Radiating element with common mode resonance suppression circuit and related base station antenna

Abstract

The invention relates to a radiating element with a common mode resonance suppression circuit and a related base station antenna. A radiating element for a base station antenna includes a feed handle printed circuit board and a dipole radiator printed circuit board mounted on the feed handle printed circuit board. The feed handle printed circuit board includes: a first ground line including a first integrated parallel LC circuit; the second ground wire comprises a second integrated parallel LC circuit; a first signal trace extending through an opening in the dipole radiator printed circuit board; and a second signal trace.

Description

Technical Field

[0001] This disclosure relates to communication systems, and more particularly to base station antennas for cellular communication systems. Background Technology

[0002] Cellular communication systems are well known in the art. In a cellular communication system, a geographical area is divided into a series of areas called “cells” served by corresponding base stations. Each base station may include one or more base station antennas configured to provide bidirectional radio frequency (“RF”) communication with mobile users within the cell served by the base station. Typically, base station antennas are mounted on towers or other elevated structures, where a radiation pattern (also referred to herein as an “antenna beam”) is generated by the outward-pointing base station antennas.

[0003] A common base station configuration is a three-sector configuration, where the cell is divided into three 120° sectors in the azimuth (horizontal) plane. A separate base station antenna provides coverage (service) for each sector. Typically, each base station antenna will include multiple vertically extending columns of radiating elements, which operate using, for example, second-generation (“2G”), third-generation (“3G”), or fourth-generation (“4G”) cellular network protocols. These vertically extending columns of radiating elements are often referred to as a “linear array” and can be a straight column of radiating elements or a column in which some of the radiating elements are horizontally interleaved to reduce the beamwidth of the antenna beam generated in the azimuth (horizontal) plane. Most modern base station antennas include a “low-band” linear array of radiating elements supporting service in some or all of the 617-960MHz frequency band, and a “mid-band” linear array of radiating elements supporting service in some or all of the 1427-2690MHz frequency band. These linear arrays are typically formed using dual-polarized radiating elements that allow each linear array to be connected to a pair of radio devices (or the radio port of a single radio device), enabling the linear array to transmit and receive RF signals in two orthogonal polarizations (i.e., generating an antenna beam in each orthogonal polarization).

[0004] Each of the linear arrays of dual-polarized radiating elements described above is coupled to two ports of the radio device (one port per polarization). An RF signal emitted by one of the linear arrays is transmitted from the radio device to an antenna, where the RF signal is split into multiple sub-components, each of which is fed to a corresponding subset of the radiating elements in the linear array. These sub-components of the RF signal are emitted through the radiating elements to generate an antenna beam covering a generally fixed coverage area (e.g., a 120° sector of a cell). Typically, these linear arrays will have remote electronic tilt (“RET”) capability, which allows the cellular operator to change the pointing angle of the generated antenna beam in the elevation (vertical) plane from a control center, thereby changing the size of the sector served by the linear array (because the more the antenna beam tilts downward in the elevation plane, the smaller the area illuminated by the antenna beam, and therefore the smaller the area covered by the antenna beam). Since the antenna beams generated by the aforementioned 2G / 3G / 4G linear arrays are static antenna beams whose shape changes only due to the adjustment of the antenna beam's downtilt angle, these linear arrays are often referred to as "passive" linear arrays.

[0005] Cellular operators are currently upgrading their networks to support fifth-generation (“5G”) cellular services. A key component of 5G cellular services is the use of multiple rows of “active” beamforming arrays that work in conjunction with beamforming radios. The beamforming radios alter the amplitude and / or phase of sub-components of the signal to be transmitted. These sub-components are fed to corresponding subsets of the radiating elements of the active beamforming array to dynamically adjust the size, shape, and pointing direction of the resulting antenna beam. These active beamforming arrays are typically formed using “high-frequency band” radiating elements operating in higher frequency bands (e.g., some or all of the 3.3–4.2 GHz band), but active beamforming radios operating in other bands, such as the higher portion of the mid-frequency range (e.g., 2.5–2.7 GHz), are also possible. The radiating elements in each vertically extending column of such an active beamforming array are typically coupled to corresponding ports of the beamforming radio, such that each column of radiating elements is fed different sub-components of the signal to be transmitted. The beamforming radios can be standalone devices or integrated with active antenna arrays. As discussed above, beamforming radios can adjust the amplitude and phase of sub-components of an RF signal fed to each port of the radio (and thus to each corresponding column of the radiating elements in a multi-column beamforming array) to generate an antenna beam with a narrowed beamwidth (and therefore a higher antenna gain) in the azimuth plane. These narrowed antenna beams can be electronically redirected throughout the sector by appropriately selecting the amplitude and phase of the RF signal sub-components. To avoid having to increase the number of antennas at cell sites, 5G antennas including such beamforming arrays typically also include passive linear arrays supporting conventional 2G, 3G, and / or 4G cellular services. Summary of the Invention

[0006] According to some embodiments of the present invention, a radiating element for a base station antenna is provided, the radiating element comprising a feed stem printed circuit board and a dipole radiator printed circuit board mounted on the feed stem printed circuit board. The feed stem printed circuit board includes: a first ground wire including a first integrated LC circuit; a second ground wire including a second integrated parallel LC circuit; a first signal trace extending through an opening in the dipole radiator printed circuit board; and a second signal trace.

[0007] In some embodiments, the second signal trace extends through the opening.

[0008] In some embodiments, the power feed shank printed circuit board includes a forward-extending tab extending through the opening, and the distal end of the first signal trace extends onto the first forward-extending tab.

[0009] In some embodiments, the dipole radiator printed circuit board includes a first dipole arm and a second dipole arm, each being at least a portion of a first dipole radiator, and a third dipole arm and a fourth dipole arm, each being at least a portion of a second dipole radiator. In some embodiments, a first signal trace current is connected to the first dipole arm, and a second signal trace current is connected to the second dipole arm. In some embodiments, the radiating element may further include a first dipole arm extension electrically connected to the first dipole arm; a second dipole arm extension electrically connected to the second dipole arm; a third dipole arm extension electrically connected to the third dipole arm; and a fourth dipole arm extension electrically connected to the fourth dipole arm. The first dipole arm extension may overlap with the first dipole arm in a forward direction and extend outward beyond the outer periphery of the first dipole arm. The first dipole arm extension may include a sheet metal dipole arm extension comprising a first portion extending parallel to the first dipole arm and a second portion extending at an oblique angle from the first portion. In some embodiments, the first dipole arm extension may be capacitively coupled to the first dipole arm. In some embodiments, the first dipole arm extension to the fourth dipole arm extension is a single piece. In other embodiments, at least two of the first dipole arm extensions to the fourth dipole arm extension are implemented in a single sheet metal piece.

[0010] In some embodiments, the first signal trace and the second signal trace each have a plurality of tortuous segments.

[0011] In some embodiments, a first portion of the first signal trace has a wave shape having at least two peaks and two valleys.

[0012] In some embodiments, no parallel LC circuit is integrated into the first signal trace or the second signal trace.

[0013] In some embodiments, the radiating element may further include a substrate printed circuit board (PCB) having a slot therethrough, wherein the base of the feed stem PCB is inserted into the substrate PCB through the slot. The rear side of the substrate PCB may include a metal pad, and multiple ground traces on the feed stem PCB may be soldered to the metal pad.

[0014] In some embodiments, the radiating element is provided in combination with a cavity phase shifter assembly, the cavity phase shifter assembly comprising: a metal housing having a first cavity and a second cavity; a first phase shifter within the first cavity; and a second phase shifter within the second cavity. The metal pad on the substrate printed circuit board can be mounted to be capacitively coupled to the metal housing. The front wall of the metal housing may include a first opening and a second opening, and the first phase shifter includes a first phase shifter printed circuit board, and the second phase shifter includes a second phase shifter printed circuit board, and the feed handle printed circuit board includes a first rearwardly extending tab extending through the first opening to contact the first phase shifter printed circuit board and a second rearwardly extending tab extending through the second opening to contact the second phase shifter printed circuit board.

[0015] According to another embodiment of the present invention, a radiating element for a base station antenna is provided, the radiating element comprising a feed stem printed circuit board; and a dipole radiator printed circuit board mounted on the distal end of the feed stem printed circuit board. The feed stem printed circuit board includes: a first ground wire including a first integrated parallel LC circuit; a second ground wire including a second integrated parallel LC circuit; a first signal trace having multiple bends, directly connected to the dipole radiator printed circuit board, and not including the integrated LC circuit; and a second signal trace having multiple bends, directly connected to the dipole radiator printed circuit board, and not including the integrated LC circuit.

[0016] In some embodiments, the feed stem printed circuit board includes a forward-extending tab that extends through an opening in the dipole radiator printed circuit board, and the first signal trace extends through the opening. In some embodiments, the second signal trace extends through the opening.

[0017] In some embodiments, no parallel LC circuit is integrated into the first signal trace or the second signal trace.

[0018] In some embodiments, the dipole radiator printed circuit board includes a first dipole arm and a second dipole arm, each being at least a portion of a first dipole radiator, and a third dipole arm and a fourth dipole arm, each being at least a portion of a second dipole radiator. In some embodiments, the first signal trace current is connected to the first dipole arm, and the second signal trace current is connected to the second dipole arm.

[0019] In some embodiments, the radiating element further includes: a first dipole arm extension electrically connected to a first dipole arm member; a second dipole arm extension electrically connected to a second dipole arm member; a third dipole arm extension electrically connected to a third dipole arm member; and a fourth dipole arm extension electrically connected to a fourth dipole arm member. In some embodiments, the first dipole arm extension includes a sheet-like metal dipole arm extension, the sheet-like metal dipole arm extension including a first portion extending parallel to the first dipole arm member and a second portion extending obliquely from the first portion.

[0020] In some embodiments, the radiating element further includes a substrate printed circuit board having a groove therethrough, wherein the base of the feed handle printed circuit board is inserted into the substrate printed circuit board through the groove. In some embodiments, the radiating element is provided in combination with a cavity phase shifter assembly, the cavity phase shifter assembly including: a metal housing having a first cavity and a second cavity; a first phase shifter within the first cavity; and a second phase shifter within the second cavity, wherein the feed handle printed circuit board includes a first rearwardly extending tab extending into the first cavity and a second rearwardly extending tab extending into the second cavity.

[0021] According to another embodiment of the present invention, a radiating element for a base station antenna is provided, the radiating element comprising: a feed stem printed circuit board; and a dipole radiator printed circuit board mounted on the feed stem printed circuit board, wherein the feed stem printed circuit board comprises: a first ground wire including a first integrated parallel LC circuit; a second ground wire including a second integrated parallel LC circuit; a first signal trace currently connected to a first metal pad on the dipole radiator printed circuit board; and a second signal trace currently connected to a second metal pad on the dipole radiator printed circuit board.

[0022] In some embodiments, no parallel LC circuit is integrated into the first signal trace or the second signal trace.

[0023] In some embodiments, the dipole radiator printed circuit board includes a first dipole arm and a second dipole arm, each being at least a portion of a first dipole radiator, and a third dipole arm and a fourth dipole arm, each being at least a portion of a second dipole radiator. In some embodiments, a first signal trace is currently connected to the first dipole arm, and a second signal trace is currently connected to the second dipole arm. In some embodiments, the first signal trace and the second signal trace each have a plurality of tortuous segments.

[0024] In some embodiments, the radiating element further includes a substrate printed circuit board having a slot therethrough, wherein the base of the feed stem printed circuit board is inserted into the substrate printed circuit board through the slot. Attached Figure Description

[0025] Figure 1A This is a front perspective view of a conventional base station antenna, including both passive linear arrays and active beamforming arrays.

[0026] Figure 1B The radome has been removed. Figure 1A A schematic front view of a conventional base station antenna.

[0027] Figure 2A This is a schematic front view of a base station antenna according to an embodiment of the present invention with the radome removed.

[0028] Figure 2B yes Figure 2A A schematic front perspective view of the four mid-band linear array components of a base station antenna, showing the main reflector of the base station antenna for context.

[0029] Figure 3A yes Figure 2B A schematic side perspective view of one of the mid-frequency radiating elements included in the mid-frequency linear array assembly.

[0030] Figure 3B yes Figure 3A A schematic top view of a mid-frequency band radiating element.

[0031] Figure 3C yes Figure 3A A schematic side view of a mid-frequency band radiating element.

[0032] Figure 3D yes Figure 3A A schematic top view of the printed circuit board for the feed handle of the mid-frequency radiating element.

[0033] Figure 3E yes Figure 3AFront view of a printed circuit board for a dipole radiator, a mid-frequency band radiating element.

[0034] Figure 4 yes Figure 2B A schematic end view of one cavity phase shifter assembly in a cavity phase shifter assembly.

[0035] Figure 5A It is installed in Figure 4 On the cavity phase shifter assembly Figures 3A-3E A schematic side perspective view of a mid-frequency band radiating element.

[0036] Figure 5B yes Figure 5A A magnified side view of a portion of the image.

[0037] It should be noted that in this document, reference numerals may be used including two numbers separated by a dashed line, and the same element may be referenced individually by its full reference numeral and may be referenced together by the first part of its reference numeral. Detailed Implementation

[0038] Figure 1A and 1B A conventional base station antenna 1 is shown, comprising both a passive low-frequency band linear array and a mid-frequency band linear array, as well as a high-frequency band active beamforming array. Specifically, Figure 1A This is a front perspective view of base station antenna 1, and Figure 1B This is a schematic front view of base station antenna 1 with its radome removed. Figure 1A and 1B In the diagram, the axes indicate the vertical (V), horizontal (H), and forward (F) directions of the base station antenna system 1. In the following description, each antenna will be described using the following terms, assuming the antenna is mounted for use on a tower, wherein the longitudinal axis L of the antenna extends along the vertical axis V, and the front surface of the antenna is mounted opposite the tower, pointing towards the antenna's coverage area.

[0039] refer to Figure 1A The base station antenna 1 has a tubular shape with a generally rectangular cross-section. The base station antenna 1 includes an antenna radome 2, a top cover 4, and a bottom cover 6. A plurality of RF ports 8, in the form of RF connectors, are mounted in the bottom cover 6. The RF ports 8 extend through the bottom cover 6 and are used to electrically connect the base station antenna 1 to external wireless equipment (not shown). The antenna radome 2, top cover 4, and bottom cover 6 can form the outer housing of the antenna 1. Antenna assembly ( Figure 1B It is contained within the shell.

[0040] Figure 1B This is a schematic front view of the antenna assembly housed within the casing of base station antenna 1. (Example) Figure 1BAs shown, the antenna assembly includes a reflector 10. The reflector 10 can serve both as a structural component of the antenna assembly and as a ground plane and reflector for at least some of the radiating elements (discussed below) of the antenna 1. The reflector 10 includes a generally flat metallic surface extending in the longitudinal direction L of the antenna 1. Various mechanical and electronic components (not shown) of the base station antenna 1 are mounted behind the reflector 10.

[0041] The antenna assembly also includes a first low-frequency band array and a second low-frequency band array 20-1, 20-2 of low-frequency band radiating elements 22; a first intermediate frequency band array and a second intermediate frequency band array 30-1, 30-2 of a first intermediate frequency band radiating element 32A; a third to sixth intermediate frequency band array 30-3 to 30-6 of a second intermediate frequency band radiating element 32B; and a multi-column high-frequency band array 40 of a high-frequency band radiating element 42. The low-frequency band array 20 and the intermediate frequency band array 30 are each implemented as a vertically extending linear array of radiating elements. The low-frequency band linear array and the intermediate frequency band linear array 20, 30 can support, for example, 2G, 3G, and / or 4G cellular services. Each of the low-frequency band linear array and the mid-frequency band linear array 20, 30 is a passive array that generates static antenna beams (e.g., antenna beams each configured to cover a 120° sector of a base station) to provide coverage to a predefined coverage area, wherein only the coverage area changes when the electronic downtilt angle of the generated antenna beams is adjusted (e.g., to change the cell size).

[0042] High-frequency radiating elements 42 are mounted in four columns in the lower central portion of reflector 10 to form a multi-column array 40. Each column of the multi-column array 40 can be coupled to a pair of ports of a beamforming radio (one port for each polarization), such that the multi-column array 40 acts as an active beamforming array that generates a narrowed antenna beam that can be manipulated in the azimuth plane throughout the coverage area.

[0043] Low-frequency radiating element 22 is configured to transmit and receive signals in the 617-960MHz frequency range or a portion thereof (e.g., the 617-896MHz band, the 696-960MHz band, etc.). First intermediate-frequency (IF) radiating element 32A is configured to transmit and receive signals in the 1427-2690MHz frequency range or a portion thereof (e.g., the 1427-1710MHz band, the 1427-2200MHz band, etc.). Second IF radiating element 32B is configured to transmit and receive signals in the 1695-2690MHz frequency range or a portion thereof (e.g., the 1710-2200MHz band, the 2300-2690MHz band, etc.). The second IF radiating element 32B may have a different design than the first IF radiating element 32A. High-frequency radiating element 42 is configured to transmit and receive signals in the 3300-4200MHz frequency range or a portion thereof. Radiation elements 22, 32A, 32B, and 42 are mounted to extend forward from reflector 10.

[0044] The low-frequency and mid-frequency radiating elements 22, 32A, and 32B can each be implemented as dual-polarized radiating elements, each including a first radiator and a second radiator configured to transmit and receive RF energy in orthogonal polarization. For example, the low-frequency and mid-frequency radiating elements 22, 32A, and 32B can be implemented as tilted -45° / +45° crossed dipole radiating elements, including a -45° dipole radiator and a +45° dipole radiator arranged to form a fork shape when viewed from the front of the radiating elements 22, 32A, and 32B. The dipole radiator of each low-frequency and mid-frequency radiating element 22, 32A, and 32B is mounted on a feed handle (not visible in the figure) that transmits the RF signal between the dipole radiator and the associated feed network.

[0045] Due to the use of dual-polarized radiating elements, each of the low-band and mid-band linear arrays 20 and 30 is connected to a pair of RF ports 8. The first RF port 8 in each pair is typically connected via a coaxial cable to the first port of a passive (non-beamforming) radio device (e.g., a remote radio head mounted on an antenna tower near the base station antenna 1). A feed cable and feed network connect the first RF port 8 to the first polarized radiator of the radiating elements 22, 32A, and 32B in the respective linear arrays 20 and 30. Similarly, the second RF port 8 in each pair is connected via a coaxial cable to the second port of the radio device, and another feed cable and feed network connect the second RF port 8 to the second polarized radiator of the radiating elements 22, 32A, and 32B in the corresponding linear array 20 and 30. RF signals transmitted by a selected one of the low-band and mid-band linear arrays 20 and 30 are transmitted from the associated radio device to one of the RF ports 8 and from the RF port 8 to the associated feed network. Each feed network may include a phase shifter assembly comprising a power divider that splits an RF signal into multiple sub-components. These sub-components are fed to a corresponding first or second radiator of radiating elements 22, 32A, 32B in linear arrays 20, 30, such that the sub-components are radiated into free space. Therefore, each linear array 20, 30 can be used to form a pair of antenna beams, i.e., antenna beams for each of two different polarizations. Each linear array 20, 30 can be configured to provide service to a sector of a base station. For example, each linear array 20, 30 can be configured to provide approximately 120° coverage in the azimuth plane, such that base station antenna 1 can be used as a sector antenna for a three-sector base station.

[0046] The high-frequency band radiating element 42 is also implemented as a dual-polarized tilted -45° / +45° cross dipole radiating element. Each column of high-frequency band radiating elements 42 is coupled to a pair of ports (one port per polarization) of a beamforming radio (not shown), which may be mounted on an antenna tower, for example, adjacent to antenna 1. The beamforming radio is capable of electronically adjusting the amplitude and / or phase of a sub-component of the RF signal output to each column of high-frequency band radiating elements 42 of the multi-column beamforming array 40. The beamforming radio can change the size, shape, and pointing direction of the generated antenna beam by adjusting the amplitude and / or phase of the sub-component of the RF signal output to each column. These adjustments can be made, for example, on a time-division multiple access basis.

[0047] like Figure 1BAs best shown, low-frequency radiating element 22 can be mounted on low-frequency feed board printed circuit board 24, intermediate-frequency radiating elements 32A and 32B can be mounted on intermediate-frequency feed board printed circuit board 34, and high-frequency radiating element 42 can be mounted on high-frequency feed board printed circuit board 44. Feed board printed circuit boards 24, 34, and 44 couple RF signals between the group of one to three radiating elements 22, 32A, 32B, and 42 and the phase shifter assembly inserted between RF port 8 and arrays 20, 30, and 40. Cables (not shown) are used to connect each feed board printed circuit board 24, 34, and 44 to the phase shifter assembly.

[0048] Although Figure 1A-1B A standard base station antenna can support a wide range of communication services, but it can be difficult to manufacture in practice. Cellular operators often impose strict limits on the acceptable physical dimensions of various types of base station antennas because base station antennas are typically mounted on tall antenna towers where they may be subjected to very high wind loads. As the size of the base station antenna increases, wind load considerations can significantly increase the structural requirements of the antenna mounting hardware and the antenna tower, which can significantly increase the cost of implementing a base station. Therefore, cellular operators typically impose strict limits on the length, width, and / or depth of each type of base station antenna.

[0049] Multiband base station antennas supporting cellular services across all three frequency bands—low, mid, and high—typically comprise at least eight columns of radiating elements, and often as many as twelve, sixteen, or more. Due to antenna size limitations, radiating elements operating in different frequency bands are often very close together within the antenna, which can cause radiating elements from adjacent arrays to interact with each other in undesirable ways. For example, mid-band and / or high-band radiating elements are often mounted behind low-band radiating elements. Therefore, RF energy emitted by mid-band / high-band radiating elements can generate RF currents on the radiators of lower-band radiating elements, and these RF currents then cause RF energy to be re-radiated from the lower-band radiators. This process tends to distort the shape of the antenna beam of the higher-band (e.g., mid-band or high-band) linear array. Therefore, some or all of the lower-band array radiating elements are often designed as “stealthy” radiating elements, which are essentially transparent to RF radiation emitted by the higher-band radiating elements in the base station antenna. As another example, RF radiation emitted and received by low-band radiating elements in a base station antenna can generate common-mode currents on nearby mid-band radiating elements. Since the combined length of the feed stem and dipole arm of most mid-band radiating elements is approximately a quarter wavelength of the wavelength for various frequencies within the low-band operating frequency range, common-mode low-band currents can form on the combination of the feed stem and dipole arm of the mid-band radiating element. Low-band RF radiation can then be emitted from the mid-band radiating element in response to these common-mode currents, which distorts the radiation pattern of the low-band linear array. As yet another example, RF radiation emitted by mid-band radiating elements may be scattered when incident on metallic structures on the feed stems of nearby low-band and / or mid-band radiating elements.

[0050] Another problem with conventional multiband base station antennas is the difficulty in identifying and correcting issues that go undetected during factory testing during antenna production. The feed networks included in multiband base station antennas are typically mounted behind the linear array, and the cables, phase shifters, and other components of the various feed networks are often tangled together. Each base station antenna is typically tested after assembly to identify problems such as sources of unintended passive intermodulation (“PIM”) distortion (e.g., poorly formed welded joints or loose metal-to-metal connections that may produce unwanted RF noise), faulty connections, inoperable components (e.g., phase shifters, RET units, etc.). When such problems are identified, it is often difficult to pinpoint the source of the problem within the assembled antenna, let alone resolve it, due to the cramped design and limited access to many antenna components (especially those behind the main reflector). Therefore, when these problems are identified, the base station antenna system often requires partial or complete disassembly to identify and resolve them. This can significantly increase production costs.

[0051] Another problem with current multi-band base station antennas is that the RF paths to at least some of the radiating elements in the low-frequency, mid-frequency, and high-frequency arrays may cross back and forth between the front and rear sides of the main reflector. Therefore, the RF performance of these arrays cannot be tested before the base station antenna is assembled. If these problems are identified, the antenna must typically be disassembled to resolve them.

[0052] According to embodiments of the present invention, a multi-band base station antenna is provided that solves the aforementioned problems of conventional multi-band base station antennas. The multi-band base station antenna according to embodiments of the present invention has a low-cost, high-performance radiating element that exhibits low interaction with arrays operating in other frequency bands. In the embodiments discussed below, these radiating elements are implemented as mid-band radiating elements by way of example; however, it should be understood that the techniques disclosed herein can be used to form radiating elements operating in other frequency bands. The radiating element according to embodiments of the present invention may have a feed stem comprising a single printed circuit board, which reduces cost and also reduces the influence of the mid-band radiating element on nearby radiating elements operating in other frequency bands. The radiating element according to embodiments of the present invention may further include: a small dipole radiator printed circuit board mounted on the distal end of the feed stem printed circuit board; and a plurality of dipole arm extensions that may be mounted on and capacitively coupled to the dipole radiator printed circuit board. The radiating element may also include a substrate printed circuit board that mechanically supports the feed handle printed circuit board and may alternatively be used to electrically connect the feed handle printed circuit board to a ground reference.

[0053] In some embodiments, the base station antenna may include “wireless” cavity phase shifter assemblies for at least some of the intermediate frequency band linear arrays. A “wireless” phase shifter assembly refers to a phase shifter assembly whose output is directly connected to the radiating element (or the feed board printed circuit board of the radiating element) of the array, thereby eliminating the need for a coaxial “phase cable” extending from the output of a conventional phase shifter assembly to the radiating element (or the feed board printed circuit board) of the array. Each cavity phase shifter assembly includes a phase shifter mounted within a grounded metal housing, such that the RF transmission line of the phase shifter operates as a low-loss stripline transmission line.

[0054] The cavity phase shifter assembly can be mounted behind the reflector of the base station antenna. The intermediate frequency (IF) radiating element according to an embodiment of the invention can be partially pre-assembled, wherein the feed arm printed circuit board is mounted on the substrate printed circuit board, and the small dipole radiator printed circuit board is mounted on the feed arm printed circuit board. This simplifies manufacturing response because the IF linear array with its associated feed network can be largely assembled before they are installed in the base station antenna. Furthermore, the dipole arm extensions can be removably mounted on the corresponding dipole radiator printed circuit board before installation in the base station antenna, allowing the IF linear array and its associated feed network to be pre-tested, enabling the identification and correction of any defects before the cavity phase shifter and partially assembled radiating element are installed in the base station antenna.

[0055] The main reflector of a base station antenna may include multiple openings at the locations where the intermediate frequency (IF) radiating elements will be mounted. These openings may be slightly larger than the footprint of the substrate printed circuit board and / or the dipole radiator printed circuit board, such that when the cavity phase shifter assembly is mounted in the base station antenna, the dipole radiator printed circuit board, the feed stalk printed circuit board, and (optionally) the substrate printed circuit board for each radiating element can be inserted through a corresponding opening in the reflector. The dipole arm extension can then be mounted (e.g., using a plastic support) on the dipole radiator printed circuit board to complete the fabrication of the IF linear array. This process simplifies the fabrication of the base station antenna and allows the base station antenna to include a common main reflector that acts as a ground plane for multiple linear arrays, which can improve performance.

[0056] One way in which low-band and mid-band linear arrays can interact undesirably is that RF radiation emitted and received by the low-band radiating element can induce common-mode currents on nearby mid-band radiating elements, because the combined length of the feed stem and dipole arm of most mid-band radiating elements is approximately a quarter wavelength of the wavelength for various frequencies within the low-band operating frequency range. Therefore, when excited by RF energy within the low-band operating frequency range, significant common-mode currents can be induced on the mid-band radiating elements. The induction of these common-mode currents on mid-band radiating elements is called common-mode resonance. These common-mode resonances can distort the radiation pattern of the low-band linear array.

[0057] Mid-band radiating elements, including common-mode resonance suppression circuitry, are known in the art to tune common-mode resonances outside the low-frequency band operating range. This can be achieved, for example, by integrating an inductor-capacitor (“LC”) circuit into the electrical connection between the feed network for the mid-band radiating element and each of the four dipole arms of the mid-band radiating element. Conventionally, these LC circuits are implemented at least partially on the feed handle of the cross-dipole radiating element. Since the cross-dipole radiating element has four dipole arms, four LC circuits can be implemented, wholly or partially, on the feed handle. These LC circuits (typically parallel LC circuits) can effectively tune common-mode resonances outside the low-frequency band operating range. However, they also require a larger feed handle size, which increases the cost and weight of the mid-band radiating element, and a larger feed handle can cause increased scattering of RF energy emitted by any nearby high-frequency band radiating elements.

[0058] According to embodiments of the invention, a cross-dipole mid-band radiating element may include only two LC circuits in its feed stem, which allows for the use of a smaller feed stem printed circuit board that is lighter and cheaper than a comparable conventional feed stem printed circuit board. In practice, the radiating element may use a single feed stem printed circuit board, which may have the additional benefit of reduced scattering relative to nearby high-frequency band radiating elements.

[0059] In some embodiments, the intermediate frequency (IF) band radiating element disclosed herein can be used in a base station antenna including a primary reflector mounted directly in front of one or more cavity phase shifter assemblies. The primary reflector can act as a ground plane for the IF band radiating element and can forward redirect RF radiation emitted backward by the IF band radiating element. The reflector may include corresponding openings at the locations where the IF band radiating element will be mounted. The dimensions of the substrate printed circuit board and dipole radiator printed circuit board for each IF band radiating element can be configured such that they can fit through these openings. This allows the IF band radiating elements to be partially pre-assembled (i.e., the substrate printed circuit board, feed arm printed circuit board, and dipole radiator printed circuit board for each radiating element can be assembled together) and soldered to appropriate locations on the cavity phase shifter assembly before the cavity phase shifter assembly is installed within the base station antenna, simplifying the manufacturing process. Additionally, the dipole arm extension and directional element of each IF band radiating element can be removably mounted on the dipole radiator printed circuit board, allowing the IF band linear array assembly to be tested before it is installed in the antenna. Therefore, poorly soldered joints, improper connections, and other manufacturing problems can be identified and corrected before antenna assembly. After testing, the dipole arm extensions and directors can be removed, allowing the cavity phase shifter assembly to be installed in the base station antenna, where the partially assembled intermediate frequency (IF) radiating element extends through an opening in the main reflector. The dipole arm extensions and directors can then be reinstalled on the partially assembled IF radiating element in front of the main reflector to complete the fabrication of the IF linear array assembly.

[0060] Now refer to Figure 2A -5. Embodiments of the present invention are described in more detail.

[0061] Figure 2A This is a schematic front view of a multi-band base station antenna 100 according to an embodiment of the present invention, with the radome removed. The multi-band base station antenna 100 is similar to the base station antenna 1 in many respects. Therefore, the following discussion will focus on the differences between the base station antenna 1 and the base station antenna 100. The same reference numerals are used to label the same elements in both base station antennas 1 and 100.

[0062] For example, through comparison Figure 1B and 2A It can be seen that the main difference between the two base station antennas 1 and 100 lies in the four intermediate frequency band linear arrays 30-3 to 30-6 of base station antenna 100 and its associated feed network (which in Figure 1A-1BThe intermediate frequency (IF) linear array components 200-1 to 200-4 in the base station antenna 100 are replaced. The reflector 10 of the base station antenna 1 is also replaced in the base station antenna 100 with a modified reflector 110. It should also be noted that the IF feed board printed circuit board 34 of the base station antenna 1 is omitted in the base station antenna 100; each of these IF feed board printed circuit boards includes two IF radiating elements 32 thereon. As will be discussed in more detail below, the feed board printed circuit board 32 of the base station antenna 1 is replaced in the base station antenna 100 with a substrate printed circuit board 380 that is part of the IF radiating element 300.

[0063] Figure 2B This is a schematic front perspective view of a portion of each of the four intermediate frequency band linear array assemblies 200-1 to 200-4 included in the base station antenna 100. Figure 2B A reflector 110 of the base station antenna 100 is also shown for context use. The intermediate frequency band radiating elements in adjacent intermediate frequency band linear array assemblies 200-1 to 200-4 are... Figure 2A The diagram shows vertical staggered (offset), but this staggered... Figure 2B Not shown in the diagram. It should be understood that any configuration is possible.

[0064] like Figure 2A As shown, the reflector 110 can extend substantially the entire length of the base station antenna 100, which provides increased structural strength. Figure 2B As shown, each intermediate frequency band linear array assembly 200 includes an intermediate frequency band linear array 210 of intermediate frequency band radiating elements 300 and a cavity phase shifter assembly 220. The cavity phase shifter assembly 220 forms a feed network for the respective intermediate frequency band linear array 210. The reflector 110 includes a plurality of openings 112. Each intermediate frequency band radiating element 300 extends through a corresponding one of the openings 112 in the reflector 110, such that a majority of each intermediate frequency band radiating element 300 is positioned in front of the reflector 110, but a small portion of each intermediate frequency band radiating element 300 extends behind the reflector 110. The cavity phase shifter assembly 220 is mounted behind the reflector 110. Each intermediate frequency band radiating element 300 can be configured to operate in the 1695-2690MHz frequency band or a portion thereof. To simplify the figure, each of the first to fourth intermediate frequency band linear arrays 210-1 to 210-4 is shown in... Figure 2B The diagram shows a total of six mid-band radiating elements 300 arranged in corresponding vertically extending columns. It should be understood that typically each mid-band linear array will include a larger number of mid-band radiating elements 300. For example, Figure 2AEach intermediate frequency band linear array 210 is shown as having thirteen radiating elements, which is more typical. The number of intermediate frequency band radiating elements 300 included in each intermediate frequency band linear array 210 can be selected, for example, based on the desired elevation beamwidth of the antenna beam generated by the intermediate frequency band linear array 210.

[0065] Each intermediate frequency band cavity phase shifter assembly 220 is connected to a pair of RF ports 8 (see...) Figure 2A This is because the intermediate frequency (IF) radiating element 300 is a dual-polarized radiating element that transmits and receives RF signals under two orthogonal polarizations. Each IF cavity phase shifter assembly 220 includes multiple output RF transmission lines that can be directly connected to the IF radiating element 300, as will be described in more detail below.

[0066] Figures 3A-3E It shows Figure 2A-2B One of the intermediate frequency band radiating elements 300 included in the intermediate frequency band linear array assembly 200. Specifically, Figure 3A This is a schematic side perspective view of the mid-frequency radiating element 300, and Figure 3B and 3C These are schematic top views and schematic side views of the mid-frequency band radiating element 300. Figure 3D This is a schematic top view of the printed circuit board 310 for the feed stem of the mid-frequency radiating element 300, and Figure 3E This is a front view of the dipole radiator printed circuit board 340 of the mid-frequency band radiating element 300.

[0067] First refer to Figures 3A-3C The mid-band radiating element 300 includes a single feed stem printed circuit board 310, a dipole radiator printed circuit board 340, multiple sheet-like metal dipole arm extensions 360-1 to 360-4, a substrate printed circuit board 380, and a directional device 390. The substrate printed circuit board 380 includes a dielectric substrate 382 with a metal pad (not visible) on its rear side. A rectangular slot 386 is formed through the dielectric substrate 382, ​​and the base 312 of the feed stem printed circuit board 310 is inserted through the slot 386. The slot 386 can be sized to provide an interference fit with the feed stem printed circuit board 310. As will be explained below, the substrate printed circuit board 380 can mechanically support the feed stem printed circuit board 310 and can be used to couple a ground signal to the feed stem printed circuit board 310. The substrate printed circuit board 380 may have a dielectric substrate 382 comprising a low-cost material such as FR4.

[0068] The feed stem printed circuit board 310 extends forward at a right angle to the substrate printed circuit board 380. The dipole radiator printed circuit board 340 is mounted on the distal end of the feed stem printed circuit board 310 and is parallel to the substrate printed circuit board 380. The dipole radiator circuit board 340 includes a dielectric substrate 342 and a metallization pattern 344 formed on the front side of the dielectric substrate 342 (see [link to documentation]). Figure 3E A rectangular slot 346 extends through the dielectric substrate 342 and the metallization pattern 344. The distal end 314 of the feed handle printed circuit board 310 extends through the rectangular slot 346 in the dipole radiator printed circuit board 340 to mechanically mount the dipole radiator printed circuit board 340 onto the feed handle printed circuit board 310. The metallization pattern 344 includes four metal pads 350-1 to 350-4, arranged in the respective four quadrants of a square defined by the dielectric substrate 342. Each metal pad 350 may form at least a portion of a corresponding dipole arm, as will be discussed in more detail below. Therefore, each metal pad 350 may also be referred to herein as a “dipole arm piece” 350.

[0069] Dipole arm extensions 360 are mounted in front of the dipole radiator printed circuit board 340. Each dipole arm extension 360 may include a bent piece of sheet metal. Although dipole arm extensions 360-1 to 360-4 are... Figures 3A-3C The diagram shows four individual pieces of sheet metal, but it should be understood that in other embodiments, all four dipole arm extensions 360 (or subsets thereof) may be formed as a single integral piece of bent sheet metal. Plastic rivets (not shown) or other attachment mechanisms may be used to mount the dipole arm extensions 360 onto the dipole radiator printed circuit board 340. Each dipole arm extension 360 includes a first segment 362A parallel to the dipole radiator printed circuit board 340 and second and third segments 362B, 362C extending forward from the first segment 362A. The second and third segments 362B, 362C increase the electrical length of each dipole arm 372 to a desired electrical length without increasing the footprint of the radiating element 300 (where the footprint is the area of ​​the radiating element 300 when viewed from the front). Each dipole arm extension 360 can be formed by stamping the dipole arm extension 360 from a sheet of metal and then bending its second and third segments 362B, 362C out of the plane of the first segment 362A.

[0070] In the depicted embodiment, each dipole arm extension 360 is electrically connected to a corresponding metal pad in the metal pad 350, such that each combination of the metal pad 350 and the dipole arm extension 360 mounted thereon forms a corresponding dipole arm 372. In other words, the metal pad 350 can be observed to include the base of each dipole arm 372, and the dipole arm extension 360 is a structure that increases the length of the base of each dipole arm to form the first to fourth dipole arms 372-1 to 372-4. The first dipole arms and the second dipole arms 372-1, 372-2 form the first dipole radiator 370-1, and the third dipole arms and the fourth dipole arms 372-3, 372-4 form the second dipole radiator 370-2. The first dipole radiator 370-1 can be configured to transmit and receive RF signals tilted at -45°, and the second dipole radiator 370-2 can be configured to transmit and receive RF signals tilted at +45°. One or more solder masks or other thin dielectric elements (not shown) can be positioned between the dipole radiator printed circuit board 340 and the dipole arm extension 360, such that the metal pad 350 is capacitively coupled to the respective dipole arm extension 360.

[0071] The director 390 is mounted in front of the first dipole radiator and the second dipole radiators 370-1, 370-2. The director 390 is configured to reduce the beamwidth of the antenna beam generated by the intermediate frequency band linear array 210 in at least a portion of the intermediate frequency band operating frequency range. The director 390 can have a conventional design.

[0072] Figure 3D This is a shaded view showing the metallization on the first and second main surfaces of the power supply shank printed circuit board 310. (See image.) Figure 3D As shown, the power supply spool printed circuit board 310 has a base 312 and a distal (front) end 314 positioned in front of the base 312. The power supply spool printed circuit board 310 includes a dielectric substrate 320 having a first metallization layer 322-1 on a main surface of the dielectric substrate 320. Figure 3D (shown in solid lines), and a second metallization layer 322-2 on another main surface of the dielectric substrate 320 (in... Figure 3D (Shown in dashed lines). Dielectric substrate 320 includes a pair of rearwardly extending tabs 316.

[0073] like Figure 3DAs shown, the first signal trace and the second signal traces 326-1, 326-2 are formed in the first metallization layer 322-1. Each signal trace 326 is implemented as a tortuous metal trace extending from the base 312 of the feed stem printed circuit board 310 to the distal end 314. As shown, the distal ends of the signal traces 326-1, 326-2 can be enlarged to facilitate passage through the corresponding first solder joints and third solder joints 334-1, 334-3 (see Figure 1). Figure 3E Each signal trace current DC is connected to a corresponding metal pad in the metal pads 350 on the dipole radiator printed circuit board 340. The first metal pad and the second metal pads 330-1, 330-2 are also formed in the first metallization layer 322-1.

[0074] The first and second grounding wires 328-1 and 328-2 are formed in the second metallization layer 322-2. Most of each grounding wire 328 is formed as a wide metal pad, but each grounding wire 328 narrows to a thinner trace near its distal end. As shown, the distal end of each grounding wire 328 can be enlarged to facilitate passage through the corresponding second and fourth weld joints 334-2 and 334-4 (see Figure). Figure 3E The ground wires 328-1 and 3282 are connected to a DC current source in a corresponding metal pad in the metal pads 350 on the dipole radiator printed circuit board 340. A first signal trace 326-1 overlaps with the first ground wire 328-1 to form a first microstrip RF transmission line 324-1, and a second signal trace 326-2 overlaps with the second ground wire 328-2 to form a second microstrip RF transmission line 324-2. First and second spiral traces 332-1 and 332-2 are also formed in the second metallization layer 322-2, forming corresponding first and second inductors L1 and L2. The first end of each spiral trace 332-1, 332-2 is currently connected to a corresponding ground wire among the first and second ground wires 328-1, 328-2, while the second end of each spiral trace 332-1, 332-2 is currently connected to a corresponding metal pad among the first and second metal pads 330-1, 330-2 through corresponding plated vias 318-1, 318-2 extending through the dielectric substrate 320. The first metal pad 330-1 overlaps with the first ground wire 328-1 and is therefore capacitively coupled to form a first capacitor C1, and the second metal pad 330-2 overlaps with the second ground wire 328-2 and is therefore capacitively coupled to form a second capacitor C2. A first spiral inductor L1 is connected in parallel with the first capacitor C1 to form a first parallel LC circuit LC1, and a second spiral inductor L2 is connected in parallel with the second capacitor C2 to form a second parallel LC circuit LC2.

[0075] Figure 3EThis is a front top view of the dipole radiator printed circuit board 340, showing the electrical connection between the feed handle printed circuit board 310 and the dipole radiator printed circuit board 340. (As shown...) Figure 3E As shown, the first and third weld joints 334-1 and 334-3 connect the first signal trace and the second signal trace 326-1 and 326-2 with DC currents to the corresponding first dipole arm and the third dipole arm 350-1 and 350-3. The second and fourth weld joints 334-2 and 334-4 connect the first ground wire and the second ground wire 328-1 and 328-2 with DC currents to the corresponding second dipole arm and the fourth dipole arm 350-2 and 350-4.

[0076] like Figure 3D As best seen in the diagram, the power supply spool printed circuit board 310 includes only two common-mode resonance suppression circuits: a first parallel LC circuit LC1 and a second parallel LC circuit LC2. The two common-mode resonance suppression circuits LC1 and LC2 are implemented on the connections between the first and second ground lines 328-1 and 328-2 and the corresponding second and fourth dipole arms 350-2 and 350-4. The connections along the first and second signal traces 326-1 and 326-2 and the corresponding first and third dipole arms 350-1 and 350-3 do not provide common-mode resonance suppression circuitry. Common-mode resonance suppression circuitry can be omitted on signal trace 326 because the first and third dipole arms 350-1 and 350-3 are not connected to ground, and therefore, no common-mode current will be induced along the signal trace 326 and the combination of the dipole arms 372 to which they are connected.

[0077] from Figure 3DIt can also be seen that the two common-mode resonance suppression circuits LC1 and LC2 occupy a large amount of space on the feed handle printed circuit board 310 because capacitors C1 and C2 and spiral inductors L1 and L2 each require a large area near the far end of the feed handle printed circuit board 310. It may be difficult to form four common-mode resonance suppression circuits on a single feed handle printed circuit board. For example, U.S. Patent No. 12,021,315 discloses a mid-frequency radiating element having four common-mode resonance suppression circuits, i.e., the common-mode resonance suppression circuits are inserted along the connections between four ground lines and four dipole arms. A total of four common-mode resonance suppression circuits can be provided because the mid-frequency radiating element of U.S. Patent No. 12,021,315 (see Figures 5C and 7A-7B) includes feed handles with two feed handle printed circuit boards for each radiating element. However, using two feed stem printed circuit boards increases the cost of the radiating element (particularly due to the expensive RF quality printed circuit boards used to implement the feed stem printed circuit board), and the larger feed stem printed circuit board with increased metallization tends to scatter RF radiation emitted by nearby high-frequency band radiating elements, thus degrading the high-frequency band antenna beam. This is especially true when scanning the high-frequency band antenna beam in the azimuth plane, as more high-frequency band radiation may be incident on the intermediate frequency (IF) feed stem. Furthermore, in the IF radiating element disclosed in U.S. Patent No. 12,021,315, the feed stem printed circuit board is arranged at angles of -45° and +45° relative to the longitudinal axis of the linear array. This means that RF radiation scanned in the azimuth plane will be incident on the feed stem printed circuit board at an angle of approximately + / -45°, resulting in RF radiation incident on a large amount of metal.

[0078] refer to Figures 3A-3E According to some embodiments of the present invention, a radiating element 300 is provided, the radiating element including a feed handle printed circuit board 310 and a dipole radiator printed circuit board 340 mounted on the feed handle printed circuit board 310. The feed handle printed circuit board includes a first ground line 328-1 and a second ground line 328-2, the first ground line including a first integrated parallel LC circuit LC1, and the second ground line including a second integrated parallel LC circuit LC2. The feed handle printed circuit board 310 also includes a first signal trace 326-1 extending through an opening 346 in the dipole radiator printed circuit board 340, and a second signal trace 326-2. In some embodiments, the second signal trace 326-2 may extend through the opening 346.

[0079] The dipole radiator printed circuit board 340 may include a first dipole arm 350-1 and a second dipole arm 350-2, each being at least a portion of the first dipole radiator 370-1; and a third dipole arm 350-3 and a fourth dipole arm 350-4, each being at least a portion of the second dipole radiator 370-2. A first signal trace 326-1 may be electrically connected to the first dipole arm 350-1, and a second signal trace 326-2 may be electrically connected to the third dipole arm 350-3.

[0080] In some embodiments, the first signal trace and the second signal traces 326-1, 326-2 each have multiple tortuous segments. For example, a first portion of the first signal trace 326-1 may have a wave shape having at least two peaks and two valleys. In some embodiments, no parallel LC circuitry is integrated into the first signal trace or the second signal traces 326-1, 326-2.

[0081] The radiating element 300 may further include a first dipole arm extension 360-1 electrically connected to a first dipole arm member 350-1, a second dipole arm extension 360-2 electrically connected to a second dipole arm member 350-2, a third dipole arm extension 360-3 electrically connected to a third dipole arm member 350-3, and a fourth dipole arm extension 360-4 electrically connected to a fourth dipole arm member 350-4. The first dipole arm extension 360-1 may overlap with the first dipole arm member 350-1 in the forward direction and / or may extend outward beyond the outer periphery of the first dipole arm member 350-1. In some embodiments, the first dipole arm extension 360-1 may include a sheet-like metal dipole arm extension comprising a first portion 362A extending parallel to the first dipole arm member 350-1 and a second portion 362B extending obliquely from the first portion 362A. In some embodiments, the first dipole arm extension 360-1 is capacitively coupled to the first dipole arm member 350-1. In some embodiments, the first dipole arm extension to the fourth dipole arm extensions 360-1 to 360-4 are separate pieces. In other embodiments, at least two of the first dipole arm extensions to the fourth dipole arm extensions 360-1 to 360-4 are implemented in a single sheet of metal.

[0082] Figure 4 yes Figure 2B A schematic end view of one cavity phase shifter assembly in cavity phase shifter assembly 220. (See diagram) Figure 4As shown, the cavity phase shifter assembly 220 includes a longitudinally extending metal housing 230. The metal housing 230 can be formed, for example, by extrusion. A first longitudinally extending cavity and a second longitudinally extending cavity 240-1, 240-2 are defined within the metal housing 230. The metal housing 230 includes a front wall 232, a rear wall 234, and a pair of main sidewalls 236-1, 236-2, which together define the first cavity and the second cavity 240-1, 240-2. As shown, in some cases, the first cavity and the second cavity 240-1, 240-2 may share a common sidewall 238. The metal housing 230 also includes a first generally C-shaped structure 250-1 extending laterally from the first main sidewall 236-1 and a second generally C-shaped structure 250-2 extending laterally from the second main sidewall 236-2. Each generally C-shaped structure 250 may have a front wall 252 extending parallel to the front wall 232, a rear wall 254 extending parallel to (and possibly coplanar with) the rear wall 234, and a side wall 256 extending parallel to the main side wall 236. A first generally C-shaped structure 250-1 and a first main side wall 236-1 define a third cavity 240-3, and a second generally C-shaped structure 250-2 and a second main side wall 236-2 define a fourth cavity 240-4. The longitudinal axis of each cavity 240 extends parallel to the longitudinal axis of the base station antenna 100.

[0083] A first phase shifter assembly 260-1 is mounted in a first cavity 240-1, and a second phase shifter assembly 260-2 is mounted in a second cavity 240-2. Each phase shifter assembly 260 may include, for example, a phase shifter printed circuit board 262 having RF transmission lines formed thereon. Each phase shifter printed circuit board 262 may include: an input RF transmission line (not shown) electrically connected to the feed network of the base station antenna 100, such as a metal pad or trace; a power divider (not shown) that divides the RF signal input through the input RF transmission line into multiple sub-components; and multiple output RF transmission lines (not shown) for phase-adjusted sub-components of the output RF signal. Each phase shifter assembly 260 may also include a phase shifter (not shown), such as a sliding dielectric phase shifter, which is configured to impart an adjustable phase taper to the sub-components of the RF signal before they reach the corresponding output RF transmission line. The first RF feed line and the second RF feed lines 242-1, 242-2 (e.g., stripline RF feed lines) can be disposed in the third cavity and the fourth cavity 240-3, 240-4. The first RF feed line and the second RF feed lines 242-1, 242-2 can be electrically connected to the corresponding input RF transmission lines on the first phase shifter printed circuit board and the second phase shifter printed circuit board 262-1, 262-2.

[0084] Cavity phase shifter assemblies are known in the art. For example, U.S. Patent No. 11,677,141 discloses various cavity phase shifter assemblies and discusses their operation. The entire contents of U.S. Patent No. 11,677,141 are incorporated herein by reference. Cavity phase shifter assemblies are commonly used because they comprise low-loss stripline RF transmission lines and because they can be designed to provide cable-free connections to radiating elements, which reduces the number of solder joints. Although Figure 4 One cavity phase shifter design is shown, but it should be understood that any suitable cavity phase shifter assembly design can be used to implement cavity phase shifter assembly 220, including any cavity phase shifter assembly disclosed in U.S. Patent No. 11,677,141.

[0085] Figure 5A It is installed in Figure 4 On the cavity phase shifter assembly 220 Figures 3A-3E A schematic side perspective view of the mid-frequency band radiating element 300. Figure 5B yes Figure 5A A magnified side view of a portion of the image.

[0086] like Figures 5A-5B As shown, the mid-frequency radiating element 300 is mounted on the front wall 232 of the metal housing 230, such that the substrate printed circuit board 380 is parallel to the front wall 232. Although in Figures 5A-5B While not visible, one or more openings are provided in the front wall 232, and rearwardly extending tabs 316-1, 316-2 on the power supply spool printed circuit board 310 are inserted through these openings, such that the base portions of the first and second signal traces 326-1, 326-2 and the first and second ground lines 328-1, 328-2 extend into the corresponding first and second cavities 240-1, 240-2. A solder mask (not shown) may be provided on the front wall 232 or on a metal pattern 384, which may be provided on the rear side of the substrate printed circuit board 380, such that the metal shell 230 is capacitively coupled to the metal pattern 384 through the solder mask (or other dielectric layer). Window 217 ( Figures 5A-5B Only one window is visible in the sidewalls 236-1, 236-2 of the metal housing 230, which allows a weld joint 336 to be applied within the respective cavities 240-1, 240-2. The weld joint 336 electrically connects portions of the signal traces 326-1, 326-2 extending onto the tabs 316-1, 316-2 to output RF transmission lines mounted on the respective phase shifter circuit boards 262 within the respective cavities 240-1, 240-2. The first and second ground lines 328-1, 328-2 can similarly be electrically connected to ground references on the respective phase shifter circuit boards 262-1, 262-2 via weld joints (not shown), which are formed through window 217. Figure 5BIt can also be seen that the feed board printed circuit board 310 of each mid-band radiating element 300 intersects the phase shifter printed circuit board 262 at a 90° angle. This is mechanically more robust than a solution where the intersection is not at a 90° angle, and also provides an improved solder joint.

[0087] As discussed above, the ground wires 328-1 and 328-2 on the feed handle printed circuit board 310 can be directly connected to the ground references on the corresponding phase shifter circuit boards 262-1 and 262-2. Alternatively, the ground wires 328-1 and 328-2 can be electrically connected to the ground references on the substrate printed circuit board 380, which are capacitively connected to the ground references on the corresponding phase shifter circuit boards 262-1 and 262-2. For example, the substrate printed circuit board 380 may include the aforementioned metal pad 384 on its rear side, which is capacitively coupled to the metal housing 230 of the cavity phase shifter assembly 220. The metal housing 230 of the cavity phase shifter assembly 220 can be electrically connected to the ground references on the corresponding phase shifter circuit boards 262-1 and 262-2. The ground wires 328-1 and 328-2 can be electrically connected to the metal pad 384 on the rear side of the substrate printed circuit board 380.

[0088] The intermediate frequency (IF) band radiating element 300 according to embodiments of the present invention can have advantages over conventional IF band linear arrays. First, they can have smaller and cheaper feed stems compared to other IF band radiating elements with common-mode resonance suppression circuitry. Second, they can comprise a single feed stem printed circuit board with a main surface extending perpendicular to the forward direction. Therefore, RF radiation from nearby high-frequency band radiating elements, scanned in the azimuth plane, will travel parallel to the metallization layer on the feed stem printed circuit board and will thus experience very low scattering levels. Therefore, the IF band radiating element 300 can have less impact on the nearby high-frequency band array. Third, since the IF band linear array assemblies 200 are modular components, they can be almost completely assembled before being installed in the base station antenna 100. This simplifies the manufacturing process. Fourth, since the dipole arm extension 360 and the directional element 390 of the intermediate frequency band radiating element 300 can be removably attached to the rest of the intermediate frequency band linear array assembly 200 before it is installed in the base station antenna 100, it can be pre-tested before the entire assembly 200 is installed in the antenna 100. Fifth, since the intermediate frequency band linear array assembly 200 is modular in nature, if a problem is later identified during antenna level testing, the intermediate frequency band linear array assembly 200 can be easily removed from the base station antenna 100 without removing various other components, making it much easier to resolve problems detected during antenna level testing (e.g., poor solder joints).

[0089] The invention has been described above with reference to the accompanying drawings. The invention is not limited to the embodiments shown. Rather, these embodiments are intended to fully and completely disclose the invention to those skilled in the art. In the drawings, the same reference numerals consistently denote the same elements. For clarity, the thickness and dimensions of some parts may be exaggerated.

[0090] For ease of description, spatially relative terms such as “below,” “under,” “lower,” “above,” “upper,” “top,” “bottom,” etc., are used herein to describe the relationship of one element or feature as shown in the accompanying drawings to one or more other elements or features. It should be understood that, in addition to the orientations shown in the figures, the spatially relative terms are also intended to cover different orientations of the device in use or operation. For example, if the device in the figures is flipped, an element described as “below” or “under” other elements or features would be oriented as “above” other elements or features. Thus, the exemplary term “below” can cover both above and below orientations. The device may be oriented in other ways (rotated 90 degrees or other orientations), and the spatially relative descriptive terms used herein shall be interpreted accordingly.

[0091] In this document, unless otherwise stated, the terms “attachment,” “connection,” “interconnection,” “contact,” “mounting,” “coupling,” etc., may refer to direct or indirect attachment or coupling between elements.

[0092] For the sake of brevity and / or clarity, well-known features or constructs may not be described in detail. As used herein, the expression "and / or" includes any and all combinations of one or more of the related listed items.

[0093] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used herein, unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “described” are also intended to include the plural forms. It will be further understood that, when used in this specification, the terms “comprises / comprising,” “includes,” and / or “including” specify the presence of the said feature, operation, element, and / or component, but do not exclude the presence or addition of one or more other features, operations, elements, components, and / or groups thereof.

Claims

1. A radiating element, comprising: Printed circuit board for power supply handle; as well as A dipole radiator printed circuit board, the dipole radiator printed circuit board being mounted on the feed handle printed circuit board, wherein the feed handle printed circuit board comprises: The first grounding wire includes a first integrated parallel inductor-capacitor ("LC") circuit; The second grounding wire includes a second integrated parallel LC circuit; A first signal trace extends through an opening in the printed circuit board of the dipole radiator; and Second signal trace.

2. The radiating element of claim 1, wherein the second signal trace extends through the opening.

3. The radiating element of claim 1, wherein the feed stem printed circuit board includes a forward-extending tab extending through the opening, and the distal end of the first signal trace extends onto the first forward-extending tab.

4. The radiating element of claim 1, wherein the dipole radiator printed circuit board includes a first dipole arm and a second dipole arm, each being at least a portion of the first dipole radiator, and a third dipole arm and a fourth dipole arm, each being at least a portion of the second dipole radiator.

5. The radiating element of claim 4, wherein the first signal trace current is connected to the first dipole arm and the second signal trace current is connected to the second dipole arm.

6. The radiating element according to claim 1, wherein the first signal trace and the second signal trace each have a plurality of tortuous segments.

7. The radiating element of claim 1, wherein a first portion of the first signal trace has a wave shape having at least two peaks and two valleys.

8. The radiating element of claim 1, wherein no parallel LC circuit is integrated into the first signal trace or the second signal trace.

9. The radiating element according to claim 4, further comprising: The first dipole arm extension is electrically connected to the first dipole arm member. The second dipole arm extension is electrically connected to the second dipole arm member. The third dipole arm extension is electrically connected to the third dipole arm member; as well as A fourth dipole arm extension, which is electrically connected to the fourth dipole arm member.

10. The radiating element of claim 9, wherein the first dipole arm extension overlaps with the first dipole arm in the forward direction and extends outward beyond the outer periphery of the first dipole arm.

11. The radiating element of claim 10, wherein the first dipole arm extension comprises a sheet-like metal dipole arm extension, the sheet-like metal dipole arm extension comprising a first portion extending parallel to the first dipole arm and a second portion extending obliquely from the first portion.

12. The radiating element of claim 10, wherein the first dipole arm extension is capacitively coupled to the first dipole arm member.

13. The radiating element of claim 9, wherein the first dipole arm extension to the fourth dipole arm extension are separate components.

14. The radiating element of claim 9, wherein at least two of the first to fourth dipole arm extensions are implemented in a single sheet of metal.

15. The radiating element of claim 1 further includes a substrate printed circuit board, the substrate printed circuit board including a groove therethrough, wherein the base of the feed stem printed circuit board is inserted into the substrate printed circuit board through the groove.

16. The radiating element of claim 15, wherein the rear side of the substrate printed circuit board includes a metal pad, and a plurality of ground traces on the feed stem printed circuit board are soldered to the metal pad.

17. The radiating element and cavity phase shifter assembly according to claim 16, wherein the cavity phase shifter assembly comprises: A metal shell having a first cavity and a second cavity; The first phase shifter within the first cavity; as well as The second phase shifter within the second cavity The metal pads on the substrate printed circuit board are mounted to couple with the metal-cased capacitor.

18. The radiating element of claim 17, wherein the front wall of the metal housing includes a first opening and a second opening, and the first phase shifter includes a first phase shifter printed circuit board, and the second phase shifter includes a second phase shifter printed circuit board, and wherein the feed handle printed circuit board includes a first rearwardly extending tab extending through the first opening to contact the first phase shifter printed circuit board and a second rearwardly extending tab extending through the second opening to contact the second phase shifter printed circuit board.

19. A radiating element, comprising: Printed circuit board for power supply handle; as well as A dipole radiator printed circuit board, wherein the dipole radiator printed circuit board is mounted on the distal end of the feed handle printed circuit board; The power supply stem printed circuit board includes: The first grounding wire includes a first integrated parallel inductor-capacitor ("LC") circuit; The second grounding wire includes a second integrated parallel LC circuit; A first signal trace, having multiple tortuous segments, is directly connected to the dipole radiator printed circuit board and does not include integrated LC circuitry; and The second signal trace, having multiple tortuous segments, is directly connected to the dipole radiator printed circuit board and does not include integrated LC circuitry.

20. The radiating element of claim 19, wherein the feed stem printed circuit board includes a forward-extending tab extending through an opening in the dipole radiator printed circuit board, and the first signal trace extending through the opening.

21. The radiating element of claim 20, wherein the second signal trace extends through the opening.

22. The radiating element of claim 19, wherein no parallel LC circuit is integrated into the first signal trace or the second signal trace.

23. The radiating element of claim 19, wherein the dipole radiator printed circuit board includes a first dipole arm and a second dipole arm, each being at least a portion of the first dipole radiator, and a third dipole arm and a fourth dipole arm, each being at least a portion of the second dipole radiator.

24. The radiating element of claim 23, wherein the first signal trace current is connected to the first dipole arm and the second signal trace current is connected to the second dipole arm.

25. The radiating element according to claim 23, further comprising: The first dipole arm extension is electrically connected to the first dipole arm member. The second dipole arm extension is electrically connected to the second dipole arm member. The third dipole arm extension is electrically connected to the third dipole arm member; as well as A fourth dipole arm extension, which is electrically connected to the fourth dipole arm member.

26. The radiating element of claim 25, wherein the first dipole arm extension comprises a sheet-like metal dipole arm extension, the sheet-like metal dipole arm extension comprising a first portion extending parallel to the first dipole arm and a second portion extending obliquely from the first portion.

27. The radiating element of claim 19 further includes a substrate printed circuit board, the substrate printed circuit board including a groove therethrough, wherein the base of the feed stem printed circuit board is inserted into the substrate printed circuit board through the groove.

28. The radiating element and cavity phase shifter assembly according to claim 27, wherein the cavity phase shifter assembly comprises: A metal shell having a first cavity and a second cavity; The first phase shifter within the first cavity; as well as The second phase shifter within the second cavity The power supply stalk printed circuit board includes a first rearwardly extending tab extending into the first cavity and a second rearwardly extending tab extending into the second cavity.

29. A radiating element, comprising: Printed circuit board for power supply handle; as well as A dipole radiator printed circuit board, the dipole radiator printed circuit board being mounted on the feed handle printed circuit board, wherein the feed handle printed circuit board comprises: The first grounding wire includes a first integrated parallel inductor-capacitor ("LC") circuit; The second grounding wire includes a second integrated parallel LC circuit; A first signal trace, the first signal trace being currently connected to a first metal pad on the printed circuit board of the dipole radiator; and A second signal trace is connected to a second metal pad on the printed circuit board of the dipole radiator.

30. The radiating element of claim 29, wherein no parallel LC circuit is integrated into the first signal trace or the second signal trace.

31. The radiating element of claim 29, wherein the dipole radiator printed circuit board includes a first dipole arm and a second dipole arm, each being at least a portion of the first dipole radiator, and a third dipole arm and a fourth dipole arm, each being at least a portion of the second dipole radiator.

32. The radiating element of claim 31, wherein the first signal trace current is connected to the first dipole arm and the second signal trace current is connected to the second dipole arm.

33. The radiating element of claim 32, wherein the first signal trace and the second signal trace each have a plurality of tortuous segments.

34. The radiating element of claim 29 further includes a substrate printed circuit board, the substrate printed circuit board including a groove therethrough, wherein the base of the feed stem printed circuit board is inserted into the substrate printed circuit board through the groove.

Images