Omnidirectional, miniature antenna system

Abstract

This document presents devices, systems, and procedures for an antenna system that can be used not only for wireless communication but also for other antenna-based applications such as proximity measurement, distance measurement, and angle of arrival measurement. The antenna system comprises a variety of antenna groups, including a first and a second antenna group. The first antenna group includes a parasitic element and a radiating element, fed by one antenna connector. The second antenna group includes a second parasitic element and a second radiating element, fed by a second antenna connector. The antenna system also includes a base plate connected to both the first and second antenna groups. The first antenna group can be separate from and mirrored by the second antenna group.

Description

Technical area

[0001] This disclosure relates generally to antenna systems and, more particularly, to omnidirectional, miniaturized antenna systems suitable for radio frequency transmission as well as for sensing, ranging, and / or localization applications. background

[0002] As wireless devices such as smartphones, tablets, wearables, notebooks, personal computers, etc. become increasingly popular, antenna systems can also be used for purposes beyond wireless communication. For example, many applications leverage a device's wireless capabilities to provide additional functionality such as proximity detection, motion detection, gesture recognition, localization, and health monitoring. Generally, such applications can repurpose the wireless system, and in particular the wireless antenna system, to provide these additional features. However, these additional features often involve more challenging antenna characteristics.

[0003] One of the biggest challenges, especially in the context of a notebook or laptop form factor, is having an omnidirectional antenna system consisting of two or more antennas, at least one of which is for transmitting (TX) and at least one of which is for receiving (RX) (sometimes both are used as RX), with their overall size small enough to fit in the lid frame or other small space, depending on the form factor of the wireless device, where the overall size includes the distance between the two or more antennas. Furthermore, the antennas may be fed via a coaxial interconnect cable, which can lead to performance degradation. In addition, it can be difficult to ensure isolation between the two or more antennas. Brief description of the drawings

[0004] In the drawings, like reference characters generally refer to the same parts throughout the several views. The drawings are not necessarily to scale, but rather emphasis is generally placed upon illustrating the exemplary principles of the disclosure. In the following description, various exemplary aspects of the disclosure are described with reference to the following drawings, in which: Fig. Figure 1 shows an example of an antenna system consisting of two separate, mutually reflecting radiator groups; Fig. Figure 2 shows an example of an antenna system consisting of three separate radiator groups that mirror each other; Fig. 3 shows an example of the reflection coefficient of the antenna system of Fig. 1; Fig. 4 shows an example of the transmission coefficient of the antenna system of Fig. 1; Fig. Figure 5 shows an example of the radiation patterns of the individual antenna groups of the antenna system of Fig. 1; Fig. Figure 6 shows an example diagram of the phase difference of arrival (PDoA) as a function of the angle of arrival (AoA) for simulations and measurements of a prototype antenna system of Fig. 1; and Fig. Figure 7 shows an example of the plot of the measured distance versus the physical AoA in azimuth. Description

[0005] The following detailed description refers to the attached drawings, which show exemplary details and features for illustrative purposes.

[0006] The word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Aspects or designs described herein as "exemplary" or "exemplary" are not necessarily to be construed as preferred or advantageous over other aspects or designs.

[0007] In the drawings, it should be noted that like reference numerals are used to represent the same or similar elements, features and structures unless otherwise indicated.

[0008] The phrase "at least one" and "one or more" may be understood to include a numerical quantity greater than or equal to one (e.g., one, two, three, four, [...], etc.). The phrase "at least one of" with reference to a group of items may be used herein to mean at least one item from the group consisting of the items. For example, the phrase "at least one of" with reference to a group of items may be used herein to mean a selection of: one of the listed items, a plurality of one of the listed items, a plurality of individual listed items, or a plurality of individual listed items.

[0009] The words "plurality" and "multiple" in the description and claims expressly refer to a quantity greater than one. Accordingly, any phrases that explicitly use the above-mentioned words (e.g., "a plurality of [elements]," "multiple [elements]") that refer to a quantity of elements expressly refer to more than one of the elements. For example, the phrase "a plurality" may be understood to include a numerical quantity greater than or equal to two (e.g., two, three, four, five, [...], etc.).

[0010] The terms "group of," "set of," "collection of," "series of," "sequence of," "grouping of," etc., when used in the description and claims, refer to a set equal to or greater than one, i.e., one or more. The terms "proper subset," "reduced subset," and "smaller subset" refer to a subset of a set that is unequal to the set, illustratively to a subset of a set that contains fewer elements than the set.

[0011] The term "data" as used herein may be understood to include, for example, information in any suitable analog or digital form provided as a file, a portion of a file, a set of files, a signal or stream, a portion of a signal or stream, a set of signals or streams, and the like. Furthermore, the term "data" may also be used to mean a reference to information, e.g., in the form of a pointer. However, the term "data" is not limited to the examples mentioned above and may take various forms and represent any information as understood in the art.

[0012] The terms "processor" or "controller," as used herein, for example, can be understood as any type of technological unit (e.g., hardware, software, and / or a combination of both) that enables the processing of data. The processor or controller can be part of a system-on-chip (SoC) and can consume power when processing data. The data can be processed according to one or more specific functions performed by the processor or controller. Furthermore, a processor or controller, as used herein, can be understood as any type of circuit, e.g., any type of analog or digital circuit.A processor or a controller can 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 implementation of the respective functions, described in more detail below, can also be considered a processor, controller, or logic circuit.It is understood that two (or more) of the processors, controllers, or logic circuits described herein may be implemented as a single unit with equivalent functionality or the like, and conversely, that any individual processor, controller, or logic circuit described herein may be implemented as two (or more) separate units with equivalent functionality or the like.

[0013] As used herein, "memory" is understood to mean a computer-readable medium (e.g., a non-transitory computer-readable medium) in which data or information can be stored for retrieval. References herein to "memory" may thus be understood to refer to volatile or non-volatile memory, including, but not limited to, random-access memory (RAM), read-only memory (ROM), flash memory, solid-state memory, magnetic tape, hard disk drive, optical drive, 3D-XPoint™, or any combination thereof. Registers, shift registers, processor registers, data buffers, among others, are also encompassed herein by the term memory. The term "software" refers to all types of executable instructions, including firmware.

[0014] Unless explicitly stated, the term "transmit" includes both direct (point-to-point) and indirect transmission (via one or more intermediate points). Similarly, the term "receive" includes both direct and indirect reception. Furthermore, the terms "send," "receive," "communicate," and similar terms include both physical transmission (e.g., the transmission of radio signals) and logical transmission (e.g., the transmission of digital data over a logical connection at the software level).For example, a processor or controller can transmit or receive data over a software-level connection with another processor or controller in the form of radio signals, with the physical transmission and reception being handled by radio-layer components such as radio frequency (RF) transceivers and antennas, and the logical transmission and reception over the software-level connection being performed by the processors or controllers. The term "communicate" includes both sending and receiving, i.e., unidirectional or bidirectional communication in one or both directions, i.e., inbound and outbound. The term "compute" includes both "direct" computations via a mathematical expression / formula / relationship and "indirect" computations via lookup or hash tables and other array indexing or searching operations.

[0015] As mentioned above, antenna systems can also be used for purposes other than wireless communication, such as proximity and motion detection, gesture recognition, localization, and health monitoring. Generally, such an application can repurpose the antenna system to provide these additional functions, but these additional functions often result in more challenging antenna characteristics, especially in the context of small form factors, such as a notebook or laptop, where the entire antenna system must fit into a small area, e.g., the lid frame of the laptop. In many cases, the antenna system can comprise two or more antennas (e.g.,A multi-band (at least one for transmitting and at least one for receiving) antenna system to enable omnidirectional wireless communication may use a coaxial interconnect cable to feed the antennas and requires adequate isolation between the receiving and transmitting antennas. Until now, it has not been possible to meet all of these requirements with a single antenna system while reliably supporting additional functions such as proximity, ranging, and angle of arrival measurement with the same antenna system.

[0016] For example, patch directional antennas are known and commonly used for ultra-wideband (UWB) sensing and ranging applications in handheld devices. However, these may not be omnidirectional, have a limited coverage angle that can restrict the field of view between the device and the user, and often have a bulky (e.g., large) dimension compared to the wavelength. A typical patch directional antenna for UWB detection, for example, measures approximately 18 mm x 18 mm, making it difficult to integrate into a laptop screen. Furthermore, a patch directional antenna cannot be easily connected to coaxial cables, making it less suitable for laptops, where the chipset is located relatively far from the antennas and may therefore need to be fed via a coaxial cable.Omnidirectional antennas are known for UWB detection applications, but these generally suffer from poor phase monotonicity, making them unsuitable for localization measurements, such as angle of arrival, where phase monotonicity can be important for reliable measurements. Planar inverted-F antennas (PIFA) have been used in omnidirectional Wi-Fi and Wi-Fi sensing applications, but these can also suffer from non-monotonic phase behavior, especially when connected via an external coaxial cable.

[0017] A new antenna system solution is presented here in which phase compensation is integrated into the design. The disclosed antenna system can enable better performance of the localization / detection functions with limited antenna size and can allow connection with a coaxial cable while maintaining good omnidirectionality and efficiency. The described antenna system can also be small. For example, the disclosed antenna system can consist of at least two antennas constructed to be less than about 1.6 mm x 30 mm in size and separated by a spacing of about half a wavelength (e.g., about 18 mm for an operating frequency range of 7.5 GHz to 8.5 GHz with a center frequency of about 8 GHz), allowing them to be integrated into notebooks, tablets, smartphones, wearables, medical devices, and other small form-factor wireless devices.The disclosed antenna system can enable the use of coaxial cables up to 50 cm long while ensuring good antenna gain, efficiency, and phase uniformity. The described antenna system can enable quasi-omnidirectional coverage with limited variation in the spherical gain pattern. The disclosed antenna system can enable monotonic phase response with and without the use of coaxial cables, making it suitable for measuring additional localization features such as angle of arrival ("AoA") measurements. The disclosed antenna system does not incur any additional costs, as the antenna can be part of the original design of the wireless device and, compared to a conventional antenna, no additional, specialized hardware is required.Overall, the disclosed antenna system can improve wireless device performance and user experience, provide omnidirectional coverage, be small in size, and be used with coaxial cables, while reliably providing additional features such as proximity detection, ranging, and AoA measurements.

[0018] Fig. Figure 1 shows an example of an antenna system 100 consisting of two separate radiator groups, one group referred to as the left group 110 and the other group as the right group 120, where each group can function as a separate antenna. The radiator groups (110, 120) of the antenna system 100 can be printed on a printed circuit board 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 form the housing of the device. Of course, other types of printed circuit board substrates with different partitivities and thicknesses can also be used. Each of the antenna groups (110, 120) can be fed via a corresponding antenna connector. For example, the left antenna group 110 is fed via the antenna connection 112 and the right antenna group 120 is fed via the antenna connection 122.In practice, the antenna connectors (112, 122) typically transmit / receive the radio frequency (RF) signals from / to the transceiver via a corresponding coaxial cable (not shown) connected to each antenna connector. The coaxial cable can be soldered to the base plate 150 and, for example, routed through the base plate 150 to reach the respective antenna connector. Any type of radio frequency (RF) connector can be used for the connection to the antenna connectors (112, 122).

[0019] The example of Fig. The dimensions shown in Figure 1 apply to a design optimized in the UWB frequency range to cover an operating frequency band from approximately 7.5 GHz to 8.5 GHz, with a center frequency of approximately 8.0 GHz. The geometric dimensions of each antenna array (110, 120) are 8.37 mm by 1.58 mm and include a radiating element (left radiating element 111 and right radiating element 121) connected to the respective feed port (112, 122) and may contain parasitic elements. As used here, the geometric extent of the antenna array refers to a dimension that covers the extent of all elements of the antenna array (e.g., all radiating elements, parasitic elements, etc.) in that dimension (for example, the geometric width of the left antenna array 110 is 8.37 mm in the width dimension and the geometric height is 1.58 mm in the height dimension).The radiating elements and parasitic elements can have any shape, including meandering elements (e.g., an L-shape, an F-shape, an E-shape, a snake shape, etc.), where the length does not extend in a single direction but can fold back on itself at various angles.

[0020] 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 dimension of each antenna group is 8.37 mm in the dimension along the ground plane (in Fig. 1, horizontal) and 1.58 mm in the dimension perpendicular to the base plate (in Fig. 1, vertical) (including both antenna groups, generally less than about 30 mm along the ground plane and less than about 5 mm perpendicular to the ground plane). The two antenna groups (110, 120) are separated at the center by a distance of about 18 mm (e.g., about half the wavelength of the center frequency of the operating band), and the distance between the nearest extensions of the antenna groups is about 9.04 mm (the geometric extension of the two antenna groups is therefore about 25.79 mm). The total exclusion zone 140 of the antenna system 100 (which includes the geometric extent of both antenna groups) may be less than about 40 mm by about 10 mm (e.g., about 28.63 mm by about 1.58 mm for an antenna operating at about 8 GHz), making it suitable for integration into small form factors, such as the lid of a laptop.

[0021] It goes without saying that the dimensions can be adjusted proportionally to the center frequency of the operating frequency band. For example, the center distance between the two antenna groups can be approximately half a wavelength of the center frequency of the operating band, and the geometric dimension of each antenna group can be approximately a quarter wavelength. This allows the antenna to be easily adapted to other frequency bands or technologies such as Wi-Fi, while retaining the same concept and the same advantages. As can be seen, Fig. 1 two parasitic elements (e.g. mirrored L-shaped elements) in each antenna group, but each antenna group can have any number of parasitic elements, preferably mirrored in each group and / or mirrored between both groups.

[0022] The antenna system 100 can be used in different modes to enable various detection and localization functions. For operation in a detection mode to provide detection features (e.g., human detection by radar), the left antenna group 110 can be used for transmitting and the right antenna group 120 for receiving (or vice versa). For operation in a ranging mode to provide ranging features (e.g., distance measurements), the left antenna group 110 can be used for transmitting and receiving, while the right antenna group 120 can also or alternatively be used for transmitting and receiving (e.g., one antenna group or both antenna groups can be used). For operation in an angle measurement mode to provide AoA functions (e.g.,For angle measurements, the left antenna group 110 can be used for receiving and the right antenna group 120 for transmitting. Of course, AoA measurement is one of the biggest challenges in this type of antenna system. For good performance, the phase difference between the two antennas (also called phase difference of arrival (PDoA)) should be monotonic when the antennas receive electromagnetic (EM) waves from different angles of arrival (AoA). A lack of monotonicity can lead to ambiguity in the AoA measurement and reduce the performance / reliability of this feature.

[0023] The design of antenna system 100 can provide monotony and good phase balance due to the mirroring of the two antennas. 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 and parasitic elements, creating a kind of EM balance that eliminates surface waves and unnecessary coupling. Furthermore, the additional L-shaped parasitic elements can help improve this balance.

[0024] As in Fig. 1, the left antenna group 110 is mirrored with respect to the right antenna group 120 at 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 mirrors the shape and position of the right radiating element 121 (of the right antenna group 120) transverse to the reflection axis 109. Similarly, the parasitic elements (L-shaped parasitic elements 115a / 115b) of the left antenna group 110 mirror the shape and orientation of the L-shaped parasitic elements 125a / 125b of the right antenna group 120 transverse to the reflection axis 109.

[0025] In Fig. 1, not only are the antenna groups mirrored to each other (at the reflection axis 109), but also the parasitic elements of each group are internally mirrored with respect to their antenna group (e.g., at the reflection axis in the geometric center of the antenna group). Using the left antenna group 110 as an example, the L-shaped parasitic element 115a mirrors the shape and position of the L-shaped parasitic element 115b of the reflection axis 119 in the geometric center of the left antenna group 110. For example, the L-shaped parasitic element 115a has a long section that runs along the direction of the ground plane (e.g., horizontally in Fig. 1) and is connected at its end to a short section that runs perpendicular to the base plate (e.g. vertically in Fig. 1). The short part is connected to the ground plane 150, and between the long part and the ground plane is a space that opens toward the right antenna group 120. The L-shaped parasitic element 115b is the mirrored version across the reflection axis 119, with the short part connected to the ground plane 150 and a space between the long part and the ground plane that opens away from the right antenna group 120. The right antenna group 120 has a similar internal mirroring across the reflection axis 129 at the geometric center of the right antenna group 120.

[0026] Although two antenna groups are discussed here, additional antenna groups may be included. For example, a third antenna group may be added, located in a plane above one of the other antenna groups. Using the right antenna group 120 as an example, a third antenna group may be located above the right antenna group 120 (toward the top of the page), also centered on the axis 129. As with the right antenna group 120 and / or the left antenna group 110 described above, the parasitic elements of the third antenna group may also be internally mirrored with respect to themselves (e.g., via a reflection axis at the geometric center of the antenna group). The third antenna group may also be mirrored with respect to the right antenna group 120 via a reflection axis perpendicular to the axis 129. This arrangement is shown in Fig. 2, wherein the first antenna group 210 is mirrored at the reflection axis 209 relative to the second antenna group 220. A third antenna group 230 is mirrored with respect to the second antenna group 220 at the reflection axis 239.

[0027] Furthermore, the parasitic elements of each antenna group can optionally be internally mirrored with respect to themselves. Thus, the parasitic elements of the first antenna group 210 can be internally mirrored with respect to themselves about the reflection axis 219, the parasitic elements of the second antenna group 220 can be internally mirrored with respect to themselves about the reflection axis 229, and the parasitic elements of the third antenna group 230 can be internally mirrored with respect to themselves about the reflection axis 229. Regarding AoA measurements, the third antenna group 230 can measure the AoA in elevation with respect to the second antenna group 220, while the first antenna group 210 can measure the AoA in azimuth with respect to the second antenna group 220, enabling three-dimensional resolution of the AoA measurements. This concept can be extended to other antennas with similar mirroring, both internally with respect to the antenna group and with respect to the other antenna groups.

[0028] Fig. 3-5 show test results of a simulation and a prototype of an antenna system according to the example of the antenna system 100 of Fig. 1. Fig. 3 shows the reflection coefficient (in dB) and Fig. 4 the transmission coefficient (in dB) of the antenna system 100 versus frequency (in GHz). As in Fig. 3 and Fig. As shown in Figure 4, the antenna system 100 covers the intended frequency band around 8 GHz with very good isolation between the two antennas (e.g., over 18 dB). A good correlation between the simulations (labeled "Sim") and the measurements (labeled "Meas") is also observed.

[0029] In Fig. 5 shows the radiation patterns of the individual antenna groups of the antenna system separately, with radiation pattern 510 for the left antenna (e.g., antenna group 110) and radiation pattern 520 for the right antenna (e.g., antenna group 120). As can be seen, the radiation characteristics show that each antenna group has a quasi-omnidirectional radiation pattern (e.g., a large 3 dB beamwidth (71 degrees)) with a relatively high sidelobe level (0.6 dB).

[0030] As already mentioned, one of the advantages of the disclosed antenna system (e.g., antenna system 100) is that it can provide a monotonic phase difference between the two antennas. In other words, the PDoA vs. AoA variation makes the antenna system suitable for AoA measurements. The general concept of an AoA measurement is that two antennas (e.g., the two antenna groups 110, 120 of antenna system 100) operate 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 the PDoA, the AoA can be calculated using the relationship Δφ=PDoA=360°λ⋅D⋅sin(AoA) where λ is the wavelength of the incident wave.

[0031] Fig. Figure 6 plots PDoA versus AoA for simulations and measurements of a prototype antenna system 100 and compares it to a theoretical value (e.g., the relationship above, depicted as "theory"). The measurements in the graph were performed using a vector network analyzer and a transmit antenna that was moved to change the AoA with respect to the receive antenna (e.g., the prototype antenna system 100). Different elevations of the receive antenna (e.g., lines in the graph showing elevation angles ("el") of -15, 0, 15, and 30 degrees with respect to vertical) were used to simulate, for example, different lid positions if the antenna system were installed in the lid of a laptop. As can be seen, the measurements and simulations show very good monotonic behavior for PDoA vs. AoA, which makes such an antenna system suitable for AoA measurements.The different deviations at different altitudes can be taken into account when calibrating the antenna system.

[0032] With a view to using the antenna system in ranging mode for sensing and localization applications, a prototype was mounted on a large metal plate (which serves as the baseplate of the housing / lid). The prototype was connected to an ultra-wideband (UWB) demo chipset via 50 cm coaxial cable. A UWB demo board with integrated antennas was used as a counterpart on the other side. Fig.Figure 7 plots the measured distance (in cm) against the physical AoA in azimuth (degrees). As can be seen, there is a small measurement error for a large field of view (FoV) and for different lid positions (open and closed lid). This allows the antenna system to be used reliably (e.g., omnidirectionality, robustness, accuracy) in a ranging mode for sensing and localization applications.

[0033] The following describes various examples that may incorporate one or more aspects of the antenna system described above. The examples given with respect to the devices may also apply to the described method(s), and vice versa.

[0034] Example 1 is an antenna system having a plurality of antenna groups, comprising a first antenna group and a second antenna group, the first antenna group comprising a first parasitic element and a first radiating element fed from a first antenna port, the second antenna group comprising a second parasitic element and a second radiating element fed from 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 being separated from the second antenna group by a distance along the ground plane, the first antenna group mirroring the second antenna group.

[0035] Example 2 is the antenna system of Example 1, in which the first antenna group mirrors the second antenna group with respect to a reflection axis at the center of the pitch, the reflection axis being perpendicular to the ground plane.

[0036] Example 3 is the antenna system of any one of examples 1 or 2, wherein the first parasitic element and the second parasitic element are each a meander-shaped parasitic element.

[0037] Example 4 is the antenna system of Example 3, wherein the meandering element is L-shaped.

[0038] Example 5 is the antenna system of any one of examples 3 or 4, wherein the meandering parasitic element comprises a first portion extending along and separated from the ground plane and a second portion extending in a direction perpendicular to the ground plane and connected thereto, one end of the first portion being connected to one end of the second portion.

[0039] Example 6 is the antenna system from Example 5, where the first part is longer than the second part.

[0040] Example 7 is the antenna system of Example 6, wherein the first parasitic element mirrors the second parasitic element with respect to a reflection axis at the center of the pitch, the first section extending along the ground plane away from the end of the second section and toward the center.

[0041] Example 8 is the antenna system of any one of examples 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 both the first additional parasitic element and the second additional parasitic element are meander-shaped.

[0042] Example 9 is the antenna system of Example 8, wherein the first parasitic element reflects the first additional parasitic element about a reflection axis of the first antenna group that is located at a geometric center of the first antenna group and perpendicular to the ground plane.

[0043] Example 10 is the antenna system according to any one of examples 1 to 9, wherein the geometric extension of the first antenna group along the ground plane and the second geometric extension of the second antenna along the ground plane each comprise approximately half the distance.

[0044] Example 11 is the antenna system of any one of Examples 1 to 10, wherein both the first antenna group and the second antenna group have an omnidirectional radiation pattern during operation.

[0045] Example 12 is the antenna system according to any one of Examples 1 to 11, wherein the first antenna group and the second antenna group are arranged on a circuit board substrate.

[0046] Example 13 is the antenna system of Example 12, wherein the circuit board substrate includes a flame-retardant material (e.g., FR4), the flame-retardant material having a dielectric constant of about 4.4 and a thickness of about 0.2 mm.

[0047] Example 14 is the antenna system of any one of Examples 1 to 13, wherein the antenna system further includes a radio frequency (RF) cable configured to connect the antenna system to a wireless module, the RF cable connected to the first antenna port to feed the first radiating element.

[0048] Example 15 is the antenna system of Example 14, wherein the antenna system further includes a second radio frequency (RF) cable configured to connect the antenna system to the radio module, the RF cable connected to the second antenna port to feed the second radiating element.

[0049] Example 16 is the antenna system of Example 14, in which the first antenna group, the second antenna group and the radio module are housed in one housing.

[0050] Example 17 is the antenna system of any one of Examples 1 to 16, wherein the first antenna group and the second antenna group are configured for wireless communication in a frequency range of about 7.5 GHz to 8.5 GHz.

[0051] Example 18 is the antenna system of any one of Examples 1 to 17, wherein the spacing is about one-half wavelength (λ) at a central frequency of a wireless communication frequency range of the antenna system.

[0052] Example 19 is the antenna system of Example 18, wherein the half-wavelength is about 18 mm when the center frequency is about 8 GHz and the frequency range for wireless communication is about 7.5 GHz to 8.5 GHz.

[0053] Example 20 is the antenna system of any one of Examples 1 to 19, wherein a geometric width along the ground plane of the first antenna array is between about a quarter wavelength and about a fifth wavelength at a center frequency of a wireless communication frequency range of the antenna system.

[0054] Example 21 is the antenna system of Example 20, wherein the geometric width is about 8.37 mm when the center frequency is about 8 GHz and the frequency range for wireless communication is about 7.5 GHz to 8.5 GHz.

[0055] Example 22 is the antenna system of any one of Examples 1 to 21, wherein the plurality of antenna groups further comprises a third antenna group having a third parasitic element and a third radiating element fed from a third antenna port, the third antenna group being separated from the second antenna group by a height distance perpendicular to the distance along the ground plane, the third antenna group mirroring the second antenna group along a reflection axis that is parallel to the distance along the ground plane.

[0056] Example 23 is the antenna system of any one of Examples 1 to 22, wherein the geometric height perpendicular to the ground plane of the first antenna array is less than about 5 mm.

[0057] Example 24 is the antenna system of Example 23, with a geometric height of approximately 1.58 mm.

[0058] Example 25 is the antenna system of any one of Examples 1 to 24, wherein the antenna system is configured to operate either the first antenna group or the second antenna group or both as a detection antenna for human radar detection.

[0059] Example 26 is the antenna system of any one of Examples 1 to 25, wherein the antenna system is configured in a sensing antenna mode for human radar detection, the sensing antenna mode comprising operating one of the first antenna group and the second antenna group as a receive antenna and operating the other of the first antenna group and the second antenna group as a transmit antenna.

[0060] Example 27 is the antenna system of any one of Examples 1 to 26, wherein the antenna system is configured in a ranging antenna mode for ranging measurements, the ranging antenna mode comprising operating either the first antenna group or the second antenna group to obtain the ranging measurements.

[0061] Example 28 is the antenna system of any one of Examples 1 to 27, wherein the antenna system is configured in a ranging antenna mode for ranging measurements, the ranging antenna mode comprising operating both the first antenna group and the second antenna group to obtain the ranging measurements.

[0062] Example 29 is the antenna system of any one of Examples 1 to 28, wherein the antenna system is configured in an angle of arrival antenna mode for angle measurements, the angle of arrival antenna mode including operation of both the first antenna group and the second antenna group as receive antennas.

[0063] Example 30 is the antenna system of any one of Examples 1 to 29, wherein the first antenna group and the second antenna group are mirrored to remove surface waves and create an electromagnetic balance within the antenna system.

[0064] Example 31 is the antenna system of any one of Examples 1 to 30, wherein a phase difference between the first antenna group and the second antenna group is monotonic for different angles of arrival of the received electromagnetic waves at the first antenna group and the second antenna group.

[0065] Example 32 is a computer system including a processor, an antenna system connected to the processor, and a housing enclosing the processor and the antenna system. The antenna system includes a first antenna array of radiating elements and parasitic elements that mirrors a second antenna array of radiating elements and parasitic elements, a ground plane connected to each of the parasitic elements of the first and second arrays, and a pair of feed terminals each connected to a corresponding one of the first and second antenna arrays on one of the radiating elements of the corresponding antenna array.

[0066] Example 33 is the computing system of Example 32, in which the antenna system is attached to the chassis with an offset between the antenna system and the chassis.

[0067] Example 34 is the computer system of Example 33, wherein the offset includes an exclusion zone between the chassis and the antenna system.

[0068] Example 35 is the computing system of Example 34, wherein the exclusion zone comprises an area of ​​less than about 40 mm by less than about 10 mm.

[0069] Example 36 is the computing system of Example 35, with the exclusion zone measuring approximately 28.63 mm by 3 mm.

[0070] While the invention has been particularly described with reference to certain aspects in the above disclosure, it should be apparent to those skilled in the art that various changes in form and detail may be made to those aspects without departing from the spirit and scope of the invention as defined by the appended claims. The scope of the invention is thus indicated by the appended claims, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced.

Claims

[1] Antenna system comprising: a plurality of antenna groups comprising a first antenna group and a second antenna group, the first antenna group comprising a first parasitic element and a first radiating element fed from a first antenna terminal, the second antenna group comprising a second parasitic element and a second radiating element fed from a second antenna terminal; and a ground plane coupled to the first antenna group and the second antenna group, the first antenna group being separated from the second antenna group by a distance along the ground plane, the first antenna group mirroring the second antenna group. [2] The antenna system of claim 1, wherein the first antenna array mirrors the second antenna array with respect to a reflection axis at the center of the pitch, the reflection axis being perpendicular to the ground plane. [3] Antenna system according to one of claims 1 or 2, wherein both the first parasitic element and the second parasitic element are meander-shaped parasitic elements; where optionally the meandering parasitic element is L-shaped. [4] The antenna system of claim 3, wherein the meandering parasitic element includes: a first portion extending along and separated from the base plate; and a second portion extending in a direction perpendicular to and connected to the base plate, one end of the first portion being connected to one end of the second portion; where optionally the first section is longer than the second section; further optionally wherein the first parasitic element mirrors the second parasitic element with respect to a reflection axis at a center of the pitch, the first portion extending along the base plate away from the end of the second portion and toward the center. [5] Antenna system according to one of claims 1 to 4, wherein the first antenna group comprises a first additional parasitic element and the second antenna group comprises a second additional parasitic element, wherein both the first additional parasitic element and the second additional parasitic element are meander-shaped; wherein optionally the first parasitic element reflects the first additional parasitic element about a reflection axis of the first antenna group that is located at a geometric center of the first antenna group and is perpendicular to the ground plane. [6] Antenna system according to one of claims 1 to 5, wherein the geometric extension of the first antenna group along the base plate and the second geometric extension of the second antenna group along the base plate are each approximately half the distance; and / or wherein the spacing is approximately half a wavelength (λ) at a central frequency of a wireless communication frequency range of the antenna system. [7] Antenna system according to one of claims 1 to 6, wherein the plurality of antenna groups further comprises a third antenna group comprising 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 a height distance perpendicular to the distance along the ground plane, wherein the third antenna group mirrors the second antenna group along a reflection axis parallel to the distance along the ground plane; and / or wherein the antenna system is configured in a detection antenna mode for human radar detection, the detection antenna mode comprising operating one of the first antenna group and the second antenna group as a receive antenna and operating the other of the first antenna group and the second antenna group as a transmit antenna. [8] Antenna system according to one of claims 1 to 7, wherein the antenna system is configured in a ranging antenna mode for ranging measurements, the ranging antenna mode comprising operating either the first antenna group or the second antenna group or both to obtain the ranging measurements; and / or wherein the antenna system is configured in an angle of arrival antenna mode for angle measurements, wherein the angle of arrival antenna mode comprises operating both the first antenna group and the second antenna group as receiving antennas; and / or wherein a phase difference between the first antenna group and the second antenna group is monotonic for different arrival angles of received electromagnetic waves at the first antenna group and the second antenna group. [9] Computing system comprising: a processor; an antenna system connected to the processor; and a housing enclosing the processor and the antenna system, the antenna system comprising: a first antenna group consisting of radiating elements and parasitic elements, which mirrors a second antenna group consisting of radiating elements and parasitic elements; a ground plane connected to each of the parasitic elements of the first and second antenna groups; and a pair of feed terminals each connected to a corresponding one of the first and second antenna groups on one of the radiating elements of the corresponding antenna group. [10] Computing system according to claim 9, wherein the antenna system is mounted to the chassis with an offset between the antenna system and the chassis; wherein the offset optionally comprises a no-go zone between the chassis and the antenna system, the no-go zone comprising an area of less than about 40 mm by less than about 10 mm; wherein further optionally each of the parasitic elements of the first and second antenna groups is L-shaped.

Images