WO2023130418A1

WO2023130418A1 - Antenna assembly capable of proxmity sensing and electronic device with the antenna assembly

Info

Publication number: WO2023130418A1
Application number: PCT/CN2022/070910
Authority: WO
Inventors: Mitsuru Mishio; Kenichiro Kodama
Original assignee: Goertek Inc.
Priority date: 2022-01-10
Filing date: 2022-01-10
Publication date: 2023-07-13
Also published as: CN116762235A

Abstract

An antenna assembly capable of proximity sensing and an electronic device including the antenna assembly are provided. The antenna assembly includes a first antenna element being driven for communication in a frequency band of radio frequency RF signals; a second antenna element positioned in vicinity of the first antenna element and electrically isolated from the first antenna element, the second antenna element being parasitically coupled to the first antenna element; a first filter coupling the second antenna element to ground; and a second filter coupling the second antenna element to a proximity sensing circuit, the proximity sensing circuit driving the second antenna element to detect proximity of a capacitive object to the antenna assembly. The antenna assembly requires limited space for supporting proximity sensing, and has lowered cost.

Description

ANTENNA ASSEMBLY CAPABLE OF PROXMITY SENSING AND ELECTRONIC DEVICE WITH THE ANTENNA ASSEMBLY

TECHNICAL FIELD

The present disclosure generally relates to antenna, and in particular, to an antenna assembly capable of proximity sensing and an electronic device including the antenna assembly.

BACKGROUND

Nowadays, electronic devices such as portable computers and handheld electronic devices are becoming increasingly popular. Such electronic devices are often provided with wireless communications capabilities and are integrated with antennas for the wireless communications. However, such electronic devices, especially handheld electronic devices, are generally manufactured with small form factors. Therefore, there is limited space for antennas in the electronic devices.

Additionally, in electronic devices, electronic components in the vicinity of an antenna can incur electromagnetic interference to the antenna, while antenna operation can also be blocked by conductive structures. It can be challenging to meet desired antenna performance criteria in a compact device. High transmit powers and wide antenna bandwidths can be desirable to ensure adequate signal strength during communications, but these attributes may give rise to challenges with controlling emitted radiation levels.

In mobile phone system there is a hard requirement on transmitter radiated power level from a mobile phone, which is called specific absorption rate (SAR) regulation to human body and head. SAR regulation places restrictions on the amount of radiation that may be emitted at any particular point within a given distance of an antenna, and therefore imposes maximum energy absorption limits on handset manufacturers.

In this concern, there is need for antenna structures to be used in electronic devices with small form factors.

SUMMARY

In view of the above, an antenna assembly capable of proximity sensing and an electronic device including the antenna assembly are provided according to embodiments of the present disclosure, in order to reduce the space needed for an antenna assembly within an electronic device. At least following technical solutions are provided to achieve the above objective.

In one aspect, an antenna assembly is provided, including: a first antenna element being driven for communication in a frequency band of radio frequency RF signals; a second antenna element positioned in vicinity of the first antenna element and electrically isolated from the first antenna element, the second antenna element being parasitically coupled to the first antenna element; a first filter coupling the second antenna element to ground; and a second filter coupling the second antenna element to a proximity sensing circuit, the proximity sensing circuit driving the second antenna element to detect proximity of a capacitive object to the antenna assembly.

In one embodiment, a drive signal is communicated from the proximity sensing circuit to drive the second antenna element to detect proximity of the capacitive object, and a frequency of the drive signal is lower than a frequency of the frequency band of RF signals.

In one embodiment, the drive signal is communicated concurrently with the RF signals being communicated.

In one embodiment, the second antenna element is configured to associate the first antenna element to form resonance and alter a radiation mode of the antenna assembly.

In one embodiment, the first filter functions as a high pass filter for allowing pass of the RF signals and direct current block.

In one embodiment, the first filter is a capacitor.

In one embodiment, the second filter functions as a low pass filter for blocking pass of the RF signals.

In one embodiment, the second filter is an inductor.

In one embodiment, the first antenna element is electrically connected to the proximity sensing circuit via a third filter, and the proximity sensing circuit further drives the first antenna element to detect proximity of the capacitive object. In one embodiment, the third filter is of a type same as the second filter.

In one embodiment, the first antenna element is electrically connected to a RF transceiver via a fourth filter to communicate the RF signals, wherein the fourth filter allows pass of the RF signals. In one embodiment, the fourth filter is of a type same as the first filter.

In one embodiment, the second antenna element includes a first portion and a second portion connected with each other.

In one embodiment, the antenna assembly supports a first frequency band of RF signals with the first portion of the second antenna element, and supports a second frequency band of RF signals with the second portion of the second antenna element, where the first frequency band is higher than the second frequency band.

In another aspect, an electronic device is provided, including: a radio frequency RF transceiver; a proximity sensing circuit; and an antenna assembly including a first antenna element being driven by the RF transceiver for communication in a frequency band of RF signals; a second antenna element positioned in vicinity of the first antenna element and electrically isolated from the first antenna element, the second antenna element being parasitically coupled to the first antenna element; a first filter coupling the second antenna element to ground; and a second filter coupling the second antenna element to the proximity sensing circuit, the proximity sensing circuit driving the second antenna element to detect proximity of a capacitive object to the antenna assembly.

In one embodiment, the first antenna element is electrically connected to a RF transceiver via a fourth filter to communicate the RF signals, wherein the fourth filter allows pass of the RF signals and the fourth filter is of a type same as the first filter.

In one embodiment, the RF transceiver is configured to lower a transmitting and receiving power in response to detecting, via the antenna assembly and the proximity sensing circuit, the proximity of the capacitive object to the antenna assembly.

According to embodiments of the present disclosure, with the antenna assembly as disclosed in the present disclosure, it is possible to have proximity sensor integrated into antenna assembly with resonate or parasitic element of antenna. Therefore, the space needed for the antenna capable of proximity sensing is reduced as compared to the conventional art. Hence, the antenna assembly will fit space-limited products such as handheld devices such as mobile phones, AR glasses and HMD and like such consumer products. Furthermore, since the antenna elements according to the present disclosure may be formed to be antenna electrode, parasitic elements and sensor electrodes, this is also a cost-saving solution.

BRIEF DESCRIPTION OF THE DRAWINGS

For clearer illustration of the technical solutions according to embodiments of the present disclosure or conventional techniques, hereinafter briefly described are the drawings to be applied in embodiments of the present disclosure or conventional techniques. Apparently, the drawings in the following descriptions are only some embodiments of the present disclosure, and other drawings may be obtained by those skilled in the art based on the provided drawings without creative efforts.

Figure 1 is a schematic structural diagram of a conventional antenna provided with proximity sensing structure having one sensor;

Figure 2 is a schematic structural diagram of a conventional antenna provided with proximity sensing structure having two sensors;

Figure 3 is a schematic structural diagram of an antenna according to an embodiment of the present disclosure;

Figure 4 is a schematic structural diagram of an antenna according to another embodiment of the present disclosure;

Figure 5 is a schematic structural diagram of an antenna according to yet another embodiment of the present disclosure;

Figure 6 is a schematic structural diagram of an antenna according to yet another embodiment of the present disclosure;

Figure 7 is a schematic diagram showing a state where an antenna assembly according to an embodiment of the present disclosure operates as an antenna for RF communication;

Figure 8 is a schematic diagram showing a state where an antenna assembly according to an embodiment of the present disclosure operates as sensor electrodes for proximity sensing;

Figure 9 is a schematic diagram showing an antenna assembly capable of proximity sensing according to an embodiment of the present disclosure being used for gesture sensing;

Figure 10 is a schematic structural diagram of an electrode device with an antenna assembly capable of proximity sensing amounted according to an embodiment of the present disclosure; and

Figure 11 is a flowchart for controlling an antenna assembly capable of proximity sensing according to an embodiment of the present disclosure.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Hereinafter technical solutions in embodiments of the present disclosure are described in conjunction with the drawings in embodiments of the present closure. Apparently, the described embodiments are only some rather than all of the embodiments of the present disclosure. Any other embodiments obtained based on the embodiments of the present disclosure by those skilled in the art without any creative effort fall within the scope of protection of the present disclosure.

It should be noted that, terms such as "first" , "second" , "third" , "fourth" and the like are only used herein to distinguish one entity or operation from another, rather than to necessitate or imply that an actual relationship or order exists between the entities or operations. Furthermore, the terms such as "include" , "comprise" or any other variants thereof means to be non-exclusive. Therefore, a process, a method, an article or a device including a series of elements include not only the disclosed elements but also other elements that are not clearly enumerated, or further include inherent elements of the process, the method, the article or the device. Unless expressively limited, the statement "including a…" does not exclude the case that other similar elements may exist in the process, the method, the article or the device other than enumerated elements.

In mobile phone system there is a hard requirement on transmitting (Tx) radiated power level from an mobile phone, which is called Specific Absorption Rate (SAR) regulation to human body and head. Currently some of proximity sensors are used in a mobile phone in order to detect proximity of human body when closing to the mobile phone, especially area of an antenna. When proximity of human body to the mobile phone is detected, Tx maximum power is set to be lower or limited in order to meet the SAR requirements.

Conventionally proximity sensor aiming for the SAR requirement is integrated next to antenna assembly. Figure1 shows an antenna assembly integrated with a proximity sensor according to a conventional solution. As shown in Figure1, a driven element 101 of the antenna is fed with radio frequency (RF) signals from a RF module 102 for wireless communication. To implement the sensing of proximity of human body or head to the antenna, a proximity sensor electrode 103 is additionally provided in vicinity of the driven element 101 of the antenna, and the sensor electrode 103 is connected with a proximity sensing integrated circuit (IC) 104 for being driven by the sensing IC to conduct the proximity sensing. Usually, the sensor electrode 103 is spaced from the driven element 101 of the antenna at a distance over 5mm.

For proximity sensing, the sensing IC 104 sends a low frequency signal to the sensor electrode 103 to drive the sensor electrode 103, and the sensor IC 104 may detect changes in measured capacitance value associated with the proximity sensor electrode 103, and determine whether an external capacitive object such as human body or head is located in the proximity of the antenna assembly. Specifically, the sensor electrode 103 may be considered as one electrode while the external capacitive object may be considered as another electrode of a capacitor, and a capacitance of the capacitor between the two electrodes is changed as a distance from the external capacitive object to the sensor electrode 103 changes. Once the proximity sensing IC 104 determines, from the change of capacitance that, the external object is too close to the sensor electrode 103, the transmitting power of the module 102 is backed off so as to meeting the SAR requirement.

In a case that the antenna assembly has a longer driven element, the solution with only one proximity sensor electrode as described above cannot cover whole antenna assembly. For example, for the case that the proximity sensor electrode is provided on the left side of the driven element as shown in Figure 1, the RF hotspots on the left side may be sensed with the sensor electrode 103, while the RF hotspots on the right side of the driven element may be missed by the sensor electrode 103. In some implementations, to provide a better coverage of the RF hotspots of the whole antenna, another one or more proximity sensor electrodes are added around the antenna assembly. An example of a solution with two sensor electrodes is shown in Figure 2. In Figure 2, two

sensor electrodes

203 and 213 are provided around the driven element 201 of the antenna assembly, to cover the whole range of the driven element 201. The

sensor electrodes

203 and 213 are connected to

sensor ICs

204 and 214 respectively, for being driven by the sensor ICs to detect the proximity of an external object. Similar to the foregoing example, the antenna element 201 is connected to the RF module 202 to communication of RF signals. The sensor electrode 203 and the sensor IC 204 may function in a way similar to that described above with reference to Figure 1, to determine the proximity of the object 206 to the antenna element 201. For an object 216, which is close to the sensor electrode 213 and is also close to the antenna element 201, may be determined by the sensor IC 204 as not close enough since the object 216 is not close to the sensor electrode 203. By adding the sensor electrode 213 and sensor IC 214, the proximity of the object 216 will not be missed.

Due to the limited space in electronic devices especially portable and handheld electronic devices, the addition of the sensor electrode (s) in the vicinity of the antenna assembly brings challenges to manufacturers of the electronic devices. Furthermore, the sensor electrodes are generally made of conductive components, which would interfere with the antenna operation due to factors such as electromagnetic interference and results in impact to overall antenna performance.

In view of the above drawbacks of conventional solutions in which sensor electrodes are added around the antenna assembly, the present disclosure proposes an improved antenna assembly which supports proximity sensing while requiring less space. Figure 3 shows a schematic structural diagram of an antenna assembly according to an embodiment of the present disclosure. As shown in Figure 3, the antenna assembly includes a first antenna element 301 and a second antenna element 302 positioned in vicinity of the first antenna element 301. The second antenna element 302 is electrically isolated from the first antenna element 301. The antenna assembly further includes a first filter 303 to couple the second antenna element 302 to a ground line, and a second filter 304 to couple the second antenna element 302 to a periphery sensing circuit 305.

The first antenna element 301 may be coupled to a feeding line of an RF transceiver, so as to be driven for communication of RF signals.

The shape of the first antenna element 301 is not limited in the present disclosure. The first antenna element 301 may be in, including but not limited to, a strip shape, a sheet shape, a rod shape, a line shape, a coating, a film, and the like. In this embodiment, the first antenna element 301 is in an elongated shape.

In the embodiment, the second antenna element 302 is positioned in vicinity of the first antenna element 301 in a way of being electronically isolated from the first antenna element. For example, the second antenna element 302 may be positioned above or beneath the first antenna element 301 in a layered structure of the antenna assembly. By virtue of positioning second antenna element 302 made of conductive material in vicinity of the first antenna element 301, the second antenna element 302 is parasitically coupled to the first antenna element 301 and therefore can alter a radiation mode of the antenna assembly. For example, the second antenna element 302 associates the first antenna element 301 to form resonance, and modifies the radiation pattern of radio waves emitted by the first antenna element 301.

In an exemplary implementation, the second antenna element 302 may be a parasitic element in the antenna assembly 300. The parasitic element is positioned within a coupling area of the first antenna element 301, forms resonance with the first antenna element 301, and functions together with the first antenna element 301 in the communication of the RF signals. By using the parasitic element of the antenna assembly as the sensor electrode of proximity sensing, less modification to the existing antenna structure is needed, therefore the cost is low. In addition, by using the existing parasitic element of the antenna assembly as the sensing electrode, no additional space is needed for accommodating the sensing electrode and therefore the antenna assembly supporting proximity sensing fits the portable or handheld electronic devices better.

The shape of the second antenna element 302 is not limited in the present disclosure. The second antenna element 302 may be in, including but not limited to, a strip shape, a sheet shape, a rod shape, a line shape, a coating, a film, and the like. In this embodiment, the second antenna element 302 is in an elongated shape.

The first antenna element 301 and the second antenna element 302 may be made of conductive materials, including but not limited to, metals such as silver, copper, etc., transparent conductive oxides (such as indium tin oxide ITO) , carbon nanotubes, graphene, etc.

In some implementations, the antenna assembly may include more antenna elements for communicating the RF signals, and the antenna elements together with the first and

second antenna elements

301 and 302 may be in a variety of structures. For example, the antenna assembly may be of a structure of, including but not limited to, inverted F antennas, strip antennas, planar inverted F antennas, slot antennas, cavity antennas, patch antennas, monopole antennas, dipole antennas, hybrid antennas, or other suitable antennas. Those skilled in the art may conceive other structures of the antenna assembly, and the present disclosure is not limited in this aspect.

Each of the first antenna element 301 and the second antenna element 302 can be formed by a conductive structure, such as a metal trace on a carrier, a conductive layer on a substrate, a metal foil, a wire in a flexible printed circuit or a rigid printed circuit, and the like. Those skilled in the art may conceive other way of forming the first antenna element 301 and the second antenna element 302, and the present disclosure is not limited in this aspect.

The second antenna element 302 is coupled to ground via the first filter 303 and is coupled to the sensing circuit 305 via the second filter 304. The first filter 303 functions as a high pass filter (HPF) for the RF signals and direct current (DC) block, which makes it possible for the second antenna element 302 to hold electrostatic charges to work as a sensor electrode. The second filter 304 may function as a low pass filter (LPF) and high impedance in RF frequency band, so that trace or routing to the proximity sensing circuit and the signals associated with proximity sensing transmitted from the sensing circuit 305 to the second antenna element 302 will not affect antenna performance of the antenna assembly 300.

In an exemplary implementation, the first filter 303 is implemented with a capacitor, which may allow the pass of the RF signals. In an exemplary implementation, the second filter 304 is implemented with an inductor, which blocks the high frequency RF signals from the sensing circuit 305 while allows a low frequency signal to be transmitted from the sensing circuit 305 to the second antenna element 302. In other implementations, the first filter 303 may be implemented with other components of functionality similar to a capacitor, and the second filter 304 may be implemented with other components of functionality similar to an inductor; or the first filter 303 and the second filter 304 may include additional components to implementing other functionalities; the present disclosure is not limited in this aspect.

In such a configuration, when a low frequency signal is sent by the sensing circuit 305, the second filter 304 allows the low frequency signal to pass and flow to the second antenna element 302; accordingly the second antenna element 302 is driven to function as a sensor electrode for proximity sensing. Once an external object (for example, human body or head) approaches, a measured capacitance associated with the second antenna element functioning as the sensor electrode may change; and the sensing circuit 305, sensing the change in the capacitance, may determine the proximity of the object. Accordingly, subsequent actions may be made to adjust the TX power of the RF transceiver, so as to meet the SAR.

It should be noted herein that, the antenna function and the sensing function of the antenna assembly 300 can work independently due to the arrangement of the first filter 303 and the second filter 304. Hence, the low frequency signal for driving the sensing may be communicated when the RF signals are not communicated, or alternatively the low frequency signal may be communicated concurrently with the communication of RF signals, both cases falling within the scope of the present disclosure.

It should be noted herein that, a frequency of the low frequency signal transmitted from the sensing circuit 305 to the second antenna element 302 is substantially lower than a frequency band of the RF signals communicated by the antenna assembly 300. In one implementation, the low frequency signal as used herein may be a signal with a frequency lower than 5MHz. In one implementation, the frequency band of the RF signals communicated by the antenna assembly 300 may be over 600MHz in cellular communication, or may be higher frequency bands such as 2.4GHz or 5GHz for Wi-Fi communication. The frequencies enumerated in the present disclosure are exemplary and are only for illustration, and the present disclosure is not limited by the enumerated frequencies.

In a preferable embodiment, the second antenna element 302 is positioned to be proximately parallel to the first antenna element 301 and has a length comparable as or longer than the first antenna element 301. In this way, when working as the sensor electrode, the second antenna element 302 can cover all RF hotspots across the whole length of the first antenna element 301. Therefore, the problem of missing some RF hotspots in case of providing only one sensor electrode in the conventional solutions may be avoided. Of course, the second antenna element 302 may be of other arrangements with respect to the first antenna element 301, or may be of other dimensions, the present disclosure is not limited in this aspect.

For the communication in the RF frequency band of the RF signals, due to the second filter 304 functioning as the LPF, the antenna assembly 300 and the loop of proximity sensing are separated from each other, to ensure the stable performance of the antenna assembly 300 and the normal operation of the loop of proximity sensing.

In some implementations, placement of the second filter 304 is close to the second antenna element 302 in order to minimize a length of electrical routing, to avoid any stub or unexpected resonances in RF frequency. However, the present disclosure is not limited in this aspect.

The sensing circuit 305 may be implemented in many ways and may be in a variety of structures. For example, the sensing circuit 305 may be an integrated circuit (IC) supporting proximity sensing by using one or more sensor electrodes. Alternatively, the sensing circuit 305 may be implemented with a market-available chip with proximity sensing function. The present disclosure is not limited in this aspect.

It should be noted that, although the antenna assembly 300 is shown as only including the first antenna element 301, the second antenna element 302, the first filter 303 and the second filter 304, the antenna assembly 300 may further includes other functionality components. For example, the antenna assembly 300 may include a tuning circuit, a power amplifier, a power adjusting circuit, and the like. For another example, an antenna matching circuit can be place between the antenna assembly and the RF transceiver.

In this embodiment, by including the first filter and the second filter, an antenna element, which may be a parasitic element of the antenna assembly, can work as a sensor electrode. And at the same time antenna function can stay the same. Integrated a sensor electrode into a parasitic element, the antenna assembly can detect proximity of human body or head to the antenna assembly because the parasitic element can be designed in order to cover wide enough of the antenna assembly.

In addition, the configuration of the antenna assembly according to the embodiment of the present disclosure make it possible to make electronics devices smaller because no extra space for proximity sensor is needed because proximity sensor can be integrated into antenna assembly with the inventive concept of the present disclosure.

To sum up, in the embodiment of the present disclosure, the second antenna element functions to not only conduct RF communication and improve the antenna performance, but also to detect proximity of external object to the antenna assembly. The second antenna element may be dimensioned to cover wide area of the antenna assembly, which reduce additional proximity sensor for the SAR. Furthermore, miss-alignment issue between sensing area and RF hotspot may be avoided. The impact configuration of the first and second antenna elements may reduce whole integration space for both antenna assembly and sensor electrodes comparing to conventional solutions.

According to another embodiment of the disclosure, an antenna assembly capable of proximity sensing is provided as shown in Figure 4. Similar to the antenna assembly as described above, the antenna assembly includes a first antenna element 401 and a second antenna element 402 positioned in vicinity of the first antenna element 401. The second antenna element 402 is electrically isolated from the first antenna element 401 and is parasitically coupled to the first antenna element 401. The first antenna element 401 is driven by a RF module 408 for communication in a frequency band of RF signals. The second antenna element 402 of the antenna assembly is coupled to ground via a first filter 403, and is further coupled to a sensor IC 405 via a second filter 404. Additionally, the antenna assembly according to this embodiment further includes a third filter 406 and a fourth filter 407, in which the first antenna element 401 is coupled to the RF module 408 via the third filter 406 and is couple to the sensor IC 405 via the fourth filter 407.

Similar to the embodiment described above, the second antenna element 402 may be a parasitic element positioned within a coupling area of the first antenna element 401, forms resonance with the first antenna element 401, and functions together with the first antenna element 401 in the communication of the RF signals.

Similar to the embodiment described above, the first filter 403 functions as a high pass filter for allowing pass of the RF signals and direct current block. The second filter 404 may function as a low pass filter and high impedance in RF frequency. And by virtue of the first filter 403 and the second filter 404, the second antenna element 402 may work as a sensor electrode, being driven by the sensor IC 405 for proximity sensing. In some implementations, the first filter 403 may be a capacitor, and the second filter 404 may be an inductor.

Furthermore, in this embodiment, the third filter 406 connected between the first antenna element 401 and the RF module 408 functions as a high pass filter for allowing pass of the RF signals and direct current block, while the fourth filter 407 connected between the first antenna element 401 and the sensor IC 405 functions as a low pass filter and high impedance in RF frequency band. In this way, the first antenna element 401 can be coupled using the fourth filter 407 to separate the high frequency RF signals at the frequency of antenna operation from the low frequency signal used for the proximity sensing function; and the first antenna element 401 can be designed to operate as another proximity sensor electrode by using the third filter 406 to present a high impedance at the lower frequencies used for proximity sensing.

In an exemplary implementation, the third filter 406 is implemented with a capacitor, and the fourth filter 407 is implemented with an inductor. In other implementations, the third filter 406 or the fourth filter 407 may be implemented with other components or may include additional components, and the present disclosure is not limited in this aspect.

In an exemplary implementation, the third filter 406 may be of a type same as the second filter 404; and the fourth filter 407 may be of a type same as the first filter 403.

With the configuration according to the embodiment shown in Figure 4, there are two channels of proximity sensing respectively implemented via the first antenna element 401 and the second antenna element 402 serving as sensing electrodes, therefore an even-more improved coverage of the whole antenna assembly is provided for proximity sensing, while substantially no extra space is needed. Therefore, the antenna assembly according to this embodiment is adapted to usage in portable or handheld electronic devices with limited space for the antenna structure.

It should be noted herein that although in Figure 4 the first antenna element 401 and the second antenna element 402 are connected to a same sensor IC 405, it is feasible that the first antenna element 401 and the second antenna element 402 are connected to separate sensing ICs, and the present disclosure is not limited in this aspect.

It should be noted herein that the sensing conducted by the first antenna element 401 may be concurrently with the sensing conducted by the second antenna element 402; or the first antenna element 401 and the second antenna element 402 may performing sensing at different moments. In other words, the sensor channel 1 and the sensor channel 2 may be activated simultaneously or asynchronously, or the two sensor channels may be alternatively be backup for each other, the present disclosure is not limited in this aspect.

It should be noted herein that the antenna function and the sensing function of the first antenna element 401 and/or the second antenna element 402 can work independently. Hence, drive signal for driving sensing of the first antenna element 401 and/or the second antenna element 402 may be communicated concurrently or not concurrently with communication of RF signals.

It is noted herein that the first antenna element and the second antenna element may be in a variety of shapes and dimensions as required for different applications. Figure 5 shows an antenna assembly capable of proximity sensing according to an exemplary embodiment of the present disclosure, in which the second antenna element, implemented with a parasitic element of the antenna assembly, is in a multi-element structure and is long in total length.

As shown in Figure 5, the antenna assembly according to this embodiment includes a first electrode 501 and a parasitic element 502 positioned in a coupling area of the first electrode 501. The first electrode 501 is connected to a RF module 508 via a capacitor 506, and is connected to a sensor IC 505 via an inductor 507. The parasitic element 502 is connected to ground via a capacitor 503, and is connected to the sensor IC 505 via an inductor 504.

In this configuration, the first electrode 501 and the parasitic element 502 are driven by the RF module 508 for communication in a radio frequency band of RF signals. In addition, the first electrode 501 and the parasitic element 502 serve as sensor electrodes for two-channel proximity sensing, i.e., the sensor channel 1 and the sensor channel 2 showing in Figure 5.

As shown in Figure 5, the parasitic element 502 may include three

portions

5021, 5022 and 5023 connected end to end to form a long parasitic element 502. The first portion 5021 of the long parasitic element 502 may be positioned parallel to the first electrode 501 and is within the coupling area of the first electrode 501. The second portion 5022 and the third portion 5023 are connected with the first portion 5021 to extend the length of the parasitic element 502. By using such a longer parasitic element, the antenna assembly can support communication in a relatively lower frequency band of RF signals, for example, 600MHz band of cellular communication. It is noted herein that the specific shape of the long parasitic element 502 is exemplary, and the long parasitic element 502 may be in other shapes, which is not limited in the disclosure.

According to another embodiment of the present disclosure, as shown in Figure 6, the antenna assembly capable of proximity sensing may include a parasitic element 602 added with a short element. The antenna assembly has a structure and connection similar to that shown in Figure 5, except for the long parasitic element 602 additionally includes a short element 612, which is connected with other portions of the parasitic element 602. By adding the short element 612 to the parasitic element 602 of the antenna assembly, as shown in Figure 6, the antenna assembly may support higher RF bands, for example, higher than 600MHz.

With the embodiments shown as in Figures 5 and 6, one can see that it is possible to make a multiband antenna assembly by using the structures as proposed in the present disclosure. And still proximity of human body or head may be detected with the parasitic element because of the filters added to isolate a low frequency of the sensing loop from a high frequency of RF communication. It should be understood that the embodiments shown in Figures 3, 4, 5, 6, although shown in different and separate drawings, may be in any combination as needed, and the present disclosure is not limited in this aspect.

With the antenna assembly as disclosed in the present disclosure, it is possible to have proximity sensor integrated into antenna assembly with resonate or parasitic element of antenna. Therefore, the space needed for the antenna capable of proximity sensing is reduced as compared to the conventional art. Hence, the antenna assembly will fit space-limited products such as handheld devices such as mobile phones, Augmented Reality (AR) glasses, Head Mounted Display (HMD) and like such consumer products. Furthermore, since the antenna elements according to the present disclosure may be formed to be antenna electrode, parasitic elements and sensor electrodes, this is also a cost-saving solution.

In the following, the operations of the antenna assembly capable of proximity sensing according to the embodiments of the present disclosure are described by reference to Figures 7 and 8.

Figure 7 is a schematic diagram showing a state where the antenna assembly operates as an antenna system for RF communication. The antenna assembly shown in Figure 7 is in a configuration similar to that shown in Figure 4, and it is understandable that any of the antenna assemblies described in the present disclosure may be operated in a way similar to those described herein.

In the state as shown in Figure 7, since the sensor IC and the routing associated with the sensor IC are separated from the antenna assembly by the inductors or other types of filters connected to the two conductive elements of the antenna assembly, the communication of RF signals in the RF frequency band, including but not limited to the frequency band of 600MHz in cellular communication or higher frequency bands such as 2.4GHz or 5GHz for Wi-Fi communication, is separated from the low frequency signals used in the sensing loop. Therefore, in this state, the antenna assembly functions as an antenna system.

During operation as an antenna, the RF module and the antenna assembly perform wireless communication with one or more external devices. The external devices include, but are not limited to, a mobile phone, a laptop, a desktop, a tablet, a router, or a base station. An external device depends on an application environment in practice. It is appreciated that the wireless communication is based on a communication protocol, such as

wireless fidelity (Wi-Fi) , global positioning system (GPS) , or Cellular.

Figure 8 is a schematic diagram showing a state where the antenna assembly operates as sensor electrodes for proximity sensing. The antenna assembly shown in Figure 7 is in a configuration similar to that shown in Figure 4, and it is understandable that any of the antenna assemblies described in the present disclosure may be operated in a way similar to those described herein.

In the state as shown in Figure 8, it is assumed that a sensor channel 2 (indicated as sensor Ch2) , in which a parasitic element 802 is located, is activated. A low frequency signal is sent from the sensor IC 805 to the parasitic element 802 for driving the parasitic element 802. In an example, the low frequency signal is at a frequency lower than 5MHz. In this case, the capacitor 803 has a high impedance value equivalent to an open circuit; while the inductor 804 passes the low frequency signal, and the parasitic element 802 of the antenna assembly works as a sensor electrode for proximity sensing. During operation, the sensor IC monitors change of capacitance associated with the electrode 802. At this time the remaining antenna element 801, the capacitor 806, together with the RF module 808, can be handled as parasitic capacitor, which can be handled or removed as a fixed capacitor in the sensing loop.

In some implementations, sensor performance adjustment like sensitivity of sensor electrode (s) will be done in the sensor IC 805.

Although the state of the antenna assembly working as the antenna system and the state of the antenna assembly working as the sensor electrode for proximity sensing are illustrated separately, it should be understood that the antenna assembly can work both functions at the same time independently, so there is no need to support time division function for antenna and sensor function.

According to an embodiment of the present disclosure, with the inventive concept of the present disclosure, the antenna assembly with this integration can be expanded into a multi-element sensor system to support user interface (UI) with multi-element touch and proximity functionalities. Figure 9 is a schematic diagram showing two antenna elements of an antenna assembly working as sensor electrodes, which make it possible to handle gesture and swipe control, for example, in a direction indicated by the arrow, according to an embodiment of the present disclosure.

Referring to Figure 10, an electronic device including an antenna assembly capable of proximity sensing is provided according to an embodiment of the present disclosure. Electronic device 1000 of Figure 10 may be a portable computer such as a laptop computer, a portable tablet computer, a mobile telephone, a mobile telephone with media player capabilities, a handheld computer, a remote control, a game player, a global positioning system (GPS) device, a desktop computer, a music player, a multi-touch electronic device, Augmented Reality (AR) glasses, Head Mounted Display (HMD) , a combination of such devices, or any other suitable electronic device. As shown in Figure 10, electronic device 1000 may include an in-out circuitry 1100, a processor 1200 and storage 1300.

The processor 1200 may be a microprocessor and other suitable integrated circuit. The processor 1200 and storage 1300 may be configured for control the operation of the electronic device 1000. In an exemplary implementation, the processor 1200 may run software stored in the storage 1300 for the electronic device 1000, such as operating system functions, phone call applications, Internet browsing, email applications, media playback applications, control functions for controlling radio-frequency power amplifiers and other radio-frequency transceiver, etc.

The storage 1300 may include one or more different types of storage such as hard disk drive storage, nonvolatile memory (e.g., flash memory or other electrically-programmable-read-only memory) , volatile memory (e.g., static or dynamic random-access-memory) .

Communications protocols that may be implemented by the processor 1200 include Internet protocols, cellular telephone protocols, wireless local area network protocols (e.g., IEEE 802.11 protocols, referred to as

) , protocols for other short-range wireless communications links such as the

protocol, etc.

The in-out circuitry 1100 is configured to implement input and output function of the electronic device 1000. The in-out circuitry 1100 may include an input-output device 1111 and a wireless communication circuitry 1120. The input-output device 1111 may be a touch screen and other user input device such as buttons, joysticks, click wheels, scrolling wheels, touch pads, key pads, keyboards, microphones, cameras, etc. Furthermore, the input-output device 1111 may include display and audio devices such as liquid-crystal display (LCD) screens, light-emitting diodes (LEDs) , organic light-emitting diodes (OLEDs) , and other components that present visual information and status data.

The wireless communications circuitry 1120 may include radio-frequency (RF) transceiver circuitry 1121 formed from one or more integrated circuits, power amplifier circuitry, low-noise input amplifiers, passive RF components, and other circuitry for handling RF wireless signals. For example, the RF transceiver circuitry 1121 may include a cellular transceiver circuitry 1122 for handling wireless communications in cellular bands such as the bands at 600 MHz, 850 MHz, 900 MHz, 1800 MHz, and 1900 MHz, and the 2100 MHz data band. The RF transceiver circuitry 1121 may also include a WIFI and Bluetooth transceiver circuitry 1123 that handles 2.4 GHz and 5 GHz bands for WiFi (IEEE 802.11) communications and the 2.4 GHz Bluetooth communications band. The Wireless communications circuitry 1120 can include circuitry for other short-range and long-range wireless links if desired. For example, wireless communications circuitry 1120 may include global positioning system (GPS) receiver equipment, wireless circuitry for receiving radio and television signals, paging circuits, etc.

The RF transceiver circuitry 1121 may be implemented using one or more integrated circuits and associated components (e.g., switching circuits, matching network components such as discrete inductors, capacitors, and resistors, and integrated circuit filter networks, etc. ) . These devices may be mounted on any suitable mounting structures. With one suitable arrangement, transceiver integrated circuits may be mounted on a printed circuit board.

The wireless communications circuitry 1120 may include antenna assembly 1124, such as the antenna assembly as described above by referring to Figures 3-6 or variations thereof. As described above, the antenna assembly 1124 may be single band antenna that each cover a particular desired communications band or may be multi-band antenna. A multiband antenna may be used, for example, to cover multiple cellular telephone communications bands.

In addition, the wireless communications circuitry 1120 may further include other circuitries for implementing different communication related functions. For example, the wireless communications circuitry 1120 may include proximity sensing circuitry (not shown) which uses element (s) of the antenna assembly 1124 as sensor electrode (s) for proximity sensing. In addition, the wireless communications circuitry 1120 may further include a power adjusting circuitry (not shown) for adjusting power of the RF transceiver circuitry 1121 in response to detecting result from the proximity sensing circuitry.

Connections within the RF circuitry 1121 may include any suitable conductive pathways over which radio-frequency signals may be conveyed including transmission line path structures such as coaxial cables, microstrip transmission lines, stripline transmission lines, etc.

As described above, to minimize space within the electronic device 1000, the antenna assembly 1124 may be implemented using conductive structures that serve as both antenna resonating element structures and capacitive proximity sensor electrodes. The conductive structures are used to form integrated antenna resonating/parasitic element and proximity sensor electrode structure of Figures 3-6. As illustrated in Figures 3-6, the antenna assembly 1124 may be coupled to a radio-frequency transceiver such as radio-frequency circuitry 1121 to transmit and receive antenna signals. The antenna assembly 1124 may also be coupled to proximity sensor processing circuitry (not shown) to make proximity sensor measurements. Proximity sensor signals from the sensor electrode (s) in structure 1124 are made using the same conductive elements that are serving as antenna elements, so these proximity sensor signals are representative of the distance between external object and the antenna.

Proximity measurements made using antenna assembly 1124 may be used in controlling the power of the antenna signals that are transmitted by device 1000 through antenna assembly 1124.

During data transmission operations, control signals from processor 1200 may be conveyed to RF circuitry 1121 to adjust output powers in real time. For example, when data is being transmitted, RF circuitry 1121 can be directed to increase or decrease the power level of the radio-frequency signal that is being provided to the antenna assembly 1124 over transmission line to ensure that regulatory limits for electromagnetic radiation emission are satisfied.

If the proximity sensing circuitry has not detected the presence of external object, power can be provided at a level of normal power-control. If, however, proximity measurement indicates that the user's finger or other body part or other external object is in the immediate vicinity of the antenna assembly (e.g., within 20 mm or less, within 15 mm or less, within 10 mm or less, etc. ) , the processor 1200 can respond accordingly by directing RF circuitry 1121 to transmit radio-frequency signals through transmission line at reduced powers.

In addition to the shown components, the electronic device 1000 may include other components for different functionalities. For example, the electronic device 1000 generally includes a housing, which may be formed to serve as ground plane of the antenna assembly 1124.

Other details of the electronic device 1000 may refer to the forgoing description concerning the antenna assembly according to the embodiments of the present disclosure, and are not repeated herein.

According to another embodiment of the present disclosure, it is provided a method for controlling an antenna assembly capable of proximity sensing as illustrated above. The method is performed by an electronic device. The electronic device is mounted with the antenna assembly according to the present disclosure, and includes a RF module and a proximity sensing circuit. The electronic device may be the electronic device as shown in Figure 10. The antenna assembly may be an antenna assembly as shown in Figure 3, 4, 5, or 6. A flow chart of a method for controlling the antenna assembly according to an embodiment of the present disclosure is shown in Figure 11.

In step 1101, a high frequency signal is transmitted, for example from a RF circuitry of the electronic device, to the antenna assembly for driving the antenna assembly to work as an antenna.

Specifically, the RF circuitry transmits a high frequency signal to the antenna assembly via transmission line, via electromagnetic coupling, or via the third filter functions as HFP allowing pass of the high frequency signal. Therefore, the first and second antenna elements can cooperatively work as an antenna.

In step 1102, a low frequency signal is transmitted, for example, from a sensing circuitry in the electronic device, to the antenna assembly for driving the element (s) of the antenna assembly to work as sensor (s) .

For the antenna assembly similar to that shown in Figure 3, by isolation of the second filter, the second antenna element, or the parasitic element of the antenna assembly, may be considered as a sensor electrode. For the antenna assembly similar to that shown in Figure 4, by isolation of the second and fourth filter, both the first antenna element (for example, driven element) and the second antenna element (for example, parasitic element) may each be considered as a sensor electrode. During operation, the sensing circuitry transmits low frequency signals to the first antenna element and/or second antenna element and monitors the capacitance associated with the elements.

It should be noted that there is no constrained sequence for performing step 1101 and step 1102, since the antenna function and the sensor function can work independently.

In some implementations, the method may further include lowering a transmitting and receiving power of the RF circuitry in response to detecting, via the antenna assembly and the proximity sensing circuit, the proximity of the capacitive object to the antenna assembly.

The above embodiments mainly focus on the improvement of the elements of the antenna assembly. The other inherent elements of the antenna assembly are not described herein in detail.

The embodiments of the present disclosure are described in a progressive manner, and each embodiment places emphasis on the difference from other embodiments. Therefore, one embodiment can refer to other embodiments for the same or similar parts. Since the methods disclosed in the embodiments correspond to the apparatuses disclosed in the embodiments, the description of the methods is simple, and reference may be made to the relevant part of the apparatuses.

According to the description of the disclosed embodiments, those skilled in the art can implement or use the present disclosure. Various modifications made to these embodiments may be obvious to those skilled in the art, and the general principle defined herein may be implemented in other embodiments without departing from the spirit or scope of the present disclosure. Therefore, the present disclosure is not limited to the embodiments described herein but confirms to a widest scope in accordance with principles and novel features disclosed in the present disclosure.

Claims

An antenna assembly comprising:

a first antenna element being driven for communication in a frequency band of radio frequency RF signals;

a second antenna element positioned in vicinity of the first antenna element and electrically isolated from the first antenna element, the second antenna element being parasitically coupled to the first antenna element;

a first filter coupling the second antenna element to ground; and

a second filter coupling the second antenna element to a proximity sensing circuit, the proximity sensing circuit driving the second antenna element to detect proximity of a capacitive object to the antenna assembly.
The antenna assembly of claim 1, wherein a drive signal is communicated from the proximity sensing circuit to drive the second antenna element to detect proximity of the capacitive object, and a frequency of the drive signal is lower than a frequency of the frequency band of RF signals.
The antenna assembly of claim 2, wherein the drive signal is communicated concurrently with the RF signals being communicated.
The antenna assembly of claim 1, wherein the second antenna element is configured to associate the first antenna element to form resonance and alter a radiation mode of the antenna assembly.
The antenna assembly of claim 1, wherein the first filter functions as a high pass filter for allowing pass of the RF signals and direct current block.
The antenna assembly of claim 1, wherein the second filter functions as a low pass filter for blocking pass of the RF signals.
The antenna assembly of any one of claims 1-6, wherein the first antenna element is electrically connected to the proximity sensing circuit via a third filter, and the proximity sensing circuit further drives the first antenna element to detect proximity of the capacitive object, wherein the third filter is of a type same as the second filter.
The antenna assembly of claim 7, wherein the first antenna element is electrically connected to a RF transceiver via a fourth filter to communicate the RF signals, wherein the fourth filter allows pass of the RF signals, and the fourth filter is of a type same as the first filter.
The antenna assembly of any one of claims 1-6, wherein the second antenna element comprises a first portion and a second portion connected with each other.
The antenna assembly of claim 9, wherein the antenna assembly supports a first frequency band of RF signals with the first portion of the second antenna element, and supports a second frequency band of RF signals with the second portion of the second antenna element, wherein the first frequency band is higher than the second frequency band.
The antenna assembly of any one of claims 1-10, wherein the second antenna element is a parasitic element of the antenna assembly, the first filter is a capacitor, and the second filter is an inductor.
An electronic device comprising:

a radio frequency RF transceiver;

a proximity sensing circuit; and

an antenna assembly comprising:

a first antenna element being driven by the RF transceiver for communication in a frequency band of RF signals;

a second antenna element positioned in vicinity of the first antenna element and electrically isolated from the first antenna element, the second antenna element being parasitically coupled to the first antenna element;

a first filter coupling the second antenna element to ground; and

a second filter coupling the second antenna element to the proximity sensing circuit, the proximity sensing circuit driving the second antenna element to detect proximity of a capacitive object to the antenna assembly.
The electronic device of claim 12, wherein a drive signal is communicated from the proximity sensing circuit to drive the second antenna element to detect proximity of the capacitive object, and a frequency of the drive signal is lower than a frequency of the frequency band of RF signals.
The electronic device of claim 12, wherein the drive signal is communicated concurrently with the RF signals being communicated.
The electronic device of claim 12, wherein the second antenna element is configured to associate the first antenna element to form resonance and alter a radiation mode of the antenna assembly.
The electronic device of claim 12, wherein the first filter functions as a high pass filter for allowing pass of the RF signals and direct current block.
The electronic device of claim 12, wherein the second filter functions as a low pass filter for blocking pass of the RF signals.
The electronic device of any one of claims 12-17, wherein the first antenna element is electrically connected to the proximity sensing circuit via a third filter, and the proximity sensing circuit further drives the first antenna element to detect proximity of the capacitive object, wherein the third filter is of a type same as the second filter.
The electronic device of claim 18, wherein the first antenna element is electrically connected to a RF transceiver via a fourth filter to communicate the RF signals, wherein the fourth filter allows pass of the RF signals, and the fourth filter is of a type same as the first filter.
The electronic device of any one of claims 12-17, wherein the second antenna element comprises a first portion and a second portion connected with each other.
The electronic device of claim 20, wherein the antenna assembly supports a first frequency band of RF signals with the first portion of the second antenna element, and supports a second frequency band of RF signals with the second portion of the second antenna element, the first frequency band is higher than the second frequency band.
The electronic device of claim 12, wherein the RF transceiver is configured to lower a transmitting and receiving power in response to detecting, via the antenna assembly and the proximity sensing circuit, the proximity of the capacitive object to the antenna assembly.