Omnidirectional Miniaturized Antenna System

Abstract

Disclosed herein are devices, systems, and methods for antenna systems that can be used not only for wireless communications, but also for other antenna-based applications (e.g., proximity sensing, ranging, and angle of arrival measurement). The antenna system includes: a plurality of antenna groups, including a first antenna group and a second antenna group. The first antenna group includes a parasitic element and a radiating element fed by an antenna port. The second antenna group includes a second parasitic element and a second radiating element fed by a second antenna port. The antenna system also includes a ground plane coupled to the first antenna group and the second antenna group. The first antenna group can be spaced apart from and mirrored to the second antenna group.

Description

Technical Field

[0001] The present disclosure relates generally to antenna systems and, more particularly, to omnidirectional miniaturized antenna systems that may be suitable for radio frequency transmission as well as sensing applications, ranging applications, and / or positioning applications. Background Art

[0002] As wireless devices (e.g., smartphones, tablets, wearable devices, notebooks, personal computers, etc.) become more popular, antenna systems can be used for purposes other than wireless communication. For example, many applications take advantage of the wireless capabilities on the device to provide additional features (e.g., proximity detection, motion detection, gesture sensing, positioning, and health monitoring). Often, such applications can repurpose wireless systems, particularly wireless antenna systems, to provide these additional features. However, these additional features often involve more challenging antenna characteristics.

[0003] One of the main challenges, especially in the context of notebook or laptop device form factors, is to have an omnidirectional antenna system formed by two or more antennas, at least one for transmission (TX) and at least one for reception (RX) (sometimes both used as RX), where, depending on the form factor of the wireless device, their global dimensions are small enough to fit into a lid bezel or other small space, where the global dimensions include the distance between the two or more antennas. In addition, the antennas may be fed by coaxial connection cables, which may introduce performance degradation. Furthermore, it may be difficult to provide isolation between the two or more antennas. BRIEF DESCRIPTION OF THE DRAWINGS

[0004] In the accompanying drawings, similar reference numerals generally refer to the same parts throughout the different views. These drawings are not necessarily drawn to scale, but generally focus on illustrating the exemplary principles of the present disclosure. In the following description, various exemplary aspects of the present disclosure are described with reference to the following drawings, in which:

[0005] Figure 1 An example of an antenna system consisting of two separate radiating groups that are mirror images of each other is shown;

[0006] Figure 2 An example of an antenna system consisting of three separate radiating groups that are mirror images of each other is shown;

[0007] Figure 3 Shows Figure 1 Example plots of reflection coefficients for antenna systems;

[0008] Figure 4 Shows Figure 1 Example plots of transmission coefficients for antenna systems;

[0009] Figure 5Depicted Figure 1 Example plots of radiation patterns for each antenna group of an antenna system;

[0010] Figure 6 An example plot of Phase Difference of Arrival (PDoA) as a function of Angle of Arrival (AoA) is shown for Figure 1 Simulation and measurement of prototype antenna systems; and

[0011] Figure 7 An example plot of measured range versus physical AoA in azimuth is shown. DETAILED DESCRIPTION

[0012] The following detailed description refers to the accompanying drawings that show exemplary details and features by way of illustration.

[0013] The word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any aspect or design described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other aspects or designs.

[0014] Throughout the drawings, it should be noted that unless otherwise described, like reference numbers are used to depict the same or similar elements, features, and structures.

[0015] The phrases "at least one" and "one or more" may be understood to include numerical numbers greater than or equal to 1 (e.g., one, two, three, four, [...], etc.). The phrase "at least one of" with respect to a group of elements may be used herein to mean at least one element from the group consisting of the elements. For example, the phrase "at least one of" with respect to a group of elements may be used herein to mean the following selections: one of the listed elements, one of a plurality of the listed elements, a plurality of individually listed elements, or a number of a plurality of individually listed elements.

[0016] The words "plurality" and "several" in the specification and claims clearly refer to numbers greater than 1. Therefore, any phrase that explicitly invokes the above words (e.g., "plurality [elements]," "several [elements]") to refer to a number of elements clearly refers to more than one of the elements. For example, the phrase "plurality" can be understood to include a numerical number greater than or equal to 2 (e.g., two, three, four, five, [...], etc.).

[0017] The phrases "group", "set", "set", "series", "sequence", "grouping", etc. in the specification and claims, if present, refer to a number equal to or greater than 1 (i.e., one or more). The terms "proper subset", "reduced subset", and "smaller subset" refer to a subset of a set that is not equal to the set, illustratively, to a subset of a set that contains fewer elements than the set.

[0018] As used herein, the term "data" may be understood to include information in any suitable analog or digital form, such as provided as a file, a portion of a file, a collection of files, a signal or stream, a portion of a signal or stream, a collection of signals or streams, etc. In addition, the term "data" may also be used to refer to a reference to information, such as in the form of a pointer. However, the term "data" is not limited to the above examples, and may take various forms and represent any information as understood in the art.

[0019] For example, the term "processor" or "controller" used herein may be understood as any kind of technical entity (e.g., hardware, software, and / or a combination of the two) that allows processing data. A processor or controller may be a system on a chip (SoC) or a portion thereof, and may consume power when processing data. Data may be processed according to one or more specific functions performed by a processor or controller. In addition, a processor or controller used herein may be understood as any kind of circuit (e.g., any kind of analog or digital circuit). Therefore, a processor or controller may be or include an analog circuit, a digital circuit, a mixed signal circuit, software, firmware, a logic circuit, a processor, a microprocessor, a central processing unit (CPU), a graphics processing unit (GPU), a digital signal processor (DSP), a field programmable gate array (FPGA), an integrated circuit, an application specific integrated circuit (ASIC), etc., or any combination thereof. Any other kind of implementation of the various functions described in further detail below may also be understood as a processor, a controller, or a logic circuit. It should be understood that any two (or more) processors, controllers, or logic circuits detailed herein may be implemented as a single entity having equivalent or similar functionality, and conversely, any single processor, controller, or logic circuit detailed herein may be implemented as two (or more) separate entities having equivalent or similar functionality.

[0020] As used herein, "memory" is understood to be a computer-readable medium (e.g., a non-transitory computer-readable medium) on which data or information can be stored for retrieval. Therefore, references to "memory" included herein may be understood to refer to volatile or non-volatile memory, including random access memory (RAM), read-only memory (ROM), flash memory, solid-state storage, magnetic tape, hard disk drives, optical drives, 3D XPoint TM etc. or any combination thereof. Registers, shift registers, processor registers, data buffers, etc. are also encompassed by the term memory in this document. The term "software" refers to any type of executable instructions, including firmware.

[0021] Unless expressly specified, the term "send" covers both direct (point-to-point) and indirect transmission (via one or more intermediary points). Similarly, the term "receive" covers both direct and indirect reception. In addition, the terms "send", "receive", "communication / transmission" and other similar terms cover both physical transmission (e.g., transmission of radio signals) and logical transmission (e.g., transmission of digital data connected via a logical software level). For example, a processor or controller can send or receive data with another processor or controller via a software-level connection in the form of a radio signal, wherein the physical transmission and reception are processed by radio layer components (e.g., radio frequency (RF) transceivers and antennas), and the logical transmission and reception connected via the software level are performed by the processor or controller. The term "communication / transmission" covers one or both of sending and receiving (i.e., one-way or two-way communication in one or both of the incoming and outgoing directions). The term "calculation" covers "direct" calculations via mathematical expressions / formulas / relational expressions and "indirect" calculations via lookup tables or hash tables and other array indexing or search operations.

[0022] As described above, the antenna system can be used for purposes other than wireless communication, including, for example, proximity detection, motion detection, gesture sensing, positioning, and health monitoring. Typically, such applications can reuse the antenna system to provide these additional features, however, these additional features often introduce more challenging antenna characteristics, especially in the context of small form factors (e.g., notebook or laptop devices), where the entire antenna system must fit into a small area (e.g., within the lid frame of the laptop device). In many cases, the antenna system may include two or more antennas (e.g., at least one for TX and at least one for RX) to provide omnidirectional wireless communication, coaxial connecting cables may be used to feed the antennas, and sufficient isolation between the RX and TX antennas may be required. Until now, it has been impossible to meet all of these requirements within a single antenna system while also reliably providing additional feature support from the same antenna system for additional antenna-related features (e.g., proximity sensing, ranging, and angle of arrival measurement).

[0023] For example, patch directional antennas are known, which may be commonly used for ultra-wideband (UWB) detection and ranging applications in handheld devices, but these may not be omnidirectional, may have a limited coverage angle that may limit the field of view between the device and the user, and often have cumbersome (e.g., large) sizes compared to the wavelength. For example, the size of a typical patch directional antenna for UWB detection may be approximately 18 mm by 18 mm, which means it will be difficult to integrate into a laptop screen. In addition, the patch directional antenna cannot be easily connected to a coaxial cable, which makes it less suitable for a laptop form factor, where the chipset is local and relatively far from the antenna, and therefore may need to be fed with a coaxial cable. Omnidirectional antennas are known for UWB detection applications, but these antennas typically suffer from poor phase monotonicity, which means it is not suitable for positioning measurements (e.g., angle of arrival, where phase monotonicity may be important for reliable measurement). Planar inverted F antennas (PIFAs) have been used in omnidirectional Wi-Fi and Wi-Fi sensing applications, but these antennas may also suffer from non-monotonic phase behavior, especially if connected via an external coaxial cable.

[0024] Disclosed herein is a new antenna system solution in which phase balance is inherently integrated into the design. The disclosed antenna system can allow better performance of positioning / sensing features in the case of limited antenna size, and can allow connection to coaxial cable while maintaining good omnidirectionality and good efficiency. The disclosed antenna system can also be small in size. For example, the disclosed antenna system can be composed of at least two antennas, and the at least two antennas are designed to be in a space less than about 1.6mm x 30mm, separated by about half a wavelength distance (for example, for an operating frequency range of 7.5GHz to 8.5GHz with a center frequency of about 8GHz, it is about 18mm), which makes it suitable for embedding in notebooks, tablets, smartphones, wearable devices, medical devices and other wireless devices with small form factors. The disclosed antenna system can allow the use of up to 50cm coaxial cable while maintaining good antenna gain, efficiency and phase monotonicity. The disclosed antenna system can allow quasi-omnidirectional coverage with limited variation of gain spherical pattern. The disclosed antenna system may allow for monotonic phase behavior with and without the use of coaxial cable, which makes it suitable for measurement of additional positioning features (e.g., angle of arrival (“AoA”) measurements). The disclosed antenna system may not add additional cost because the antenna may be part of the initial design of the wireless device and no additional specific hardware is required compared to conventional antennas. In summary, the disclosed antenna system may improve the performance and user experience of wireless devices, provide omnidirectional coverage, be small, and be used with coaxial cable, while reliably providing the additional features of proximity detection, ranging, and AoA measurements.

[0025] Figure 1 An example of an antenna system 100 consisting of two separate radiating groups is shown, where one group is labeled as a left group 110 and the other group is labeled as a right group 120, where each group can act as a separate antenna. The radiating groups (110, 120) of the antenna system 100 can be printed on a printed circuit board (PCB) substrate (e.g., flame retardant four (FR4)) with a dielectric constant of 4.4 and a thickness of 0.2 mm, and connected to a ground plane 150, which can be connected to or become the chassis of the device. It should be understood that other types of PCB substrates with different dielectric constants and thicknesses can be used. Each of the antenna groups (110, 120) can be fed by a corresponding antenna port. For example, the left antenna group 110 is fed by antenna port 112, and the right antenna group 120 is fed by antenna port 122. In practice, the antenna ports (112, 122) typically send / receive radio frequency signals (RF) to / from a transceiver via corresponding coaxial cables (not shown) connected to each antenna port. The coaxial cables may be soldered to the ground plane 150 and may be fed, for example, through the ground plane 150 to reach the respective antenna ports. Any type of radio frequency (RF) connector may be used for the connections at the antenna ports (112, 122).

[0026] Figure 1 The dimensions presented in the example of are for a design optimized in the UWB frequency range to cover an operating band from about 7.5 GHz to 8.5 GHz, with a center frequency of about 8.0 GHz. The geometric extent of each antenna group (110, 120) is 8.37 mm by 1.58 mm, and includes radiating elements (left radiating element 111 and right radiating element 121) connected to corresponding feed ports (112, 122), and may include parasitic elements. As used herein, the geometric extent of an antenna group refers to the dimensions of the extent covering all elements (e.g., all radiating elements, parasitic elements, etc.) of the antenna group in that dimension (thus, the geometric width of the left antenna group 110 is 8.37 mm along the width dimension, and the geometric height is 1.58 mm along the height dimension). The radiating elements and parasitic elements can be of any shape, including zigzag elements (e.g., L-shaped, F-shaped, E-shaped, serpentine, etc.), where the length may not be an extent in a single direction, but may be folded in half on itself at different angles.

[0027] For example, the left antenna group 110 has two L-shaped parasitic elements (right parasitic element 115a and left parasitic element 115b) connected to the ground plane 150. Similarly, the right antenna group 120 has two L-shaped parasitic elements: right parasitic element 125a and left parasitic element 125b. In this case, the geometric extent of each antenna group is 1 / 2 of the dimension along the ground plane (in Figure 1The horizontal dimension is 8.37 mm, and the dimension perpendicular to the ground plane is Figure 1 The antenna system 100 has a geometrical extent of about 100 mm (e.g., about 25.79 mm) and a distance between the closest extents of the antenna groups (e.g., about 10.79 mm). The antenna system 100 has a geometrical extent of about 100 mm (e.g., about 25.79 mm) and a distance between the closest extents of the antenna groups (e.g., about 25.79 mm). The antenna system 100 has a geometrical extent of about 100 mm (e.g., about 25.79 mm) and a distance between the closest extents of the antenna groups (e.g., about 10 ...

[0028] It should be understood that the size can be adjusted in proportion to the center frequency of the operating band. For example, the center distance between two antenna groups can be approximately half a wavelength of the center frequency of the operating band, and the geometric range of each antenna group can be approximately one-quarter wavelength. Thus, the antenna can be easily tuned to cover other frequency bands or technologies (e.g., Wi-Fi) while maintaining the same concepts and advantages. It should be understood that although Figure 1 Two parasitic elements (eg, mirrored L-shaped elements) within each antenna group are shown, but each antenna group may have any number of parasitic elements, preferably mirrored within each group and / or mirrored between the two groups.

[0029] The antenna system 100 can be used in different modes to provide different sensing and positioning features. To operate in the sensing mode to provide sensing features (e.g., radar human detection), the left antenna group 110 can be used for TX and the right antenna group 120 can be used for RX (or vice versa). To operate in the ranging mode to provide ranging features (e.g., distance measurement), the left antenna group 110 can be used for TX and RX, and the right antenna group 120 can also or alternatively be used for TX and RX (e.g., one antenna group or both antenna groups can be used). To operate in the angle measurement mode to provide AoA features (e.g., angle measurement), the left antenna group 110 can be used for RX, and the right antenna group 120 can be used for TX. It should be understood that AoA measurement is one of the main challenges in antenna systems of this type. For good performance, the phase difference between the two antennas (also called the phase difference of arrival (PDoA)) should be monotonic when the antennas are receiving electromagnetic (EM) waves from different angles of arrival (AoA) . Non-monotonicity may introduce ambiguity in the AoA measurement and reduce the performance / reliability of this feature.

[0030] Due to the mirroring of the two antennas, the design of the antenna system 100 can provide monotonicity and good phase balance. In other words, the stability of the phase difference between the two antennas (e.g., the two antenna groups 110, 120) can be ensured by the mirroring of the radiating elements and the parasitic elements (which can cause a certain EM balance that eliminates surface waves and unnecessary coupling). In addition, the additional L-shaped parasitic element can help improve this balance.

[0031] like Figure 1 As shown, the left antenna group 110 is mirrored with the right antenna group 120 across the reflection axis 109. This can be seen, for example, in the shape of the left radiating element 111 (of the left antenna group 110), which is mirrored with the shape and position of the right radiating element 121 (of the right antenna group 120) across the reflection axis 109. Similarly, the parasitic elements (L-shaped parasitic elements 115a / 115b) of the left antenna group 110 are mirrored with the shape and orientation of the L-shaped parasitic elements 125a / 125b of the right antenna group 120 across the reflection axis 109.

[0032] exist Figure 1 , not only are the antenna groups mirrored to each other (across the reflection axis 109), but the parasitic elements of each group are also mirrored internally about its antenna group (e.g., across the reflection axis at the geometric center of the antenna group). Thus, using the left antenna group 110 as an example, the shape and position of the L-shaped parasitic element 115a and the L-shaped parasitic element 115b are mirrored about the reflection axis 119 at the geometric center of the left antenna group 110. For example, the L-shaped parasitic element 115a has a direction along the ground plane (e.g., at Figure 1 The long section running horizontally in the middle is connected at its end to a section running perpendicular to the ground plane (e.g. Figure 1 The short portion is connected to the ground plane 150, and there is a space between the long portion and the ground plane that is open toward the right antenna group 120. The L-shaped parasitic element 115b is a mirrored version across the reflection axis 119, where the short portion is connected to the ground plane 150, and there is a space between the long portion and the ground plane that is open away from the right antenna group 120. The right antenna group 120 has a similar internal mirror image across the reflection axis 129 at the geometric center of the right antenna group 120.

[0033] It should be understood that although two antenna groups are discussed herein, additional antenna groups may be included. For example, a third antenna group may be added that is located in a plane above one of the other antenna groups. Using the right antenna group 120 as an example, the third antenna group may be located above the right antenna group 120 (towards the top of the page) and also centered on axis 129. As with the right antenna group 120 and / or the left antenna group 110 discussed above, the parasitic elements of the third antenna group may also be mirrored relative to themselves internally (e.g., across a reflection axis at the geometric center of the antenna group). The third antenna group may also be mirrored relative to the right antenna group 120 across a reflection axis that is perpendicular to axis 129. This arrangement Figure 2 2, wherein the first antenna group 210 is mirrored across the reflection axis 209 relative to the second antenna group 220. The third antenna group 230 is mirrored across the reflection axis 239 relative to the second antenna group 220.

[0034] In addition, the parasitic elements of each antenna group can optionally be mirrored internally relative to itself. Thus, the parasitic elements of the first antenna group 210 can be mirrored internally relative to itself across reflection axis 219, the parasitic elements of the second antenna group 220 can be mirrored internally relative to itself across reflection axis 229, and the parasitic elements of the third antenna group 230 can be mirrored internally relative to itself across reflection axis 229. With respect to AoA measurements, the third antenna group 230 can measure AoA in elevation relative to the second antenna group 220, while the first antenna group 210 can measure AoA in azimuth relative to the second antenna group 220, thereby allowing three-dimensional resolution of AoA measurements. This concept can be extended to additional antennas that have similar mirroring internally relative to the antenna group and relative to other antenna groups.

[0035] Figure 3-Figure 5 Shown according to Figure 1 Examples of antenna system 100 include simulation and prototype test results of the antenna system. Figure 3 The reflection coefficient (in dB) is plotted, and Figure 4 The transmission coefficient (in dB) of the antenna system 100 is shown as a function of frequency (in GHz). Figure 3 and Figure 4 As can be seen in , antenna system 100 covers the designed frequency band centered at 8 GHz with very good isolation between the two antennas (eg, greater than 18 dB). A good correlation between simulations (labeled “Sim”) and measurements (labeled “Meas”) is also observed.

[0036] Figure 5The radiation pattern of each antenna group in the antenna system is plotted separately, where radiation pattern 510 is for the left antenna (e.g., antenna group 110) and radiation pattern 520 is for the right antenna (e.g., antenna group 120). It can be seen that the radiation characteristics show that each antenna group has a quasi-omnidirectional shape of radiation (e.g., a large 3dB beamwidth (71 degrees)), and a relatively high sidelobe level (0.6dB).

[0037] As described above, one of the benefits of the disclosed antenna system (e.g., antenna system 100) is that it can provide a monotonic phase difference between two antennas. In other words, the PDoA vs. AoA variation makes the antenna system suitable for AoA measurement. The general concept of AoA measurement is that two antennas (e.g., the two antenna groups 110, 120 of antenna system 100) are operated in RX mode to receive signals with a specific phase difference (PDoA). Knowing the distance (D) between the two antennas and the measured value of PDoA, it can be based on the relationship to determine AoA, where λ is the wavelength of the incident wave.

[0038] Figure 6 PDoA vs. AoA for simulations and measurements of a prototype of the antenna system 100 and compared to theoretical values ​​(e.g., the relationship described above, plotted as "Theory") are plotted. The measurements in the graphs were performed using; a vector network analyzer; and a transmit antenna that was moved to vary the AoA relative to a receive antenna (e.g., a prototype of the antenna system 100), using different elevation angles of the receive antenna (e.g., the lines on the graph show elevation ("el") angles of -15, 0, 15, and 30 degrees relative to vertical) to simulate, for example, different lid positions (if the antenna system were mounted on a lid of a laptop). As can be seen, the measurements and simulations show very nice monotonic behavior with respect to PDoA vs. AoA, which makes this antenna system suitable for AoA measurements. As part of the calibration of the antenna system, different variations at different elevation angles may be considered.

[0039] Regarding the use of the antenna system for sensing and positioning applications in ranging mode, the prototype was attached to a large metal plate (to act as the ground plane of the chassis / lid. A 50cm coaxial cable was used to connect the prototype to an ultra-wideband (UWB) demo chipset. On the other hand, a UWB demo board with an embedded antenna was used as a counterpart. Figure 7 The measured distance (in cm) is plotted against the physical AoA in azimuth (degrees). It can be seen that for a large field of view (FoV) and at different lid positions (open lid and closed lid), there is a small ranging error. Thus, the antenna system can be reliably used in ranging mode (e.g., omnidirectional, robust, accurate) for sensing and positioning applications.

[0040] In the following, various examples are provided, which may include one or more aspects described with respect to the antenna system described above. The examples provided in relation to the device may also be applicable to the described method, and vice versa.

[0041] Example 1 is an antenna system, comprising: a plurality of antenna groups, including a first antenna group and a second antenna group, wherein the first antenna group comprises a first parasitic element and a first radiating element fed by a first antenna port, wherein the second antenna group comprises a second parasitic element and a second radiating element fed by a second antenna port. The antenna system further comprises: a ground plane coupled to the first antenna group and the second antenna group, wherein the first antenna group is separated from the second antenna group by a distance along the ground plane, wherein the first antenna group and the second antenna group form a mirror image.

[0042] Example 2 is the antenna system of Example 1, wherein the first antenna group is mirrored with the second antenna group about a reflection axis at the center of the distance, wherein the reflection axis is perpendicular to the ground plane.

[0043] Example 3 is the antenna system as described in any one of Examples 1 or 2, wherein each of the first parasitic element and the second parasitic element is a meander-shaped parasitic element.

[0044] Example 4 is the antenna system of Example 3, wherein the meander-shaped element is L-shaped.

[0045] Example 5 is an antenna system as described in any one of Examples 3 or 4, wherein the zigzag parasitic element includes: a first part extending along the ground plane and separated from the ground plane; and a second part extending in a direction perpendicular to the ground plane and connected to the ground plane, wherein an end of the first part is connected to an end of the second part.

[0046] Example 6 is the antenna system of Example 5, wherein the first portion is longer than the second portion.

[0047] Example 7 is the antenna system of Example 6, wherein the first parasitic element is mirrored with the second parasitic element about a reflection axis at a center of the distance, wherein the first portion extends along the ground plane away from an end of the second portion and toward the center.

[0048] Example 8 is an antenna system as described in any of Examples 1-7, wherein the first antenna group includes a first additional parasitic element and the second antenna group includes a second additional parasitic element, wherein each of the first additional parasitic element and the second additional parasitic element is a zigzag shape.

[0049] Example 9 is the antenna system of Example 8, wherein the first parasitic element is mirrored with the first additional parasitic element across a reflection axis of the first antenna group, the reflection axis being located at a geometric center of the first antenna group and perpendicular to the ground plane.

[0050] Example 10 is an antenna system as described in any of Examples 1-9, wherein each of the geometric range of the first antenna group along the ground plane and the second geometric range of the second antenna group along the ground plane includes approximately half of the distance.

[0051] Example 11 is an antenna system as described in any of Examples 1-10, wherein each of the first antenna group and the second antenna group has a quasi-omnidirectional radiation pattern when in operation.

[0052] Example 12 is an antenna system as described in any of Examples 1-11, wherein the first antenna group and the second antenna group are arranged on a printed circuit board substrate.

[0053] Example 13 is the antenna system of Example 12, wherein the printed circuit board substrate comprises a flame retardant material (e.g., FR4), wherein the flame retardant material has a dielectric constant of approximately 4.4 and a thickness of approximately 0.2 mm.

[0054] Example 14 is an antenna system as described in any of Examples 1-13, wherein the antenna system further includes: a radio frequency (RF) cable configured to connect the antenna system to a wireless module, wherein the RF cable is connected to the first antenna port to feed the first radiating element.

[0055] Example 15 is an antenna system as described in Example 14, wherein the antenna system also includes: a second radio frequency antenna (RF) cable configured to connect the antenna system to the wireless module, wherein the RF cable is connected to the second antenna port to feed the second radiating element.

[0056] Example 16 is the antenna system of Example 14, wherein the first antenna group, the second antenna group, and the wireless module are housed in a chassis.

[0057] Example 17 is an antenna system as described in any of Examples 1-16, wherein the first antenna group and the second antenna group are configured for wireless communication in a frequency range of approximately 7.5 GHz to 8.5 GHz.

[0058] Example 18 is an antenna system as described in any of Examples 1-17, wherein the distance is approximately half a wavelength (λ) at a center frequency of a wireless communication frequency range of the antenna system.

[0059] Example 19 is the antenna system of Example 18, wherein when the center frequency is approximately 8 GHz and the wireless communication frequency range is approximately 7.5 GHz to 8.5 GHz, the half wavelength is approximately 18 mm.

[0060] Example 20 is an antenna system as described in any of Examples 1-19, wherein the geometric width of the first antenna group along the ground plane is between approximately one-quarter wavelength and approximately one-fifth wavelength at a center frequency range of a wireless communication frequency range of the antenna system.

[0061] Example 21 is the antenna system of Example 20, wherein when the center frequency is approximately 8 GHz and the wireless communication frequency range is approximately 7.5 GHz to 8.5 GHz, the geometric width is approximately 8.37 mm.

[0062] Example 22 is an antenna system as described in any one of Examples 1-21, wherein the multiple antenna groups further include: a third antenna group, including a third parasitic element and a third radiating element fed by a third antenna port, wherein the third antenna group is separated from the second antenna group by an elevation distance perpendicular to the distance along the ground plane, and wherein the third antenna group is mirrored with the second antenna group along a reflection axis parallel to the distance along the ground plane.

[0063] Example 23 is an antenna system as described in any of Examples 1-22, wherein a geometric height of the first antenna group perpendicular to the ground plane is less than approximately 5 mm.

[0064] Example 24 is the antenna system of Example 23, wherein the geometric height is approximately 1.58 mm.

[0065] Example 25 is an antenna system as described in any of Examples 1-24, wherein the antenna system is configured to: operate either or both of the first antenna group and the second antenna group as a sensing antenna for human radar detection.

[0066] Example 26 is an antenna system as described in any of Examples 1-25, wherein the antenna system is configured in a sensing antenna mode for human radar detection, wherein the sensing antenna mode includes: operating one of the first antenna group and the second antenna group as a receiving antenna, and operating the other of the first antenna group and the second antenna group as a transmitting antenna.

[0067] Example 27 is an antenna system as described in any of Examples 1-26, wherein the antenna system is configured in a ranging antenna mode for distance measurement, wherein the ranging antenna mode includes: operating the first antenna group or the second antenna group to obtain distance measurement.

[0068] Example 28 is an antenna system as described in any of Examples 1-27, wherein the antenna system is configured in a ranging antenna mode for distance measurement, wherein the ranging antenna mode includes: operating both the first antenna group and the second antenna group to obtain distance measurement.

[0069] Example 29 is an antenna system as described in any of Examples 1-28, wherein the antenna system is configured in an arrival angle antenna mode for angle measurement, wherein the arrival angle antenna mode includes: operating both the first antenna group and the second antenna group as receiving antennas.

[0070] Example 30 is an antenna system as described in any of Examples 1-29, wherein the first antenna group and the second antenna group form a mirror image so as to remove surface waves and induce electromagnetic balance within the antenna system.

[0071] Example 31 is an antenna system as described in any of Examples 1-30, wherein, for different arrival angles of electromagnetic waves received at the first antenna group and the second antenna group, the phase difference between the first antenna group and the second antenna group is monotonic.

[0072] Example 32 is a computing system comprising: a processor; an antenna system connected to the processor; and a chassis housing the processor and the antenna system. The antenna system comprises: a first antenna group of reflective elements and parasitic elements, mirrored with a second antenna group of radiating elements and parasitic elements; a ground plane connected to each parasitic element of the first antenna group and the second antenna group; and a pair of feed ports, each feed port connected to the corresponding antenna group at one of the radiating elements of the corresponding antenna group in the first antenna group and the second antenna group.

[0073] Example 33 is the computing system of Example 32, wherein the antenna system is attached to the chassis with an offset between the antenna system and the chassis.

[0074] Example 34 is the computing system of Example 33, wherein the offset comprises an exclusion zone between the chassis and the antenna system.

[0075] Example 35 is the computing system of Example 34, wherein the exclusion zone comprises an area less than approximately 40 mm by less than approximately 10 mm.

[0076] Example 36 is the computing system of Example 35, wherein the exclusion zone is approximately 28.63 mm by approximately 3 mm.

[0077] Although the present invention has been particularly described above with reference to specific aspects in the above disclosure, it will be understood by those skilled in the art that various changes in form and details of these aspects may be made without departing from the spirit and scope of the present invention as defined in the appended claims. The scope of the present invention is thus indicated by the appended claims, and is therefore intended to cover all changes within the meaning and scope of the equivalents of the claims.

Claims

1. An antenna system, comprising: a plurality of antenna groups, including a first antenna group and a second antenna group, wherein the first antenna group includes a first parasitic element and a first radiating element fed by a first antenna port, wherein the second antenna group includes a second parasitic element and a second radiating element fed by a second antenna port; and A ground plane is coupled to the first antenna group and the second antenna group, wherein the first antenna group is separated from the second antenna group by a distance along the ground plane, and wherein the first antenna group and the second antenna group form a mirror image.

2. The antenna system according to claim 1, wherein: The first antenna group is mirrored with the second antenna group about a reflection axis at a center of the distance, wherein the reflection axis is perpendicular to the ground plane.

3. The antenna system according to claim 1, wherein: Each of the first parasitic element and the second parasitic element is a meander-line parasitic element.

4. The antenna system according to claim 3, wherein: The meander-shaped parasitic element is L-shaped.

5. The antenna system according to claim 3, wherein: The meander-shaped parasitic element comprises: a first portion extending along and spaced apart from the ground plane; and A second portion extends in a direction perpendicular to the ground plane and is connected to the ground plane, wherein an end of the first portion is connected to an end of the second portion.

6. The antenna system according to claim 5, wherein: The first portion is longer than the second portion.

7. The antenna system according to claim 6, wherein: The first parasitic element is mirrored with the second parasitic element about a reflection axis at a center of the distance, wherein the first portion extends along the ground plane away from an end of the second portion and toward the center.

8. The antenna system according to any one of claims 1 to 7, wherein: The first antenna group includes a first additional parasitic element, and the second antenna group includes a second additional parasitic element, wherein each of the first additional parasitic element and the second additional parasitic element is in a zigzag shape.

9. The antenna system according to claim 8, wherein: The first parasitic element is mirrored with the first additional parasitic element across a reflection axis of the first antenna group, the reflection axis being located at a geometric center of the first antenna group and perpendicular to the ground plane.

10. The antenna system according to any one of claims 1 to 7, wherein: Each of a geometric extent of the first antenna group along the ground plane and a second geometric extent of the second antenna group along the ground plane includes approximately half of the distance.

11. The antenna system according to any one of claims 1 to 7, wherein: The distance is approximately half a wavelength (λ) at a center frequency of a wireless communication frequency range of the antenna system.

12. The antenna system according to any one of claims 1 to 7, wherein: The plurality of antenna groups further include a third antenna group including a third parasitic element and a third radiating element fed by a third antenna port, wherein the third antenna group is separated from the second antenna group by an elevation angle distance perpendicular to the distance along the ground plane, The third antenna group is mirrored with the second antenna group along a reflection axis parallel to the distance along the ground plane.

13. The antenna system according to any one of claims 1 to 7, wherein: The antenna system is configured in a sensing antenna mode for human radar detection, The sensing antenna mode includes: operating one of the first antenna group and the second antenna group as a receiving antenna, and operating the other of the first antenna group and the second antenna group as a transmitting antenna.

14. The antenna system according to any one of claims 1 to 7, wherein: The antenna system is configured in a ranging antenna mode for distance measurement, The ranging antenna mode includes: operating either or both of the first antenna group and the second antenna group to obtain distance measurement.

15. The antenna system according to any one of claims 1 to 7, wherein: The antenna system is configured in an angle-of-arrival antenna mode for angle measurement, The angle-of-arrival antenna mode includes: operating both the first antenna group and the second antenna group as receiving antennas.

16. The antenna system according to any one of claims 1 to 7, wherein: For different arrival angles of electromagnetic waves received at the first antenna group and the second antenna group, the phase difference between the first antenna group and the second antenna group is monotonic.

17. The antenna system according to any one of claims 1 to 7, wherein: The geometric width of the first antenna group along the ground plane is between about one quarter wavelength and about one fifth wavelength at a center frequency range of a wireless communication frequency range of the antenna system.

18. The antenna system of claim 17, wherein: When the center frequency is approximately 8 GHz and the wireless communication frequency range is approximately 7.5 GHz to 8.5 GHz, the geometric width is approximately 8.37 mm.

19. The antenna system according to any one of claims 1 to 7, further comprising: a radio frequency (RF) cable configured to connect the antenna system to a wireless module, Wherein, the RF cable is connected to the first antenna port to feed the first radiating element.

20. The antenna system of claim 19, further comprising: a second radio frequency (RF) cable configured to connect the antenna system to the wireless module, Wherein, the RF cable is connected to the second antenna port to feed the second radiating element.

21. The antenna system according to any one of claims 1 to 7, wherein: Each of the first antenna group and the second antenna group has an omnidirectional radiation pattern when operated.

22. A computing system comprising: processor; an antenna system connected to the processor; and A chassis, accommodating the processor and the antenna system, wherein the antenna system comprises: a first antenna group of a reflective element and a parasitic element, wherein the first antenna group is a mirror image of a second antenna group of a radiating element and a parasitic element; a ground plane coupled to each parasitic element of the first antenna group and the second antenna group; and A pair of feed ports, each feed port connected to a corresponding one of the first antenna group and the second antenna group at one of the radiating elements of the corresponding antenna group.

23. The computing system of claim 22, wherein: The antenna system is attached to the chassis with an offset between the antenna system and the chassis.

24. The computing system of claim 23, wherein: The offset includes an exclusion zone between the chassis and the antenna system, Wherein, the exclusion zone includes an area less than about 40 mm by less than about 10 mm.

25. The computing system of claim 24, wherein: Each of the parasitic elements of the first antenna group and the second antenna group is L-shaped.

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