Phased array antenna with independent signal calibration

Abstract

To provide a phased array antenna in which phase calibration for each antenna device can be managed easily and accurately.SOLUTION: An antenna device includes: a substrate; a ground plate 326 arranged in a first layer and disposed on the substrate; a first signal port 302 and a second signal port 304 arranged in a second layer adjacent to the first layer and configured to transmit a first RF signal and a second RF signal, respectively; a first feed line 312 and a second feed line 314 arranged in the second layer and connected to the first signal port and the second signal port, respectively; and a radiation element 206 disposed over the substrate. The substrate is arranged to provide a first signal channel and a second signal channel between the radiation element 206 and the first or second feed line. The first feed line and the second feed line have different line lengths. The radiation element 206 at least partially overlaps the first and second signal channels.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] (PRIORITY CLAIM AND CROSS REFERENCE) This application claims priority to U.S. Provisional Application No. 63 / 366,939, filed June 24, 2022, and U.S. Non-Provisional Application No. 18 / 065,957, filed December 14, 2022, the disclosures of which are incorporated by reference in their entireties herein.

[0002] The present invention relates to a phased array antenna. [Background technology]

[0003] In modern wireless communication technology, satellite communication has attracted much attention because it has advantages such as better signal coverage and high bandwidth compared with traditional terrestrial communication technology. It seems promising to incorporate satellite communication into general cellular terrestrial communication to increase the coverage and bandwidth of wireless communication networks. In addition, phased array antenna technology in cooperation with satellite communication is usually adopted to improve power efficiency over relatively long transmission distances. However, the phase delay of each antenna device constituting the antenna array needs to be controlled with short delay and high precision, and the cost of phased array antennas is still very high. Therefore, commercialization using satellite communication is not satisfactory. Therefore, in order to reduce its manufacturing cost, it is necessary to develop a new phased array antenna with an improved phase control design and its test method. Summary of the Invention

[0004] According to an embodiment of the present disclosure, an antenna device includes a substrate, a first ground plane arranged on the substrate, a first signal port and a second signal port arranged on a second layer adjacent to the first layer and configured to transmit a first radio frequency (RF) signal and a second RF signal, respectively, a first feed line and a second feed line arranged on the second layer and connected to the first signal port and the second signal port, respectively, and a radiating element arranged on the substrate, the substrate is arranged to provide a first signal channel and a second signal channel between the radiating element and the first or second feed line for transmitting the first and second RF signals, the first feed line and the second feed line having different line lengths, and the radiating element at least partially overlaps the first signal channel and the second signal channel in a top view.

[0005] According to an embodiment of the present disclosure, an antenna array includes a substrate and an array of antenna devices formed on the substrate, each of the antenna devices comprising a first ground plane arranged in a first layer and disposed on a first surface of the substrate, a first signal port and a second signal port arranged in a second layer adjacent to the first layer and configured to transmit a first radio frequency (RF) signal and a second RF signal, a first feed line and a second feed line arranged in the second layer and connecting to the first signal port and the second signal port, respectively, and a third layer radiating element arranged on a second surface of the substrate opposite the first surface. The first ground plane is arranged to form a first slit and a second slit in the first layer for transmitting the first and second RF signals, the first feed line and the second feed line having different line lengths, and the radiating element at least partially overlaps the first slit and the second slit in a top view.

[0006] Through the proposed phased array antenna arrangement, the phase calibration of each antenna unit of the phased array antenna can be easily and more accurately managed, and therefore the RF transmitter and receiver can be manufactured more cheaply and operate with less power, and the reliability of the devices can be improved. [Brief description of the drawings]

[0007] Aspects of the present disclosure are best understood from the following detailed description when read in conjunction with the accompanying drawings, in which: It should be noted that, in accordance with standard practice in the industry, various features have not been drawn to scale, and in fact, dimensions of various features may be arbitrarily increased or decreased for clarity of discussion.

[0008] [Figure 1] 1 is a schematic diagram illustrating a wireless communication system in a next generation communication scenario, in accordance with some embodiments of the present disclosure. [Figure 2A] 2 is a schematic perspective view of an antenna array of a user equipment transmitter or receiver according to some embodiments; [Figure 2B] 2B is a schematic cross-sectional view of the transmitter or receiver shown in FIG. 2A according to some embodiments. [Figure 2C] 2B is a schematic top view of a radio frequency (RF) chip in the transmitter or receiver shown in FIG. 2A according to some embodiments. [Diagram 3] 2B is a schematic plan view of an antenna arrangement of the transmitter or receiver shown in FIG. 2A according to some embodiments. [Figure 4] 4 is a close-up view of a slit of the antenna device shown in FIG. 3 according to some embodiments. [Diagram 5] 4 is a schematic top view of the slit of the antenna device shown in FIG. 3 according to some other embodiments. [Figure 6] FIG. 2 is a schematic block diagram of a phase calibration table, according to some embodiments. [Figure 7A] 1 is a schematic perspective view of an electromagnetic shielding structure according to some embodiments. [Figure 7B] 7B is a schematic cross-sectional view of the electromagnetic shielding structure shown in FIG. 7A according to some embodiments. [Figure 8] 1 is a schematic cross-sectional view of a test probe apparatus according to some embodiments. [Figure 9] 1 is a schematic flow chart of a method for testing a phased antenna array, in accordance with some embodiments. [Figure 10A] 10 is a schematic block diagram of the test operation shown in FIG. 9 according to some embodiments. [Figure 10B] 10 is a schematic block diagram of the test operation shown in FIG. 9 according to some embodiments. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] The following disclosure provides many different embodiments or examples for implementing different features of the provided subject matter. To simplify the disclosure, specific examples of components and arrangements are described below. Of course, these are merely examples and are not intended to be limiting. For example, in the following description, forming a first feature over or on a second feature may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which additional features may be formed between the first and second features such that the first and second features may not be in direct contact. Furthermore, the disclosure may repeat reference numbers and / or letters in various examples. This repetition is for simplicity and clarity, and does not in itself dictate a relationship between the various embodiments and / or configurations discussed.

[0010] Additionally, spatially relative terms such as "below," "under," "lower," "upper," "top," and the like may be used herein to describe the relationship of one element or feature to another element or feature as shown in the drawings for ease of description. The spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the drawings. The device may be otherwise oriented (e.g., rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein may likewise be interpreted accordingly.

[0011] Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the present disclosure are approximations, the numerical values ​​set forth in the specific examples are reported as precisely as possible. However, any numerical value inherently contains certain errors necessarily resulting from the standard deviation found in each testing measurement. Also, as used herein, the terms "about", "substantial", or "substantially" generally mean within 10%, 5%, 1% or 0.5% of a given value or range. Alternatively, the terms "about", "substantial", and "substantially" mean within an acceptable standard error of the mean as considered by one of ordinary skill in the art. Other than in the operating / operating examples, or unless otherwise indicated, all numerical ranges, amounts, values ​​and percentages, such as amounts of materials, durations, temperatures, operating conditions, ratios of amounts, etc., disclosed herein should be understood as being modified in all instances by the terms "about", "substantial", or "substantially". Thus, unless indicated to the contrary, the numerical parameters set forth in this disclosure and the appended claims are approximations that may be varied as desired. At the very least, each numerical parameter should be construed by applying ordinary rounding techniques in light of the number of reported significant digits. Ranges can be expressed herein as from one endpoint to another endpoint, i.e., between two endpoints. All ranges disclosed herein include the endpoints unless otherwise stated.

[0012] As used herein, the term “connected” may be interpreted as “electrically connected,” and the term “coupled” may be interpreted as “electrically coupled.” “Connected” and “coupled” may be used to indicate that two or more elements co-operate or interact with each other.

[0013] The embodiments of the present disclosure discuss a phased array antenna design suitable for terrestrial and non-terrestrial wireless communications, where the antenna structure includes two feed lines configured to provide two identical radio frequency (RF) input signals with a well-managed phase delay to generate a circularly polarized RF signal. The phased array antenna structure also includes a glass-based substrate, on which antenna components and RF chips are formed. In some embodiments, the glass-based substrate is suitable for large-scale antenna panels due to its high planarity and low cost. Furthermore, a pair of slits formed in and defined by the antenna ground is provided to couple the RF signal between the radiating element of the antenna and the pair of slits. In some embodiments, there is substantially no conductive element organized in the glass-based substrate between the radiating element of the antenna and the pair of slits, thereby saving the cost of forming a through glass via (TGV) for the antenna. The dual input RF signals of each antenna device are suitable for amplitude or phase calibration before combining the dual input RF signals and coupling them to the radiating element, or after receiving the output RF signal from the radiating element and before combining the RF signals. As a result, a highly accurate phased antenna array can be realized with a relatively simple design and low manufacturing cost.

[0014] FIG. 1 is a schematic diagram illustrating a wireless communication system 10 in a next-generation communication scenario, according to some embodiments of the present disclosure. The wireless communication system 10 includes one or more user devices 12, 14, 16, 18, a terrestrial base station 22, and a non-terrestrial base station 24. In some embodiments, the user devices 12, 14 are carried or moved by humans and are referred to as handheld devices. In some embodiments, the user device 16 is a mobile device mounted on a vehicle moving on land, such as an automobile, a train, etc. In some embodiments, the user device 18 is a user device mounted on a vessel moving on seas, rivers, etc.

[0015] In some embodiments, the terrestrial base station 22 is an example of a base station deployed in a communication network, such as a cellular communication network. The terrestrial base station 22 is configured to provide a communication network for the user devices 12, 14, and 16, which can transmit or receive information between each other through the network established by the plurality of terrestrial base stations 22. The terrestrial base station 22 may also be referred to as a low altitude platform. In some embodiments, the non-terrestrial base station 24 is an example of a communication satellite deployed in a communication satellite network. The non-terrestrial base station 24 is configured to provide a communication network for the user devices 12, 14, 16, and 18, which can transmit or receive information between each other through the satellite network. The plurality of terrestrial base stations 22 and the plurality of non-terrestrial base stations 24 can be linked together to form a combined communication network, which can provide a global communication network that covers user devices around the world, whether they are located at low altitude locations, high altitude locations, or locations not covered by the network of the terrestrial base stations 22.

[0016] To achieve the goal of a global communication network exemplified by the wireless communication system 10, the user equipment 12, 14, 16 or 18 may need to be redesigned to include a transmitter or receiver with greater communication capabilities to communicate with the non-terrestrial base station 24 located at high altitude. Among various transmitter or receiver designs, phased array antenna technology can significantly increase the transmission or reception gain with higher reliability, and is a promising solution for realizing beamforming technology suitable for satellite communication.

[0017] 2A is a schematic perspective view of an antenna array of a transmitter or receiver 200 of a user device 12, 14, 16, or 18, according to some embodiments. In some embodiments, the transmitter or receiver 200 is an RF transmitter or receiver. In some embodiments, the transmitter or receiver 200 functions as a transmitter or receiver of a terrestrial base station 22 or a non-terrestrial base station 24. In some embodiments, although not separately shown, the transmitter or receiver 200 includes a control circuit board and an RF circuit board configured to generate and control an RF signal to be transmitted by the transmitter 200 or configured to receive and control an RF signal to be received by the receiver 200. In some embodiments, each of the user devices 12, 14, 16, 18, the terrestrial base station 22, and the non-terrestrial base station 24 includes a transmitter 200 and a receiver 200 that operate at a different operating frequency (e.g., about 28 GHz and 18 GHz, respectively).

[0018] 2A, a transmitter or receiver 200 includes an antenna array formed of multiple antenna components, such as radiating elements 206, formed on a substrate 202 of an RF circuit board of the transmitter or receiver 200. In some embodiments, an exemplary antenna device 200A includes a substrate 202 and an interconnect structure 204 arranged below the substrate 202. The interconnect structure 204 has a bottom surface and the substrate 202 has a top surface. In some embodiments, an array of radiating elements 206 is formed on the top surface of the substrate 202 and multiple RF chips 208 are arranged on the bottom surface of the interconnect structure 204. The RF chips 208 may be interconnected via multiple conductive lines (not shown separately) on the bottom surface of the interconnect structure 204. In some embodiments, the conductive lines may be encapsulated by an electrically insulating material or may be exposed through a surface of the interconnect structure 204. In some embodiments, each of the antenna devices 200A of the transmitter or receiver 100 includes a patch antenna structure, and each radiating element 206 includes a patch structure of the antenna device 200A, such as a circular, elliptical or oval shape, and is referred to as an antenna patch 206 of the respective antenna device 200A.

[0019] FIG. 2B is a schematic cross-sectional view of an antenna arrangement 200A of the transmitter 200 or receiver 200 shown in FIG. 2A according to some embodiments. The cross-sectional view is taken along the cross-sectional line AA of FIG. 2A. Referring to FIG. 2B, the substrate 202 is formed of a transparent material such as glass, fused silica, silicon oxide, quartz, etc. In some embodiments, the substrate 202 separates the antenna patch 206 from the electronic circuitry of the interconnect structure 204 or the RF chip 208. In some embodiments, the RF signal is transmitted from the RF chip 208 formed on the underside of the substrate 202, through the RF circuitry formed on the interconnect structure 204, across the signal channel 212 of the transparent substrate 202, and coupled to the antenna patch 206 formed on the top side of the substrate 202. In some embodiments, the antenna patch 206 includes additional patches on the circumference of the circle or ellipse of the antenna patch 206 to generate a better field profile of the output RF signal. In some embodiments, the antenna patch 206 may be trimmed to include a truncated portion or semicircle on the circumference of the circle or ellipse of the antenna patch 206 to obtain a better field profile of the output RF signal. The signal channel 212 may be formed in the transparent material of the substrate 202. In some embodiments, the thickness of the substrate 202 is determined based on the operating frequency of the RF signal of the antenna device 200A. Since the material of the substrate 202 is transparent to the RF signal, the substrate 202 may not require a conductive member in the projection area of ​​the antenna patch 206, but still be operable to electromagnetically connect the interconnect structure 204 to the antenna patch 206.

[0020] In some other embodiments, the substrate 202 is formed of a non-transparent material such as a base semiconductor material, e.g., bulk silicon. In some embodiments, the substrate 202 includes conductive vias formed in the signal channel 212 to electrically connect the RF circuitry in the interconnect structure 204 to the antenna patch 206. As a result, the RF signal is transmitted from the RF chip 208 formed on the underside of the substrate 202, through the RF circuitry formed in the interconnect structure 204, through the conductive vias in the signal channel 212 of the non-transparent substrate 202, and to the antenna patch 206 formed on the top side of the substrate 202. In some embodiments, an insulating film is deposited between the conductive vias and the surrounding silicon material of the substrate 202 to provide better electrical insulation.

[0021] In some embodiments, the interconnect structure 204 is formed of multiple metallization layers in a stack. The metallization layers include patterned conductive lines or conductive vias that are patterned or electrically interconnected to form interconnect paths and other parts of the antenna device 200A. For example, a first metallization layer formed on the bottom surface of the substrate 202 includes a first conductive line or pad 222A. The first conductive line or pad 222A may be patterned as a ground plane, and the remaining space may be formed as a slit or aperture for coupling an RF signal to or from the antenna patch 206. In some other embodiments, the conductive line or pad 222A is formed as a signal contact for relaying the RF signal to a conductive via in the non-transparent substrate 202.

[0022] A second metallization layer is formed below the first metallization layer and includes a first conductive via, e.g., exemplary first conductive via 224A. Similarly, a third metallization layer is formed below the second metallization layer and includes a second conductive line or pad 222B, and a fourth metallization layer is formed below the third metallization layer and includes a plurality of second conductive vias, e.g., exemplary second conductive via 224B. The second conductive line 222B may be patterned to form a power line or a signal transmission line. A fifth metallization layer is formed below the fourth metallization layer and includes a third conductive line 222C. In some embodiments, a plurality of conductive pads 210 are arranged below the sixth metallization layer and electrically connect the conductive line 222C to the RF chip 208. In some embodiments, the conductive lines 222A, 222B, 222C are interconnected via the conductive vias 224A, 224B. In some embodiments, a plurality of conductive pads 210 are arranged under the sixth metallization layer to electrically connect the conductive line 222C to the RF chip 208.

[0023] It should be noted that the RF chips 208 correspond to, but may not be aligned with, their respective antenna patches 206 due to the presence of signal channels 212. The RF chips 208 are shown aligned with the antenna patches 206 for illustrative purposes only and are not intended to dictate any necessary alignment between the antenna patches 206 and their respective RF chips 208.

[0024] In some embodiments, the conductive lines 222A, 222B, 222C, and 210 and the conductive vias 224A and 224B are formed of a conductive material such as copper, tungsten, aluminum, titanium, tantalum, alloys thereof, etc. The conductive lines 222A, 222B, 222C and the conductive vias 224A, 224B are further electrically insulated by an insulating material 226A, 226B, or 226C, such as a polymer-based material, e.g., polyimide or epoxy resin.

[0025] 2C is a schematic top view of an RF chip 208 in the antenna arrangement 200A of the transmitter 200 or receiver 200 shown in FIG. 2A according to some embodiments. In an embodiment involving the transmitter 200, each RF chip 208 includes input ports for receiving an RF input signal RF_in, a power supply voltage VD, calibration data Din, a data clock signal CLK, and a synchronization clock signal SYNC. In some embodiments, each RF chip 208 includes output ports for outputting calibration data Dout and two components of the RF output signal RF_out (i.e., an in-phase RF signal RF_out_I and a quadrature RF signal RF_out_Q).

[0026] In some embodiments, the RF output signal RF_out is formed from an in-phase component RF_out_I and a quadrature component RF_out_Q, which respectively correspond to the horizontal (H)-polarized component and the vertical (V)-polarized component of the RF output signal RF_out. The separated signal components RF_out_I and RF_out_Q represent the in-phase component RF_out_I and the quadrature component RF_out_Q, which after phase calibration are to be adjusted in quadrature with each other before being combined together for transmission. The organization of separating the quadrature components of the RF output signal RF_out can assist in independently calibrating the components of the RF signal RF_in.

[0027] In embodiments involving receiver 200, each RF chip 208 includes input ports for receiving two components of an RF signal, RF_out_I and RF_out_Q, a power supply voltage VD, calibration data Din, a data clock signal CLK, and a synchronizing clock signal SYNC. In some embodiments, each RF chip 208 includes output ports for outputting calibration data Dout and an RF signal RF_in. The calibration data Din, the data clock signal CLK, and the synchronizing clock signal SYNC are collectively referred to herein as control signals.

[0028] In some embodiments, the above-mentioned control signals Din, CLK and SYNC are generated by a controller of the transmitter or receiver 200. The calibration data Din may include amplitude calibration data or phase calibration data, or both. In some embodiments, the calibration data Din is used to independently calibrate the amplitude or phase of the RF output signals RF_out_I and RF_out_Q in the transmitter 200 according to the calibration data Din before they are combined and transmitted. At this stage, the RF output signals RF_out_I and RF_out_Q are in phase with each other before being phase calibrated and output from the chip 208. In some embodiments, the calibration data Din is used to independently calibrate the amplitude or phase of the input RF signals RF_out_I and RF_out_Q in the receiver 200 after the RF signals RF_out_I and RF_out_Q are received from the antenna patch 206 and before being combined in the RF chip 208. After amplitude and phase calibration, the input RF signals RF_out_I and RF_out_Q will be made in phase with each other before they are combined and transmitted.

[0029] In some embodiments, the data clock signal CLK is used to provide a general clock for registers in the components of the RF chip 208. The frequency of the data clock signal CLK may represent the working frequency of the digital data processing in the RF chip 208. In some embodiments, the synchronous clock signal SYNC may be used to provide a clock for synchronizing the operation of the RF chip 208 and / or may be used to provide a clock for some of the registers of different stages to output the calibration data at the same clock time. The synchronous clock signal SYNC may represent the update rate of the calibration data. In some embodiments, since the control signals include a digital form, they are also referred to as digital control signals.

[0030] Figure 3 is a schematic plan view of an exemplary antenna device 200A of an antenna array in the transmitter or receiver 200 shown in Figure 2A, according to some embodiments. The cross-sectional view in Figure 2B is also taken from the cross-sectional line BB in Figure 3. In some embodiments, the antenna device 200A includes signal ports 302 and 304, which are configured as output signal ports in the transmitter 200 for transmitting an RF signal RF_in from an RF signal source via the RF chip 208 to the antenna device 200A. Alternatively, the signal ports 302 and 304 are configured as input ports in the receiver 200 for forming and receiving the RF signal RF_in from the antenna patch 206 through the RF chip 208 to a signal receiving module (not shown separately). In some embodiments, referring to FIGS. 2B and 3, the signal ports 302 and 304 are formed in a second metallization layer of the interconnect structure 204 below the first metallization layer and are electrically connected to the input / output ports of the RF signals RF_out_I and RF_out_Q of the corresponding RF chip 208, as shown in FIG. 2C.

[0031] In some embodiments, the antenna device 200A further includes a first feed line 312 and a second feed line 314 adjacent to the first feed line 312. In some embodiments, the length, width, orientation, and shape values ​​of the first feed line 312 and the second feed line 314 may be designed or adjusted during the design or manufacturing stage to match the impedance of the transmission line. In some embodiments, the first feed line 312 or the second feed line 314 is designed to have an input impedance of about 50 Ω to match the output impedance of the signal ports 302, 304.

[0032] In some embodiments, the first feed line 312 and the second feed line 314 have different lengths to provide different phases at the coupling nodes 312P and 314P of the first feed line 312 and the second feed line 314, respectively (see FIG. 2B for referencing the coupling node 314P). In some embodiments, the second feed line 314 is longer than the first feed line 312, and the length difference is designed such that the phase difference between the coupling nodes 312P and 314P is substantially 90°. In other words, the first feed line 312 and the second feed line 314 are configured to provide the same RF signal RF_in with the same initial phase at the signal ports 302 and 304 in an ideal situation. The power of the RF signal RF_in is split into two halves for the RF output signals RF_out_I and RF_out_Q. After propagating along the first and second feed lines 312 and 314, the length difference between the first and second feed lines 312 and 314 causes the RF output signals RF_out_I and RF_out_Q at the combined nodes 312P and 314P to be orthogonal to each other, or equivalently, substantially 90° out of phase with each other. In some embodiments, if a phase error is identified, a phase calibration is performed after the RF output signals RF_out_I and RF_out_Q are split and before they are fed to the first and second feed lines 312 and 314, respectively. The phase calibration is performed to compensate for the phase error between the actual phase difference between the RF output signals RF_out_I and RF_out_Q at the combined nodes 312P and 314P and the ideal phase difference, i.e., 90°. In some embodiments, the phase error may occur due to process variations or impedance mismatches in the manufacturing of the first feed line 312 and the second feed line 314, leading to an undesirable phase error between the first feed line 312 and the second feed line 314.

[0033] In some embodiments, the antenna device 200A further includes a first slit 306 and a second slit 308 formed in the first metallization layer of the interconnect structure 204. In some embodiments, the first slit 306 and the second slit 308 are formed on the lower surface of the substrate 202 and are arranged between the substrate 202 and the first feed line 312 and the second feed line 314, respectively (see FIG. 2B for reference to the second slit 308). The first slit 306 and the second slit 308 may be separated from each other to aid in signal separation and isolation. In some embodiments, the antenna device 200A also includes a local ground plate 316 that defines and laterally surrounds the first slits 306 and 308. The local ground plate 316 may include a portion that separates the first slit 306 from the second slit 308. In some embodiments, the local ground plate 316 is circular or elliptical in shape. In some embodiments, the local ground plane 316 has a truncated sector shape on its circumference to compensate for non-ideal field profiles resulting from non-ideal amplitude or phase of the RF output signals RF_out_I and RF_out_Q, even after amplitude and phase calibration.

[0034] In some embodiments, each of the first feed line 312 and the second feed line 314 has a first end (around the RF chip 208) that is connected to the signal ports 302 and 304, respectively, and a second end (around the coupling nodes 312P and 314P) that overlaps the first slit 306 and the second slit 308, respectively. In some embodiments, as shown in FIG. 3, the second end includes a protrusion that crosses the first slit 306 or the second slit 308 to meet impedance matching requirements.

[0035] The in-phase RF signal RF_out_I and the quadrature RF signal RF_out_Q are coupled to the antenna patch 206, combined, and radiated outward through the antenna patch 206. The combined RF signal RF_out from the in-phase RF signal RF_out_I and the quadrature RF signal RF_out_Q results in a circularly polarized RF signal RF_out. In some embodiments, the combined RF signal RF_out is a right-hand circularly polarized RF signal or a left-hand circularly polarized RF signal depending on the phase order of the in-phase signal RF_out_I relative to the quadrature RF signal RF_out_Q. In some embodiments, the validity of the calibration data Din plays an important role since the ideal circular polarization of the RF signal output RF_out depends on the equal amplitude and precise phase difference of 90° between the in-phase RF signal RF_out_I and the quadrature RF signal RF_out_Q. In some embodiments, the in-phase RF signal RF_out_I and the quadrature RF signal RF_out_Q are split and independently subjected to amplitude and phase calibration before being transmitted to the antenna patch 206. Alternatively, in some embodiments, the in-phase RF signal RF_out_I and the quadrature RF signal RF_out_Q are received from the antenna patch 206 and independently subjected to amplitude and phase calibration at the RF chip 208 before they are combined and transmitted from the RF chip 208. Therefore, the calibration task can be easily accomplished without complex calibration circuitry.

[0036] In some embodiments, the local ground plane 312, the first slit 306 and the second slit 308 are formed on the first metallization layer of the interconnect structure 204 by patterning a conductive layer of the first metallization layer, and the first slit 306 and the second slit 308 are formed by further patterning the local ground plane 312. The first slit 306 and the second slit 308 at least partially overlap the coupling nodes 312P and 314P, respectively, to maximize signal radiation from the first slit 306 and the second slit 308. In some embodiments, the coupling nodes 312P or 314P extend beyond the first slit 306 or the second slit 308 to form a protrusion of the first feed line 312 or the second feed line 314 for better impedance matching.

[0037] As mentioned above, the substrate 202 can be transparent or non-transparent according to the selection of the material of the substrate 202. In the depicted embodiment, the substrate 202 is formed of a transparent material such as glass, fused silica, silicon oxide, quartz, etc. Thus, the first slit 306, the second slit 308, and the portions of the substrate 202 aligned with the first slit 306 and the second slit 308 form a first signal channel and a second signal channel, respectively, as exemplified by the signal channel 212 shown in FIG. 2B. The first signal channel and the second signal channel are substantially arranged within the coverage area of ​​the antenna patch 206 of the antenna device 200A and are configured to electrically or electromagnetically couple the RF signals RF_out_I and RF_out_Q between the antenna patch 206 and the feed lines 312 and 314 through the respective first slit 306 and second slit 308, constituting the first and second signal channels.

[0038] In some embodiments, the antenna device 200A also includes a common ground plane 326 arranged in the first metallization layer. The common ground plane 326 may be separated from the local ground plane 316 by an annular opening. In some embodiments, the local ground plane 316 and the common ground plane 326 are grounded to a common ground terminal (not shown separately) of the antenna device 200A or the transmitter or receiver 200. In some embodiments, the common ground plane 326 is used to separate each antenna device 200A from adjacent antenna devices 200A. The common ground plane 326 may include a rectangular or square periphery. In some other embodiments, the common ground plane 326 is of other shapes to compensate for the electric field generated by the antenna patch 206. In some embodiments, the common ground plane 326 has four sides, and each side of the common ground plane 326 is substantially parallel to one side of the antenna array, for example along the X-axis or Y-axis, as shown in FIG. 2A and FIG. 3. In some embodiments, each side of the common ground plate 326 is substantially parallel or perpendicular to the direction of at least one section of the first slit 306 or the second slit 308, for example along the X-axis or Y-axis. In some embodiments, the four sides of the common ground plate 326 have an angle with the first slit 306 or the second slit 308, for example 45°. The four sides of the common ground plate still maintain a rectangular shape. In some embodiments, adjacent common ground plates 326 are connected to each other to form a common ground, for example via a bridge portion between adjacent common ground plates 326.

[0039] 4 is a close-up view of the first slit 306 and the second slit 308 of the antenna device 200A shown in FIG. 3 according to some embodiments. In some embodiments, the first slit 306 and the second slit 308 are substantially completely covered or at least partially overlapped by the antenna patch 206 to maximize the coupling efficiency of the RF signals RF_out_I and RF_out_Q. In some embodiments, the first slit 306 has a primary section 306 extending in the X-axis direction, and the second slit 308 has a primary section 308A extending in the Y-axis direction (see FIG. 2B to see the primary section 308A). The primary sections 306 and 308A of the respective first slit 306 and second slit 308 are substantially perpendicular to each other, whereby the RF quadrature signals RF_out_I and RF_out_Q can be transmitted separately through the primary sections 306 and 308A, respectively, or vice versa. In some embodiments, the in-phase RF signal RF_out_I and the quadrature RF signal RF_out_Q represent RF signals in horizontal and vertical polarization, respectively, or alternatively, represent RF signals in vertical and horizontal polarization, respectively.

[0040] In some embodiments, the first slit 306 is bar-shaped, strip-shaped, linear, or "I"-shaped. In some embodiments, either the first slit 306 or the second slit 308, or both, include one or more secondary sections extending from their respective primary sections. The secondary sections may not aid in improving transmit or receive power, but may aid in achieving impedance matching. As shown in FIG. 4, the second slit 308 includes a first secondary section 308B and a second secondary section 308C, which are connected to opposite ends of the primary section 308A to form a U-shaped slit. In some embodiments, the secondary sections 308B and 308C are perpendicular to the primary section 308A and parallel to the primary section 306.

[0041] In some embodiments, the first slit 306 has a length 306L measured along the X-axis. In some embodiments, the primary section 308A of the second slit 308 has a length 308L measured along the Y-axis. The length 306L or 308L is determined based on design requirements. In some embodiments, the longer the length 306L or 308L, the more power of the RF signal passes through the first slit 306 or the second slit 308. However, if the first slit 306 or the second slit 308 extends beyond the projected area of ​​the antenna patch 206, the coupling efficiency of the RF signal decreases.

[0042] In some embodiments, the first slit 306 has a width 306W measured along the Y-axis. In some embodiments, the primary section 308A of the second slit 308 has a width 308W measured along the X-axis. The width 306W or the width 308W is determined based on the range of the operating frequency for the antenna device 200A. On the one hand, if the width 306W or the width 308W is smaller than the minimum width limit, for example, smaller than the wavelength of the in-phase RF signal RF_out_I or the quadrature RF signal RF_out_Q, the RF signal may refract into the first slit 306 or the second slit 308, causing undesired destructive interference. On the other hand, if the width 306W or the width 308W is larger than the maximum width limit, a wideband signal of an undesired frequency other than the operating frequency of the antenna device 200A may be introduced into the RF signal. Therefore, the width 306W or the width 308W needs to be determined within a suitable range and adapted to the operating frequency of the antenna device 200A.

[0043] In some embodiments, the primary section 306 and the primary section 308A are separated by a distance Ds or spacing. In some embodiments, the greater the distance Ds, the better the quadrature signal isolation can be achieved. When the signal coupling between the in-phase RF signal RF_out_I and the quadrature RF signal RF_out_Q is lower (i.e., when the signal isolation is high), the performance of independent amplitude or phase calibration of the in-phase RF signal RF_out_I and the quadrature RF signal RF_out_Q is improved. However, the increase in the distance Ds comes at the expense of the antenna footprint. Therefore, a trade-off must be made between signal isolation and antenna size.

[0044] FIG. 5 is a schematic top view of the slit of the antenna device 300A shown in FIG. 3 according to some other embodiments. The antenna device 300A is similar to the antenna device 200A, and therefore similar features are not repeated for brevity. The antenna device 300A mainly differs from the antenna device 200A in that the first slit 306 further includes a first secondary section 306B and a second secondary section 306C extending in the Y-axis direction. In some embodiments, the first secondary section 306B and the second secondary section 306C are connected to both ends of the primary section 306A, respectively, thereby forming a U-shaped slit. In some embodiments, the secondary section 306B or 306C is perpendicular to the primary section 306A and the secondary sections 308B, 308C, or parallel to the primary section 308A. In some embodiments, one or both of the first slit 306 and the second slit 308 have only one secondary section, and thus the first slit 306 or the second slit 308, or both, comprise an L-shape.

[0045] 6 is a schematic block diagram of a phase calibration table 500A according to some embodiments. The phase calibration table 500A represents phase compensation values ​​for each of the antenna units of an exemplary 12x12 antenna array. The phase compensation value values ​​are shown in degrees and indicate the phase compensation values ​​of the quadrature RF signal RF_out_Q relative to the in-phase RF signal RF_out_I that serves as a calibration reference.

[0046] From the phase calibration table 500A, it can be seen that the phase compensation value is substantially zero near the central region of the 12x12 antenna array. This is believed to be due to the antenna devices organized around the central region experiencing a more uniform or symmetric grounding in that vicinity provided by the common ground plane 326 (see FIG. 3). For antenna devices close to the peripheral region of the antenna array, the condition of grounding symmetry provided by the common ground plane 326 continues to deteriorate until the antenna device 200A is organized at the edge of the antenna array. As a result, the antenna devices organized at the edge of the antenna array experience the worst electric field symmetry and, therefore, the worst phase distortion. However, as shown in FIG. 6, even for a large 12x12 antenna array, the worst phase error is within about 16 degrees, which can be easily calibrated by the proposed simplified digital phase calibration procedure. Thus, the phase distortion of the phased antenna array can be calibrated at a low cost.

[0047] 7A is a schematic perspective view of an electromagnetic shielding array 700 according to some embodiments. In some embodiments, the electromagnetic shielding array 700 is used in an antenna testing method to block radiating elements of an antenna, for example, the antenna patch 206 of the antenna device 200A, from radiating RF signals. In some embodiments, the electromagnetic shielding array 700 includes an array of electromagnetic shielding structures 700A organized in rows and columns. In some embodiments, the shape of the electromagnetic shielding array 700 follows the shape of the antenna array 200, as shown in FIG. 2A. In some embodiments, the electromagnetic shielding array 700 includes a substrate 702. The substrate 702 may be formed of a semiconductor material, for example, silicon, or a dielectric material, such as silicon oxide, silicon nitride, or a polymer material, such as epoxy resin, polyimide, or other suitable material. The electromagnetic shielding array 700 or substrate 702 may include a front surface 700F and a back surface 700B opposite the front surface 700F.

[0048] Each of the electromagnetic shielding structures 700A is formed with an array of conductive pads 704 formed on the front surface 700F of the substrate 702. In some embodiments, the conductive pads 704 are rectangular in shape. The conductive pads 704 are spaced apart from each other by a predetermined distance Dx. A common conductive layer 708 is formed on the back surface 700B of the substrate 702. A plurality of conductive vias 706 are formed through the substrate 702 to electrically connect the common conductive layer 708 to the corresponding conductive pads 704. In some embodiments, the common conductive layer 708 has a larger area than each of the conductive pads 704. In the depicted embodiment, each electromagnetic shielding structure 700A includes a 5x5 array of conductive pads 704, although the present disclosure is not limited thereto. Other numbers of array sizes of the electromagnetic shielding structures 700A are also within the contemplated scope of the present disclosure.

[0049] FIG. 7B is a schematic cross-sectional view of the electromagnetic shielding structure 700A shown in FIG. 7A according to some embodiments. The common conductive layer 708 serves as a common ground of the electromagnetic shielding structure 700A. In some embodiments, the electromagnetic shielding structure 700A can be viewed as a cascade of multiple equivalent inductor-capacitor (LC) circuits, in which an inductor L is connected in parallel with a capacitor C. The LC circuit provides the effect of a bandpass filter to pass some frequencies while blocking other frequencies. In some embodiments, the frequency response or stopband of the electromagnetic shielding structure 700A will be determined by the dimensions or width Lx of the conductive pads 704 and the distance Wx or spacing between the conductive pads 704. Through appropriate determination of the conductive pads 704 and the distance Dx, a bandpass filter for the RF signal RF_out can be realized by the electromagnetic shielding structure 700A.

[0050] 8 is a schematic cross-sectional view of a test probe array 800 according to some embodiments. In some embodiments, the test probe array 800 is used in an antenna test method using the electromagnetic shielding array 700, and when the RF signals RF_out, including the in-phase RF signal RF_out_I and the quadrature RF signal RF_out_Q, which would otherwise be radiated from the antenna patch 206 of the antenna device 200A, are shielded by the electromagnetic shielding array 700, the RF signals RF_out_I and RF_out_Q can be obtained and inspected through the feed line 312 or 314.

[0051] In some embodiments, the test probe array 800 includes an array of test probe devices 800A organized in rows and columns. In some embodiments, the shape of the test probe array 800 follows the shape of the antenna array 200, as shown in FIG. 2A. In some embodiments, the test probe array 800 includes a substrate 802. The substrate 802 may be formed of a semiconductor material, for example, silicon, or a dielectric material, such as silicon oxide, silicon nitride, or a polymer material, such as epoxy resin, polyimide, or other suitable material. The test probe array 800 or substrate 802 may include a front surface 800F and a back surface 800B opposite the front surface 800F. A plurality of probe needle sets 812 are formed on the front surface 800F. The probe needle set 812 may include a pair of probe needles 804, 806 configured to probe the first feed line 312 and the second feed line 314, respectively, and check whether the RF signals RF_out_I and RF_out_Q have substantially equal amplitudes and a predetermined phase difference of substantially 90 degrees. In some embodiments, the probe needles 314, 316 include spring needles or other suitable test probes.

[0052] In some embodiments, the substrate 802 includes patterned transmission lines 805, 807 formed on the front surface 800F or sealing surface of the substrate 802. The transmission lines 805, 807 may be electrically connected to a test tool, such as an oscilloscope, a signal analyzer, or a network analyzer. In some embodiments, the probe needles 314, 316 are electrically connected to the test tool via the transmission lines 805, 807, respectively. In some embodiments, the first feed line 312 and the second feed line 314 include respective probing areas, and the positions of the probe needles 314, 316 and the spacing between the probe needles 314 and 316 are determined to align with the probing areas of the first feed line 312 and the second feed line 314, respectively.

[0053] Fig. 9 is a schematic flow chart of a method 900 for testing an antenna array, for example, antenna array 200, according to some embodiments. Fig. 10A and Fig. 10B show a schematic block diagram of a test operation according to some embodiments. It should be understood that additional steps can be provided before, between, and after the steps of method 900, and some of the steps described below can be replaced or eliminated in other embodiments. The order of the steps shown in Fig. 9 may be interchangeable. Some of the steps may be performed simultaneously or independently.

[0054] At step 902, a shielding structure is received or provided that includes an antenna array, a probe needle set, and an array of conductive pads. In some embodiments, the antenna array is similar to antenna array 20. The probe needle set may be similar to probe needle set 812. The shielding structure may be similar to electromagnetic shielding structure 700A.

[0055] 10A and 10B, the shielding structure is adapted to cover at least one radiating element or antenna patch 206 of the antenna device 200A. In some embodiments, the electromagnetic shielding structure 700A is aligned with the antenna device 200A or the antenna patch 206 of the antenna device 200A. In some embodiments, the conductive pads 704 of the electromagnetic shielding structure 700A are in physical contact with the antenna patch 206.

[0056] In step 906, the probe needle set is brought into contact with the first feed line and the second feed line. In some embodiments, the two probe needles 804, 806 are adapted to contact the first feed line 314 and the second feed line 316 to receive the in-phase RF signal RF_out_I and the quadrature RF signal RF_out_Q. In some embodiments, referring to FIG. 2B, FIG. 3 and FIG. 10A, the first feed line 312 and the second feed line 314 respectively include probing regions 312T, 314T exposed from the insulating material 226C. In some embodiments, the conductive lines 222A, 222B or 222C are formed of a conductive material such as copper or other suitable material. In some embodiments, as shown in FIG. 10B, the first feed line 312 and the second feed line 314 include respective probing regions 312T, 314T adapted to receive or contact the probe needles 804 and 806. In some embodiments, the probing regions 312T and 314T are positioned to overlap the coupling nodes 312P and 314P of the first and second feed lines 312 and 314T, e.g., the first and second slits 306 and 308, respectively, to reflect the actual RF signal amplitude and phase when coupled to or from the antenna patch 206.

[0057] In some embodiments, when the probing regions 312T and 314T are not protected by the insulating material 226C, the probing regions 312T and 314T may include an anti-erosion coating formed on the exposed surfaces of the probing regions 312T and 314T to prevent erosion of the underlying conductive material, such as copper. In some embodiments, the anti-erosion coating is a composite nickel-gold layer, or what is referred to as an electroless nickel immersion gold (ENIG) layer. Through treatment of the probing regions 312T and 314T with an ENIG layer, testing can be performed more reliably without the adverse effects of conductivity loss due to erosion in the probing regions 312T and 314T.

[0058] At step 908, a first test signal and a second test signal are provided from an RF signal source, e.g., an RF signal generator of a test tool, to a first signal port (e.g., signal port 302) and a second signal port (e.g., signal port 304), respectively, of at least one antenna device. For example, the first signal port 302 and the second signal port 304 are configured to receive the first test signal and the second test signal, respectively, from the RF chip 208. In some embodiments, in the absence of antenna device amplitude calibration or phase calibration information, the first test signal and the second test signal are provided at substantially equal amplitude and the same phase, e.g., zero degrees.

[0059] In step 910, the first output signal and the second output signal are respectively acquired by a signal analyzer from the probe needle set 812 via the first feed line (e.g., the first feed line 312) and the second feed line (e.g., the second feed line 314) of the at least one antenna device. With the assistance of one or more of the electromagnetic shielding array 700 or the electromagnetic shielding structure 700A, the RF signals RF_out_I and RF_out_Q will not be radiated outward by the antenna patch 206. Rather, the antenna patch 206 is considered as an open circuit, and thus the RF signals RF_out_I and RF_out_Q can be received as the first output signal and the second output signal via the first feed line 312 and the second feed line 314 at the corresponding probing regions 312T and 314T, respectively.

[0060] At step 912, a first phase difference between the first phase of the first output signal and the second phase of the second output signal is determined, for example, by a test tool or a signal analyzer. In some embodiments, the test tool or signal analyzer identifies whether a phase error exists between the first output signal and the second output signal. In some embodiments, the identification or determination of the phase error proceeds simultaneously for all or a portion of the antenna devices 200A of the antenna array 200. In some embodiments, the identification or determination of the phase error proceeds with the antenna elements 200A one at a time.

[0061] In some embodiments, the electromagnetic shielding array 700 (or one or more of the electromagnetic shielding structures 700A), the test probe array 800 (or one or more of the test probe devices 800A) and the test tool (including an RF signal generator and a signal analyzer) are collectively referred to herein as a test system for simultaneously testing an array of antenna devices 200A or for performing testing of the antenna devices 200A one at a time.

[0062] In some embodiments, the phase error Ph_e is the first phase Ph_1 of the first output signal minus the second phase Ph_2 of the second output signal, according to the following formula: Ph_2-Ph_1=90+Ph_e It is specified as represented by:

[0063] In the above equation, the phase error Ph_e is a non-zero value. Then, a second test operation is performed to compensate for the phase error, and a first test signal and a third test signal are provided in the second test operation from an RF signal source or an RF signal generator of the test tool, the first test signal and the third test signal are the same RF signal, and a second phase difference Ph_k is defined as a first phase Ph_1 of the first test signal minus a third phase Ph_3 of the third test signal with an initial phase equal to the phase error, i.e. Ph_k=Ph_1-Ph_3=Ph_e It becomes.

[0064] In this way, the third test signal after phase calibration is given an initial phase of −Ph_k, so that the phase difference between the third output signal and the first output signal is Ph_3-Ph_1=-Ph_k+90+Ph_e=90 Because it will be like this.

[0065] The resulting phase difference between the first feed line and the second feed line will be a perfect 90° difference after phase calibration. In some embodiments, the second test operation is omitted and the RF chip 208 directly sets the output signals of the first signal port 302 and the second signal port 304 with initial phases of zero and Ph_k degrees, respectively. The resulting in-phase RF signal RF_out_I and quadrature RF signal RF_out_Q will be in quadrature with a phase difference of substantially 90°.

[0066] Although the amplitude calibration procedure is not described in detail herein, the same phase calibration procedure described above can also be applied to the amplitude calibration.

[0067] The foregoing has outlined features of several embodiments so that those skilled in the art may better understand aspects of the present disclosure. Those skilled in the art should appreciate that the present disclosure may be readily used as a basis for designing or modifying other processes and structures to carry out the same purposes and / or achieve the same advantages of the embodiments presented herein. Those skilled in the art should also recognize that such equivalent constructions do not depart from the spirit and scope of the present disclosure, and that various changes, substitutions, and alterations can be made herein without departing from the spirit and scope of the present disclosure.

Claims

1. 1. An antenna device, comprising: A substrate; a first ground plane arranged in a first layer and disposed on the substrate; a first signal port and a second signal port arranged in a second layer adjacent to the first layer and configured to transmit a first radio frequency (RF) signal and a second RF signal, respectively; a first feed line and a second feed line arranged in the second layer and connected to the first signal port and the second signal port, respectively; a radiating element disposed on the substrate; Equipped with the substrate is arranged to provide a first signal channel and a second signal channel between the radiating element and the first or second feed line for transmitting the first and second RF signals, the first feed line and the second feed line having different line lengths, the radiating element at least partially overlapping the first signal channel and the second signal channel in a top view; The antenna apparatus further comprising a second ground plane arranged in the first layer, the second ground plane laterally surrounding the first ground plane and separated from the first ground plane.

2. 2. The antenna apparatus of claim 1, wherein the first ground plane is configured to form a first slit that functions as part of the first signal channel and a second slit adjacent to the first slit that functions as part of the second signal channel.

3. The antenna apparatus of claim 2 , wherein the first slit and the second slit are separated by a portion of the first ground plate.

4. The antenna device according to claim 2 , wherein the radiating element substantially overlaps the entire first slit and the entire second slit.

5. 3. The antenna device according to claim 2, wherein the substrate is transparent in color and no conductive element is present within the projection area of ​​the radiating element.

6. The antenna apparatus of claim 2 , wherein the first slit includes a first section and the second slit includes a second section substantially perpendicular to the first section.

7. The antenna apparatus according to claim 6 , wherein the first slit further comprises a third section connected to the first section and substantially perpendicular to the first section.

8. 2. The antenna apparatus of claim 1, further comprising an RF chip disposed under the second layer and configured to independently perform amplitude or phase calibration on the first and second RF signals before the first and second RF signals are transmitted to the radiating element or after the first and second RF signals are received from the radiating element.

9. 2. The antenna device of claim 1, further comprising a first conductive via and a second conductive via extending into the substrate and connecting the radiating element to the first feed line and the second feed line, the first conductive via and the second conductive via functioning as the first signal channel and the second signal channel, respectively.

10. The antenna apparatus of claim 9 , wherein the first conductive via or the second conductive via is electrically insulated from the first ground plane.

11. 2. The antenna apparatus of claim 1, wherein a feed line length difference between the first feed line and the second feed line corresponds to a phase difference of substantially 90 degrees between the first RF signal and the second RF signal.

12. A substrate; an array of antenna devices formed on the substrate; each of the antenna devices comprising: a first ground plane arranged in a first layer and disposed on a first surface of the substrate; a first signal port and a second signal port arranged in a second layer adjacent to the first layer and configured to transmit a first radio frequency (RF) signal and a second RF signal; a first feed line and a second feed line arranged in the second layer and connected to the first signal port and the second signal port, respectively; a third layer of radiating elements disposed on a second surface of the substrate opposite the first surface; Equipped with the first ground plane is arranged to form a first slit and a second slit in the first layer for transmitting the first and second RF signals, the first feed line and the second feed line have different line lengths, and the radiating element at least partially overlaps the first slit and the second slit in a top view; Each of the antenna devices further comprises a second ground plane separating each of the first ground planes of each of the antenna devices from each other and arranged in the first layer.

13. 13. The antenna array of claim 12, wherein the radiating elements of each of the antenna arrangements have a substantially circular or elliptical shape.

14. The antenna array of claim 12 , wherein the first slit comprises a line shape and the second slit comprises a U-shape.

15. The antenna array of claim 12 , wherein the second ground plane has a substantially rectangular perimeter.

16. The antenna array of claim 12 , wherein the first ground plane is circular or elliptical.

17. 13. The antenna array of claim 12, wherein the first feed line includes a first node and the second feed line includes a second node, the first node and the second node overlapping the first slit and the second slit, respectively.

18. The antenna array of claim 12 , wherein the first feed line or the second feed line further comprises a protrusion across the corresponding first slit or the second slit.

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