Calibration circuit board and antenna device comprising the same

Abstract

The present disclosure relates to a calibration circuit board and an antenna device including the same. A calibration circuit board for an antenna is provided, including: a first metal layer; a first substrate disposed on the first metal layer; a second substrate disposed on the first substrate; and a plurality of couplers. Each coupler includes: a transmission line provided with an input port and an output port at respective ends thereof; and a coupling line coupled with the transmission line and including two first portions respectively located on both sides of the transmission line as seen from a direction perpendicular to the calibration circuit board and a second portion connected between the two first portions. Wherein the coupling lines of the plurality of couplers are connected in series to provide a first calibration port and a second calibration port. Wherein one of the transmission lines and the coupling lines of the plurality of couplers is disposed between the first substrate and the second substrate, and the other of the transmission lines and the coupling lines of the plurality of couplers is disposed on the second substrate.

Description

Technical Field

[0001] This disclosure generally relates to the field of antennas, and more specifically, to a calibration circuit board and an antenna device including the calibration circuit board. Background Technology

[0002] Smart antennas, also known as adaptive array antennas, are widely used in modern mobile communication systems. By adjusting the amplitude and phase characteristics of the signals sent to each antenna radiating element (or group of radiating elements), smart antennas can generate spatially directional radiation beams, aligning the main antenna beam towards a specific user direction. Beamforming networks are a crucial component of smart antennas. In a base station containing smart antennas, signals transmitted by the radio frequency (RF) transceiver enter the beamforming network, where the signals are split into multiple paths corresponding to multiple radiating elements or multiple rows of radiating elements. In some cases, beamforming is performed within the RF transceiver, and multiple radiating elements or multiple rows of radiating elements are coupled to corresponding ports of the RF transceiver. The amplitude, phase, and delay characteristics of each path are independently adjusted. The beamformed multiple signals are then sent to the corresponding radiating elements or rows of radiating elements in the radiating element unit. Each radiating element or row of radiating elements generates an independent spatially directional beam, which, through interferometry and superposition, results in a final beam with excellent directivity.

[0003] To form the desired ideal beam, the amplitude and phase characteristics of each transmit / receive channel from the RF transceiver to each radiating element or column of radiating elements must be consistent to ensure that the actual beam matches the beam expected to be obtained through beamforming network adjustments. However, the transmit and receive channels may have inconsistent transmission characteristics, causing the final beam pattern to differ from the expectation even when the desired gain and phase are applied to each channel. Furthermore, relative changes may occur between the transmit and receive channels during smart antenna operation. Therefore, it is necessary to detect, calibrate, and compensate for the differences and changes in transmission characteristics between the transmit and receive channels. Summary of the Invention

[0004] According to one aspect of this disclosure, a calibration circuit board for an antenna is provided. The calibration circuit board includes: a first metal layer; a first substrate disposed on the first metal layer; a second substrate disposed on the first substrate; and a plurality of couplers. Each coupler includes: a transmission line having an input port and an output port at corresponding ends; and a coupling line coupled to the transmission line and including two first portions located on opposite sides of the transmission line when viewed perpendicularly to the calibration circuit board, and a second portion connected between the two first portions. The coupling lines of the plurality of couplers are connected in series to provide a first calibration port and a second calibration port. One of the transmission line and the coupling line of the plurality of couplers is disposed between the first substrate and the second substrate, and the other of the transmission line and the coupling line of the plurality of couplers is disposed on the second substrate.

[0005] In some embodiments, the coupling lines of the plurality of couplers are disposed between the first substrate and the second substrate, and the transmission lines of the plurality of couplers are disposed on the second substrate.

[0006] In some embodiments, a first portion of the coupling line of at least one of the plurality of couplers shares a common portion with the first portion of the coupling line of an adjacent coupler among the plurality of couplers.

[0007] In some embodiments, the transmission lines of each of the plurality of couplers are parallel to each other, and two first portions of the coupling line of each of the plurality of couplers are coupled parallel to the transmission line of that coupler.

[0008] In some embodiments, the transmission line of each of the plurality of couplers is located between the two first portions of the coupling line of that coupler.

[0009] In some embodiments, the calibration circuit board is configured to operate on radio frequency signals in a first frequency band, and wherein at least one of the first portions of the coupling lines of each of the plurality of couplers has a length equal to one-quarter wavelength of the center frequency of the first frequency band.

[0010] In some embodiments, the length of the second portion of the coupling line of each of the plurality of couplers is configured to meet impedance matching requirements.

[0011] In some embodiments, when viewed from a direction perpendicular to the calibration circuit board, the transmission lines of the multiple couplers extend beyond the area where the coupling lines of the multiple couplers are located.

[0012] In some embodiments, all input ports of the transmission lines of the multiple couplers are located on the first side of the region where the coupling lines of the multiple couplers are located, and all output ports of the transmission lines of the multiple couplers are located on the second side of the region where the coupling lines of the multiple couplers are located.

[0013] In some embodiments, the calibration circuit board further includes: a third substrate disposed on the second substrate such that the transmission line and the other of the multiple couplers are located between the second substrate and the third substrate; and a second metal layer disposed on the third substrate.

[0014] In some embodiments, the calibration circuit board is implemented as a multilayer printed circuit board.

[0015] In some embodiments, the transmission lines and coupling lines of the plurality of couplers are metal traces formed on the upper and lower sides of the second substrate, respectively.

[0016] In some embodiments, the calibration circuit board does not include a second substrate, such that the transmission lines and coupling lines of the multiple couplers are disposed together between the first substrate and the third substrate.

[0017] According to another aspect of this disclosure, an antenna device is provided, comprising: a plurality of radiating elements; a plurality of radio frequency ports; and a calibration circuit board according to any embodiment of this disclosure, wherein the input port of each coupler of the calibration circuit board is connected to a corresponding radio frequency port among the plurality of radio frequency ports, and the output port of each coupler of the calibration circuit board is connected to a corresponding radiating element among the plurality of radiating elements.

[0018] Other features and advantages of this disclosure will become clearer from the following detailed description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0019] The foregoing and other features and advantages of this disclosure will become clear from the following description of embodiments illustrated in conjunction with the accompanying drawings. The drawings, incorporated herein and forming a part of the specification, are further used to explain the principles of this disclosure and to enable those skilled in the art to make and use it. Wherein:

[0020] Figure 1 This is an exploded view of a calibration circuit board according to some embodiments of the present disclosure;

[0021] Figure 2 yes Figure 1 Top view of the calibration circuit board;

[0022] Figure 3 yes Figure 1 An enlarged schematic diagram of the coupler included in the calibration circuit board;

[0023] Figure 4 This is an exploded view of a calibration circuit board according to some embodiments of the present disclosure;

[0024] Figure 5 yes Figure 4 Top view of the calibration circuit board;

[0025] Figure 6 yes Figure 4 An enlarged schematic diagram of the coupler included in the calibration circuit board;

[0026] Figure 7 This is an exploded view of a calibration circuit board according to some embodiments of the present disclosure;

[0027] Figure 8 This is an exploded view of a calibration circuit board according to some embodiments of the present disclosure;

[0028] Figure 9 This is an exploded view of a calibration circuit board according to some embodiments of the present disclosure; and

[0029] Figure 10 This is a schematic diagram of the structure of an antenna device according to some embodiments of the present disclosure.

[0030] Note that in the embodiments described below, the same reference numerals are sometimes used across different figures to denote the same parts or parts with the same function, and repeated descriptions are omitted. In some cases, similar reference numerals and letters are used to denote similar items, so once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0031] For ease of understanding, the positions, dimensions, and extents of the structures shown in the accompanying drawings and other materials may not represent actual positions, dimensions, and extents. Therefore, this disclosure is not limited to the positions, dimensions, and extents disclosed in the accompanying drawings and other materials. Detailed Implementation

[0032] Various exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the present disclosure.

[0033] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the scope of this disclosure or its application or use. That is, the structures and methods herein are shown in an exemplary manner to illustrate different embodiments of the structures and methods in this disclosure. However, those skilled in the art will understand that they merely illustrate exemplary ways that can be used to implement this disclosure, and not exhaustive ways. Furthermore, the drawings are not necessarily drawn to scale, and some features may be enlarged to show details of specific components.

[0034] In addition, techniques, methods and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods and equipment should be considered part of the specification.

[0035] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0036] A calibration network for a beamforming antenna can be used (potentially in real time) to monitor the power and phase of the RF signal input at each port of the smart antenna to ensure that the relative amplitude and phase of the RF signal received at different ports are correct. This allows the antenna to operate with the optimal broadcast and service beams for optimal communication. Therefore, the design of the calibration network is critical to the entire smart antenna.

[0037] With the rapid development of antenna technology, the number of RF ports and radiating elements in antennas is increasing. For example, for 5G massive MIMO (Multiple-Input Multiple-Output) antennas, the number of RF ports will increase from 8 to 16 or even more. Calibration circuit boards require more couplers to cope with the increased number of RF ports and radiating elements, making conventionally designed calibration circuit boards larger and less capable of meeting the requirements for high antenna integration and miniaturization.

[0038] Furthermore, the calibration network itself may introduce amplitude / phase inconsistencies. When channel inconsistencies are observed at the calibration port, it is impossible to determine whether the source of the discrepancy is the beamforming network and / or other feed networks between the RF transceiver and the radiating element, or the calibration network between the radiating element and the calibration port.

[0039] One aspect of this disclosure provides a calibration circuit board comprising: a first metal layer; a first substrate disposed on the first metal layer; a second substrate disposed on the first substrate; and a plurality of couplers. Each coupler includes: a transmission line having an input port and an output port at corresponding ends; and a coupling line coupled to the transmission line and including two first portions located on opposite sides of the transmission line when viewed perpendicularly to the calibration circuit board, and a second portion connected between the two first portions. The coupling lines of the plurality of couplers are connected in series to provide a first calibration port and a second calibration port. One of the transmission lines and coupling lines of the plurality of couplers is disposed between the first substrate and the second substrate, and the other of the transmission lines and coupling lines of the plurality of couplers is disposed on the second substrate.

[0040] The calibration circuit board according to this disclosure can be used to perform initial calibration of an antenna as well as continuous monitoring and adjustment during normal use of the antenna. The calibration circuit board according to this disclosure has multiple couplers connected in series with their coupling lines to provide two independent calibration ports, which not only significantly reduces the size compared to conventional parallel calibration configurations but also eliminates channel variability introduced by the calibration circuit board itself, thereby more accurately detecting amplitude / phase inconsistencies caused by the transmit / receive channels. Furthermore, the transmission lines and coupling lines of the multiple couplers included in the calibration circuit board according to this disclosure are arranged on different layers, wherein the calibration signal is coupled from the transmission line of the coupler to the coupling line through one of the substrates. Since the transmission lines and coupling lines of the couplers can be arranged in separate, corresponding layers, the transmission lines and coupling lines can each have a more compact arrangement, thereby further reducing the size of the calibration circuit board.

[0041] Now for reference Figures 1 to 3 The present disclosure provides a detailed description of a calibration circuit board 100 according to some embodiments thereof. It should be noted that an actual calibration circuit board may contain other components, but these are not shown in the accompanying drawings and will not be discussed herein in order to avoid obscuring the essential points of the disclosure.

[0042] like Figure 1 As shown, the calibration circuit board 100 may include a first metal layer 101, a first substrate 102, and a second substrate 103. The first metal layer 101 may be configured to be grounded (i.e., attached to a ground reference voltage). The first substrate 102 is disposed on the first metal layer 101. The second substrate 103 is disposed on the first substrate 102.

[0043] Reference Figure 2 The calibration circuit board 100 may include multiple couplers. For example, Figure 2 The calibration circuit board 100 is schematically shown to include 16 couplers 110-1, 110-2, 110-3, ..., 110-16, but this is merely an example and is not intended to limit the present disclosure. It is understood that the calibration circuit board 100 may be provided with more or fewer couplers as needed. For example, the number of couplers included in the calibration circuit board 100 may depend on the specific number of ports and / or radiating elements in the applied antenna array. Hereinafter, couplers 110-1, 110-2, 110-3, ..., 110-16 may be collectively referred to as "coupler 110".

[0044] Multiple couplers 110 can have individual transmission lines 111 and coupling lines 112 connected in series. From Figure 1 and Figure 2As can be seen, the coupling lines 112 of multiple couplers 110 are connected in series. The first end of the first coupler 110-1 serves as the first calibration port 120a, and the second end of the last coupler 110-16 serves as the second calibration port 120b. The first calibration port 120a and the second calibration port 120b can provide outputs independently of each other. By connecting the coupling lines 112 of multiple couplers 110 in series, the calibration circuit board 100 is able to obtain the coupling amount of the input signal at both the first calibration port 120a and the second calibration port 120b when a signal is input to the input port of any coupler 110. These two coupling amounts are obtained by the input signal being coupled and propagated through two different paths, each path being independent of the other. For example, for each transmit channel connected to the corresponding coupler, the amplitude / phase coherence between the transmit channels can be determined by comparing the outputs of the first calibration port 120a and the second calibration port 120b. The specific calibration algorithm can employ any suitable algorithm known in the art or developed hereafter, without being particularly limited by this disclosure. The two independent calibration ports 120a and 120b can be used to eliminate channel differences introduced by the calibration board itself, thereby more accurately detecting amplitude / phase inconsistencies caused by the transmit / receive channels.

[0045] The transmission lines 111 and coupling lines 112 of the multiple couplers 110 can be arranged on different layers. One of the transmission lines 111 and coupling lines 112 of the multiple couplers 110 can be disposed between the first substrate 102 and the second substrate 103, and the other of the transmission lines 111 and coupling lines 112 of the multiple couplers 110 can be disposed on the second substrate 103. Figure 1 In the non-limiting example shown, the coupling lines 112 of the plurality of couplers 110 of the calibration circuit board 100 are disposed between the first substrate 102 and the second substrate 103, and the transmission lines 111 of the plurality of couplers 110 are disposed on the second substrate 103.

[0046] Because the transmission lines and coupling lines of multiple couplers are arranged on different layers in the calibration circuit board 100, the calibration circuit board can have a more compact layout. Compared to a conventional 16-port series calibration circuit board, the area of ​​the calibration circuit board 100 can be reduced by 40%. The calibration signal can be coupled from the transmission line 111 of the coupler 110 to the coupling line 112 through the second substrate 103.

[0047] In some embodiments, the first metal layer 101 may be in the form of a metal plate. In some embodiments, the first metal layer 101 may be deposited on the lower surface of the first substrate 102 by means such as electroplating. In some embodiments, the first substrate 102 and the second substrate 103 may be in the form of dielectric plates. In some embodiments, the thickness of the second substrate 103 may be between 20 mil and 40 mil (e.g., 30 mil). The thickness of the second substrate 103 may be specifically set in consideration of factors such as the coupling strength requirements between the transmission line and the coupling line. In some embodiments, the transmission line 111 and the coupling line 112 may be any of a stripline, a microstrip line, and other transmission lines. In some embodiments, the transmission line 111 and the coupling line 112 may be formed of a conductive material. In some embodiments, the transmission line 111 and the coupling line 112 may be made of a metal such as copper.

[0048] For example, with Figure 1 Taking the calibration circuit board 100 shown as an example, in some embodiments, the transmission line 111 and the coupling line 112 can be made of metal foil such as copper foil, and the coupling line 112 disposed between the first substrate 102 and the second substrate 103 can be simultaneously bonded (e.g., by adhesive) to the upper surface of the first substrate 102 and the lower surface of the second substrate 103, while the transmission line 111 disposed on the second substrate 103 can be bonded (e.g., by adhesive) to the upper surface of the second substrate 103. In some embodiments, the first substrate 102 can be a double-sided metal-bonded dielectric substrate, for example, a double-sided copper-bonded dielectric substrate. In such embodiments, the lower surface of the double-sided metal-bonded dielectric substrate 102 can be considered as the first metal layer 101 for grounding of the calibration circuit board 100, and the metal on the upper surface of the double-sided metal-bonded dielectric substrate 102 can be etched to form the coupling line 112. In some embodiments, the second substrate 103 can be a double-sided metal-bonded dielectric substrate, for example, a double-sided copper-bonded dielectric substrate. In such embodiments, the metal on the lower surface of the double-sided metal-bonded dielectric substrate 103 can be etched to form coupling lines 112, and the metal on the upper surface of the double-sided metal-bonded dielectric substrate 103 can be etched to form transmission lines 111. In some embodiments, the transmission lines and coupling lines of the plurality of couplers can be metal traces formed on the upper and lower sides of the second substrate, respectively. In embodiments where the transmission lines and coupling lines are formed on different surfaces of the second substrate, when the main functional components of the calibration circuit board 100, such as the couplers, fail, only the second substrate can be replaced without replacing the first substrate and the first metal layer, thereby facilitating repair and / or maintenance and saving costs.

[0049] Next, refer to Figure 3The structure of coupler 110 is described in detail below. Each coupler 110 may include a transmission line 111 and a coupling line 112. An input port 111a and an output port 111b are provided at corresponding ends of the transmission line 111. The transmission line 111 can be used to transmit signals between a corresponding RF port and a radiating element. The input port 111a can be used to receive RF signals, for example, from a beamforming network or other feed network, and then the RF signals are transmitted to the corresponding radiating element via the output port 111b. The coupling line 112 is coupled to the transmission line 111 and includes two first portions (also referred to as coupling portions) 112a and 112c located on both sides of the transmission line 111 when viewed from a direction perpendicular to the calibration board, and a second portion (also referred to as a connection portion) 112b connected between the two first portions 112a and 112c.

[0050] The coupling between transmission line 111 and the first portions 112a and 112c of coupling line 112 can be achieved using various known coupling techniques. For example, Figure 3 As shown, transmission line 111 can be parallel to the first portions 112a and 112c of coupling line 112, respectively, thereby achieving coupling between transmission line 111 and the first portions 112a and 112c of coupling line 112 via parallel coupling through second substrate 103. In some embodiments, the transmission lines 111 of each of the plurality of couplers 110 are parallel to each other, and the two first portions 112a and 112c of the coupling line 112 of each of the plurality of couplers 110 are coupled in parallel to the transmission line 111 of that coupler 110.

[0051] In some embodiments, the coupling lines 112 of multiple couplers 110 can collectively form a continuous line. For example, from... Figure 1 and Figure 2 As seen in the diagram, the transmission lines 111 of the multiple couplers 110 are parallel to each other, and the coupling lines 112 of the multiple couplers 110 can together form a continuous serpentine line. This serpentine line has multiple parallel line segments (used as coupling parts) that are parallel to each other and parallel to the transmission lines 111, and multiple connecting line segments 112b (used as connecting parts) that connect the multiple parallel line segments end to end. Two adjacent parallel line segments can be coupled parallel to the corresponding transmission lines above to form a coupler.

[0052] In some embodiments, the transmission line 111 of each of the plurality of couplers 110 is located between two first portions of the coupling line 112 of that coupler 110. For example, as Figure 3 As shown, viewed from a direction perpendicular to the calibration circuit board 100, the transmission line 111 may be located at the midpoint of the first portions 112a and 112c of the coupling line 112. In some embodiments, see, for example, [reference needed]. Figure 2Viewed from a direction perpendicular to the calibration circuit board 100, the transmission lines 111 of the multiple couplers 110 extend beyond the area where the coupling lines 112 of the multiple couplers 110 are located. This has the advantage that the pads formed by providing input and output ports at opposite ends of the transmission lines 111 are located outside the area where the coupling lines 112 of the multiple couplers 110 are located, and not within the area enclosed by the first and second portions of the coupling lines, resulting in better amplitude flatness of the coupling.

[0053] The effective coupling length L of the transmission line 111 and coupling line 112 of coupler 110 can be the projected length of transmission line 111 on a first portion of coupling line 112. In some embodiments, the effective coupling length L of coupler 110 can be equal to a quarter wavelength of the RF signal provided to transmission line 111 of coupler 110. Figure 2 In the example shown, the effective coupling length L of the transmission line 111 and coupling line 112 of coupler 110 is the length of the first portion of coupling line 112. In some embodiments, the calibration circuit board 100 is configured to operate on RF signals in a first frequency band, and the length of at least one of the first portions of the coupling line 112 of each of the plurality of couplers 110 is equal to a quarter wavelength of the center frequency of the first frequency band. In some embodiments, the length of the first portion of the coupling line 112 of each of the plurality of couplers 110 is equal to a quarter wavelength of the RF signal provided to the transmission line 111 of that coupler 110. For example, see... Figure 3 The length of the first portions 112a and 112c of the coupling line 112 can be set to be one-quarter wavelength of the RF signal input to the transmission line 111 at the input port 111a. In some embodiments, such as those described later... Figure 5 In this context, the effective coupling length L can be less than the length of the first part of the coupling line 112. It is understood that the effective coupling length L of the coupler 110 can be set according to specific requirements such as the coupling strength of the coupler.

[0054] The shape of the second portion 112b is not particularly limited. In some embodiments, the length of the second portion 112b can be designed to meet impedance matching requirements. In some examples, the length of the second portion 112b is designed to provide an impedance of 50 ohms. When a signal is input to the input port 111a of the coupler 110, signal coupling occurs only on the first portions 112a, 112c of the coupling lines 112, while there is no power output on the second portion 112b.

[0055] Next, refer to the references. Figure 2 and Figure 3This describes the process by which the coupling amount of a signal reaches the calibration port via two different paths when a signal is provided to coupler 110. Taking coupler 110-2 as an example, when a signal is input from input port 111a of coupler 110-2, coupling amounts are obtained at the first portions 112a and 112c of the coupling line of coupler 110-2, respectively. Next, the main energy of the coupling amount obtained at the first portion 112a of the coupling line of coupler 110-2 sequentially reaches the first calibration port 120a through the coupling line of coupler 110-1, and the main energy of the coupling amount obtained at the first portion 112c of the coupling line of coupler 110-2 sequentially reaches the second calibration port 120b through the coupling lines of couplers 110-3 to 110-16. The individual couplers 110 do not need to guarantee complete consistency in circuit structure, because such differences in circuit structure can be eliminated in the calibration algorithm based on the two sets of coupling amounts at the first calibration port 120a and the second calibration port 120b.

[0056] In some embodiments, all input ports and all output ports of the transmission lines of the plurality of couplers are located on the same side relative to the region where the coupling lines of the plurality of couplers are located. In some embodiments, all input ports of the transmission lines of the plurality of couplers are located on a first side of the region where the coupling lines of the plurality of couplers are located, and all output ports of the transmission lines of the plurality of couplers are located on a second side of the region where the coupling lines of the plurality of couplers are located. For example, in Figure 2 In the non-limiting example shown, all input ports of the transmission lines of the multiple couplers are close to each other. Figure 2 The top side, and all output ports are close to Figure 2 The lower side. The advantage of this is that the input ports are all concentrated on one side of the base, making it easy to connect to other components.

[0057] In some embodiments, a first portion of the coupling line of at least one of the plurality of couplers 110 shares a portion with the first portion of the coupling line of an adjacent coupler among the plurality of couplers 110. Figures 4 to 6 A calibration circuit board 200 according to some embodiments of the present disclosure is shown. The calibration circuit board 200 differs from the calibration circuit board 100 in that the first portion of the coupling line of one of the plurality of couplers of the calibration circuit board 200 shares a portion with the first portion of the coupling line of an adjacent coupler among the plurality of couplers. Apart from this, the calibration circuit board 200 may have substantially the same configuration as the calibration circuit board 100, and therefore the above discussion regarding the calibration circuit board 100 also applies to the calibration circuit board 200, and will not be repeated here.

[0058] like Figure 4As shown, the calibration circuit board 200 may include a first metal layer 201, a first substrate 202 disposed on the first metal layer 201, and a second substrate 203 disposed on the first substrate 202. The calibration circuit board 200 may also include a coupling line 212 disposed between the first substrate 202 and the second substrate 203, and a transmission line 211 disposed on the second substrate 203. (Refer to reference...) Figure 5 The calibration circuit board 200 includes multiple couplers 210-1, 210-2, 210-3, ..., 210-16 (hereinafter sometimes collectively referred to as couplers 210). The coupling lines of the multiple couplers 210 are connected in series to provide two independent calibration ports 220a and 220b.

[0059] The first portion of the coupling lines of adjacent couplers in the plurality of couplers of the calibration circuit board 200 has a common part. See below for reference. Figure 6 The following description uses adjacent couplers 210-1 and 210-2 as examples. Coupler 210-1 includes a transmission line 211-1, with an input port 211-1a and an output port 211-1b provided at both ends of the transmission line 211-1. Coupler 210-2 includes a transmission line 211-2, with an input port 211-2a and an output port 211-2b provided at both ends of the transmission line 211-2. Furthermore, the coupling line of coupler 210-1 includes two first portions 212a and 212c located on both sides of its transmission line 211-1 when viewed from a direction perpendicular to the calibration circuit board 200, and a second portion 212b connected between the two first portions 212a and 212c. The coupling line of coupler 210-2 includes two first portions 212c and 212e located on both sides of its transmission line 211-2 when viewed from a direction perpendicular to the calibration circuit board 200, and a second portion 212d connected between the two first portions 212c and 212e. Coupler 210-1 and coupler 210-2 share the first portion 212c. Figure 5 As shown, multiple couplers 210 are arranged in a manner similar to Figure 6 The method shown allows for the sharing of coupling lines in a series connection. Because there is a shared portion between the first parts of the coupling lines of adjacent couplers, the arrangement of the couplers can be more compact, reducing the size of the calibration circuit board. Furthermore, since the path from the input port to the calibration port is shortened, the insertion loss at the calibration port relative to the input port is also reduced.

[0060] In some embodiments, the calibration circuit board according to the present disclosure may further include: a third substrate disposed on the second substrate such that one of the transmission lines and coupling lines of the plurality of couplers disposed on the second substrate is located between the second substrate and the third substrate; and a second metal layer disposed on the third substrate.

[0061] For example, such as Figure 7 The calibration circuit board 100' shown further includes, compared to the calibration circuit board 100, a third substrate 104 disposed on the second substrate 103 and a second metal layer 105 disposed on the third substrate 104, wherein the transmission line 111 is disposed between the second substrate 103 and the third substrate 104. Figure 8 The calibration circuit board 200' shown further includes, compared to calibration circuit board 200, a third substrate 204 disposed on the second substrate 203 and a second metal layer 205 disposed on the third substrate 204, wherein transmission lines 211 are disposed between the second substrate 203 and the third substrate 204. The second metal layers 105 and 205 can be configured to be grounded (i.e., attached to a ground reference voltage). The third substrates 104 and 204 can be similar to the first and second substrates as described above, and the second metal layers 105 and 205 can be similar to the first metal layer as described above, and therefore will not be described further here. Compared to the open design of calibration circuit boards 100 and 200 where transmission lines are exposed to the outside, the closed design of calibration circuit boards 100' and 200' is more resistant to external interference, especially at higher signal frequencies, which reduces signal amplitude / phase fluctuations.

[0062] In some embodiments, the calibration circuit board can be implemented as a multilayer printed circuit board. In some embodiments, the calibration circuit board can be implemented comprising three separate boards, wherein the first board may include a first metal layer and a first substrate, the second board may include coupling lines, a second substrate, and transmission lines, and the third board may include a third substrate and a second metal layer. For example, as a non-limiting example, the first and third boards may be dielectric boards with metal layers deposited on their surfaces, and the second board may be a dielectric board with metal lines formed on its top and bottom sides. When a major functional component of the calibration circuit board, such as a coupler, fails, only the second board can be replaced without replacing the first and third boards, thereby facilitating repair and / or maintenance and saving costs.

[0063] In some embodiments, the calibration circuit board including the third substrate may not include the second substrate, such that the transmission lines and coupling lines of multiple couplers are shared between the first and third substrates. For example, Figure 9 As shown, the difference between calibration circuit board 300 and calibration circuit board 200' is that it does not include the second substrate 203. For example... Figure 9As shown, the calibration circuit board 300 includes a first metal layer 301, a first substrate 302 disposed on the first metal layer 301, a third substrate 304 disposed on the first substrate 302, and a second metal layer 305 disposed on the third substrate 304. Multiple coupler transmission lines 311 and coupling lines 312 are jointly disposed between the first substrate 302 and the third substrate 304. This enclosed design resists external interference, especially at higher signal frequencies, thereby reducing signal amplitude / phase fluctuations.

[0064] Another aspect of this disclosure provides an antenna device comprising: a plurality of radiating elements; a plurality of RF ports; and a calibration circuit board according to any embodiment of this disclosure, wherein the input ports of each coupler of the calibration circuit board are connected to a corresponding RF port among the plurality of RF ports, and the output ports of each coupler of the calibration circuit board are connected to a corresponding radiating element among the plurality of radiating elements.

[0065] Now for reference Figure 10 Antenna device 400 according to some embodiments of the present disclosure is described. It should be noted that actual antenna devices may have other components, but these are not shown in the drawings and will not be discussed herein in order to avoid obscuring the key points of the present disclosure.

[0066] Antenna device 400 may include RF processing module 401, calibration circuit board 402, and antenna array 403. Antenna array 403 may include multiple radiating elements 403-1, 403-2, ..., 403-n (n is a positive integer), each radiating element may include one radiating element or a vertically arranged column of multiple radiating elements. RF processing module 401 typically includes antenna interface unit, RF transceiver, beamforming network, etc. For example, when antenna device 400 operates in transmit mode, antenna interface unit can receive the signal to be transmitted from baseband unit, divide the signal into multiple identical sub-components (e.g., the number of sub-components may be equal to the number of radiating elements 403-1, 403-2, ..., 403-n), apply a predetermined gain and phase to each sub-component, and then provide each sub-component to the corresponding RF transceiver. The individual sub-components of the signal are converted into analog signals at the RF transceiver and then reach the corresponding radiating element via the beamforming network. The signals radiated from the radiating elements are interferometrically superimposed to form the desired beam pattern. The RF processing module 401 provides multiple RF ports 401-1, 401-2, ..., 401-n (n is a positive integer) to provide signals to multiple radiating elements 403-1, 403-2, ..., 403-n respectively.

[0067] The calibration circuit board 402 can be any of the calibration circuit boards according to this disclosure, and it can be disposed between the RF processing module 401 and the antenna array 403. The calibration circuit board 402 may include a plurality of couplers 402-1, 402-2, ..., 402-n (n is a positive integer). The coupling lines of the plurality of couplers 402-1, 402-2, ..., 402-n are connected in series with each other. Figure 10 (Not specifically described in the text). The input ports 402-1a, 402-2a, ..., 402-na of each coupler 402-1, 402-2, ..., 402-n of the calibration circuit board 402 can be connected to the corresponding RF ports among the multiple RF ports 401-1, 401-2, ..., 401-n, and the output ports 402-1b, 402-2b, ..., 402-nb of each coupler 402-1, 402-2, ..., 402-n of the calibration circuit board can be connected to the corresponding radiation units among the multiple radiation units 403-1, 403-2, ..., 403-n.

[0068] For example, to calibrate the transmission channel, calibration test signals are transmitted from RF ports 401-1, 401-2, ..., 401-n to radiating units 403-1, 403-2, ..., 403-n. A portion of the power of the calibration test signals transmitted on the transmission channel is extracted via couplers 402-1, 402-2, ..., 402-n of the calibration circuit board 402 and output from the calibration port of the calibration circuit board.

[0069] The gain and phase of all transmit / receive channels of the antenna device 400 can be accurately monitored and adjusted, thereby enabling the formation of a desired beam pattern. Furthermore, the antenna device 400 according to embodiments of this disclosure can achieve a large number of ports while maintaining a small size, meeting the requirements of high antenna integration and miniaturization.

[0070] The terms “left,” “right,” “front,” “back,” “top,” “bottom,” “upper,” “lower,” “high,” “lower,” etc., used in the specification and claims, if present, are for descriptive purposes and not necessarily for describing unchanging relative positions. It should be understood that such terms are interchangeable where appropriate, enabling the embodiments of this disclosure described herein to operate, for example, in orientations different from those shown or otherwise described herein. For example, when the device in the drawings is reversed, a feature previously described as “above” other features may now be described as “below” other features. The device may also be oriented in other ways (rotated 90 degrees or in other orientations), in which case the relative spatial relationships will be interpreted accordingly.

[0071] In the specification and claims, when an element is described as being "on top of," "attached to," "connected to," "coupled to," or "in contact with" another element, the element may be directly located on top of, directly attached to, directly connected to, directly coupled to, or directly in contact with the other element, or one or more intermediate elements may be present. Conversely, when an element is described as being "directly" located on top of, directly attached to, directly connected to, directly coupled to, or directly in contact with another element, no intermediate elements are present. In the specification and claims, when a feature is arranged "adjacent" to another feature, it may mean that a feature has a portion overlapping with the adjacent feature or a portion located above or below the adjacent feature.

[0072] As used herein, the term "exemplary" means "serving as an example, instance, or illustration," and not as a "model" to be precisely copied. Any implementation described herein by example is not necessarily to be construed as preferred or advantageous over other implementations. Furthermore, this disclosure is not limited to any theory expressed or implied as given in the art, background, summary of the invention, or detailed description.

[0073] As used herein, the term "substantially" means any minor variation resulting from design or manufacturing defects, device or component tolerances, environmental influences, and / or other factors. The term "substantially" also allows for differences from the perfect or ideal situation due to parasitic effects, noise, and other practical considerations that may exist in the actual implementation.

[0074] Additionally, terms such as “first,” “second,” etc., may be used in this document for reference purposes only and are not intended to be limiting. For example, unless the context clearly indicates otherwise, the words “first,” “second,” and other such numerical terms relating to structures or elements do not imply order or sequence.

[0075] It should also be understood that when the term “including / contains” is used herein, it indicates the presence of the indicated feature, whole, step, operation, unit and / or component, but does not preclude the presence or addition of one or more other features, wholes, steps, operations, units and / or components and / or combinations thereof.

[0076] In this disclosure, the term “provide” is used broadly to cover all ways of obtaining an object, and therefore “provide an object” includes, but is not limited to, “purchasing,” “preparing / manufacturing,” “arranging / setting up,” “installing / assembling,” and / or “ordering” an object.

[0077] As used herein, the term “and / or” includes any and all combinations of one or more of the listed items in association. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of this disclosure. As used herein, the singular forms “a,” “an,” and “the” are also intended to include the plural forms unless the context clearly indicates otherwise.

[0078] Those skilled in the art will recognize that the boundaries between the above operations are merely illustrative. Multiple operations may be combined into a single operation, a single operation may be distributed among additional operations, and operations may be performed with at least partial overlap in time. Moreover, alternative embodiments may include multiple instances of a particular operation, and the order of operations may be changed in various other embodiments. However, other modifications, variations, and substitutions are equally possible. Aspects and elements of all the embodiments disclosed above may be combined in any way and / or in combination with aspects or elements of other embodiments to provide multiple additional embodiments. Therefore, this specification and the accompanying drawings should be considered illustrative rather than restrictive.

[0079] This disclosure may include examples such as:

[0080] 1. A calibration circuit board for an antenna, comprising:

[0081] First metal layer;

[0082] A first substrate disposed on the first metal layer;

[0083] A second base disposed on the first base; and

[0084] Multiple couplers, each coupler including:

[0085] The transmission line has input and output ports at its respective ends; and

[0086] A coupling line, coupled to the transmission line, includes two first portions located on opposite sides of the transmission line when viewed from a direction perpendicular to the calibration circuit board, and a second portion connecting the two first portions.

[0087] The coupling lines of the plurality of couplers are connected in series to provide a first calibration port and a second calibration port.

[0088] In this configuration, one of the transmission lines and coupling lines of the plurality of couplers is disposed between the first substrate and the second substrate, and the other of the transmission lines and coupling lines of the plurality of couplers is disposed on the second substrate.

[0089] 2. The calibration circuit board according to Example 1, wherein the coupling lines of the plurality of couplers are disposed between the first substrate and the second substrate, and the transmission lines of the plurality of couplers are disposed on the second substrate.

[0090] 3. The calibration circuit board according to Example 1, wherein a first portion of the coupling line of at least one of the plurality of couplers shares a common portion with a first portion of the coupling line of an adjacent coupler among the plurality of couplers.

[0091] 4. The calibration circuit board according to Example 1, wherein the transmission lines of each of the plurality of couplers are parallel to each other, and two first portions of the coupling line of each of the plurality of couplers are coupled parallel to the transmission line of that coupler.

[0092] 5. The calibration circuit board according to Example 4, wherein the transmission line of each of the plurality of couplers is located between the two first portions of the coupling line of the coupler.

[0093] 6. The calibration circuit board according to Example 4, wherein the calibration circuit board is configured to operate on radio frequency signals in a first frequency band, and wherein at least one of the first portions of the coupling lines of each of the plurality of couplers has a length equal to one-quarter wavelength of the center frequency of the first frequency band.

[0094] 7. The calibration circuit board according to Example 4, wherein the length of the second portion of the coupling line of each of the plurality of couplers is configured to meet impedance matching requirements.

[0095] 8. The calibration circuit board according to Example 1, wherein, viewed from a direction perpendicular to the calibration circuit board, the transmission lines of the plurality of couplers extend beyond the area where the coupling lines of the plurality of couplers are located.

[0096] 9. The calibration circuit board according to Example 8, wherein all input ports of the transmission lines of the plurality of couplers are located on a first side of the region where the coupling lines of the plurality of couplers are located, and all output ports of the transmission lines of the plurality of couplers are located on a second side of the region where the coupling lines of the plurality of couplers are located.

[0097] 10. The calibration circuit board according to any one of Examples 1 to 9 further includes:

[0098] A third substrate is disposed on the second substrate such that the transmission line and the other of the coupling lines of the plurality of couplers are located between the second substrate and the third substrate; and

[0099] A second metal layer is disposed on the third substrate.

[0100] 11. The calibration circuit board according to Example 10, wherein the calibration circuit board is implemented as a multilayer printed circuit board.

[0101] 12. The calibration circuit board according to Example 10, wherein the transmission lines and coupling lines of the plurality of couplers are metal traces formed on the upper and lower sides of the second substrate, respectively.

[0102] 13. The calibration circuit board according to Example 10, wherein the calibration circuit board does not include the second substrate, such that the transmission lines and coupling lines of the plurality of couplers are disposed together between the first substrate and the third substrate.

[0103] 14. An antenna device, comprising:

[0104] Multiple radiating units;

[0105] Multiple RF ports; and

[0106] The calibration circuit board according to any one of Examples 1 to 13,

[0107] The input ports of each coupler on the calibration circuit board are connected to the corresponding radio frequency ports among the plurality of radio frequency ports, and the output ports of each coupler on the calibration circuit board are connected to the corresponding radiation units among the plurality of radiation units.

[0108] While specific embodiments of this disclosure have been described in detail by way of example, those skilled in the art should understand that the examples are for illustrative purposes only and not intended to limit the scope of this disclosure. The various embodiments disclosed herein can be combined in any way without departing from the spirit and scope of this disclosure. Those skilled in the art should also understand that various modifications can be made to the embodiments without departing from the scope and spirit of this disclosure. The scope of this disclosure is defined by the appended claims.

Claims

1. A calibration circuit board for an antenna, the calibration circuit board comprising: a first metal layer; a first substrate disposed on the first metal layer; a second substrate disposed on the first substrate; and a plurality of couplers each comprising: a transmission line provided with an input port and an output port at respective ends thereof; and a coupling line coupled with the transmission line and comprising two first portions respectively located on two sides of the transmission line as seen from a direction perpendicular to the calibration circuit board and a second portion connected between the two first portions, wherein the coupling lines of the plurality of couplers are connected in series to provide a first calibration port and a second calibration port, wherein one of the transmission lines and the coupling lines of the plurality of couplers is disposed between the first substrate and the second substrate and the other of the transmission lines and the coupling lines of the plurality of couplers is disposed on the second substrate, wherein the transmission lines of the respective couplers of the plurality of couplers are parallel to each other and the two first portions of the coupling line of each coupler of the plurality of couplers are coupled with the transmission line of the coupler in parallel, wherein the first portions of the coupling lines of at least one coupler of the plurality of couplers have a common portion with the first portions of the coupling lines of an adjacent coupler of the plurality of couplers. the coupling lines of the plurality of couplers are disposed between the first substrate and the second substrate and the transmission lines of the plurality of couplers are disposed on the second substrate.

2. The calibration circuit board of claim 1, wherein, the transmission line of each coupler of the plurality of couplers is located in the middle of the two first portions of the coupling line of the coupler.

3. The calibration circuit board of claim 1, wherein, the calibration circuit board is configured to operate on radio frequency signals in a first frequency band, and wherein a length of at least one of the first portions of the coupling line of each coupler of the plurality of couplers is equal to a quarter wavelength of a center frequency of the first frequency band.

4. The calibration circuit board of claim 1, wherein, a length of the second portion of the coupling line of each coupler of the plurality of couplers is configured to satisfy an impedance matching requirement.

5. The calibration circuit board of claim 1, wherein, the transmission lines of the plurality of couplers extend beyond an area where the coupling lines of the plurality of couplers are located as seen from the direction perpendicular to the calibration circuit board.

6. The calibration circuit board of claim 1, wherein, all the input ports of the transmission lines of the plurality of couplers are respectively located on a first side of the area where the coupling lines of the plurality of couplers are located, and wherein all the output ports of the transmission lines of the plurality of couplers are respectively located on a second side of the area where the coupling lines of the plurality of couplers are located.

7. The calibration circuit board of claim 6, wherein, 8. The calibration circuit board of any one of claims 1 to 7, further comprising: a third substrate disposed on the second substrate such that the other of the transmission lines and the coupling lines of the plurality of couplers are located between the second substrate and the third substrate; and a second metal layer disposed on the third substrate. the calibration circuit board is implemented as a multi-layer printed circuit board. the transmission lines and the coupling lines of the plurality of couplers are metal traces respectively formed on upper and lower sides of the second substrate.

9. The calibration circuit board of claim 8, wherein, 11. A calibration circuit board for an antenna, the calibration circuit board comprising:

10. The calibration circuit board of claim 8, wherein, a first metal layer; a first substrate disposed on the first metal layer; ​ ​ a third substrate disposed above the first substrate, wherein there is no second substrate between the first substrate and the third substrate; a second metal layer disposed above the third substrate; and a plurality of couplers, each coupler comprising: a transmission line provided with an input port and an output port at respective ends thereof; and a coupling line coupled with the transmission line and comprising two first portions respectively located on two sides of the transmission line as seen from a direction perpendicular to the calibration circuit board and a second portion connected between the two first portions, wherein the coupling lines of the plurality of couplers are connected in series to provide a first calibration port and a second calibration port, wherein the transmission lines and the coupling lines of the plurality of couplers are collectively disposed between the first substrate and the third substrate.

12. An antenna apparatus comprising: a plurality of radiating elements; a plurality of radio frequency ports; and the calibration circuit board of any one of claims 1 to 11, wherein the input port of each coupler of the calibration circuit board is connected to a respective radio frequency port of the plurality of radio frequency ports and the output port of each coupler of the calibration circuit board is connected to a respective radiating element of the plurality of radiating elements.

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