firmly attached between the first director arm, the second director arm, the third director arm, and the fourth director arm.

[0010] In an exemplary embodiment, each respective director arm of the first pair of director arms and the second pair of director arms may include a respective plurality of slots. In an exemplary embodiment, the respective plurality of slots may be uniformly distributed on each respective director arm. In an exemplary embodiment, every two successive slots of the respective plurality of slots may be vertically extended from opposing horizontal sides of each respective director arm through inside each respective director arm.

[0011] An exemplary LB crossed-dipole antenna may further include a metal stand. An exemplary metal stand may be firmly attached to the cross-shaped radiator and may couple the feed line to the cross-shaped radiator. An exemplary LB crossed-dipole antenna may further include an acrylonitrile butadiene styrene (ABS) stand. An exemplary ABS stand may be firmly attached between the metal stand and the cross-shaped director and may hold the cross- shaped director fixed relative to the metal stand.

[0012] An exemplary LB crossed-dipole antenna may further include a power divider that may be attached below the metal stand. An exemplary power divider may include a primary segment and a secondary segment. In an exemplary embodiment, each of the primary segment and the secondary segment may include a first transmission line, a +45 degree polarization port, a second transmission line, a -45 degree polarization port, a straight line, a ground node, a first plate, a second plate, a first gap between the first plate and the second plate, a third plate, a fourth plate, and a second gap between the third plate and the fourth plate.

[0013] An exemplary first transmission line may be printed on a first half of the power divider. An exemplary +45 degree polarization port may be connected to a first end of the first transmission line. An exemplary second transmission line may be printed on a second half of the power divider. An exemplary -45 degree polarization port may be connected to a first end of the second transmission line. In an exemplary embodiment, each of the first transmission line and the second transmission line may include three to six transmission line segments. Each exemplary transmission line segment may include a different thickness.

[0014] An exemplary straight line may be printed on a middle of the power divider and may electrically isolate the first half from the second half. An exemplary ground node may extend from the first half to the second half through the straight line. An exemplary first plate may be printed on the first half and may be attached to the ground node. An exemplary second plate may be printed on the first half and may be attached to a second end of the first transmission line. An exemplary first gap may be attached to a first end of the feed line. An exemplary third plate may be printed on the second half and may be attached to the ground node. An exemplary fourth plate may be printed on the second half and may be attached to a second end of the second transmission line. An exemplary second gap may be attached to a second end of the feed line.

[0015] Other exemplary systems, methods, features and advantages of the implementations will be, or will become, apparent to one of ordinary skill in the art upon examination of the following figures and detailed description. It is intended that all such additional systems, methods, features and advantages be included within this description and this summary, be within the scope of the implementations, and be protected by the claims herein. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The drawing figures depict one or more implementations in accord with the present teachings, by way of example only, not by way of limitation. In the figures, like reference numerals refer to the same or similar elements.

[0017] FIG.1 shows a schematic of a low band (LB) crossed-dipole antenna, consistent with one or more exemplary embodiments of the present disclosure.

[0018] FIG. 2A shows a schematic of a top view of a cross-shaped radiator, consistent with one or more exemplary embodiments of the present disclosure.

[0019] FIG. 2B shows a schematic of a dipole arm, consistent with one or more exemplary embodiments of the present disclosure.

[0020] FIG.3 shows a schematic of a top view of a cross-shaped director, consistent with one or more exemplary embodiments of the present disclosure.

[0021] FIG.4 shows a schematic of an exploded view of a metal stand holding a cross-shaped director, consistent with one or more exemplary embodiments of the present disclosure.

[0022] FIG. 5 shows a schematic of a feed line, consistent with one or more exemplary embodiments of the present disclosure.

[0023] FIG.6 shows a schematic of a power divider, consistent with one or more exemplary embodiments of the present disclosure.

[0024] FIG. 7 shows a schematic of an ABS stand, consistent with one or more exemplary embodiments of the present disclosure.

[0025] FIG.8A shows radiation patterns of a middle band (MB) antenna in a vertical plane at 1.7 GHz placed alone, below a conventional LB antenna, and below an LB crossed-dipole antenna, consistent with one or more exemplary embodiments of the present disclosure.

[0026] FIG.8B shows radiation patterns of an MB antenna in a horizontal plane at 1.7 GHz placed alone, below a conventional LB antenna, and below an LB crossed-dipole antenna, consistent with one or more exemplary embodiments of the present disclosure. DESCRIPTION OF EMBODIMENTS

[0027] In the following detailed description, numerous specific details are set forth by way of examples in order to provide a thorough understanding of the relevant teachings. However, it should be apparent that the present teachings may be practiced without such details. In other instances, well known methods, procedures, components, and / or circuitry have been described at a relatively high-level, without detail, in order to avoid unnecessarily obscuring aspects of the present teachings.

[0028] The following detailed description is presented to enable a person skilled in the art to make and use the methods and devices disclosed in exemplary embodiments of the present disclosure. For purposes of explanation, specific nomenclature is set forth to provide a thorough understanding of the present disclosure. However, it will be apparent to one skilled in the art that these specific details are not required to practice the disclosed exemplary embodiments. Descriptions of specific exemplary embodiments are provided only as representative examples. Various modifications to the exemplary implementations will be readily apparent to one skilled in the art, and the general principles defined herein may be applied to other implementations and applications without departing from the scope of the present disclosure. The present disclosure is not intended to be limited to the implementations shown, but is to be accorded the widest possible scope consistent with the principles and features disclosed herein.

[0029] Herein is disclosed an exemplary low band (LB) crossed-dipole antenna with meandered arms. An exemplary LB antenna may have a radiator with crossed-dipole arms. Each exemplary dipole arm may have a number of meander-shaped segments that may beimplemented by creating two or more slots on each segment. An exemplary LB antenna may further have a director with four arms placed above the radiator. Each exemplary director arm may have a number of slots that may be successively extended from opposing horizontal sides of the director arm to the inside. An exemplary LB antenna may further have a power divider that may be attached below the LB antenna and may be able to provide electric power to feed lines to two adjacent LB antennas. Exemplary slots and meander-shaped segments may significantly reduce interference of the LB antenna on higher band antennas that may be placed nearby the LB antenna in an antenna array, thereby facilitating design and implementation of efficient multiband antenna arrays, such as multiband base station antennas (BSAs).

[0030] FIG.1 shows a schematic of an LB crossed-dipole antenna, consistent with one or more exemplary embodiments of the present disclosure. An exemplary LB crossed-dipole antenna 100 may include at least a cross-shaped radiator 102 and a feed line 104. In an exemplary embodiment, feed line 104 may electrically feed cross-shaped radiator 102 by being electrically coupled to cross-shaped radiator 102.

[0031] FIG. 2A shows a schematic of a top view of a cross-shaped radiator, consistent with one or more exemplary embodiments of the present disclosure. In an exemplary embodiment, cross-shaped radiator 102 may include a first pair 202 of dipole arms and a second pair 204 of dipole arms. In an exemplary embodiment, first pair 202 may include a first dipole arm 206 and a second dipole arm 208. In an exemplary embodiment, first dipole arm 206 and second dipole arm 208 may be aligned along a first horizontal axis 210. In an exemplary embodiment, second pair 204 may include a third dipole arm 212 and a fourth dipole arm 214. In an exemplary embodiment, third dipole arm 212 and fourth dipole arm 214 may be aligned along a second horizontal axis 216. In an exemplary embodiment, second horizontal axis 216 may be perpendicular to first horizontal axis 210. In an exemplary embodiment, cross-shaped radiator 102 may further include a square-shaped air gap 217 between first dipole arm 206, the second dipole arm 208, the third dipole arm 212, and the fourth dipole arm 214.

[0032] FIG. 2B shows a schematic of a dipole arm, consistent with one or more exemplary embodiments of the present disclosure. Referring to FIGs. 2A and 2B, in an exemplary embodiment, each respective dipole arm of first pair 202 and second pair 204 may include a respective plurality of slotted meander-shaped segments. For example, dipole arm 206 may include a plurality of slotted meander-shaped segments 218. In an exemplary embodiment, plurality of slotted meander-shaped segments 218 may be distributed along dipole arm 206.

[0033] In an exemplary embodiment, dipole arm 206 may have a rectangular shape. An exemplary length ^^and an exemplary width ^^of the rectangular shape may satisfy a set of dipole arm conditions defined by the following: 0.2^^^ ≤ ^^ ≤ 0.35^^^ Inequation (1A)0.045^^^ ≤ ^^ ≤ 0.065^^^ Inequation (1B)where ^^^is a low band wavelength corresponding to a central frequency of LB crossed-dipole antenna 100. An exemplary central frequency may be equal to about 820 MHz in a frequency range of about 690-960 MHz.

[0034] In an exemplary embodiment, each respective slotted meander-shaped segment of the respective plurality of slotted meander-shaped segments may include a meander-shaped path that may pass through two or more adjacent slots that are positioned in each respective arm along the width of the rectangular shape. For example, a slotted meander-shaped segment 218A may include a meander-shaped path 220 that may pass through three adjacent slots 222, 224, and 226. In an exemplary embodiment, every two successive slots of the two or more adjacent slots (for example, slots 222 and 224) may be vertically extended from opposing horizontal sides of the rectangular shape through inside the rectangular shape.

[0035] In an exemplary embodiment, each of the two or more adjacent slots (for example, slot 222) satisfies a set of slot conditions defined by the following: 0.02^^^ ≤ ^^ ≤ ^^ − 5.5 × 10^^^^^Inequation (2A) 0.002^^^ ≤ ^^ ≤ 0.008^^^ Inequation (2B)5.5Inequation (2C)where ^^is a length of each of the two or more adjacent slots (for example slot 222), ^^is a width of each of the two or more adjacent slots (for example slot 222), and ^^is a thickness of a meander-shaped path (for example, meander-shaped path 220) between each two successive slots (for example, slots 222 and 224) of the two or more adjacent slots.

[0036] In an exemplary embodiment, a distancebetween each two successive meander- shaped segments (for example, meander-shaped segments 218A and 218B) of plurality of meander-shaped segments 218 satisfies a condition defined by the following: 0.1^^^ ≤ ^^ ≤ 0.2^^^ Inequation (3)where ^^^is a high-band wavelength corresponding to a central frequency of an exemplary high band antenna. An exemplary central frequency may be about 2.75 GHz in a frequency range of about 2.3-3.8 GHz.

[0037] FIG.3 shows a schematic of a top view of a cross-shaped director, consistent with one or more exemplary embodiments of the present disclosure. Referring to FIGs.1 and 3, in an exemplary embodiment, LB crossed-dipole antenna 100 may further include a cross-shaped director 106. In an exemplary embodiment, cross-shaped director 106 may be positioned above cross-shaped radiator 102. In an exemplary embodiment, cross-shaped director 106 may include a first pair 302 of director arms, a second pair 304 of director arms, and a solid plate 306. In an exemplary embodiment, first pair 302 may include a first director arm 308 and a second director arm 310 that may be aligned along first horizontal axis 210 of FIG. 2A. In other words, in an exemplary embodiment, first pair 302 may be placed above and parallel with first pair 202 of FIG.2A. In an exemplary embodiment, second pair 304 may include a third director arm 312 and a fourth director arm 314 that may be aligned along second horizontal axis 216 of FIG. 2A. In other words, in an exemplary embodiment, second pair 304 may be placed above and parallel with second pair 204 of FIG.2A. In an exemplary embodiment, solid plate 306 may be firmly attached between first director arm 308, second director arm 310, third director arm 312, and fourth director arm 314.

[0038] In an exemplary embodiment, a distance ^^between a distal end 316 of first director arm 308 and a distal end 318 of second arm 310 satisfies a condition according to the following: 0.1^^^ ≤ ^^ ≤ 0.2^^^ Inequation (4)

[0039] In an exemplary embodiment, a width ^^of each respective director arm of first pair 302 and second pair 304 (for example, fourth director arm 314) satisfies a condition according to the following: 0.01^^^ ≤ ^^ ≤ 0.035^^^ Inequation (5)

[0040] In an exemplary embodiment, each respective director arm of first pair 302 and second pair 304 may include a respective plurality of slots. For example, first director arm 308 may have a plurality of slots 320A (extended from a lower side of first director arm 308 through inside first director arm 308) and 320B (extended from an upper side of first director arm 308 through inside first director arm 308).

[0041] In an exemplary embodiment, plurality of slots 320A and 320B may be uniformly distributed on first director arm 308. In an exemplary embodiment, every two successive slots of plurality of slots 320A and 320B may be vertically extended from opposing horizontal sides of first director arm 308 through inside first director arm 308. For example, a slot 322 ofplurality of slots 320A and a slot 324 of plurality of slots 320B extend from opposing horizontal sides of first director arm 308 through inside first director arm 308.

[0042] In an exemplary embodiment, a length ^^^and a width ^^^of each of plurality of slots 320A and 320B satisfy a set of slot conditions according to the following: 0.008^^^ ≤ ^^^ ≤ 0.03^^^ Inequation (6A)0.002^^^ ≤ ^^^ ≤ 0.003^^^ Inequation (6B)

[0043] In an exemplary embodiment, cross-shaped radiator 102 and cross-shaped director 106 may be printed on respective printed circuit boards (PCBs). For this purpose, in an exemplary embodiment, slots of each arm of cross-shaped radiator 102 (for example, slots 222, 224, and 226) and cross-shaped director 106 (for example, plurality of slots 320A and 320B) may be printed on respective PCBs by etching a conductive material (such as copper) based on a pattern of exemplary slots on an insulating layer of each respective PCB.

[0044] FIG.4 shows a schematic of an exploded view of a metal stand holding a cross-shaped director, consistent with one or more exemplary embodiments of the present disclosure. Referring to FIGs.1 and 4, in an exemplary embodiment, LB crossed-dipole antenna 100 may further include a metal stand 108. In an exemplary embodiment, metal stand 108 may be firmly attached to cross-shaped radiator 102. In an exemplary embodiment, each respective dipole arm of cross-shaped radiator 102 may be connected to a corresponding leg of metal stand 108. For example, dipole arm 206 may be connected to a leg 402 of metal stand 108. In an exemplary embodiment, leg 402 may be fixedly attached to a base 404 by being inserted into a corresponding slot 406.

[0045] FIG. 5 shows a schematic of a feed line, consistent with one or more exemplary embodiments of the present disclosure. Referring to FIGs. 1, 4, and 5, in an exemplary embodiment, metal stand 108 may couple feed line 104 to the cross-shaped radiator 102. In an exemplary embodiment, feed line 104 may have a +45 degree polarization line 502 and a -45 degree polarization line 504. In an exemplary embodiment, +45 degree polarization line 502 and -45 degree polarization line 504 may be Γ shaped. In an exemplary embodiment, each of +45 degree polarization line 502 and -45 degree polarization line 504 may be placed between two corresponding sides of an acrylonitrile butadiene styrene (ABS) base 506. To couple feed line 104 to cross-shaped radiator 102 via metal stand 108, in an exemplary embodiment, each leg of metal stand 108 may be screwed to feed line 104 through a corresponding side of base506. For example, a screw 407 may be utilized to attach leg 402 to -45 degree polarization line 504 through a hole 508 on a corresponding side of ABS base 506.

[0046] FIG.6 shows a schematic of a power divider, consistent with one or more exemplary embodiments of the present disclosure. Referring to FIGs. 1 and 6, in an exemplary embodiment, LB crossed-dipole antenna 100 may further include a power divider 600 that may be attached below metal stand 108. In an exemplary embodiment, power divider 600 may include a primary segment 602 and a secondary segment 604. In an exemplary embodiment, primary segment 602 and a secondary segment 604 may have similar elements and functionality and may facilitate placement multiple antennas similar to LB crossed-dipole antenna 100 in a single array by providing electric power to two LB antennas with structures similar to LB crossed-dipole antenna 100. In an exemplary embodiment, each of primary segment 602 may provide electric power to LB crossed-dipole antenna 100 and may include a first transmission line 605, a +45 degree polarization port 606, a second transmission line 608, a -45 degree polarization port 610, a straight line 612, a ground node 614, a first plate 616, a second plate 618, a first gap 620 between first plate 616 and second plate 618, a third plate 622, a fourth plate 624, and a second gap 626 between third plate 622 and fourth plate 624.

[0047] In an exemplary embodiment, first transmission line 604 may be printed on a first half 628 of power divider 600. In an exemplary embodiment, +45 degree polarization port 606 may be connected to a first end of first transmission line 605. In an exemplary embodiment, second transmission line 608 may be printed on a second half 630 of power divider 600. In an exemplary embodiment, -45 degree polarization port 610 may be connected to a first end of second transmission line 608. In an exemplary embodiment, straight line 612 may be printed on a middle of power divider 600 and may electrically isolate first half 628 from second half 630. In an exemplary embodiment, ground node 614 may extend from first half 628 to second half 630 through straight line 612. In an exemplary embodiment, each of first transmission line 605 and second transmission line 608 may include three to six transmission line segments. Each exemplary transmission line segment may include a different thickness.

[0048] Referring again to FIGs.4, 5, and 6, in an exemplary embodiment, first plate 616 may be printed on first half 628 and may be attached to ground node 614. In an exemplary embodiment, second plate 618 may be printed on first half 628 and may be attached to a second end of first transmission line 605. In an exemplary embodiment, first gap 620 may be attached to a first end 510 of feed line 104 by inserting first end 510 into slot 406. In an exemplaryembodiment, third plate 622 may be printed on second half 630 and may be attached to ground node 614. In an exemplary embodiment, fourth plate may be printed on the second half 630 and may be attached to a second end of second transmission line 608. In an exemplary embodiment, second gap 626 may be attached to a second end 512 of feed line 104 by inserting second end 512 into a slot 408 on base 404.

[0049] FIG. 7 shows a schematic of an ABS stand, consistent with one or more exemplary embodiments of the present disclosure. Referring to FIGs. 1, 5, and 7, in an exemplary embodiment, LB crossed-dipole antenna 100 may further include an ABS stand 110. In an exemplary embodiment, ABS stand 110 may be firmly attached between metal stand 108 and cross-shaped director 106 and may hold cross-shaped director 106 fixed relative to metal stand 108. For this purpose, exemplary legs 702 of ABS stand 110 may be inserted into corresponding holes 514 on a top side of ABS base 506, thereby fixedly attaching ABS stand 110 to ABS base 506. EXAMPLE

[0050] In this example, performance of an LB crossed-dipole antenna (similar to LB crossed- dipole antenna 100 of FIG.1) is demonstrated. FIG.8A shows radiation patterns of a middle band (MB) antenna in a vertical plane at 1.7 GHz placed alone, below a conventional LB antenna, and below an LB crossed-dipole antenna similar to LB crossed-dipole antenna 100, consistent with one or more exemplary embodiments of the present disclosure. FIG.8B shows radiation patterns of an MB antenna in a horizontal plane at 1.7 GHz placed alone, below a conventional LB antenna, and below an LB crossed-dipole antenna similar to LB crossed- dipole antenna 100, consistent with one or more exemplary embodiments of the present disclosure. The frequency band of the MB antenna is in a range of about 1.4-2.7 GHz. Patterns 802 and 808 show radiations of the MB antenna in vertical and horizontal planes, respectively, when there is no LB antenna nearby. Patterns 804 and 810 show radiations of the MB antenna in vertical and horizontal planes, respectively, when there is a conventional LB antenna above the MB antenna. Patterns 806 and 812 show radiations of the MB antenna in vertical and horizontal planes, respectively, when there is an exemplary LB crossed-dipole antenna with meandered arms above the MB antenna. As shown in FIGs.8A and 8B, patterns 804 and 810 are significantly distorted compared to patterns 802 and 808, respectively, showing a significant impact of a conventional LB antenna on the performance of the MB antenna. Onthe other hand, patterns 806 and 812 are almost the same as patterns 802 and 808, respectively, showing that the exemplary LB crossed-dipole antenna is almost transparent to the MB antenna at its working frequency and has nearly no impact on the radiation pattern of the MB antenna.

[0051] While the foregoing has described what are considered to be the best mode and / or other examples, it is understood that various modifications may be made therein and that the subject matter disclosed herein may be implemented in various forms and examples, and that the teachings may be applied in numerous applications, only some of which have been described herein. It is intended by the following claims to claim any and all applications, modifications, and variations that fall within the true scope of the present teachings.

[0052] Unless otherwise stated, all measurements, values, ratings, positions, magnitudes, sizes, and other specifications that are set forth in this specification, including in the claims that follow, are approximate, not exact. They are intended to have a reasonable range that is consistent with the functions to which they relate and with what is customary in the art to which they pertain.

[0053] The scope of protection is limited solely by the claims that now follow. That scope is intended and should be interpreted to be as broad as is consistent with the ordinary meaning of the language that is used in the claims when interpreted in light of this specification and the prosecution history that follows and to encompass all structural and functional equivalents.

[0054] Except as stated immediately above, nothing that has been stated or illustrated is intended or should be interpreted to cause a dedication of any component, step, feature, object, benefit, advantage, or equivalent to the public, regardless of whether it is or is not recited in the claims.

[0055] It will be understood that the terms and expressions used herein have the ordinary meaning as is accorded to such terms and expressions with respect to their corresponding respective areas of inquiry and study except where specific meanings have otherwise been set forth herein. Relational terms such as first and second and the like may be used solely to distinguish one entity or action from another without necessarily requiring or implying any actual such relationship or order between such entities or actions. The terms “comprises,” “comprising,” or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element proceeded by “a” or “an” does not,without further constraints, preclude the existence of additional identical elements in the process, method, article, or apparatus that comprises the element.

[0056] The Abstract of the Disclosure is provided to allow the reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. In addition, in the foregoing Detailed Description, it can be seen that various features are grouped together in various implementations. This is for purposes of streamlining the disclosure, and is not to be interpreted as reflecting an intention that the claimed implementations require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter lies in less than all features of a single disclosed implementation. Thus, the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separately claimed subject matter.

[0057] While various implementations have been described, the description is intended to be exemplary, rather than limiting and it will be apparent to those of ordinary skill in the art that many more implementations and implementations are possible that are within the scope of the implementations. Although many possible combinations of features are shown in the accompanying figures and discussed in this detailed description, many other combinations of the disclosed features are possible. Any feature of any implementation may be used in combination with or substituted for any other feature or element in any other implementation unless specifically restricted. Therefore, it will be understood that any of the features shown and / or discussed in the present disclosure may be implemented together in any suitable combination. Accordingly, the implementations are not to be restricted except in light of the attached claims and their equivalents. Also, various modifications and changes may be made within the scope of the attached claims.

Claims

What is claimed is:

1. A low band (LB) crossed-dipole antenna, comprising: a cross-shaped radiator, comprising: a first pair of dipole arms comprising a first dipole am and a second dipole arm aligned along a first horizontal axis; and a second pair of dipole arms comprising a third dipole arm and a fourth dipole arm aligned along a second horizontal axis perpendicular to the first horizontal axis, wherein each respective dipole arm of the first pair and the second pair comprises a respective plurality of slotted meander-shaped segments distributed along the each respective dipole arm; and a feed line configured to electrically feed the cross-shaped radiator by being electrically coupled to the cross-shaped radiator.

2. The LB crossed-dipole antenna of claim 1, wherein the each respective dipole arm comprises a rectangular shape, a length ^^and a width ^^of the rectangular shape satisfying a set of dipole arm conditions defined by the following: 0.2^^^ ≤ ^^ ≤ 0.35^^^0.045^^^ ≤ ^^ ≤ 0.065^^^where ^^^is a low band wavelength associated with the LB crossed-dipole antenna.

3. The LB crossed-dipole antenna of claim 2, wherein each respective slotted meander-shaped segment of the respective plurality of slotted meander-shaped segments comprises a meander- shaped path passing through two or more adjacent slots positioned in the each respective arm along the width of the rectangular shape, every two successive slots of the two or more adjacent slots vertically extended from opposing horizontal sides of the rectangular shape through inside the rectangular shape.

4. The LB crossed-dipole antenna of claim 3, wherein each of the two or more adjacent slots satisfies a set of slot conditions defined by the following: 0.02^^^ ≤ ^^ ≤ ^^ − 5.5 × 10^^^^^0.002^^^ ≤ ^^ ≤ 0.008^^^5.5 × 10^^^^^ ≤ ^^ ≤ 0.011^^^where: ^^is a length of each of the two or more adjacent slots, ^^is a width of each of the two or more adjacent slots, and ^^is a thickness of the meander-shaped path between each two successive slots of the two or more adjacent slots.

5. The LB crossed-dipole antenna of claim 4, wherein a distance ^^between each two successive meander-shaped segments of the respective plurality of meander-shaped segments satisfies a condition defined by the following: 0.1^^^ ≤ ^^ ≤ 0.2^^^where ^^^is a high-band wavelength associated with the LB crossed-dipole antenna.

6. The LB crossed-dipole antenna of claim 1, wherein the cross-shaped radiator further comprises a square-shaped air gap between the first dipole arm, the second dipole arm, the third dipole arm, and the fourth dipole arm.

7. The LB crossed-dipole antenna of claim 1, further comprising a cross-shaped director positioned above the cross-shaped radiator, the cross-shaped director comprising: a first pair of director arms comprising a first director arm and a second director arm aligned along the first horizontal axis; a second pair of director arms comprising a third director arm and a fourth director arm aligned along the second horizontal axis; and a solid plate and firmly attached between the first director arm, the second director arm, the third director arm, and the fourth director arm, wherein: a distance ^^between a distal end of the first arm and a distal end of the second arm satisfies a condition according to the following: 0.2^^^ ≤ ^^ ≤ 0.35^^^where ^^^is a low band wavelength associated with the LB crossed-dipole antenna; anda width ^^of each respective director arm of the first pair of director arms and the second pair of director arms satisfies a condition according to the following: 0.01^^^ ≤ ^^ ≤ 0.035^^^ .

8. The LB crossed-dipole antenna of claim 7, wherein each respective director arm of the first pair of director arms and the second pair of director arms comprises a respective plurality of slots.

9. The LB crossed-dipole antenna of claim 8, wherein the respective plurality of slots are uniformly distributed on the each respective director arm, every two successive slots of the respective plurality of slots vertically extended from opposing horizontal sides of the each respective director arm through inside the each respective director arm.

10. The LB crossed-dipole antenna of claim 9, wherein a length ^^^and a width ^^^of each of the respective plurality of slots satisfy a set of slot conditions according to the following: 0.008^^^ ≤ ^^^ ≤ 0.03^^^0.002^^^ ≤ ^^^ ≤ 0.003^^^11. The LB crossed-dipole antenna of claim 7, further comprising a metal stand firmly attached to the cross-shaped radiator and configured to couple the feed line to the cross-shaped radiator.

12. The LB crossed-dipole antenna of claim 11, further comprising a power divider attached below the metal stand, the power divider comprising a primary segment and a secondary segment, each of the primary segment and the secondary segment comprising: a first transmission line printed on a first half of the power divider; a +45 degree polarization port connected to a first end of the first transmission line; a second transmission line printed on a second half of the power divider; a -45 degree polarization port connected to a first end of the second transmission line; a straight line printed on a middle of the power divider and electrically isolating the first half from the second half; a ground node extending from the first half to the second half through the straight line; a first plate printed on the first half and attached to the ground node;a second plate printed on the first half and attached to a second end of the first transmission line; a first gap between the first plate and the second plate, the first gap configured to be attached to a first end of the feed line; a third plate printed on the second half and attached to the ground node; a fourth plate printed on the second half and attached to a second end of the second transmission line; and a second gap between the first plate and the second plate, the second gap configured to be attached to a second end of the feed line.

13. The LB crossed-dipole antenna of claim 12, wherein each of the first transmission line and the second transmission line comprises three to six transmission line segments, each of the three to six transmission line segments comprising a different thickness.

14. The LB crossed-dipole antenna of claim 11, further comprising an acrylonitrile butadiene styrene (ABS) stand firmly attached between the metal stand and the cross-shaped director and configured to hold the cross-shaped director fixed relative to the metal stand.

15. The LB crossed-dipole antenna of claim 7, wherein the cross-shaped radiator and the cross- shaped director are printed on respective printed circuit boards (PCBs).

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