Electronic device with non-stationary object detection functionality

Abstract

This disclosure relates to an electronic device with non-static object detection capabilities. The electronic device may include a voltage standing wave ratio (VSWR) sensor disposed along a radio frequency transmission line between a signal generator and an antenna. The VSWR sensor acquires VSWR measurements based on a radio frequency signal transmitted by the signal generator through the transmission line. Control circuitry identifies changes in these VSWR measurements over time and compares these changes to a threshold to determine whether an external object near the antenna is living or inanimate. When the external object is living, the control circuitry reduces the maximum transmission power level of the antenna, and when the external object is inanimate, the control circuitry maintains or increases the maximum transmission power level. This can be used to maximize the wireless performance of the electronic device while ensuring that the device complies with prescribed limits for radio frequency energy exposure.

Description

[0001] This patent application claims priority to U.S. Patent Application No. 17 / 332,221, filed May 27, 2021, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This disclosure relates in general to electronic devices, and more specifically to electronic devices having wireless circuitry. Background Technology

[0003] Electronic devices often possess wireless capabilities. Wireless electronic devices have wireless circuitry that includes one or more antennas. Wireless circuitry is sometimes used to perform spatial ranging operations, where radio frequency signals are used to estimate the distance between the electronic device and external objects.

[0004] Providing an accurate distance estimate via wireless circuitry can be challenging. For example, wireless circuitry often exhibits blind spots near the device, making it difficult to accurately detect the presence of external objects within these blind spots. Furthermore, wireless circuitry may struggle to distinguish between living and inanimate external objects. Summary of the Invention

[0005] Electronic devices may include wireless circuitry controlled by one or more processors. The wireless circuitry may include an antenna coupled to a signal generator via a radio frequency (RF) transmission line. A voltage standing wave ratio (VSWR) sensor may be positioned along the RF transmission line. The signal generator may transmit an RF signal via the RF transmission line. The RF signal may be a communication signal, radar signal, or a dedicated test signal. The VSWR sensor may acquire a VSWR measurement value based on the transmitted RF signal during the sampling period.

[0006] The one or more processors can identify changes in VSWR measurements acquired during a sampling period over time. These processors can compare the changes to a threshold to determine whether an external object near the antenna is living or inanimate. When the change exceeds the threshold, the one or more processors can identify the external object as living. When the change is less than the threshold, the one or more processors can identify the external object as inanimate. The one or more processors can reduce the maximum transmit power level of the antenna and optionally detect the distance to the external object in response to identifying it as living. The one or more processors can maintain or increase the maximum transmit power level and optionally perform removable housing detection in response to identifying the external object as inanimate. This can be used to maximize the wireless performance of the electronic device while also ensuring that the device complies with prescribed limits for radio frequency energy exposure.

[0007] One aspect of this disclosure provides an electronic device that can operate in an environment including external objects. The electronic device may include an antenna. The electronic device may include a voltage standing wave ratio (VSWR) sensor communicatively coupled to the antenna. The VSWR sensor may be configured to perform VSWR measurements based on radio frequency signals emitted by the antenna. The electronic device may include one or more processors. The one or more processors may be configured to identify changes in the VSWR measurement over time. The one or more processors may be configured to determine whether the external object is living or inanimate based on the identified changes in the VSWR measurement.

[0008] One aspect of this disclosure provides a method for operating an electronic device to perform live object detection on an object external to the electronic device. The method may include using a signal generator to transmit a radio frequency signal via a radio frequency transmission line communicatively coupled to an antenna during a sampling period. The method may include using a voltage standing wave ratio (VSWR) sensor disposed along the radio frequency transmission line to perform a VSWR measurement based on the radio frequency signal transmitted via the radio frequency transmission line during the sampling period. The method may include using one or more processors to identify changes in the VSWR measurement value over time during the sampling period. The method may include using the one or more processors to identify that the object is alive when the identified change exceeds a threshold. The method may include using the one or more processors to identify that the object is inanimate when the identified change is less than a threshold.

[0009] One aspect of this disclosure provides an electronic device. The electronic device may include an antenna. The electronic device may include a voltage standing wave ratio (VSWR) sensor communicatively coupled to the antenna. The VSWR sensor may be configured to measure a VSWR value based on a radio frequency signal emitted by the antenna. The electronic device may include one or more processors. The one or more processors may be configured to identify changes in the VSWR value over time. The one or more processors may be configured to reduce the maximum transmit power level of the antenna when the identified change exceeds a threshold. The one or more processors may be configured to maintain or increase the maximum transmit power level of the antenna when the identified change is less than a threshold. Attached Figure Description

[0010] Figure 1 This is a functional block diagram of an exemplary electronic device according to some implementation schemes, the exemplary electronic device having a transmitting antenna for performing live external object detection.

[0011] Figure 2 It is a graph of the reflection coefficient versus frequency according to some implementation schemes, which can be generated by an exemplary voltage standing wave ratio (VSWR) sensor in response to the absence and presence of an external object near the transmitting antenna.

[0012] Figure 3 This is a circuit diagram of an exemplary VSWR sensor according to some implementation schemes, which has a directional coupler for performing live external object detection using a transmitting antenna.

[0013] Figure 4 It is a graph based on some implementation schemes, which shows how the reflectivity measured by an exemplary VSWR sensor can change at different times when there is a living object near the transmitting antenna.

[0014] Figure 5 It is a graph based on some implementation schemes, which shows how the reflectance measured by an exemplary VSWR sensor can change over time in the presence of an inanimate external object near the transmitting antenna, in the presence of a living external object, and in the absence of an external object.

[0015] Figure 6 It is a graph based on some implementation schemes, which shows how the return loss measured by an exemplary VSWR sensor can change when an electronic device is equipped with different types of removable housings.

[0016] Figure 7 This is a flowchart illustrating exemplary operations involved in using a VSWR sensor to acquire VSWR measurements for performing live object detection, according to some implementation schemes.

[0017] Figure 8 This is a flowchart illustrating exemplary operations involved in performing live object detection based on changes in VSWR measurements acquired by a VSWR sensor, according to some implementation schemes.

[0018] Figure 9 It is a graph based on some implementation schemes, which shows how the change in reflection coefficient can be related to the distance between the transmitting antenna and the external object.

[0019] Figure 10 An exemplary timing diagram is shown according to some embodiments for using a VSWR sensor to acquire VSWR measurements to perform live object detection. Detailed Implementation

[0020] Figure 1The electronic device 10 may be: a computing device, such as a laptop computer, desktop computer, computer monitor containing an embedded computer, tablet computer, cellular phone, media player, or other handheld or portable electronic device; a smaller device, such as a wristwatch, a wristband, a headset or handset, a device embedded in glasses; or other equipment worn on a user's head; or other wearable or micro-devices, televisions, computer monitors without an embedded computer, gaming devices, navigation devices, embedded systems (such as systems in which electronic equipment with a display is installed in a kiosk or vehicle), voice-controlled speakers connected to the wireless Internet, home entertainment devices, remote control devices, game controllers, peripheral user input devices, wireless base stations or access points, equipment that enables the functions of two or more of these devices; or other electronic equipment.

[0021] like Figure 1 As shown in the functional block diagram, device 10 may include components located on or within an electronic device housing, such as housing 12. Housing 12 (sometimes referred to as a shell) may be formed of plastic, glass, ceramic, fiber composite material, metal (e.g., stainless steel, aluminum, metal alloys, etc.), other suitable materials, or combinations of these materials. In some cases, housing 12 may be partially or entirely formed of dielectric or other low-conductivity materials (e.g., glass, ceramic, plastic, sapphire, etc.). In other cases, housing 12 or at least some of the structures constituting housing 12 may be formed of metallic elements.

[0022] Device 10 may include control circuitry 14. Control circuitry 14 may include storage devices, such as storage circuitry 16. Storage circuitry 16 may include hard disk drive storage devices, non-volatile memory (e.g., flash memory configured to form a solid-state drive or other electrically programmable read-only memory), volatile memory (e.g., static random access memory or dynamic random access memory), etc. Storage circuitry 16 may include storage devices and / or removable storage media integrated within device 10.

[0023] Control circuitry 14 may include processing circuitry, such as processing circuitry 18. Processing circuitry 18 may be used to control the operation of device 10. Processing circuitry 18 may include one or more microprocessors, microcontrollers, digital signal processors, host processors, baseband processor integrated circuits, application-specific integrated circuits, central processing units (CPUs), etc. Control circuitry 14 may be configured to perform operations in device 10 using hardware (e.g., dedicated hardware or circuitry), firmware, and / or software. Software code for performing operations in device 10 may be stored on storage circuitry 16 (e.g., storage circuitry 16 may include a non-transitory (tangible) computer-readable storage medium storing software code). This software code may sometimes be referred to as program instructions, software, data, commands, or code. The software code stored on storage circuitry 16 may be executed by processing circuitry 18.

[0024] Control circuitry 14 can be used to run software on device 10, such as satellite navigation applications, internet browsing applications, Voice over Internet Protocol (VoIP) telephone calling applications, email applications, media playback applications, operating system functions, etc. To support interaction with external equipment, control circuitry 14 can be used to implement communication protocols. Communication protocols that can be implemented using control circuitry 14 include: Internet Protocol, Wireless Local Area Network (WLAN) protocols (e.g., IEEE 802.11 protocol—sometimes referred to as...). Protocols for other short-range wireless communication links, such as This protocol may be any of the following: wireless personal area network (WPAN) protocols, IEEE 802.11ad protocols (e.g., ultra-wideband protocols), cellular phone protocols (e.g., 3G, 4G (LTE), 5G, etc.), antenna diversity protocols, satellite navigation system protocols (e.g., Global Positioning System (GPS), Global Navigation Satellite System (GLONASS), etc.), antenna-based spatial ranging protocols (e.g., radio detection and ranging (RADAR) protocols for signals transmitted at millimeter and centimeter wave frequencies or other desired distance detection protocols), or any other desired communication protocol. Each communication protocol may be associated with a corresponding radio access technology (RAT), which specifies the physical connection method used to implement the protocol.

[0025] Device 10 may include input-output circuitry 20. Input-output circuitry 20 may include input-output devices 22. Input-output devices 22 may be used to allow data to be supplied to device 10 and to allow data to be supplied from device 10 to external devices. Input-output devices 22 may include user interface devices, data port devices, and other input-output components. For example, input-output devices 22 may include touch sensors, displays (e.g., touch-sensitive displays and / or force-sensitive displays), light-emitting components such as displays without touch sensor capability, buttons (mechanical, capacitive, optical, etc.), scroll wheels, touchpads, keypads, keyboards, microphones, cameras, buttons, speakers, status indicators, audio jacks and other audio port components, digital data port devices, motion sensors (accelerometers, gyroscopes, and / or compasses for detecting motion), capacitive sensors, temperature sensors, proximity sensors, magnetic sensors, force sensors (e.g., force sensors coupled to a display to detect pressure applied to the display), etc. In some configurations, keyboards, headsets, monitors, clicking devices (such as touchpads, mice, and joysticks) and other input-output devices may be coupled to device 10 using wired or wireless connections (e.g., some devices in input-output devices 22 may be peripherals of the main processing unit or other parts of device 10 coupled to it via wired or wireless links).

[0026] Input-output circuitry 20 may include wireless circuitry 24 to support wireless communication and / or radio-based spatial ranging operations. Wireless circuitry 24 may include two or more antennas 40. Wireless circuitry 24 may also include baseband processor circuitry, transceiver circuitry, amplifier circuitry, filter circuitry, switching circuitry, analog-to-digital converter (ADC) circuitry, digital-to-analog converter (DAC) circuitry, RF transmission lines, and / or any other circuitry for transmitting and / or receiving RF signals using antennas 40.

[0027] Antenna 40 can be formed using any desired antenna structure. For example, antenna 40 may include an antenna with a resonant element, formed from a loop antenna structure, patch antenna structure, inverted F-shaped antenna structure, slot antenna structure, planar inverted F-shaped antenna structure, helical antenna structure, monopole antenna, dipole, a combination of these designs, etc. Adjustable filter circuits, switching circuits, impedance matching circuits, and / or other antenna tuning components can be used to adjust the frequency response and wireless performance of antenna 40 over time.

[0028] Antenna 40 may include one or more transmit (TX) antennas, such as transmit antenna 40TX, and one or more receive (RX) antennas, such as receive antenna 40RX. Antenna 40 may include zero, one, or more additional antennas used for transmitting and / or receiving radio frequency signals. Transmit antenna 40TX may transmit radio frequency signals, such as radio frequency signal 42 and / or radio frequency signal 38. Receive antenna 40RX may receive radio frequency signals, such as radio frequency signal 44 and / or radio frequency signal 38. Wireless circuit 24 may use antenna 40 to transmit and / or receive radio frequency signal 38 to transmit wireless communication data between device 10 and external wireless communication equipment 48 (e.g., one or more other devices, such as device 10, a wireless access point, or a base station). Wireless communication data may be transmitted bidirectionally or unidirectionally by wireless circuit 24. Wireless communication data may include, for example, data encoded into corresponding data packets, such as wireless data associated with telephone calls, streaming media content, internet browsing, wireless data associated with software applications running on device 10, email messages, etc.

[0029] Wireless circuit 24 may include communication circuitry 26 (sometimes referred to herein as wireless communication circuitry 26) for transmitting and / or receiving wireless communication data using antenna 40. Communication circuitry 26 may include baseband circuitry (e.g., one or more baseband processors) and one or more radio components (e.g., radio frequency transceivers, modems, etc.) for transmitting radio frequency signals 38 using one or more antennas 40 (e.g., transmitting antenna 40TX, receiving antenna 40RX, and / or other antennas 40).

[0030] Communication circuit 26 can transmit and / or receive radio frequency signals 38 within a corresponding frequency band of a radio frequency (sometimes referred to herein as a communication band or simply a "band"). The frequency band processed by communication circuit 26 may include: a wireless local area network (WLAN) band (e.g., (IEEE 802.11) or other WLAN communication bands, such as the 2.4GHz WLAN band (e.g., 2400MHz-2480MHz), the 5GHz WLAN band (e.g., 5180MHz-5825MHz), 6E band (e.g., 5925MHz-7125MHz) and / or others Frequency bands (e.g., 1875MHz-5160MHz); Wireless Personal Area Network (WPAN) frequency bands such as 2.4GHz Frequency bands or other WPAN communication bands; cellular telephone bands (e.g., bands from approximately 600 MHz to approximately 5 GHz, 3G bands, 4G LTE bands, 5G NR frequency range 1 (FR1) band below 10 GHz, 5G NR frequency range 2 (FR2) band between 20 GHz and 60 GHz, etc.); other centimeter wave or millimeter wave bands between 10 GHz and 300 GHz; near-field communication bands (e.g., 13.56 MHz); satellite navigation bands (e.g., GPS bands from 1565 MHz to 1610 MHz, Global Navigation Satellite System (GLONASS) bands, BeiDou Navigation Satellite System (BDS) bands, etc.); ultra-wideband (UWB) bands operating under the IEEE 802.15.4 protocol and / or other ultra-wideband communication protocols; communication bands belonging to the 3GPP wireless communication standard family; communication bands belonging to the IEEE 802.XX standard family; and / or any other desired bands of interest.

[0031] Communication circuit 26 may be coupled to antenna 40 using one or more transmit paths and / or one or more receive paths. Communication circuit 26 uses the transmit path to transmit radio frequency signal 38 and uses the receive path to receive radio frequency signal 38. If desired, communication circuit 26 may be coupled to transmit antenna 40TX via a transmit path such as transmit path 34. Communication circuit 26 may use transmit path 34 to transmit radio frequency signal 38 using transmit antenna 40TX. Transmit path 34 (sometimes referred to herein as transmit chain 34) may include one or more signal paths (e.g., radio frequency transmission lines), amplifier circuitry, filter circuitry, switching circuitry, radio frequency front-end circuitry (e.g., components on a radio frequency front-end module), and / or any other desired path or circuitry for transmitting radio frequency signals from communication circuit 26 to transmit antenna 40TX.

[0032] In addition to transmitting wireless communication data, wireless circuit 24 can also use antenna 40 to perform spatial ranging operations. Wireless circuit 24 may include a long-range spatial ranging circuit 28 for performing spatial ranging operations. The long-range spatial ranging circuit 28 may include mixer circuitry, amplifier circuitry, transmitter circuitry (e.g., signal generator, synthesizer, etc.), receiver circuitry, filter circuitry, baseband circuitry, ADC circuitry, DAC circuitry, and / or any other desired components used in performing spatial ranging operations using antenna 40. The long-range spatial ranging circuit 28 may include, for example, radar circuitry (e.g., frequency modulated continuous wave (FMCW) radar circuitry, OFDM radar circuitry, FSCW radar circuitry, phase-coded radar circuitry, other types of radar circuitry). Antenna 40 may include a separate antenna for transmitting wireless communication data and radio frequency signals for spatial ranging, or may include one or more antennas 40 for transmitting wireless communication data and performing spatial ranging. Using a single antenna 40 to transmit wireless communication data and perform spatial ranging can, for example, be used to minimize the amount of space occupied in device 10 by means of antenna 40.

[0033] In one embodiment described herein as an example, wireless circuit 24 may use transmitting antenna 40TX to transmit wireless communication data to communication circuit 26 and to perform spatial ranging operations for long-range spatial ranging circuit 28. Therefore, long-range spatial ranging circuit 28 may be coupled to transmitting antenna 40TX via transmitting path 34. When performing spatial ranging operations, long-range spatial ranging circuit 28 may use transmitting antenna 40TX to transmit radio frequency signal 42. Radio frequency signal 42 may include one or more tone signals, continuous waves of radio frequency energy, broadband signals, linear frequency modulated signals, or any other desired transmission signal for spatial ranging operations (e.g., radar signals). Unlike radio frequency signal 38, radio frequency signal 42 may not contain wireless communication data (e.g., cellular communication data packets, WLAN communication data packets, etc.). Radio frequency signal 42 may also be referred to herein as spatial ranging signal 42, long-range spatial ranging signal 42, or radar signal 42. The long-distance spatial ranging circuit 28 can transmit radio frequency signals 42 at one or more carrier frequencies in a corresponding radio frequency band (e.g., a band including frequencies greater than about 10 GHz, greater than about 20 GHz, less than 10 GHz, 20-30 GHz, greater than 40 GHz, etc.).

[0034] Radio frequency signal 42 can be reflected away from an object outside device 10 (such as external object 46). External object 46 can be, for example, the ground, a building, part of a building, a wall, furniture, a ceiling, a person, a body part, an animal, a vehicle, a landscape or geographical feature, an obstacle, external communication equipment such as external wireless communication equipment 48, another device of the same type as device 10, or a peripheral device such as a game controller or remote control, or any other physical object or entity outside device 10. Receiving antenna 40RX can receive the reflected radio frequency signal 44. The reflected signal 44 can be a reflected form of the transmitted radio frequency signal 42, which has been reflected away from external object 46 and returned to device 10.

[0035] The receiving antenna 40RX can be coupled to the long-range spatial ranging circuit 28 via the receiving path 36 (sometimes referred to herein as receiving chain 36). The long-range spatial ranging circuit 28 can receive the reflected signal 44 from the receiving antenna 40RX via the receiving path 36. The receiving path 36 may include one or more signal paths (e.g., radio frequency transmission lines), amplifier circuitry (e.g., low-noise amplifier (LNA) circuitry), filter circuitry, switching circuitry, radio frequency front-end circuitry (e.g., components on a radio frequency front-end module), and / or any other desired path or circuitry for transmitting radio frequency signals from the receiving antenna 40RX to the long-range spatial ranging circuit 28.

[0036] Control circuit 14 can process the transmitted radio frequency signal 42 and the received reflected signal 44 to detect or estimate the distance R between device 10 and external object 46. If needed, control circuit 14 can also process the transmitted and received signals to identify the two-dimensional or three-dimensional spatial position (or orientation) of external object 46, the velocity of external object 46, and / or the angle of arrival of reflected signal 44. If needed, a loopback path, such as loopback path 50, can be coupled between transmit path 34 and receive path 36. Loopback path 50 can be used to transmit the transmitted signal on transmit path 34 to the receiver circuit in long-distance spatial ranging circuit 28. For example, in an implementation where long-distance spatial ranging circuit 28 performs spatial ranging using an FMCW scheme, loopback path 50 can be a delinear frequency modulation path that transmits the linear frequency modulated signal on transmit path 34 to the delinear frequency modulated mixer in long-distance spatial ranging circuit 28. In these implementations, Doppler drift in the continuous wave transmitted signal can be detected and processed to identify the velocity of the external object 42, and the time-dependent frequency difference between the radio frequency signal 42 and the reflected signal 44 can be detected and processed to identify the distance R and / or the position of the external object 46. For example, using a continuous wave signal to estimate the distance R allows the control circuit 14 to reliably distinguish the external object 46 from other background or slower-moving objects. This example is merely illustrative, and generally, the long-range spatial ranging circuit 28 can be implemented in any desired radar or long-range spatial ranging scheme.

[0037] The radio frequency transmission lines in transmit path 34 and receive path 36 may include coaxial cables, microstrip transmission lines, stripline transmission lines, edge-coupled microstrip transmission lines, edge-coupled stripline transmission lines, and transmission lines formed by combinations of these types of transmission lines. If desired, the transmission lines in the device may be integrated into rigid and / or flexible printed circuit boards. One or more radio frequency lines may be shared between transmit path 34 and receive path 36 if desired. Components of wireless circuit 24 may be formed on one or more common substrates or modules (e.g., rigid printed circuit boards, flexible printed circuit boards, integrated circuits, chips, packages, systems-on-chips, etc.).

[0038] Figure 1 The examples are merely illustrative. Although for clarity, in Figure 1In the example, control circuitry 14 is shown separate from wireless circuitry 24, but wireless circuitry 24 may include processing circuitry and / or storage circuitry, the processing circuitry forming part of processing circuitry 18, and the storage circuitry forming part of storage circuitry 16 of control circuitry 14 (e.g., portions of control circuitry 14 may be implemented on wireless circuitry 24). For example, some or all of the baseband circuitry in wireless circuitry 24 may form part of control circuitry 14. Additionally, wireless circuitry 24 may include any desired number of antennas 40. Antennas 40 may include more than one transmit antenna 40TX, more than one receive antenna 40RX, and zero, one, or more other antennas 40. Each antenna 40 may be coupled to communication circuitry 26 and / or long-range spatial ranging circuitry 28 via a dedicated transmit and / or receive path or one or more transmit and / or receive paths shared between antennas.

[0039] The long-range spatial ranging circuit 28 does not need to be coupled to all antennas 40 in the wireless circuit 24. Similarly, the communication circuit 26 does not need to be coupled to all antennas 40 in the wireless circuit 24 (e.g., some antennas 40 may be used to perform spatial ranging operations without transmitting wireless communication data or to transmit wireless communication data without performing spatial ranging). Antennas 40 used only for receiving signals may be coupled to the communication circuit 26 and / or the long-range spatial ranging circuit 28 using one or more receiving paths (e.g., receiving path 36). Antennas 40 used only for transmitting signals may be coupled to the communication circuit 26 and / or the long-range spatial ranging circuit 28 using one or more transmitting paths (e.g., transmitting path 34). One or more antennas 40 may be used for both transmitting and receiving signals. In these scenarios, antennas may be coupled to the communication circuit 26 and / or the long-range spatial ranging circuit 28 using both transmitting and receiving paths, and one or more components or signal paths (e.g., radio frequency transmission lines) may be shared between the transmitting and receiving paths if necessary. Although described herein as a transmitting antenna for simplicity, the transmitting antenna 40TX can also be used to receive radio frequency signals for the communication circuit 26 if needed (e.g., an additional receiving path (not shown) can couple the transmitting antenna 40TX to the communication circuit 26). Similarly, the receiving antenna 40RX can also be used to transmit radio frequency signals if needed. Although the receiving antenna 40RX is shown only for providing reflected signal 44 to the long-distance spatial ranging circuit 28, the receiving antenna 40RX can also provide received radio frequency signal 38 to the communication circuit 26 (e.g., a receiving path 36 can also couple the receiving antenna 40RX to the communication circuit 26).

[0040] When the external object 46 is at a relatively far distance from the device 10, the long-distance spatial ranging circuit 28 can be used to accurately identify the distance R. However, in practice, the long-distance spatial ranging circuit 28 is less effective at distances less than a threshold distance R from the device 10.TH A blind spot is created at a distance of approximately 1 to 2 cm from nearby external objects. When an external object 46 is within this blind spot (e.g., at a threshold distance R from the transmitting antenna 40TX),... TH (Inside), the long-distance spatial ranging circuit 28 may not be able to identify the presence, location, and / or velocity of an external object 46 with satisfactory accuracy. At the threshold distance R of the transmitting antenna 40TX... TH An external object 46 may be exposed to relatively high amounts of radio frequency energy (e.g., from radio frequency signals 38 and / or 42 emitted by the transmitting antenna 40TX). In scenarios where the external object 46 is a body part or a person, the emitted radio frequency energy could, if inadvertently, cause the wireless circuit 24 to exceed specified limits or other limits regarding a specific absorption rate (SAR) (e.g., when the frequency of the transmitted signal is below 6 GHz) and / or the maximum permissible exposure (MPE) (e.g., when the frequency of the transmitted signal is above 6 GHz). This is to detect at a threshold distance R from the transmitting antenna 40TX. TH The presence of an external object 46 within the wireless circuit 24 allows the wireless circuit 24 to include an ultra-short range (USR) object detector, such as a USR detector 30. The USR detector 30 can be used to detect objects at ultra-short ranges (e.g., at a threshold distance R from the transmitting antenna 40TX). TH The USR detector 30 can detect external objects 46 at a distance within the range of the long-distance spatial ranging circuit 28. In other words, the USR detector 30 can perform external object detection within the blind spot of the long-distance spatial ranging circuit 28.

[0041] USR detector 30 may include a voltage standing wave ratio (VSWR) sensor (detector), such as VSWR sensor 32. VSWR sensor 32 may be inserted into transmit path 34. VSWR sensor 32 may acquire VSWR values ​​using transmit antenna 40TX. VSWR values ​​may include complex scattering parameter values ​​(S-parameter values), such as reflection coefficient (return loss) values ​​(e.g., S...). 11 Value). S 11 The magnitude of the value (e.g., |S) 11 The VSWR value can indicate the amount of transmitted radio frequency energy reflected in the opposite direction along the transmission path 34 (e.g., in response to the presence of an external object 46 at or near the transmitting antenna 40TX). The VSWR value acquired by the VSWR sensor 32 may be relevant if the external object 46 is located at a threshold distance R from the transmitting antenna 40TX. TH The situation at a distance is not sensitive. However, the VSWR value acquired by the VSWR sensor 32 allows the control circuit 14 to identify when an external object 46 is within a threshold distance R from the transmitting antenna 40TX. TH Inside (e.g., within the blind spot of the long-distance spatial ranging circuit 28).

[0042] In this way, the USR detector 30 and the long-range spatial ranging circuit 28 can identify the presence of an external object 46 and optionally the distance R to the external object 46, regardless of whether the external object 46 has moved to a position relatively closer to or relatively farther from the device 10 over time. Furthermore, the USR detector 30 can identify the presence of the external object 46 within the blind spot of the long-range spatial ranging circuit 28, allowing appropriate action to be taken to ensure that the wireless circuit 24 continues to meet any applicable SAR and / or MPE regulations. By using the same transmitting antenna 40TX to transmit radio frequency signals 38 / 42 and measuring VSWR, the VSWR measurement will be very closely correlated with the amount of radio frequency energy absorbed by the external object 46 from the transmitted radio frequency signals 38 / 42, thus providing high confidence in the use of the USR detector 30 to meet any applicable SAR and / or MPE regulations (e.g., more than a proximity sensor separate from the transmitting antenna or transmission chain used to identify objects at a threshold distance R from the device 10). TH The existence of internal and external objects in a scenario increases credibility.

[0043] Figure 2 This is a graph showing how the VSWR measurement value taken by VSWR sensor 32 changes due to the presence of an external object 46 adjacent to the transmitting antenna 40TX. Curve 60 plots the distance R where no threshold is present. TH The S-parameter S of the reflection of an internal and external object at frequency 46. 11 The value of |S 11 |). As shown by curve 60, when there is no external object 46, |S 11 |In the frequency band of interest B (e.g., for transmission) Figure 1 The radio frequency signal (in the 38 or 42 frequency band) can have a relatively high value.

[0044] Curve 62 plots the threshold distance R when the external object 46 is at a distance of 40TX from the transmitting antenna. TH Internal time based on frequency |S 11 As shown by curve 62, due to the presence of external object 46, |S 11 | It can have relatively low values ​​in frequency band B. Generally speaking, once the external object 46 is within the threshold distance R... TH Inside, as the object approaches the transmitting antenna 40TX, |S 11 | will continue to decrease, as indicated by arrow 64. Control circuit 14 can use VSWR sensor 32 to acquire VSWR values ​​(e.g., |S, as shown in curves 60 and 62). 11 | value), and can process the acquired VSWR values ​​to identify when an external object 46 is within a threshold distance R. TH Internal (e.g., by collecting |S) 11| The value is compared with one or more threshold levels. (The distance R exceeds the threshold.) TH Then, in response to the change in distance between the transmitting antenna 40TX and the external object 46, |S 11 |There will be no change or negligible change. At these relatively long distances, long-distance spatial ranging circuit 28 ( Figure 1 It can be used to detect the presence, location (e.g., distance R) and / or velocity of an external object 46.

[0045] Figure 3 This is a circuit diagram showing how the VSWR sensor 32 might be positioned on the transmission path 34. (See diagram for example.) Figure 3 As shown, transmit path 34 may include a power amplifier (PA), such as PA 96. The input of PA 96 may be coupled to... Figure 1 The long-range spatial ranging circuit 28 and / or communication circuit 26 are included. The output of PA 96 can be coupled to the transmitting antenna 40TX via a switch such as antenna switch 94. The output of PA 96 can also be coupled to a matching load 88 via a switch such as matching load switch 90. The matching load 88 can be coupled in series between the matching load switch 90 and ground 82. If necessary, the matching load 88, matching load switch 90, and / or antenna switch 94 can be omitted.

[0046] exist Figure 3 In the example, VSWR sensor 32 is a directional switch coupler. This is merely illustrative, and in general, any desired VSWR sensor architecture can be used to implement VSWR sensor 32. Figure 3 As shown, the VSWR sensor 32 may include a directional coupler 72 inserted into a transmit path 34 between PA 96 and transmit antenna 40TX (e.g., along an RF transmission line in the transmit path 34 coupled between the output of PA 96 and transmit antenna 40TX). The directional coupler 72 may have a first port (P1) coupled to the output of PA 96 and a second port (P2) communicatively coupled to transmit antenna 40TX. The directional coupler 72 may have a third port (P3) coupled to a first terminal, which includes a resistor 84 coupled in series between a terminal switch 78 and ground 82. The directional coupler 72 may also have a fourth port (P4) coupled to a second terminal, which includes a resistor 86 coupled in series between a terminal switch 80 and ground 82. The VSWR sensor 32 may have a positive (FW) switch 74 coupled between port P3 and measurement circuitry 70 (e.g., an amplitude and / or phase detector). The VSWR sensor 32 may also have a reverse (RW) switch 76 coupled between port P4 and the measurement circuit 70.

[0047] The measurement circuit 70 may be coupled to the USR detector 30 or the control circuit 14. Figure 1 The control paths of other components in the measurement circuit 70, and / or some or all of the circuitry in the measurement circuit 70, may form part of the control circuit 14 (e.g., the operation of some or all of the circuitry in the measurement circuit 70 may be performed using one or more processors). The measurement circuit 70 may include, for example: power detectors such as power detector 98, in-phase and quadrature-phase (I / Q) detectors (e.g., ADC), logic such as comparator / logic 102 (e.g., one or more logic gates), and / or memory such as memory 104. Memory 104 may form, for example... Figure 1 It is part of the storage circuit 16. If needed, the I / Q detector 100 can be connected via the receiving path 36 ( Figure 1 One or more ADCs are formed in the process.

[0048] When performing VSWR measurements (e.g., S-parameter values, such as S...) 11 When the value is specified, PA 96 can output a transmit test signal sigtx (e.g., when antenna switch 94 is closed). The test signal sigtx can be a radar transmit signal emitted by long-range spatial ranging circuit 28 (e.g., ...). Figure 1 Radio frequency signal 42), wireless communication data transmission signal (e.g., transmitted by communication circuit 26) Figure 1 RF signal 38) or a dedicated test signal used in VSWR measurements (e.g., generated by a signal generator, local oscillator and / or Figure 1 The USR detector 30 may generate one or more tones emitted by other signal generation circuitry. For example, a sequence signal generator 108 may be used to generate a test signal sigtx. The sequence signal generator 108 may be part of a long-range spatial ranging circuit 28 (e.g., the test signal sigtx may be a continuous wave or broadband signal that can also be used to perform long-range spatial ranging operations), may be part of a communication circuit 26 (e.g., the test signal sigtx may also carry wireless communication data), or may be formed as part of a USR detector 30 separate from the long-range spatial ranging circuit 28 and the communication circuit 26. Alternatively or additionally, a simple local oscillator such as a local oscillator (LO) 106 may generate the test signal sigtx.

[0049] When performing a VSWR measurement, the VSWR sensor 32 can use the transmitted signal sigtx to perform forward and reverse path measurements. During a forward path measurement, FW switch 74 is closed, RW switch 76 is open, switch 80 is closed, and switch 78 is open, decoupling the test signal sigtx from the transmit path 34 via directional coupler 72 and routing it to the measurement circuit 70 via FW switch 74. The measurement circuit 70 can measure and store the amplitude and / or phase of the test signal sigtx for further processing (e.g., as a forward signal phase and amplitude measurement). For example, a power detector 98 (e.g., a peak detector, diode, and capacitor, etc.) can measure the amplitude of the test signal sigtx and store that amplitude in memory 104. As another example, an I / Q detector 100 can perform the I / Q measurements stored in memory 104 for the forward path.

[0050] At least some of the test signals in the test signal sigtx will be reflected away from the transmitting antenna 40TX (e.g., due to impedance discontinuity between the transmitting path 34 and the transmitting antenna 40TX caused by impedance load from any external object at or near the transmitting antenna 40TX) and returned to PA 96 as the reflected test signal sigtx'. When performing a reverse path measurement, FW switch 74 is open, RW switch 76 is closed, switch 80 is open, and switch 78 is closed, such that the reflected test signal sigtx' is decoupled from the transmitting path 34 via directional coupler 72 and routed to the measurement circuit 70 via RW switch 76. The measurement circuit 70 (e.g., power detector 98 or I / Q detector 100) can measure and store the amplitude (amplitude) and / or phase of the reflected test signal sigtx' for further processing (e.g., as a reverse signal phase and amplitude measurement). Comparator / logic 102 and / or control circuit 14 ( Figure 1 It can process stored forward and reverse phases, as well as amplitude measurements, to identify complex scattering parameter values, such as S. 11 Value. S 11 The characteristic of the value lies in the scalar value |S 11 | and the corresponding phase. Thus, the VSWR sensor 32 can measure the VSWR value (e.g., S). 11 Value, |S 11 These VSWR values ​​(such as | values) can be used to determine when an external object 46 is located at a distance less than or equal to a threshold R. TH The distance R. When the external object 46 is located at a distance R greater than the threshold distance R from the transmitting antenna 40TX. TH When the distance is R, the long-distance spatial ranging circuit 28 ( Figure 1 The 40TX transmitting antenna can also be used to identify the distance R.

[0051] It may be expected that the USR detector 30 can distinguish the vicinity of the transmit antenna 40TX (e.g., at a threshold distance R from the transmit antenna 40TX). TH The USR detector 30 can detect both living and non-living external objects 46 within the transmit antenna 40TX. For example, a non-living object may not be subject to SAR or MPE limits, while a living object may be a human body part subject to SAR or MPE limits. TH If the external object 46 is an inanimate object, then the wireless circuit 24 may be able to continue transmitting signals through the transmitting antenna 40TX at a relatively high transmission power level (e.g., the maximum transmission power level of PA 96) without violating the specified limits of SAR or MPE. This can be used to maximize the wireless performance of the device 10 when performing wireless communication and / or long-range spatial ranging operations (relative to the threshold distance R). TH In the presence of an external object (whether animate or inanimate), the wireless circuit must reduce its transmission power level or reach its maximum transmission power level. Simultaneously, if the USR detector 30 can detect a threshold range R present at the transmitting antenna 40TX... TH If the external object 46 is a living object, then the wireless circuit 24 may have a relatively high confidence that the external object is a body part subject to SAR / MPE limits, and may therefore reduce the transmission power level or maximum transmission power level of the transmitting antenna 40TX to ensure that the specified limits of SAR or MPE are met.

[0052] If needed, control circuit 14 ( Figure 1 The VSWR measurement performed by the VSWR sensor 32 over time can be used to determine whether an external object 46 near the transmitting antenna 40TX is alive or inanimate. Figure 4 This illustrates a VSWR measurement performed by the VSWR sensor 32 in the presence of an external object near the transmitting antenna 40TX (e.g., |S 11 The value can be plotted as a curve showing how it changes over time.

[0053] Figure 4 Curve C1 shows that it can be measured by circuit 70 ( Figure 3 |S| generated at different frequencies and in the first time 11 | value (e.g., in response to a test signal sigtx scanned within a frequency range). Curve C2 shows the |S value that can be generated by the measurement circuit 70 at different frequencies and at a second time. 11 | value. As shown in curves C1 and C2, the |S value is acquired by the measurement circuit 70. 11The measured value can differ at a given frequency F due to the difference (variation) 110 between the first and second times. Generally, living objects produce |S| at a given frequency more than inanimate objects. 11 The measured values ​​will change more significantly over time. Therefore, control circuit 14 can acquire a sufficient number of VSWR measurements over time, and process these VSWR measurements to identify the differences (changes) in the VSWR measurements over time (e.g., differences such as...). Figure 4 The difference (110) can be processed to determine whether the external object 46 is inanimate or alive. Figure 4 The examples are merely illustrative, and in practice, curves C1 and C2 may have other shapes.

[0054] Examples of inanimate objects 46 that may be present near the transmitting antenna 40TX include: furniture, countertops, desktop computers, vehicle dashboards, or removable housings of device 10 (e.g., removable plastic housings, rubber housings, leather housings, composite material housings, etc.). If needed, control circuitry 14 may also use the identified time-varying difference (change) in VSWR measurements to determine whether device 10 has been placed within a removable housing (e.g., to determine whether external object 46 is a removable housing of device 10). Since different users place device 10 in different types of removable housings with different dielectric properties, control circuitry 14 may further determine, if needed, what type of removable housing is present and / or the impact of the removable housing on calibrating the operation of other devices. For example, control circuit 14 can use the presence of the removable housing and / or information about the type of removable housing present to: calibrate subsequent radar operations performed by long-range spatial ranging circuit 28 (e.g., adjust the range R estimate to account for path loss effects of transmitted and received signals that must pass through the removable housing), adjust the impedance matching and / or tuning of the transmit antenna 40TX (e.g., compensate for the dielectric load of the removable housing to minimize signal reflection at the transmit antenna and to prevent the transmit antenna from undesirably detuning away from its desired operating frequency), and adjust future VSWR measurements, etc.

[0055] Figure 5 The VSWR sensor 32 can measure different reflection coefficients (return loss) values ​​in the presence of different types of external objects 46 (|S 11 A graph showing how the value changes over time. Figure 5 Point 114 shows the |S| measured by the VSWR sensor 32 in the absence of any external objects. 11|Measurement (e.g., at five different sampling times, such as times T0, T1, T2, T3, and T4). For example, point 114 could be a predetermined point generated during the factory calibration of device 10. As shown by point 114, in the absence of external objects, |S 11 The change over time is relatively small (e.g., no change).

[0056] Point 112 shows the |S| measured by VSWR sensor 32 from time T0 to time T4 in the presence of an inanimate object near the transmitting antenna 40TX. 11 |Measurement. For example, an inanimate object could be the removable housing of device 10. As shown at point 112, in the presence of an inanimate object (such as a removable device housing), |S 11 The change over time is relatively small. Control circuitry 14 can compare point 112 with a predetermined point 114 to determine the presence of inanimate objects (such as removable device housings). If needed, control circuitry 14 can compare point 114 with other predetermined points known to be associated with different types of removable device housings (e.g., predetermined points stored on device 10 during factory calibration in the case of different types of removable housings) to identify the type of removable device housing present.

[0057] Point 116 shows the |S| measured by VSWR sensor 32 from time T0 to time T4 in the presence of a living object near the transmitting antenna 40TX. 11 |Measurement. For example, a living object can be a body part. As shown in point 116, in the presence of a living object (such as a body part) (e.g., due to the minute movement of an external object relative to a static / inanimate object (such as a removable device housing), |S 11 The amount of change over time is relatively large. Control circuit 14 can execute |S| at different times (e.g., time T0 to time T4). 11 |Measurements are used to perform liveness detection to generate points (such as...) Figure 5 (Points 114, 112, or 116). Control circuit 14 can recognize |S 11 |Measurements over time are used to determine whether an external object near the transmit antenna 40TX is an inanimate object (and if so, whether the inanimate object is a device housing and optionally the type of device housing) or an inanimate object subject to specified limits of SAR / MPE.

[0058] Control circuit 14 may be based on VSWR (e.g., |S 11|) Any desired metric of how the measured value changes over time can be used to perform live object detection. For example, control circuit 14 can perform live object detection based on the maximum |S measured at each time point in the sampling time. 11 |Value and Minimum|S 11 The difference between values ​​is used to perform liveness detection. For point 116, control circuit 14 can identify (e.g., calculate, compute, generate, determine, etc.) the difference Δ, which is equal to the maximum |S value at point 116. 11 |Value|S 11 | MAX (For example, as measured at time T1) the minimum |S with point 116 11 |Value|S 11 | MIN The difference between (e.g., as measured at time T2). For point 112, this difference is relatively small (or it lies at the same |S| at every point 112). 11 In the case of |S, the difference is zero). Control circuit 14 can compare the difference Δ with one or more thresholds to determine whether the external object is alive or inanimate (e.g., if the difference Δ exceeds a threshold, control circuit 14 can determine that the external object is alive). This example is merely illustrative, and in general, control circuit 14 can identify |S 11 |Any expected measure of change, used to compare against one or more thresholds to determine whether an external object is alive or inanimate. As another example, control circuit 14 can identify |S 11 |The mean and variance of the measured values ​​over time,|S 11 The rate of change of the measured value over time and / or any other desired measure of change is used to compare it against one or more thresholds to determine whether an external object is alive or inanimate.

[0059] Figure 5 The examples provided are merely illustrative. Points 114, 116, and 112 may have other values ​​in practice. Figure 5 In the example, five sampling times T0 to T4 are used to identify |S 11 The variation of |S is used to perform liveness detection. This is merely illustrative, and in general, any desired number of sampling times n can be used to identify |S. 11 The sampling time can be varied to perform liveness detection. Each sampling time can be spaced 10ms, 20ms, 1ms-20ms, greater than 20ms, 10ms-50ms, or any other desired period. The sampling time does not need to be uniformly spaced.

[0060] Figure 6 It is the return loss (e.g., |S 44The graph 122 shows the effect of different removable housings on the VSWR measurement performed by the VSWR sensor 32. Curve 122 plots the |S| value in the absence of a removable housing and any other external objects. 44 Curve 118 plots |S| in the case of a first type of removable housing (e.g., a removable housing made of a first material with a first thickness, etc.). 44 Curve 120 plots |S| in the case of the presence of a second type of removable housing (e.g., a removable housing made of a second material with a second thickness, etc.). 44 |

[0061] As shown in curves 122, 120, and 118, the presence of the removable housing causes a shift in the VSWR measurement value taken by the VSWR sensor 32 (also caused by...). Figure 5 The difference between points 112 and 114 is shown. As shown by curves 120 and 118, different types of housings may have different effects on VSWR measurements taken by VSWR sensor 32. However, in the presence of either type of removable housing or in the absence of any external object, the VSWR measurement changes the same over time (e.g., as shown by...). Figure 5 (As shown at points 114 or 112). If needed, control circuitry 14 can compare the VSWR measurement with expected VSWR measurements associated with different removable housing types (e.g., curves 118 and 120) to identify what type of removable housing is present on device 10. In other words, control circuitry 14 can compare the change in VSWR measurement over time with one or more thresholds to perform live object detection, and can further compare the magnitude of the VSWR measurement (or the magnitude of the mean of the VSWR measurement) with one or more thresholds to perform removable housing detection and identification. Figure 6 The examples shown are merely illustrative. Curves 118 to 122 may have other shapes in practice.

[0062] Figure 7 This is a flowchart illustrating the exemplary operations involved in using VSWR sensor 32 to determine whether an external object near transmit antenna 40TX is alive or inanimate. At operation 124, VSWR sensor 32 can begin performing VSWR measurements (sampling) for a given sampling period to perform live object detection. The sampling period can begin periodically (e.g., at predetermined times, between other scheduled communication or signal transmissions, etc.) or can begin in response to a triggering condition. For example, once VSWR sensor 32 has detected that external object 46 has entered a threshold distance R of transmit antenna 40TX. TH Internal (e.g., once VSWR measurements such as |S11 Once the measured value reaches a predetermined threshold, the sampling period can begin.

[0063] As another example, the sampling period can begin once device 10 has determined that the collected wireless performance metric data falls outside a predetermined range. In this example, wireless circuit 24 can collect wireless performance metric data associated with the radio frequency performance of transmit antenna 40TX and / or receive antenna 40RX. For example, the wireless performance metric data may include signal-to-noise ratio (SNR) data, received signal strength indication (RSSI) data, or other data. Figure 1 Any other desired performance metric data acquired during the transmission of radio frequency signal 38, the transmission of radio frequency signal 42, the reception of radio frequency signal 38, and / or the reception of reflected signal 44. Control circuitry 14 can compare the collected wireless performance metric data with wireless performance metric values ​​within a predetermined range, which are associated with the following: at a threshold distance R TH Satisfactory radio frequency performance and / or operation of wireless circuit 24 when no external objects are present (e.g., satisfactory RSSI values, SNR values, etc. within a predetermined range). The predetermined range of wireless performance metrics can be characterized by an upper threshold or value and / or a lower threshold or value.

[0064] Wireless performance metric data can be used to determine whether an external object 46 is within a threshold distance R. TH A rough indicator within. For example, if the external object 46 is at a distance R... TH Internally, external objects 46 may partially block or cover one or more antennas 40 (thus preventing the antennas from properly receiving radio frequency signals), or may undesirably load or detune one or more antennas 40 in the device 10, etc. This can indicate a threshold distance R when the collected wireless performance metric data falls outside a predetermined range. TH The potential presence of external object 46 within the area. However, this can indicate the presence of external object 46 when the collected wireless performance metric data falls within a predetermined range. TH It is highly unlikely that an external object exists inside (e.g., because there is no threshold distance R). TH When an external object is inside, wireless circuit 24 is performing a predictable, localized operation. If the collected wireless performance metric data falls within a predetermined range (thus indicating a threshold distance R),... TH If no external object exists within the VSWR sensor 32, the VSWR sensor 32 can acquire background VSWR measurements for background removal when needed.

[0065] VSWR sensor 32 can perform n VSWR measurements, such as |S|, during any given sampling period. 11| Measurement (sometimes referred to as sampling in this paper). Each of the n VSWR measurements can be performed at the corresponding sampling time within the sampling period (e.g., at...). Figure 5 The sampling period (from time T0 to time T4) occurs. The sampling period can have any desired length (e.g., n can be any desired integer, such as 2, between 3 and 5, between 5 and 10, between 10 and 20, 100, more than 100, more than 10, more than 20, more than 5, more than 2, etc.).

[0066] At operation 126, wireless circuit 24 (e.g., Figure 3 The sequence signal generator 108 or LO106 can transmit the test signal sigtx via transmit path 34. The test signal sigtx can be transmitted at a single frequency (e.g., single tone), multiple frequencies (e.g., as a dual tone or multi-tone), or can be scanned within a frequency range. The transmit antenna 40TX can transmit the test signal sigtx. If necessary, the transmit antenna 40TX can abandon the transmission of the test signal sigtx (e.g., ...). Figure 3 Antenna switch 94 can be turned on.

[0067] At operation 128, the VSWR sensor 32 can perform VSWR measurements based on the emitted test signal sigtx (or perform multiple VSWR measurements if the test signal sigtx is scanned within the frequency range) (e.g., |S 11 | value), and can (for example, in Figure 3 The VSWR measurement value is stored in memory 104 for subsequent processing. This measurement can be performed at the corresponding sampling time within the sampling period (e.g., ...). Figure 5 The sampling occurs at a time between T0 and T4. If a complete sampling period has not yet elapsed (e.g., if fewer than n iterations of sampling or operations 126 to 128 have occurred within the current sampling period), processing can loop back to operation 126 via path 130. Each iteration of operations 126 to 128 may require a corresponding duration or period (e.g., 10 ms, 20 ms, 1 ms to 20 ms, more than 20 ms, etc.) to be performed. Each VSWR measurement (e.g., each iteration of operation 128) can therefore be spaced out at time intervals, allowing VSWR measurements to be performed over time (e.g., within the sampling period) to identify changes in VSWR measurements over time for subsequent processing.

[0068] If the sampling period has elapsed (e.g., sampling or iterations from operation 126 to operation 128 have occurred n times), then processing can proceed from operation 128 to operation 134 via path 132. At operation 134, control circuitry 14 (e.g., Figure 3 Comparator / Logic 102 OR AND Figure 3The measurement circuit 70, separated from other control circuits, can identify the amount by which the VSWR measurement value acquired and stored during the sampling period changes over time. For example, control circuit 14 can identify a difference Δ in the variation of a metric such as the VSWR measurement value, which is equal to the maximum stored |S| during the sampling period. 11 | value (e.g., Figure 5 |S 11 | MAX ) and minimum storage |S 11 | value (e.g., Figure 5 |S 11 | MIN The difference between ) is merely illustrative, and in general, control circuit 14 can identify other metrics of change, such as storage |S, if needed. 11 |The mean and variance of the values.

[0069] At operation 136, control circuitry 14 may perform liveness detection based on identified changes in VSWR measurements acquired and stored during the sampling period. For example, control circuitry 14 may compare identified changes (e.g., differences Δ) with one or more thresholds indicating whether an external object 46 is alive or inanimate. Liveness detection allows control circuitry 14 to distinguish between living external objects 46 (such as desktops or removable housings) and inanimate external objects 46 (such as body parts of the user of device 10 or other people's body parts).

[0070] If needed, control circuitry 14 can process VSWR measurements acquired and stored during the sampling period to identify the presence of a removable housing on device 10, and optionally identify the type of removable housing present on device 10 (at operation 138). For example, these housing detection operations can be performed in response to the identification that external object 46 is an inanimate object.

[0071] If needed, control circuit 14 can identify the distance to external object 46 based on identified changes in VSWR measurements acquired and stored during the sampling period (at operation 140). For example, control circuit 14 can correlate the identified changes with an indication that external object 46 exists at a threshold distance R. TH One or more thresholds at different distances within the range are compared.

[0072] If necessary, control circuitry 14 may, in response to determining that external object 46 is a living object, reduce the transmit power level of antenna 40TX, reduce the maximum transmit power level of antenna 40TX (e.g., the upper limit or maximum limit of the transmit power level used by antenna 40TX), switch to using a different transmit antenna, and / or disable transmit antenna 40TX. This ensures that living external objects that may or are very likely to be human body parts are not exposed to excessive radio frequency energy, thereby ensuring that device 10 continues to meet any specified limits for SAR or MPE.

[0073] Figure 7 The examples are merely illustrative. Operations 138, 140, and / or 142 may be omitted. Control circuitry 14 may perform any other desired operation in response to the detection of a living or inanimate external object near transmit antenna 40TX. If necessary, control circuitry 14 may increase the transmission power level, increase the maximum transmission power level, and / or switch to using transmit antenna 40TX in response to determining that external object 46 is an inanimate object.

[0074] Figure 8 This is a flowchart illustrating the operations involved in performing liveness detection. For example, Figure 8 The operation can be controlled by control circuit 14 (e.g., with...). Figure 3 The measurement circuit 70 is separated from and / or includes one or more processors (parts of which are processors) in the execution Figure 7 The operation is executed at time 136.

[0075] exist Figure 8 At operation 144, control circuit 14 can compare the identified change in the VSWR measurement value within the sampling period with a minimum change threshold. For example, control circuit 14 can compare the difference Δ with the minimum change threshold. If the identified change (e.g., the difference Δ) exceeds the minimum change threshold (e.g., if a sufficiently large |S| exists within the sampling period), the control circuit 14 will determine the minimum change threshold. 11 If the change is |, then the processing can proceed to operation 148 via path 146.

[0076] At operation 148, control circuit 14 can identify external object 46 as a living (non-static) external object (e.g., because |S| acquired during the sampling period). 11A relatively high change in the value indicates that an external object has moved at least slightly closer to the transmitting antenna 40TX, suggesting the possible presence of a human body part. If necessary, the control circuit 14 may, in response to determining that the external object 46 is a living object, reduce the transmission power level of the transmitting antenna 40TX, reduce the maximum transmission power level of the transmitting antenna 40TX, disable the transmitting antenna 40TX, switch to using a different transmitting antenna, and / or perform any other desired processing (e.g., a software application running on device 10 may use the presence of a living object near the device as a control input, etc.). This ensures that device 10 continues to meet the prescribed limits for SAR / MPE, taking into account the possibility (or high probability) of the presence of body parts near the transmitting antenna 40TX.

[0077] In optional operation 150, control circuitry 14 may identify the distance to external object 46 based on identified changes in stored VSWR measurements. For example, the amount of change in stored VSWR measurements may be correlated with the distance between the living external object and transmitting antenna 40TX. Control circuitry 14 may compare the identified change (e.g., a difference Δ) with one or more additional thresholds indicating that the living external object is located at different distances from transmitting antenna 40TX to identify the distance between device 10 and the living external object. Control circuitry 14 may use the identified distance for any other desired processing or application task. Optional operation 150 may be omitted if necessary.

[0078] If the identified change (e.g., the difference Δ) is less than the minimum change threshold (e.g., if there is no sufficiently large |S| within the sampling period), 11 If the change in |S| is known, then the processing can proceed from operation 144 to operation 154 via path 152. At operation 154, control circuit 14 can identify that external object 46 is an inanimate (static) external object (e.g., because |S| is acquired during the sampling period). 11 A relatively low change in the value indicates a stationary external object, which is unlikely to be a human body part. If necessary, control circuitry 14 may forgo reducing the transmission power level or the maximum transmission power level of transmitting antenna 40TX. In other words, control circuitry 14 may maintain the current maximum transmission power level of transmitting antenna 40TX, or it may increase the maximum transmission power level of transmitting antenna 40TX. If necessary, control circuitry 14 may increase the transmission power level of transmitting antenna 40TX, switch to using transmitting antenna 40TX, and / or perform any other desired processing in response to determining that external object 46 is an inanimate object (e.g., a software application running on device 10 may use the presence of an inanimate object near the device as a control input, etc.). Relative to a threshold distance R THThe transmission power level or maximum transmission power level of all external objects 46 within the device is reduced, regardless of whether the external objects are living or inanimate. This helps to maximize the radio frequency performance of the wireless circuit 24 when performing wireless communication and / or long-range spatial ranging operations (e.g., maximizing throughput, signal quality, signal-to-noise ratio, etc.). Since inanimate objects are not human body parts, omitting the reduction in transmission power level or maximum transmission power level will not cause the device 10 to exceed the specified limits for SAR / MPE.

[0079] If needed, control circuit 14 can also perform housing detection at operation 154. For example, control circuit 14 can compare one or more VSWR measurements (or the average of stored VSWR measurements) from the stored VSWR measurements with one or more predetermined VSWR measurements stored on device 10 (e.g., |S... 11 The VSWR value is compared to determine whether a removable housing exists on device 10. For example, the predetermined VSWR measurement value could be the expected VSWR measurement value collected for device 10 in the absence of any external objects or removable housing (e.g., during factory calibration). Figure 5 (One or more points in point 114, or the mean of point 114).

[0080] If the difference between the stored VSWR measurement and the predetermined VSWR measurement is less than a threshold difference (or if the stored VSWR measurement is otherwise sufficiently similar to the predetermined VSWR measurement), the process can proceed to operation 158 via path 156. At operation 158, control circuitry 14 can identify that the inanimate external object is not a removable housing or is not present near the transmit antenna 40TX. However, if the difference between the stored VSWR measurement and the predetermined VSWR measurement exceeds a threshold difference (or if the stored VSWR measurement is sufficiently dissimilar to the predetermined VSWR measurement), the process can proceed to optional operation 162 via path 160.

[0081] At optional operation 162, control circuitry 14 can identify the type of removable housing present on device 10. For example, control circuitry 14 can compare one or more VSWR measurements from stored VSWR measurements (e.g., the mean of stored VSWR measurements, VSWR measurements varying with frequency) with one or more predetermined VSWR measurements stored on device 10 to determine the type of removable housing present. For example, these predetermined VSWR measurements could be expected VSWR measurements acquired for device 10 while it is being placed in various types of removable housings (e.g., during factory calibration). As an example, control circuitry 14 can compare stored VSWR measurements with curves such as... Figure 6 Curves 118 and 120 are compared to determine whether a removable housing associated with curve 118 or curve 120 is present on device 10. If necessary, operation 162 can be combined with operation 154 (e.g., control circuitry 14 can compare a stored VSWR measurement with predetermined VSWR measurements associated with different removable housing types, and if the VSWR measurement is not sufficiently similar to any predetermined VSWR measurement, processing can proceed from operation 154 to operation 158). Operation 162 can be omitted if necessary.

[0082] At operation 164, control circuitry 14 can identify an inanimate external object as a removable device housing (and optionally identify the type of removable device housing). Control circuitry 14 can perform additional processing based on the detected presence of the removable device housing and / or the identified housing type. For example, control circuitry 14 can perform additional processing at a threshold distance R. TH In the absence of other external objects, VSWR sensor 32 is used to acquire background VSWR measurements, which take into account the presence of the removable device housing. Control circuitry 14 can then use the background VSWR measurements to perform background removal on subsequent VSWR measurements (e.g., by subtracting the background VSWR measurements from subsequent VSWR measurements taken at a threshold distance R while the device 10 is placed within the removable housing). THThe memory is acquired in the presence of another external object. In other words, the VSWR detector 32 can perform VSWR background cancellation based on the presence of a removable device housing on the detected device 10. As another example, the control circuit 14 can control the impedance matching and / or antenna tuning of the transmitting antenna 40TX based on the presence of the removable device housing and optionally based on the type of the removable device housing (e.g., to compensate for impedance loading or detuning of the antenna due to the presence of the removable device housing). As yet another example, the control circuit 14 can use the presence of the removable housing and optionally the type of the removable housing to calibrate long-distance spatial ranging operations performed using the transmitting antenna 40TX (e.g., to compensate for path delay effects of transmitted and / or reflected signals passing through the removable housing).

[0083] Figure 9 Curve 168 shows |S 11 Here's an example of how the change in | can be correlated with the distance between an external object and the transmitting antenna 40TX. If needed, control circuitry 14 can compare the identified changes in the stored VSWR measurements with curve 168 to identify the corresponding distance between the external object and the transmitting antenna 40TX (e.g., in...). Figure 8 (During processing operation 150). Curve 168 may be stored on device 10 (e.g., during factory calibration, manufacturing, assembly, testing, etc.). Figure 9 The example is merely illustrative, and in practice, curve 168 may have other shapes.

[0084] Figure 10 Two exemplary timing diagrams are shown for performing VSWR measurements for live object detection. Timing diagram 170 illustrates an arrangement in which the VSWR measurements for performing live object detection are time-division multiplexed with other transmit operations. During sampling period 172, control circuitry 14 can perform n times. Figure 7 The iterations of operations 126 and 128 are performed. n VSWR measurements during each sampling period 172 can be processed to identify corresponding changes, and these changes can be processed to determine whether the external object 46 is alive or inanimate (e.g., during processing operations 134 through 136). During period 174, the transmitting antenna 40TX can be used to transmit other signals, such as wireless communication signals or radar signals for performing long-term space ranging. Figure 7 Operations 134 to 136 can be performed during each sampling period 172, or extended into subsequent periods 174 if necessary.

[0085] Timing diagram 176 illustrates an alternative arrangement in which VSWR measurements for performing live object detection are performed during rolling sampling periods 172. As shown in timing diagram 176, each sampling period for identifying changes in VSWR measurements may include a subset of samples from previous sampling periods as well as additional samples after the previous sampling period has elapsed. For example, this allows wireless circuit 24 to continuously determine whether external object 46 is alive or inanimate. Figure 10 The examples provided are merely illustrative. Timing arrangements of timing diagrams 170 and 176 can be combined if desired. The signal transmitted during period 174 can be used as a test signal sigtx if desired (e.g., the separate sampling period 172 can be omitted). Other timing arrangements for sampling period 172 can be used if desired.

[0086] The above combination Figures 1 to 10 The described methods and operations can be performed by components of device 10 using software, firmware, and / or hardware (e.g., dedicated circuitry or hardware). The software code for performing these operations can be stored on a non-transitory computer-readable storage medium (e.g., a tangible computer-readable storage medium) stored on one or more components of device 10 (e.g., ...). Figure 1 The storage circuit 16). This software code may sometimes be referred to as software, data, instructions, program instructions, or code. Non-transitory computer-readable storage media may include drives, non-volatile memory such as non-volatile random access memory (NVRAM), removable flash drives or other removable media, other types of random access memory, etc. The software stored on the non-transitory computer-readable storage medium may be processed by processing circuitry on one or more components of device 10 (e.g., Figure 1 The processing circuitry (e.g., 18) performs the execution. The processing circuitry may include a microprocessor, a central processing unit (CPU), an application-specific integrated circuit (ASIC) with processing circuitry, or other processing circuitry. Figure 1 and Figure 3 The components can be implemented using hardware (e.g., circuit components, digital logic gates, etc.) and / or using suitable software.

[0087] According to an embodiment, an electronic device is provided that can operate in an environment including external objects, the electronic device comprising: an antenna; a voltage standing wave ratio (VSWR) sensor communicatively coupled to the antenna, the VSWR sensor being configured to perform a VSWR measurement using a radio frequency signal emitted by the antenna; and one or more processors configured to identify changes in the VSWR measurement over time and determine whether the external object is living or non-living based on the identified changes in the VSWR measurement.

[0088] According to another implementation, the one or more processors are further configured to reduce the maximum transmission power level of the antenna in response to determining that an external object is alive.

[0089] According to another implementation, the one or more processors are further configured to increase the maximum transmission power level of the antenna in response to determining that the external object is inanimate.

[0090] According to another implementation, in response to determining that an external object is inanimate, the one or more processors are configured to determine whether the external object is a removable device housing based on the magnitude of a VSWR measurement.

[0091] According to another embodiment, the VSWR sensor is configured to perform a background VSWR measurement in response to the one or more processors determining that the external object is a removable device housing, and the one or more processors are further configured to perform background removal on subsequent VSWR measurements performed by the VSWR sensor based on the background VSWR measurement.

[0092] According to another implementation, the one or more processors are further configured to identify the distance between the external object and the antenna based on the identified changes in the VSWR measurement in response to determining that the external object is alive.

[0093] According to another embodiment, the electronic device includes radar circuitry communicatively coupled to an antenna, the radar circuitry being configured to use the antenna to perform long-range spatial ranging operations.

[0094] According to another embodiment, the radar circuit includes a sequence signal generator, and the sequence signal generator is configured to generate radio frequency signals.

[0095] According to another embodiment, the one or more processors are further configured to: compare the identified changes in the VSWR measurement with a threshold; determine that the external object is alive when the identified changes in the VSWR measurement exceed the threshold; and determine that the external object is inanimate when the identified changes in the VSWR measurement are less than the threshold.

[0096] According to an implementation scheme, a method is provided for operating an electronic device to perform live object detection on an object outside the electronic device. The method includes: using a signal generator to transmit a radio frequency signal via a radio frequency transmission line communicatively coupled to an antenna during a sampling period; using a voltage standing wave ratio (VSWR) sensor disposed along the radio frequency transmission line to perform a VSWR measurement based on the radio frequency signal transmitted via the radio frequency transmission line during the sampling period; using one or more processors to identify changes in the VSWR measurement value over time during the sampling period; using the one or more processors to identify that the object is alive when the identified change exceeds a threshold; and using the one or more processors to identify that the object is inanimate when the identified change is less than the threshold.

[0097] According to another implementation, the method includes reducing the maximum transmission power level of the antenna in response to identifying the object as alive.

[0098] According to another embodiment, identifying changes in VSWR measurements includes: identifying the maximum VSWR measurement from the VSWR measurements performed during the sampling period; identifying the minimum VSWR measurement from the VSWR measurements performed during the sampling period; and identifying the difference between the maximum and minimum VSWR measurements as a change in VSWR measurements.

[0099] According to another implementation, performing a VSWR measurement includes performing at least two VSWR measurements with an interval of at least 10 ms between them.

[0100] According to another implementation, the method includes identifying the distance between the antenna and the object by comparing the identified changes with at least one additional threshold in response to the identification that the object is alive.

[0101] According to another embodiment, the method includes identifying whether an object is a removable device housing by comparing the magnitude of one or more VSWR measurements with one or more predetermined VSWR measurements in response to the identification that the object is inanimate.

[0102] According to another embodiment, the method includes: transmitting a radar signal via a radio frequency transmission line during a time period following the sampling period; transmitting an additional radio frequency signal via the transmission line during an additional sampling period following the time period using a signal generator; and performing an additional VSWR measurement based on the additional radio frequency signal transmitted via the radio frequency transmission line during the additional sampling period using a VSWR sensor.

[0103] According to another implementation, the sampling period includes a rolling sampling period.

[0104] According to an embodiment, an electronic device is provided, comprising: an antenna; a voltage standing wave ratio (VSWR) sensor communicatively coupled to the antenna, the VSWR sensor being configured to acquire a VSWR value based on a radio frequency signal emitted by the antenna; and one or more processors configured to identify changes in the VSWR value over time, reduce the maximum transmission power level of the antenna when the identified change exceeds a threshold, and maintain or increase the maximum transmission power level of the antenna when the identified change is less than the threshold.

[0105] According to another implementation, the one or more processors are further configured to perform removable housing detection when the identified change is less than a threshold.

[0106] According to another implementation, VSWR values ​​are acquired during a sampling period, and the one or more processors are configured to identify changes in VSWR values ​​by subtracting the minimum value of the VSWR values ​​acquired during the sampling period from the maximum value of the VSWR values ​​acquired during the sampling period.

[0107] The foregoing description is merely illustrative and various modifications can be made to the described implementation scheme. The described implementation scheme can be implemented independently or in any combination.

Claims

1. An electronic device capable of operating in an environment including external objects, the electronic device comprising: antenna; A transmitter coupled to the antenna via a radio frequency transmission line path, the transmitter being configured to transmit radio frequency signals to another electronic device using the antenna and the radio frequency transmission line path; A voltage standing wave ratio (VSWR) sensor is disposed on the radio frequency transmission line path and is configured to perform VSWR measurement using the radio frequency signal emitted by the transmitter; A radar circuit, communicatively coupled to the antenna, and configured to transmit and receive radar signals using the antenna; and One or more processors are configured to detect the distance to an external object based on radar signals transmitted by the antenna and received by the radar circuitry, and the one or more processors are configured to calibrate the detected distance to compensate for path loss associated with a removable housing detected based on VSWR measurements.

2. The electronic device of claim 1, wherein the one or more processors are further configured to reduce the maximum transmission power level of the antenna in response to determining, based on the VSWR measurement, that the external object is alive.

3. The electronic device of claim 2, wherein the one or more processors are further configured to increase the maximum transmission power level of the antenna in response to determining, based on the VSWR measurement, that the external object is inanimate.

4. The electronic device of claim 1, wherein the one or more processors are configured to detect the removable housing based on the magnitude of the VSWR measurement.

5. The electronic device of claim 4, wherein the VSWR sensor is configured to perform a background VSWR measurement in response to the one or more processors determining that the external object is the removable device housing, and the one or more processors are further configured to perform background removal on subsequent VSWR measurements performed by the VSWR sensor based on the background VSWR measurement.

6. The electronic device of claim 1, wherein the one or more processors are further configured to identify the distance between the external object and the antenna based on changes in the VSWR measurement.

7. The electronic device of claim 1, wherein the radar circuitry includes a sequence signal generator, and the sequence signal generator is configured to generate the radar signal.

8. The electronic device of claim 1, wherein the one or more processors are further configured to: The change in the VSWR measurement value is compared with a threshold. When the identified change in the VSWR measurement exceeds the threshold, it is determined that the external object is alive; and When the identified change in the VSWR measurement is less than the threshold, the external object is determined to be inanimate.

9. A method of operating an electronic device, the method comprising: A signal generator is used to transmit radio frequency signals through a radio frequency transmission line that can be communicatively coupled to the antenna during the sampling period; A voltage standing wave ratio (VSWR) sensor disposed along the radio frequency transmission line is used to perform VSWR measurement based on the radio frequency signal transmitted through the radio frequency transmission line during the sampling period. One or more processors are used to detect removable housings on the electronic device based on VSWR measurements. Radar circuitry is used to transmit and receive radar signals using an antenna; Using the one or more processors, the distance to an external object is detected based on the transmitted and received radar signals; as well as Using the one or more processors, the detected distance is calibrated to compensate for path loss associated with the removable housing detected based on VSWR measurements.

10. The method of claim 9, wherein performing the VSWR measurement comprises performing at least two VSWR measurements, the interval between the at least two VSWR measurements being at least 10 ms.

11. The method of claim 9, wherein the sampling period includes a rolling sampling period.

12. An electronic device, comprising: antenna; A transmitter coupled to the antenna via a radio frequency transmission line path, the transmitter being configured to transmit radio frequency signals using the antenna and the radio frequency transmission line path; A voltage standing wave ratio (VSWR) sensor, the VSWR sensor being disposed on the radio frequency transmission line path, the VSWR sensor being configured to acquire VSWR values ​​based on the radio frequency signal emitted by the antenna; and One or more processors, the one or more processors being configured to The distance to an external object is detected based on the radio frequency signal emitted by the antenna and the reflected pattern of the radio frequency signal emitted by the antenna. The detected distance is calibrated based on the removable housing detected by the one or more processors according to the VSWR value.

13. The electronic device of claim 12, wherein the one or more processors are further configured to perform removable housing detection when the change in the VSWR value is less than a threshold.

14. The electronic device of claim 13, wherein the VSWR value is acquired during a sampling period, and the one or more processors are further configured to identify the change in the VSWR value by subtracting the minimum value of the VSWR values ​​acquired during the sampling period from the maximum value of the VSWR values ​​acquired during the sampling period.

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