Multi-port end-fire beam-controlled planar antennas and antenna systems

Abstract

This paper describes a multi-port planar antenna system with digital reconfigurability to adjust the beamdirection function of the system. A substrate is provided, and a grid of parasitic elements is printed on the surface of the substrate. One or more driving radiating elements, such as monopole antennas or dipole antennas, are printed on the substrate near the parasitic elements. Switching elements between adjacent parasitic elements are then configured to guide the radiation direction in a specific direction in the azimuth plane. The small form factor of this planar antenna system can be used in MIMO applications employed by fifth-generation (5G) devices such as mobile phones, Internet of Things (IoT) devices, and vehicles.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority to U.S. Provisional Application No. 63 / 102,295, filed June 8, 2020, and U.S. Provisional Application No. 63 / 204,145, filed September 16, 2020, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to, and more specifically, to, a multi-port end-fire beam-controlled planar antenna. Background Technology

[0004] Wireless communication systems for transmitting and receiving radio wave signals over an air interface are widely used in consumer electronics and other devices. Antenna performance significantly alters the quality of service (GSS) of these devices. Multiple-input multiple-output (MIMO) antenna technology has emerged as a promising approach to improve GSS. Furthermore, beam-steering can significantly enhance the signal-to-noise ratio (SNR) on a specific channel. However, the state of a wireless channel is always dynamic due to device mobility and multipath propagation caused by obstacles in the environment. Even when devices are stationary, objects in the environment can move, thus altering the channel state.

[0005] The new revision of the IEEE (Institute of Electrical and Electronics Engineers) 802.11 Wireless Local Area Network (LAN) standard, 802.11ax (also known as the High Efficiency Wireless Standard (HEW)), increases the average throughput per user by at least four times in dense user environments. Multi-user MIMO (MU-MIMO) allows for simultaneous beamdirection to multiple clients in both the uplink and downlink. Antennas can be designed to be reconfigurable to enhance performance in the frequency, spatial, and polarization domains. However, the form factor of various devices such as cellular phones or wireless routers is typically planar, which allows for beamdirection in a planar direction, rather than in both the planar direction and azimuth, to account for the three-dimensional nature of the natural environment.

[0006] Conventional beam-controlled MIMO devices rely on phase shifting of multiple radiating elements. For example, each of multiple dipole antennas can transmit the same signal with a phase shift to form a plane wave propagating in a specific direction. At any position relative to the antenna array, in-phase signals are amplified while out-of-phase signals are canceled out, resulting in a strong beam in one direction and significantly weakened signals in other directions. However, such phased antenna arrays have drawbacks such as limited scanning range (i.e., the beamdirection range can be limited to, for example, 120 degrees of azimuth), complex structure (e.g., each radiating element is connected to a separate delay element or phase shifter), and high power loss. Other methods for beamdirection can include mechanical mechanisms or the use of lenses unsuitable for planar applications. Therefore, there is a need to develop multi-port beam-controlled planar antennas that provide polarization diversity and a 360-degree beamdirection angle covering the azimuth plane. Summary of the Invention

[0007] On one hand, an antenna is provided, comprising: a substrate; and at least one radiating element located on the front side of the substrate, the at least one radiating element being configured to generate a radiating beam under the drive of a radio frequency signal; a plurality of parasitic elements located on the front side of the substrate and distributed around the at least one radiating element; and a plurality of switching elements respectively connected between adjacent parasitic elements among the plurality of parasitic elements, or connected between adjacent portions of parasitic elements.

[0008] In one embodiment, the plurality of parasitic elements are arranged along N rings concentrically surrounding the at least one radiating element, where N is a positive integer; the number of parasitic elements arranged along each ring is the same.

[0009] In one embodiment, the at least one radiating element includes four rotationally symmetric dipole arms located at the center of the front side of the substrate, the plurality of parasitic elements are arranged along the N rings surrounding the four dipole arms, each parasitic element is an arc-shaped metal wire, and the plurality of switching elements are respectively connected between adjacent parasitic elements among the plurality of parasitic elements.

[0010] In one embodiment, the plurality of switching elements are connected between adjacent parasitic elements in the same ring and between adjacent parasitic elements in adjacent rings located in the N rings, excluding the outermost ring furthest from the four dipole arms.

[0011] In one embodiment, the antenna further includes a hardwired inductor connected between adjacent parasitic elements in the outermost ring and between adjacent parasitic elements located in the outermost ring and in the ring adjacent to the outermost ring.

[0012] In one embodiment, the antenna further includes four baluns located on the back side of the substrate and configured to convert unbalanced signals into balanced signals for energizing the four dipole arms on the front side of the substrate.

[0013] In one embodiment, the balance-to-unbalance converter has four arms, each arm comprising a first, straight section connected to each other and an L-shaped second section, the width of the first section being different from the width of the second section.

[0014] In one embodiment, the at least one radiating element comprises a circular monopole disk located at the center of the front side of the substrate, and the plurality of parasitic elements are arranged along N concentric rings surrounding the circular monopole disk, where N is a positive integer. Each parasitic element is a fan-shaped annular metal sheet, with its short arc edge close to the circular monopole disk and its long arc edge away from the circular monopole disk. Every N parasitic elements located in the N rings are arranged along the same radial direction.

[0015] In one embodiment, each parasitic element includes a first part and a second part with different shapes and areas, and each switching element is connected between the first part and the second part of the same parasitic element.

[0016] In one embodiment, the antenna further includes: another monopole disk located on the back side of the substrate and a plurality of integrated metal segments. The other monopole disk is connected to the circular monopole disk on the front side of the substrate via a short-circuit pin. Each of the plurality of integrated metal segments is connected to a first portion of a corresponding fan-shaped metal sheet on the front side of the substrate via a short-circuit pin.

[0017] In one embodiment, the plurality of parasitic elements form a grid of metallic pixels having a plurality of rows and columns. The at least one radiating element includes two dipole antennas, each corresponding to a different port of the antenna and located outside the grid of the metallic pixels. Each of the plurality of switching elements is connected between two adjacent parasitic elements along either a row or column direction.

[0018] In one embodiment, the two dipole antennas are located on opposite sides of the grid.

[0019] In one embodiment, the number of rows in the grid of the metallic pixel is equal to the number of columns. The two dipole antennas are located on adjacent sides of the grid.

[0020] In one embodiment, the two dipole antennas are located on the same side of the grid.

[0021] In one embodiment, the plurality of switching elements includes any one of PIN diodes, field-effect transistors, and microelectromechanical systems (MEMS) devices.

[0022] In one embodiment, the substrate is a glass-reinforced epoxy resin board.

[0023] On the other hand, an antenna system is provided, comprising: a first planar antenna configured to generate horizontally polarized radiation under the drive of a first radio frequency signal; and a second planar antenna configured to generate vertically polarized radiation under the drive of a second radio frequency signal. The first planar antenna and the second planar antenna are separated by a specific distance. At least one of the first planar antenna and the second planar antenna includes: a substrate; at least one radiating element located on the front side of the substrate, the at least one radiating element being configured to generate a radiating beam under the drive of the radio frequency signal; and a plurality of parasitic elements located on the front side of the substrate and distributed around the at least one radiating element; and a plurality of switching elements respectively connected between adjacent parasitic elements or between adjacent portions of the parasitic elements.

[0024] In one embodiment, the first planar antenna includes: a first substrate; four rotationally symmetric dipole arms located at the center of the front side of the first substrate; a plurality of first parasitic elements arranged along N rings surrounding the four dipole arms on the front side of the first substrate, where N is a positive integer, each parasitic element being an arc-shaped metal wire; and a plurality of first switching elements respectively connected between adjacent first parasitic elements. The second planar antenna includes: a second substrate; a circular monopole disk located at the center of the front side of the second substrate; a plurality of second parasitic elements arranged along M concentric rings surrounding the circular monopole disk on the front side of the second substrate, where M is a positive integer, each parasitic element being a fan-shaped annular metal sheet including a first portion and a second portion of different shapes and areas; and a plurality of second switching elements, each second switching element connected between the first portion and the second portion of the same second parasitic element.

[0025] In one embodiment, the antenna system further includes a controller configured to generate a DC signal for controlling the state of a plurality of switching elements in order to control the direction of the radiated beam generated from the first planar antenna and / or the second planar antenna.

[0026] In one embodiment, the antenna system further includes a power source located between the first planar antenna and the second planar antenna. Attached Figure Description

[0027] Figure 1 An end-fire beam-controlled planar antenna according to some embodiments is shown.

[0028] Figures 2A to 2B Top and bottom views of an end-fire beam-controlled planar antenna according to some embodiments are shown.

[0029] Figure 3A A table depicts the switching configuration of an indicated end-fire beam-controlled vertically polarized planar antenna according to some embodiments, corresponding to the zero-degree beam direction (Φ = 0°).

[0030] Figure 3B A table depicts the switching configuration of an indicated end-fire beam-controlled vertically polarized planar antenna according to some embodiments, corresponding to the zero-degree beam direction (Φ = 30°).

[0031] Figure 3C A table depicts the switching configuration of an indicated end-fire beam-controlled vertically polarized planar antenna according to some embodiments, corresponding to the zero-degree beam direction (Φ = 60°).

[0032] Figure 4 A simulated far-field radiation pattern corresponding to the zero-degree beam direction (Φ = 0°) of an end-fire beam-controlled vertically polarized planar antenna according to some embodiments is depicted.

[0033] Figure 5 A graph depicting the simulated frequency response of an end-fire beam-controlled vertically polarized planar antenna according to some embodiments, corresponding to the zero-degree beam direction (Φ = 0°).

[0034] Figures 6A to 6B Top and bottom views of an end-fire beam-controlled vertically polarized planar antenna according to some embodiments are shown.

[0035] Figure 7A A table depicts the switching configuration of an indicated end-fire beam-controlled vertically polarized planar antenna according to some embodiments, corresponding to the zero-degree beam direction (Φ = 0°).

[0036] Figure 7B A table depicts the switching configuration of an indicated end-fire beam-controlled vertically polarized planar antenna according to some embodiments, corresponding to a 30-degree beam direction (Φ = 30°).

[0037] Figure 7C A table depicts the switching configuration of an indicated end-fire beam-controlled vertically polarized planar antenna according to some embodiments, corresponding to a 60-degree beam direction (Φ = 60°).

[0038] Figure 8 A simulated far-field radiation pattern corresponding to the zero-degree beam direction (Φ = 0°) of an end-fire beam-controlled vertically polarized planar antenna according to some embodiments is depicted.

[0039] Figure 9 A graph depicting the simulated frequency response of an end-fire beam-controlled vertically polarized planar antenna according to some embodiments, corresponding to the zero-degree beam direction (Φ = 0°).

[0040] Figure 10 A dual-port dual-polarized end-fire beam controllable planar antenna according to some embodiments is shown.

[0041] Figure 11A and Figure 11B A simulated far-field radiation pattern corresponding to the zero-degree beam direction (Φ = 0°) of a dual-port dual-polarized end-fire beam-controlled planar antenna according to some embodiments is depicted.

[0042] Figure 12 A graph depicting the simulated frequency response of a dual-port dual-polarized end-fire beam-controlled planar antenna according to some embodiments, corresponding to the zero-degree beam direction (Φ = 0°).

[0043] Figure 13 A single-port reconfigurable planar antenna according to some embodiments is shown.

[0044] Figures 14A to 14B A top view and a bottom view of a single-port reconfigurable planar antenna according to some embodiments are shown.

[0045] Figures 15A to 15C Three alternative arrangements of a dual-port reconfigurable planar antenna system according to some embodiments are shown.

[0046] Figure 16A Illustrations based on some embodiments Figure 15C A dual-port reconfigurable planar antenna system.

[0047] Figure 16B A table depicts the switching configurations of an indicator antenna system corresponding to different beam directions according to some embodiments.

[0048] Figures 17A to 17F The simulated frequency response curves of the antenna system according to some embodiments are depicted, corresponding to beam directions Φ = 0°, 30°, 60°, 90°, 300° and 330° respectively.

[0049] Figures 18A to 18F The measured frequency response curves of the antenna system according to some embodiments are depicted, corresponding to beam directions Φ = 0°, 30°, 60°, 90°, 300° and 330° respectively.

[0050] Figures 19A to 19F The graphs depict the simulated total E-field patterns of the antenna system according to some embodiments, corresponding to beam directions Φ = 0°, 30°, 60°, 90°, 300° and 330° respectively.

[0051] Figures 20A to 20F The graphs depict the measured total E-field patterns of the antenna system according to some embodiments, corresponding to beam directions Φ = 0°, 30°, 60°, 90°, 300° and 330° respectively. Detailed Implementation

[0052] This disclosure relates to a multi-port end-fire beam-controlled planar antenna system. In one embodiment, the planar antenna system includes two separate planar antenna elements, corresponding to horizontally polarized radiation and vertically polarized radiation, respectively. The beam-directing mechanism of the antenna system is based on the configuration of parasitic elements located outside the radiating elements (e.g., monopole or dipole antennas) printed on a substrate. The parasitic elements are made of a metallic material and distributed around the radiating elements.

[0053] By configuring parasitic elements as directors and / or reflectors, the radiated beam can be controlled and directed approximately 360 degrees in the azimuth plane. As used herein, the azimuth plane can refer to a plane on which the substrate on which the antenna system is printed is located. End-fired radiation can refer to any plane extending along the azimuth plane.

[0054] Depending on the state of various wireless communication channels, the two polarized radiation beams from a dual-polarized system can be controlled and directed to the same or different azimuth angles. Directional control of the electron beam can be achieved by using digitally controlled switching elements to control the connection between parasitic elements. Controlling the beamforming capability of the antenna system can improve the signal-to-noise ratio (SNR) in wireless transmission. Furthermore, due to the orthogonality of the polarizations, the two antennas can achieve low mutual coupling, a key factor in multiple-input multiple-output (MIMO) applications.

[0055] Figure 1 An end-fire beam-controllable planar antenna 100 is shown according to some embodiments. For example... Figure 1 As shown, antenna 100 includes a substrate 101 containing a dielectric material. The substrate 101 may be a circular plate of, for example, glass-reinforced epoxy resin (e.g., FR-4 dielectric material), but any other suitable dielectric material is within the scope of this disclosure.

[0056] Antenna 100 also includes a radiating element 102, an antenna feed element 103, and a parasitic element 104. The radiating element 102 is located at the center of the substrate 101 and can be printed on the substrate 101 material by, for example, photolithography. The radiating element 102 can be used to generate horizontally polarized radiation or vertically polarized radiation, depending on the structure of the radiating element 102 and the corresponding radiation mechanism.

[0057] The antenna feed element 103 is used to excite the radiating element 102 and can also be referred to as an interface for connecting other radio frequency (RF) devices, such as the miniature version A (SMA) connector.

[0058] The parasitic element 104 is made of metallic material and can also be printed on the substrate 101 by photolithography. The parasitic element 104 is not limited to any particular shape or number of elements, but can be distributed or arranged around the radiating element 102.

[0059] The operation of antenna 100 essentially allows for the reconfiguration of parasitic elements 104 to form different Yagi antennas pointing in various directions on the azimuth plane. Parasitic elements 104 can be connected together as directors in the forward direction and / or as reflectors in the rearward direction. Therefore, by changing the configuration of parasitic elements 104 via switching elements, antenna 100 can be adjusted to direct the radiated beam in a new direction.

[0060] Figures 2A to 2B Top and bottom views of an end-fire beam-controlled vertically polarized planar antenna 200 according to some embodiments are shown. Figure 2A The top view of antenna 200 is shown in the figure. Figure 2B The image shows a bottom view of antenna 200. (See image for reference.) Figure 2A As shown, four rotationally symmetric radiating dipole arms 202 are printed on the middle or center of the substrate 201. In one embodiment, the substrate 201 is a circular FR-4 plate with a diameter of 82 mm. The dipole arms 202 can be printed by photolithography. In one embodiment, the dielectric constant and thickness of the substrate 201 are 2.2 mm and 1.575 mm, respectively.

[0061] Interface 203 (e.g., an SMA connector) is soldered to the center of dipole arm 202 as an interface with other RF devices. Parasitic elements 204 to 207 are printed on the exterior of dipole arm 202 in the form of N arc-shaped metal segments, for example, four concentric rings. Multiple switching elements are respectively connected between adjacent parasitic elements among the multiple parasitic elements 204 to 207. In other embodiments, parasitic elements 204 to 207 can be implemented in other shapes and do not necessarily need to be arranged concentrically.

[0062] It should be noted that the figure shows four rings of the parasitic element; however, the number of rings can be designed practically, and can be five, six, or more rings, and this disclosure is not limited thereto. The more rings N there are, the higher the antenna gain, but the antenna size also increases. When N is 2, the antenna gain is 6 dBi; when N is 3, the antenna gain is 8 dBi; and when N is 4, the antenna gain is 10 dBi.

[0063] The three inner ring-shaped parasitic elements 204 to 206 can be configured as directors or reflectors based on the connection state in the gaps 208 between the parasitic elements or based on the state of the switching elements connected between the parasitic elements. Specific connection configurations are used to direct radiation at different angles in the azimuth plane. In some embodiments, the connections are made via fixed interconnects (e.g., metal wires). In other embodiments, the connections are made via switching elements (e.g., microelectromechanical systems (MEMS) devices, PIN diodes, or field-effect transistors (FETs)). When switching elements are used for connections in the three inner rings, the outer ring parasitic element 207 is kept DC grounded, and the connections in the gaps between the outer ring parasitic elements include inductors.

[0064] like Figure 2B As shown, four baluns, each with two portions 211 and 212, are printed on the back side of substrate 201. Portion 211 may have a different width than portion 212, the width being selected for impedance matching. The core of interface 210 is soldered to the four baluns, allowing unbalanced signals to be converted into balanced signals for use in energizing the dipole arms 202 on the front side of substrate 201.

[0065] Figure 3A A table is depicted indicating the switch configurations of the end-fire beam-controlled vertically polarized planar antenna 200 corresponding to the zero-degree beam direction (Φ = 0°) according to some embodiments. There are 60 numbered switches, each representing one of the connections between adjacent parasitic elements 204 to 206 in the three inner rings. It is understood that the connections can be between parasitic elements within the same ring, between adjacent parasitic elements between the first and second rings, and between adjacent parasitic elements between the second and third rings. In one embodiment, the switch element can be connected between parasitic elements in the first ring 204, between parasitic elements in the second ring 205, and between parasitic elements in the third ring 206. The switch element can also be connected between a parasitic element in the first ring 204 and a parasitic element adjacent to that element in the second ring 205. The switch element can also be connected between a parasitic element in the second ring 205 and a parasitic element adjacent to that element in the third ring 206.

[0066] The connections between the parasitic elements in the outer ring 207 and between the parasitic elements in the third and fourth rings are hardwired and include inductors. In one embodiment, hardwired inductors can be connected between the parasitic elements in the fourth ring 207. Hardwired inductors can also be connected between a parasitic element in the fourth ring 207 and a parasitic element in the third ring 206 adjacent to that element. It should be understood that each ring has 12 parasitic elements, meaning there are a total of 36 connections between the parasitic elements in the three rings and a total of 24 connections between parasitic elements in different rings. Note that the number of parasitic elements in each ring is not limited to this. The number of parasitic elements in each ring is the same. If North corresponds to... Figure 2A At the top of the plate, connections numbered 1, 2, and 3 are located at 0 degrees relative to true north, with connection 1 located at... Figure 2A The third ring 206 at gap 208 is associated with the second ring 205 directly below gap 208, and connection 3 is associated with the first ring 204 directly below gap 208. Connection 4 corresponds to the connection between the parasitic elements in the third ring 206 and the second ring 205 between approximately 0 and 30 degrees east of due north, and connection 5 corresponds to the connection between the parasitic elements in the second ring 205 and the first ring 204 between approximately 0 and 30 degrees east of due north. Connections 6 to 60 continue clockwise around the ring, with the three connections between two adjacent parasitic elements in different rings arranged in the same radial direction and the two connections between corresponding parasitic elements in different rings arranged in the same radial direction alternating in a clockwise direction.

[0067] Each connection configuration is listed as closed ("Yes" or "No"), where a closed connection (i.e., "Yes") means the switch is closed and has low impedance, allowing charge to conduct between the two parasitic elements, while an open connection (i.e., "No") means the switch is open and has high impedance, preventing charge from conducting between the two parasitic elements. All 60 connections in the gaps between the three rings of internal parasitic elements 204 to 206 are listed in Table 300. It will be understood that this configuration is optimized via electromagnetic simulation based on a 0-degree azimuth angle. By changing the state of the 60 connections, the radiation beam can be directed according to different angles in the azimuth plane.

[0068] Figure 3B A table depicts the switching configuration of an indicated end-fire beam-controlled vertically polarized planar antenna according to some embodiments, corresponding to the zero-degree beam direction (Φ = 30°). Figure 3C A table depicts the switching configurations of an indicated end-fire beam-controlled vertically polarized planar antenna according to some embodiments, corresponding to the zero-degree beam direction (Φ = 60°). It should be understood that the switching configurations are similar due to the rotational symmetry of the arrangement of parasitic elements 204-207, only offset by an amount corresponding to the desired angle.

[0069] Figure 4 A graph 400 depicts the simulated far-field radiation pattern of an end-fire beam-controlled vertically polarized planar antenna 200 according to some embodiments, corresponding to a zero-degree beam direction (Φ = 0°). The dashed and solid lines correspond to E-phi radiation and E-theta radiation, respectively. It can be understood that the antenna 200 produces horizontally polarized radiation. Furthermore, the radiated beam is directed along the positive X-axis because the gap configuration has been optimized to a direction Φ = 0°.

[0070] Figure 5 A graph 500 depicts the simulated frequency response of an end-fire beam-controlled vertically polarized planar antenna 200 according to some embodiments, corresponding to a zero-degree beam direction (Φ = 0°). As shown in graph 500, the antenna 200 exhibits low-power reflections at its antenna port in the 5.8 GHz band, indicating that the antenna 200 resonates within this frequency range.

[0071] Figures 6A to 6B Top and bottom views of an end-fire beam-controlled vertically polarized planar antenna 600 according to some embodiments are shown. Figure 6A The top view of antenna 600 is shown in the figure. Figure 6B The image shows a bottom view of antenna 600. (See image for reference.) Figure 6A As shown, a circular monopolar disk 602 (i.e., a radiating element) is printed at the center of the substrate 601. In one embodiment, the substrate 601 is a circular FR4 plate with a diameter of 104 mm. The monopolar disk 602 can be printed by photolithography. In one embodiment, the dielectric constant and thickness of the substrate 601 are 2.42 mm and 1.5 mm, respectively.

[0072] Interface 603 (e.g., an SMA connector) is soldered to the center of monopole disk 602 as an interface with other RF devices. Five shorting pins 604 (e.g., through-holes) are distributed on monopole disk 602 to connect to the top and bottom sides of substrate 601. Shorting pins 604 may be, for example, drilled holes in the board, which are subsequently filled with solder or otherwise plated with a conductive material (e.g., copper). In one embodiment, shorting pins 604 may be evenly distributed around the central axis of monopole disk 602 (i.e., radially symmetrical). Parasitic element group 605 (which takes the form of three concentric rings of fan-shaped metal sheets) is printed on the exterior of monopole disk 602. In other embodiments, each parasitic element in parasitic element group 605 may also be implemented in other shapes and need not be arranged concentrically. In one embodiment, a plurality of parasitic elements are arranged along N rings concentrically around the circular monopole disk 602, where N is a positive integer. The more rings N, the higher the antenna gain, but the antenna size increases. When N is 2, the antenna gain is 6 dBi; when N is 3, the antenna gain is 8 dBi; and when N is 4, the antenna gain is 10 dBi.

[0073] Each parasitic element is a fan-shaped annular metal sheet, with its shorter arc edge close to the circular monopole disk 602 and its longer arc edge away from the circular monopole disk 602. Every three parasitic elements located in the three rings are arranged along the same radial direction.

[0074] Please note, Figure 6A The diagram shows multiple parasitic elements arranged concentrically around a circular monopole disk 602 in three rings, but the number of rings is not limited to this; it could be four, five, or even more rings. Each ring contains the same number of parasitic elements. For example, as shown... Figure 6A As shown, each ring has 12 parasitic elements. However, the number of parasitic elements in each ring is not limited to this.

[0075] Each sector-shaped metal sheet comprises two portions separated by a gap 608: a first portion 606 and a second portion 607. The first portion 606 and the second portion 607 may have different shapes and areas. Based on the state of the connection in the gap 608 between the first portion 606 and the corresponding second portion 607, the metal sheet can be used as a director or a reflector. In one embodiment, a switching element is connected between the first portion 606 and the second portion 607 of the same parasitic element. Specific connection configurations are used to direct radiation at different angles in the azimuth plane. In some embodiments, the connection is made via a fixed interconnect (e.g., a metal wire). In other embodiments, the connection is made via a switching element such as a microelectromechanical system (MEMS) or a PIN diode. In one embodiment, a shorting pin 609 is inserted into the first portion 606 of each metal sheet to connect the first portion 606 to a corresponding metal segment (e.g., an integrated metal segment 610) on the bottom side of the substrate 601. The shorting pin 609 is structurally similar to the shorting pin 604. In one embodiment, each of the plurality of integrated metal segments 610 is connected via a short-circuit pin 609 to a first portion 606 of a corresponding fan-shaped metal sheet on the front side of the substrate 601.

[0076] like Figure 6B As shown, another monopole disk 612 is printed on the center of the substrate 601 and is connected to the monopole disk 602 via a shorting pin 604. An interface 611 (e.g., an SMA connector) is soldered to the monopole disk 612.

[0077] Figure 7A A table 700 is depicted, indicating the switch configurations of the end-fire beam-controlled vertically polarized planar antenna 600 according to some embodiments, corresponding to the zero-degree beam direction (Φ = 0°). There are 36 numbered switches, each representing one of the connections in the gap 608 between the corresponding first portion 606 and second portion 607 of the metal segment. It should be understood that each ring has 12 parasitic elements. If north corresponds to... Figure 6A At the top of the plate, connections numbered 1, 2, and 3 are located at 0 degrees relative to true north, with connection 1 associated with the outer ring, connection 2 with the middle ring, and connection 3 with the inner ring. Connections 4, 5, and 6 correspond to the connections between the first part 606 and the second part 607 of the parasitic elements located approximately 30 degrees east of true north, in ascending order from the outer ring to the inner ring. Connections 6 through 36 continuously surround these rings in a clockwise direction.

[0078] Each connection configuration is listed as closed ("Yes" or "No"), where a closed connection (i.e., "Yes") means that the switch is closed and has low impedance, allowing charge to conduct between part 606 and component 607 of the parasitic element, while an open connection (i.e., "No") means that the switch is open and has high impedance, preventing charge from conducting between the two parts of the parasitic element. All 36 connections between the gaps between the parts of the parasitic element are listed in Table 700. It will be understood that this configuration is optimized via electromagnetic simulation based on a 0-degree azimuth angle. By changing the state of the 36 connections, the radiation beam can be manipulated according to different angles in the azimuth plane.

[0079] Figure 7B A table depicts the switching configuration of an indicated end-fire beam-controlled vertically polarized planar antenna according to some embodiments, corresponding to a 30-degree beam direction (Φ = 30°). Figure 7C A table depicts the switching configuration of an indicated end-fire beam-controlled vertically polarized planar antenna according to some embodiments, corresponding to a 60-degree beam direction (Φ = 60°).

[0080] Figure 8 A graph 800 depicts the simulated far-field radiation pattern of an end-fire beam-controlled vertically polarized planar antenna 600 according to some embodiments, corresponding to a zero-degree beam direction (Φ = 0°). The dashed and solid lines correspond to E-phi radiation and E-theta radiation, respectively. It can be understood that the antenna 600 produces vertically polarized radiation. Furthermore, the radiated beam is directed along the positive X-axis because the gap configuration has been optimized to a direction Φ = 0°.

[0081] Figure 9 A graph 900 depicts the simulated frequency response of an end-fire beam-controlled vertically polarized planar antenna according to some embodiments, corresponding to a zero-degree beam direction (Φ = 0°). As shown in graph 900, antenna 600 exhibits low-power reflections at its antenna port in the 5.8 GHz band, indicating that antenna 200 resonates within this frequency range.

[0082] Figure 10A dual-port, dual-polarized, end-fire beam-controlled planar antenna system 1000 is illustrated according to some embodiments. System 1000 includes two antenna elements 1001 and 1002, which respectively refer to a (horizontally polarized) antenna 200 and a (vertically polarized) antenna 600, and vice versa. Antenna system 1000 can be mounted in a low-profile housing 1003, such as an access point or router, which is typically mounted on the ceiling of a room. Associated circuitry and a battery (e.g., a power source) can be housed within a region 1004 between the two antenna elements 1001 and 1002, separated by a distance sufficient to accommodate the circuitry.

[0083] In one embodiment, the circuitry includes a controller disposed in region 1004 and configured to generate a DC signal for each switching element. The controller may be configured to determine a direction associated with a particular channel for signal transmission and to look up the configuration of the switching element associated with that direction in a lookup table. This configuration may be used to generate multiple DC signals controlling the state of the switching elements to control the radiation beam generated from each of the antenna elements 1001 and 1002 to achieve an optimal direction.

[0084] Figure 11A A graph 1100 depicts a simulated far-field radiation pattern from port 1 of a dual-port dual-polarized end-fire beam-controlled planar antenna system 1000 according to some embodiments, corresponding to the zero-degree beam direction (Φ = 0°). Port 1 corresponds to a horizontally polarized antenna element such as antenna 200. In one embodiment, the spacing between antenna elements 1001 and 1002 is 20 mm. The dashed and solid lines correspond to E-phi radiation and E-theta radiation, respectively. It is understood that antenna 200 produces horizontally polarized radiation. Furthermore, the radiated beam is directed along the positive X-axis because the spacing configuration has been optimized to a direction Φ = 0°.

[0085] Figure 11B A graph 1110 depicts a simulated far-field radiation pattern from port 2 of a dual-port dual-polarized end-fire tunable planar antenna system 1000 according to some embodiments, corresponding to the zero-degree beam direction (Φ = 0°). Port 2 corresponds to a vertically polarized antenna element, such as antenna 600. In one embodiment, the spacing between antenna elements 1001 and 1002 is 20 mm. The dashed and solid lines correspond to E-phi radiation and E-theta radiation, respectively. It can be understood that antenna 600 produces vertically polarized radiation. Furthermore, the radiated beam is directed along the positive X-axis because the spacing configuration has been optimized to a direction Φ = 0°.

[0086] Figure 12A graph 1200 depicts the simulated frequency response of a dual-port, dual-polarized, end-fire tunable planar antenna system 1000 according to some embodiments, corresponding to the zero-degree beam direction (Φ = 0°). As shown in graph 1200, the antenna system 1000 exhibits low-power reflections at the antenna ports in the 5.8 GHz band, indicating that the antenna system 1000 resonates in this frequency range. Due to the orthogonality of the polarization of each antenna element, the mutual coupling between the two antenna elements is low.

[0087] Figure 13 A single-port reconfigurable planar antenna 1300 according to some embodiments is shown. The antenna 1300 includes a grid of parasitic elements 1303 and a driving element 1302. Both the driving element 1302 and the parasitic element 1303 are made of a metallic material (e.g., copper) and are printed on a substrate 1301 (e.g., an FR4 PCB). The driving element 1302 is excited through an interface (e.g., an SMA connector) connected to external RF circuitry. Signals from the RF circuitry cause the driving element 1302 to radiate in the RF band.

[0088] The grid of parasitic element 1303 comprises an array of small metallic regions on the surface of substrate 1301, which may be referred to as pixels. The number and shape of pixels are not limited to... Figure 13 In the illustrated arrangement, in an exemplary embodiment, the pixel size can be approximately 0.1 times the wavelength of the resonant frequency. For a resonant frequency of 5.8 GHz, the pixel size is approximately 5 mm.

[0089] All pixels are spaced apart from each other; adjacent pixels do not directly contact each other, but any two adjacent pixel pairs can be connected via switching elements (e.g., MEMS devices, PIN diodes, or field-effect transistors (FETs)). When the switching element is in the "on" state, it allows charge to conduct between the corresponding pixels. Otherwise, when the switching element is in the "off" state, the corresponding pixels are electrically isolated. By changing the state of all connections distributed between the pixels, the direction of the beam formed by antenna 1300 can be controlled.

[0090] Figure 14A and 14B The illustration shows a top and bottom view of a single-port reconfigurable planar antenna 1400 according to some embodiments. Figure 14A The image depicts a top view of antenna 1400, and... Figure 14B The bottom view of antenna 1400 is depicted in the image. Figure 14AAs shown, antenna 1400 includes a driving element 1402, which is a dipole antenna printed on the top layer of substrate 1401. In an embodiment, substrate 1401 is a printed circuit board, which may be formed of one or more layers of FR4 and conductive layers such as a copper ground plane. The driving element 1402 is connected to ground plane 1404 for reflecting radiation generated by the driving element 1402 back to the grid of parasitic element 1403.

[0091] In one embodiment, the grid of parasitic element 1403 comprises thirty pixels arranged in five rows and six columns. Switching elements 1405 are used to connect adjacent parasitic elements 1403. Thus, a total of forty-nine switching elements 1405 are shown in the grid of parasitic element 1403.

[0092] like Figure 14B As shown, on the bottom surface of substrate 1401, an open-ended stripline 1406 is directly printed below the driving element 1402 on the top surface of substrate 1401. The open-ended stripline 1406 is fed along the edge of substrate 1401 to excite the driving element 1402 on the top surface of substrate 1401. This excitation is achieved through inductive coupling. All 49 switching elements 1405 can be individually controlled via DC interconnects 1407 routed on the bottom surface of substrate 1401. In one embodiment, the DC interconnects 1407 can be divided into several shorter sections, where each adjacent section uses a lumped inductor to control the signal on another section. Dividing the DC interconnects in this way can help minimize RF interference caused by relatively long DC interconnects. It is understood that vias (i.e., shorting pins) can be formed in substrate 1401 to connect elements on the top and bottom surfaces.

[0093] Figures 15A to 15C Three alternative arrangements of a dual-port reconfigurable planar antenna system 1500 according to some embodiments are shown. For example... Figure 15A As shown, the antenna system 1500 includes a pair of dipole antennas, wherein a first port corresponds to a first dipole antenna 1502 connected to a first ground plane 1503, and a second port corresponds to a second dipole antenna 1504 connected to a second ground plane 1505. In some embodiments, the ground planes 1503 and 1505 consist of a single ground plane shared by the dipole antennas 1502 and 1504. The two dipole antennas are located on opposite sides of a grid of parasitic elements 1506 printed in the central region of the substrate 1501. Similarly, each pair of adjacent parasitic elements 1506 can be connected via a switching element 1507. The grid of parasitic elements 1506 is shared by the dipole antenna pair 1502 and 1504. Each switching element 1507 is connected between two adjacent parasitic elements 1506 in a row or column direction.

[0094] like Figure 15B As shown, the antenna system 1510 includes a pair of dipole antennas, wherein a first port corresponds to a first dipole antenna 1512 connected to a first ground plane 1513, and a second port corresponds to a second dipole antenna 1514 connected to a second ground plane 1515. In some embodiments, the ground planes 1513 and 1515 consist of a single ground plane shared by the dipole antennas 1512 and 1514. The two dipole antennas are located on adjacent sides of a grid of parasitic elements 1516 printed in the central region of the substrate 1511. Similarly, each pair of adjacent parasitic elements 1516 can be connected via a switching element 1517. The grid of the parasitic elements 1516 is shared by the dipole antenna pair 1512 and 1514. It will be understood that, due to the symmetrical geometry of the two dipole antennas 1512 and 1514, the grid of the parasitic element 1516 should be square in shape, that is, the grid of the parasitic element 1516 should have an equal number of rows and columns, and the shape of the pixels should also be square (i.e., have the same dimensions in length and width).

[0095] like Figure 15C As shown, the antenna system 1520 includes a pair of dipole antennas, with a first port corresponding to a first dipole antenna 1522 connected to a first ground plane 1523, and a second port corresponding to a second dipole antenna 1524 connected to a second ground plane 1525. In some embodiments, the ground planes 1523 and 1525 consist of a single ground plane shared by the dipole antennas 1522 and 1524. The two dipole antennas are located on the same side of a grid of parasitic elements 1526 printed in the central region of the substrate 1521. Similarly, each pair of adjacent parasitic elements 1526 can be connected via a switching element 1527. The grid of the parasitic elements 1526 is shared by the dipole antenna pair 1522 and 1524.

[0096] In one embodiment, the antenna system 1520 includes two or more pairs of dipole antennas, such as three or four pairs of dipole antennas, wherein the two or more pairs of dipole antennas (e.g., three or four pairs of dipole antennas) correspond to two or more ports of the antenna, and the two or more ports correspond to two or more ground planes of the antenna.

[0097] Figure 16A Illustrations are shown according to some embodiments Figure 15C The dual-port reconfigurable planar antenna system 1520. All switching elements 1527 are numbered 1 to 49 respectively. In one embodiment, each switching element 1527 includes a PIN diode. By "turning on" or "turning off" the PIN diode, a wide range of different pixel configurations can be achieved, which are used to change the direction of the radiated beam generated by the dipole antennas 1522, 1524.

[0098] In one embodiment, the pixel configuration can be calculated or determined based on an algorithm called the Internal Multiport Method (IMPM). In IMMM, the grid of parasitic element 1526 and dipole antennas 1522, 1524 are treated as a multiport network, and only one complete electromagnetic (EM) calculation is needed to obtain the initial impedance matrix with all PIN diodes set to the "off" state. Network circuit analysis can be performed by treating each pixel port as an equivalent circuit component such as an open circuit, short circuit, or switch. Using an optimization genetic algorithm (GA), the radiating beams generated by dipole antennas 1522, 1524 can be directed at different angles depending on the pixel configuration. A genetic algorithm is a search algorithm based on the theory of natural evolution. It reflects the process of natural selection, selecting the most suitable individuals to reproduce in order to produce the next generation of offspring. The objective function in the genetic algorithm can be set to simultaneously optimize multiple antenna reflections, mutual coupling between antennas, and the desired beam direction of a single antenna.

[0099] Figure 16B Table 1600 depicts the switching configurations of antenna system 1520 according to some embodiments, corresponding to different beam directions. The indices of the PIN diodes listed in Table 1600 indicate which PIN diodes are set to the "on" state. Those indices set to the "off" state are omitted from the table entries. Table 1600 lists the configurations of switching elements 1526 in the right half-space corresponding to azimuth angles of 0°, 30°, 60°, 90°, 300°, and 330°. By considering a mirror image of the PIN diode configurations in Table 1600, directional beams directed in the left half-space are also possible due to the symmetrical geometry. Antenna system 1520 can provide a total of 300° of end-fire beam directionality.

[0100] Figures 17A to 17F Simulated frequency response graphs of the antenna system 1520 according to some embodiments are depicted, corresponding to beam directions Φ = 0°, 30°, 60°, 90°, 300°, and 330°, respectively. These graphs represent different beam direction angles.

[0101] Figures 18A to 18F The diagrams depict measured frequency responses of the antenna system 1520 according to some embodiments, corresponding to beam directions Φ = 0°, 30°, 60°, 90°, 300°, and 330°, respectively. These diagrams represent different beam direction angles.

[0102] Figures 19A to 19FGraphs depicting simulated total E-field patterns of the antenna system 1520 according to some embodiments, corresponding to beam directions Φ = 0°, 30°, 60°, 90°, 300°, and 330°, are presented. These graphs represent different beam direction angles. Solid and dashed lines correspond to port 1 and port 2, respectively.

[0103] Figures 20A to 20F Graphs depicting the measured total E-field patterns of the antenna system 1520 according to some embodiments, corresponding to beam directions Φ = 0°, 30°, 60°, 90°, 300°, and 330°, respectively. These graphs represent different beam direction angles. Solid and dashed lines correspond to port 1 and port 2, respectively.

[0104] Note that the techniques described herein for determining the configuration of parasitic elements can be implemented in executable instructions stored in a computer-readable medium for use by or in conjunction with a processor-based instruction execution machine, system, apparatus, or device. Those skilled in the art will understand that, for some embodiments, various types of computer-readable media may be included for storing data. As used herein, "computer-readable medium" includes one or more of any suitable media for storing executable instructions of a computer program, such that an instruction execution machine, system, apparatus, or device can read (or retrieve) the instructions from the computer-readable medium and execute the instructions for performing the described embodiments. Suitable storage formats include one or more of electronic, magnetic, optical, and electromagnetic formats. A non-exhaustive list of conventional exemplary computer-readable media includes: portable computer disks; random access memory (RAM); read-only memory (ROM); erasable programmable read-only memory (EPROM); flash memory devices; and optical storage devices, including portable optical discs (CDs), portable digital video discs (DVDs), etc.

[0105] It should be understood that the arrangement of components shown in the accompanying drawings is for illustrative purposes, and other arrangements are possible. For example, one or more elements described herein may be implemented wholly or partially as electronic hardware components. Other elements may be implemented in software, hardware, or a combination of software and hardware. Furthermore, some or all of these other elements may be combined, some may be omitted entirely, and additional components may be added while still achieving the functionality described herein. Therefore, the subject matter described herein can be implemented in many different variations, and all such variations are considered to be within the scope of the claims.

[0106] To facilitate understanding of the subject matter described herein, many aspects are described in sequence of actions. Those skilled in the art will recognize that various actions can be performed by dedicated circuitry or circuit systems, program instructions executed by one or more processors, or a combination of both. The description of any sequence of actions herein is not intended to imply that a specific order for performing that sequence must be followed. Unless otherwise stated herein or clearly contradicted by the context, all methods described herein can be performed in any suitable order.

[0107] The terms “a,” “an,” and “the,” and similar references used in the context of describing the subject matter (particularly in the context of the claims) are to be interpreted to cover both singular and plural forms, unless otherwise stated herein or clearly contradicted by the context. Unless otherwise stated herein or clearly contradicted by the context, the use of the term “at least one” followed by a list of one or more items (e.g., “at least one of A and B”) should be understood to refer to one item selected from the listed items (A or B) or any combination of two or more of the listed items (A and B). Furthermore, the foregoing description is for illustrative purposes only and not for limiting purposes, as the scope of protection sought is defined by the claims as set forth below and any equivalents thereof. The use of any and all instances or exemplary language provided herein (e.g., “such as”) is intended only to better illustrate the subject matter and does not impose a limitation on the scope of the subject matter unless otherwise required. In the claims and written description, the use of the term “based on” and other similar phrases indicates a condition that produces the result and does not exclude any other conditions that produce that result. The language in the specification should not be construed as indicating that any unclaimed element is necessary for implementing the claimed embodiments.

Claims

1. An antenna, comprising: a substrate; and at least one radiating element located on a front side of the substrate, the at least one radiating element configured to generate a radiating beam under driving of a radio frequency signal; a plurality of parasitic elements located on the front side of the substrate and distributed around the at least one radiating element; and a plurality of switch elements respectively connected between adjacent parasitic elements in the plurality of parasitic elements, the plurality of parasitic elements are arranged along N rings concentrically surrounding the at least one radiating element, N ≥ 2, wherein a first ring is closest to the at least one radiating element and an outermost ring is farthest from the at least one radiating element; a number of parasitic elements arranged along each ring is the same, and each parasitic element is an arc-shaped metal wire, the antenna further comprises hardwired inductors connected between every two adjacent arc-shaped metal wires in the outermost ring in a circumferential direction and connected between two opposite arc-shaped metal wires in the outermost ring and a next outer ring adjacent to the outermost ring. 2.The antenna according to claim 1, wherein the at least one radiating element comprises four rotationally symmetric dipole arms located in a middle part of the front side of the substrate, the plurality of parasitic elements are arranged along the N rings surrounding the four dipole arms. 3.The antenna according to claim 2, wherein the plurality of switch elements are connected between adjacent parasitic elements in a same ring and connected between adjacent parasitic elements respectively located in adjacent rings in the N rings except for the outermost ring farthest from the four dipole arms.

4. The antenna of claim 2, further comprising: four baluns located on a back side of the substrate and configured to convert unbalanced signals into balanced signals for exciting the four dipole arms of the front side of the substrate. 5.The antenna according to claim 4, wherein the balun has four arms, each arm comprising a first part in a straight line and a second part in an L shape connected to each other, a width of the first part is different from a width of the second part. 6.An antenna, comprising: a substrate; and at least one radiating element located on a front side of the substrate, the at least one radiating element configured to generate a radiating beam under driving of a radio frequency signal; a plurality of parasitic elements located on the front side of the substrate and distributed around the at least one radiating element; and a plurality of switch elements connected between adjacent parts of parasitic elements, the at least one radiating element comprises a circular monopole disc located in a middle part of the front side of the substrate, the plurality of parasitic elements are arranged along N rings concentrically surrounding the circular monopole disc, N being a positive integer, each parasitic element is a sector ring-shaped metal sheet, a short arc side of each sector ring-shaped metal sheet is close to the circular monopole disc and a long arc side is far from the circular monopole disc, every N parasitic elements respectively located in the N rings are arranged along a same radial direction, each sector ring-shaped metal sheet comprises a first part and a second part different in shape and area, and a switch element is connected between the first part and the second part of a same sector ring-shaped metal sheet, The antenna further comprises another monopole disc and a plurality of integrated metal segments on the back side of the substrate, wherein the another monopole disc is connected to the circular monopole disc on the front side of the substrate via a shorting pin, and each of the plurality of integrated metal segments is connected to the first portion of a corresponding sectoral annular metal patch on the front side of the substrate via a shorting pin.

7. The antenna according to any one of the preceding claims, wherein the plurality of switching elements comprises any one of a PIN diode, a field effect transistor, a microelectromechanical system device.

8. The antenna according to any one of the preceding claims, wherein the substrate is a glass reinforced epoxy resin board.

9. An antenna system comprising: a first planar antenna configured to generate horizontally polarized radiation under the drive of a first radio frequency signal; and a second planar antenna configured to generate vertically polarized radiation under the drive of a second radio frequency signal, wherein the first planar antenna is separated from the second planar antenna by a certain distance, and at least one of the first planar antenna and the second planar antenna comprises: a substrate; at least one radiating element on a front side of the substrate, the at least one radiating element being configured to generate a radiation beam under the drive of a radio frequency signal; and a plurality of parasitic elements on the front side of the substrate and distributed around the at least one radiating element; and a plurality of switching elements respectively connected between adjacent ones of the plurality of parasitic elements, or between adjacent portions of a parasitic element, the second planar antenna comprises: a second substrate; a circular monopole disc in the middle of a front side of the second substrate, a plurality of sectoral annular metal patches arranged along M rings concentrically surrounding the circular monopole disc on the front side of the second substrate, M being a positive integer, each sectoral annular metal patch comprising a first portion and a second portion different in shape and area, and a plurality of second switching elements, each second switching element being connected between the first portion and the second portion of a same sectoral annular metal patch, the second planar antenna further comprises another monopole disc and a plurality of integrated metal segments on the back side of the second substrate, wherein the another monopole disc is connected to the circular monopole disc on the front side of the second substrate via a shorting pin, and each of the plurality of integrated metal segments is connected to the first portion of a corresponding sectoral annular metal patch on the front side of the second substrate via a shorting pin.

10. The antenna system according to claim 9, wherein the first planar antenna comprises: a first substrate; four rotationally symmetric dipole arms in the middle of a front side of the first substrate, a plurality of first parasitic elements arranged along N rings surrounding the four dipole arms on the front side of the first substrate, N being a positive integer, each first parasitic element being an arc-shaped metal wire, and a plurality of first switching elements respectively connected between adjacent ones of the plurality of first parasitic elements. ​ 11. The antenna system of claim 9, further comprising a controller configured to generate a direct current signal for controlling a state of a plurality of switching elements in order to control a direction of a radiated beam generated from the first planar antenna and / or the second planar antenna.

12. The antenna system of claim 9, further comprising a power source located between the first planar antenna and the second planar antenna.

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