Patent Publication Number: US-2022232329-A1

Title: Hearing device system incorporating phased array antenna arrangement

Description:
RELATED APPLICATIONS 
     This application is a continuation of PCT Application No. PCT/US2020/052015, filed Sep. 22, 2020, which claims priority to U.S. Provisional Application No. 62/907,086, filed Sep. 27, 2019, the content of which are hereby incorporated by reference in their entireties. 
    
    
     TECHNICAL FIELD 
     This application relates generally to hearing devices, including ear-worn electronic devices, hearing aids, personal amplification devices, and other hearables. 
     BACKGROUND 
     Hearing devices provide sound for the wearer. Some examples of hearing devices are headsets, hearing aids, speakers, cochlear implants, bone conduction devices, and personal listening devices. For example, hearing aids provide amplification to compensate for hearing loss by transmitting amplified sounds to a wearer&#39;s ear canals. Hearing devices may be capable of performing wireless communication with other devices, such as receiving streaming audio from a streaming device via a wireless link. Wireless communication may also be performed for programming the hearing device and receiving information from the hearing device. For performing such wireless communication, hearing devices such as hearing aids may each include a wireless transceiver and an antenna. 
     SUMMARY 
     Embodiments are directed to a hearing device system comprising a first hearing device and a second hearing device adapted to be worn at first and second ears of a wearer. The system comprises a first hearing device and a second hearing device each comprising a housing configured to be supported at, on or in the wearer&#39;s ear, a processor coupled to memory, a radio frequency transceiver coupled to the processor, and an antenna arrangement disposed in or on the housing and coupled to the transceiver and the processor. The antenna arrangement comprises an antenna coupled to a phase shifter. The processor is configured to adjust a phase shift of the phase shifter. The system also comprises a clock synchronization link between the transceivers, a second link configured to communicate received signal information between the transceivers, and a master processor defined by the processor of the first or second hearing device. The master processor is configured to cause the first and second hearing devices to operate the antenna arrangements as a phased array antenna arrangement via the clock synchronization link and the second link. 
     Embodiments are directed to a hearing device system comprising a first hearing device and a second hearing device adapted to be worn at first and second ears of a wearer. The system comprises a first hearing device and a second hearing device each comprising a housing configured to be supported at, on or in the wearer&#39;s ear, a processor coupled to memory, a radio frequency transceiver coupled to the processor, and an antenna arrangement disposed in or on the housing and coupled to the transceiver and the processor. The antenna arrangement comprises an antenna coupled to a phase shifter and a variable gain amplifier. The processor is configured to adjust a phase shift of the phase shifter and a gain of the variable gain amplifier. The system also comprises a clock synchronization link between the transceivers, a second link configured to communicate received signal information between the transceivers, and a master processor defined by the processor of the first or second hearing device. The master processor is configured to cause the first and second hearing devices to operate the antenna arrangements as a phased array antenna arrangement via the clock synchronization link and the second link. 
     Embodiments are directed to a method implemented by a hearing device system comprising a first hearing device and a second hearing device each adapted to be worn at, on or in an ear of a wearer. The method comprises providing, at the first and second hearing devices, an antenna arrangement coupled to a radio frequency transceiver and a processor, the antenna arrangement comprising an antenna coupled to a phase shifter. The method also comprises adjusting a phase shift of the phase shifters by the processors of the first and second hearing devices. The method further comprises causing the first and second hearing devices to operate the antenna arrangements as a phased array antenna arrangement by a master processor defined by the processor of the first or second hearing device. 
     Embodiments are directed to a hearing device system comprising a first hearing device and a second hearing device adapted to be worn at first and second ears of a wearer. The system comprises a first hearing device and a second hearing device each comprising a housing configured to be supported at, on or in the wearer&#39;s ear, a processor coupled to memory, a radio frequency transceiver coupled to the processor, and an antenna arrangement disposed in or on the housing and coupled to the transceiver and the processor. The antenna arrangement comprises an antenna coupled to a phase shifter. The processor is configured to adjust a phase shift of the phase shifter. The system also comprises a clock synchronization link between the transceivers and a master processor defined by the processor of the first or second hearing device. The master processor is configured to cause the first and second hearing devices to operate the antenna arrangements as a phased array antenna arrangement in a coherent transmit mode by phase-locking the transceivers via the clock synchronization link. 
     Embodiments are directed to a hearing device system comprising a first hearing device and a second hearing device adapted to be worn at first and second ears of a wearer. The system comprises a first hearing device and a second hearing device each comprising a housing configured to be supported at, on or in the wearer&#39;s ear, a processor coupled to memory, a radio frequency transceiver coupled to the processor, and an antenna arrangement disposed in or on the housing and coupled to the transceiver and the processor. The antenna arrangement comprises an antenna coupled to a phase shifter. The processor is configured to adjust a phase shift of the phase shifter. The system also comprises a clock synchronization link between the transceivers, a second link configured to communicate received signal information between the transceivers, and a master processor defined by the processor of the first or second hearing device. The master processor is configured to cause the first and second hearing devices to operate the antenna arrangements as a phased array antenna arrangement in a coherent receive mode by phase-locking local oscillators of the transceivers via the clock synchronization link and the second link. 
     Embodiments are directed to a hearing device system comprising a first hearing device and a second hearing device adapted to be worn at first and second ears of a wearer. The system comprises a first hearing device and a second hearing device each comprising a housing configured to be supported at, on or in the wearer&#39;s ear, a processor coupled to memory, a radio frequency transceiver coupled to the processor, and an antenna arrangement disposed in or on the housing and coupled to the transceiver and the processor. The antenna arrangement comprises an antenna coupled to a phase shifter. The processor is configured to adjust a phase shift of the phase shifter. The system also comprises a clock synchronization link between the transceivers, a second link configured to communicate received signal information between the transceivers, and a master processor defined by the processor of the first or second hearing device. The master processor is configured to cause the first and second hearing devices to operate the antenna arrangements as a phased array antenna arrangement in a coherent transmit mode by phase-locking the transceivers via the clock synchronization link and operate the antenna arrangements as the phased array antenna arrangement in a coherent receive mode by phase-locking local oscillators of the transceivers via the clock synchronization link and the second link. 
     The above summary is not intended to describe each disclosed embodiment or every implementation of the present disclosure. The figures and the detailed description below more particularly exemplify illustrative embodiments. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Throughout the specification reference is made to the appended drawings wherein: 
         FIG. 1A  illustrates a hearing device system comprising first and second hearing devices whose antennas form a phased array antenna arrangement in accordance with any of the embodiments disclosed herein; 
         FIG. 1B  illustrates a hearing device system comprising first and second hearing devices whose antennas form a phased array antenna arrangement in accordance with any of the embodiments disclosed herein; 
         FIG. 1C  illustrates that an antenna array pattern of a phased array antenna arrangement can be electronically steered in one or both of an azimuth plane and an elevation plane in accordance with any of the embodiments disclosed herein; 
         FIG. 1D  shows a representative antenna pattern on the azimuth plane; 
         FIG. 1E  shows a representative antenna pattern on the elevation plane; 
         FIG. 1F  shows a representative antenna pattern which includes a main lobe, side lobes, and a null; 
         FIG. 2  illustrates a hearing device system comprising first and second hearing devices whose antennas form a phased array antenna arrangement in accordance with any of the embodiments disclosed herein; 
         FIGS. 3A and 3B  illustrate a hearing device system comprising first and second hearing devices each including a phased array antenna arrangement which, together, are controlled to form a combined phased array antenna arrangement in accordance with any of the embodiments disclosed herein; 
         FIG. 3C  is a block diagram of a variable gain amplifier shown in  FIGS. 3A and 3B  with accompanying switching circuitry in accordance with any of the embodiments disclosed herein; 
         FIG. 3D  is a block diagram of a variable gain amplifier arrangement with accompanying switching circuitry for use in the hearing device shown in  FIGS. 3A and 3B  in accordance with any of the embodiments disclosed herein; 
         FIG. 4  illustrates a method of operating a phased array antenna arrangement of a hearing device system in accordance with any of the embodiments disclosed herein; 
         FIG. 5  illustrates a method of operating a phased array antenna arrangement of a hearing device system in accordance with any of the embodiments disclosed herein; 
         FIG. 6  illustrates a method of operating a phased array antenna arrangement of a hearing device system in accordance with any of the embodiments disclosed herein; and 
         FIG. 7  is a block diagram showing various components of hearing devices whose antennas form a phased array antenna arrangement in accordance with any of the embodiments disclosed herein. 
     
    
    
     The figures are not necessarily to scale. Like numbers used in the figures refer to like components. However, it will be understood that the use of a number to refer to a component in a given figure is not intended to limit the component in another figure labeled with the same number. 
     DETAILED DESCRIPTION 
     It is understood that the embodiments described herein may be used with any ear-worn electronic hearing device without departing from the scope of this disclosure. The devices depicted in the figures are intended to demonstrate the subject matter, but not in a limited, exhaustive, or exclusive sense. Ear-worn electronic hearing devices (referred to herein as “hearing devices”), such as hearables (e.g., wearable earphones, ear monitors, and earbuds), hearing aids, and hearing assistance devices, typically include an enclosure, such as a housing or shell, within which internal components are disposed. Typical components of a hearing device can include a digital signal processor (DSP), memory, power management circuitry, one or more communication devices (e.g., a radio, a near-field magnetic induction (NFMI) device), one or more antennas, one or more microphones, and a receiver/speaker, for example. Hearing devices can incorporate a long-range communication device, such as a Bluetooth® transceiver or other type of radio frequency (RF) transceiver. A communication device (e.g., a radio or NFMI transceiver) of a hearing device can be configured to facilitate communication between a left ear device and a right ear device of the hearing device. 
     Individual hearing devices of the present disclosure which together define a hearing device system can incorporate a single antenna or a phased array antenna arrangement coupled to a high-frequency transceiver, such as a 2.4 GHz radio. The RF transceiver can conform to an IEEE 802.11 (e.g., WiFi®) or Bluetooth® (e.g., BLE, Bluetooth® 4. 2 or 5.0) specification, for example. It is understood that hearing devices of the present disclosure can employ other transceivers or radios, such as a 900 MHz radio. Hearing devices of the present disclosure can be configured to receive streaming audio (e.g., digital audio data or files) from an electronic or digital source. Representative electronic/digital sources (e.g., accessory devices) include an assistive listening system, a TV streamer, an audio player, a radio, a smartphone, a laptop, a cell phone/entertainment device (CPED) or other electronic device that serves as a source of digital audio data or other types of data files. Hearing devices of the present disclosure can be configured to effect bi-directional communication (e.g., wireless communication) of data with an external source, such as a remote server via the Internet or other communication infrastructure. 
     The term hearing device of the present disclosure refers to a wide variety of ear-level electronic devices that can aid a person with impaired hearing. The term hearing device also refers to a wide variety of devices that can produce processed sound for persons with normal hearing. Hearing devices of the present disclosure include hearables (e.g., wearable earphones, headphones, earbuds, virtual reality headsets), hearing aids (e.g., hearing instruments), cochlear implants, and bone-conduction devices, for example. Hearing devices include, but are not limited to, behind-the-ear (BTE), in-the-ear (ITE), in-the-canal (ITC), invisible-in-canal (IIC), receiver-in-canal (RIC), receiver-in-the-ear (RITE) or completely-in-the-canal (CIC) type hearing devices or some combination of the above. 
     Embodiments of the disclosure are directed to a hearing device system comprising a pair of hearing devices, each of which incorporates a radio frequency (RF) transceiver coupled to at least one antenna. The two hearing devices are configured such that their antennas operate cooperatively as a phased array antenna arrangement. The phased array antenna arrangement defined by the combined antennas of the pair of hearing devices is configured to electronically steer an antenna array pattern of the phased array antenna arrangement in a direction that improves a wireless link between the hearing devices and an external device or system. The term antenna array pattern refers to a radiation pattern of a phase array antenna arrangement. In some cases, the phased array antenna arrangement is controlled to electronically steer a main beam or main lobe of the antenna array pattern towards the best position for the wireless link. In other cases, the phased array antenna arrangement is controlled to electronically steer a null of the antenna array pattern towards a source of interference, thereby improving the wireless link between the hearing devices and a target external device or system. For example, a null of the antenna array pattern can be steered in a direction of a radio frequency noise source or a multipath null contributor. In some cases, the phased array antenna arrangement is controlled to electronically steer both a main beam or lobe and a null of the antenna array pattern towards the best positions for the wireless link. 
     With increasing numbers of collocated devices utilizing technology in the 2.4 GHz ISM frequency band, it is increasingly likely that the wireless link between a hearing device system and another device will be impacted by these external sources. By steering the antenna array pattern of the hearing device system, the wireless link between the hearing device system and other device can be improved. For example, hearing aids, hearables, wireless headsets, automobile/smartphone links, and WiFi®, all extensively use the 2.4 GHz ISM frequency band. By way of further example, a single in-band WiFi® transmitter due to its large bandwidth of up to 40 MHz is likely to cause interference to hearing devices (e.g., hearing instruments, hearing aids) using the 83.5 MHz wide ISM band. Additionally, even if not directly on-channel, large high-power access points and nearby Bluetooth® users risk overloading the relatively low-power receivers in hearing devices (e.g., hearing aids). In addition to these interference sources, LTE cellphone bands  7 ,  40 , and  41  are allocated for operation just below and above the 2.4 GHz ISM band. These interferers can run even more power, with SAW filtering unable to provide sufficient selectivity to reject this type of interference. This out-of-band interference can significantly desensitize the 2.4 GHz receivers of a hearing device system. Steering the antenna pattern null to the source of maximum interference can keep the hearing device&#39;s receiver from being desensitized due to the finite interference rejection of a low power receiver. The antenna pattern may need to be steered/adjusted on a per-frequency/per-channel basis for frequency hopped/agile systems due to propagation being frequency dependent (e.g., due to multipath, etc.). 
     Typically, an antenna array is designed with multiple antennas in the same device. The present disclosure describes implementations of an antenna array with the antennas distributed across multiple discrete devices. As such, the hardware implementation of a hearing device system as disclosed herein is able to utilize the entire size of the device for the antenna. As the antenna performance is highly dependent on electrical size, utilizing the entire size of the hearing device for the antenna eliminates the need for high dielectric materials. This also allows for antenna arrays to be implemented in custom or in-ear hearing devices, where fitting a single antenna is already a challenge and there is no space for a second antenna. Additionally, the spatial/electrical separation of each of the two (independent) antenna elements in the antenna array may be a relatively large percentage of a wavelength at the frequency of operation due to each antenna being separated by approximately a human head width. 
     Embodiments of the disclosure are defined in the claims. However, below there is provided a non-exhaustive listing of non-limiting examples. Any one or more of the features of these examples may be combined with any one or more features of another example, embodiment, or aspect described herein. 
     Example Ex1 
     A hearing device system comprising a first hearing device and a second hearing device adapted to be worn at first and second ears of a wearer, the system comprising a first hearing device and a second hearing device each comprising a housing configured to be supported at, on or in the wearer&#39;s ear, a processor coupled to memory, the processor and memory disposed in the housing, a radio frequency transceiver coupled to the processor and disposed in the housing, and an antenna arrangement disposed in or on the housing and coupled to the transceiver and the processor, the antenna arrangement comprising an antenna coupled to a phase shifter, the processor configured to adjust a phase shift of the phase shifter. The system also includes a clock synchronization link between the transceivers, a second link configured to communicate received signal information between the transceivers, and a master processor defined by the processor of the first or second hearing device, the master processor configured to cause the first and second hearing devices to operate the antenna arrangements as a phased array antenna arrangement via the clock synchronization link and the second link. 
     Example Ex2 
     The hearing device system according to Ex1, wherein the master processor is configured to coordinate adjustment of the phase of the phase shifters to steer an antenna array pattern of the phased array antenna arrangement. 
     Example Ex3 
     The hearing device system according to Ex2, wherein the master processor is configured adjust the phase of the phase shifters to steer a main lobe of the antenna array pattern in a direction of a desired radio frequency signal source that increases or maximizes a signal-to-noise ratio of a radio frequency signal received from the radio frequency signal source. 
     Example Ex4 
     The hearing device system according to Ex2 or Ex3, wherein the master processor is configured to steer a main lobe of the antenna array pattern in a direction that increases or maximizes a signal-to-noise ratio of a received radio frequency signal on a per channel frequency basis. 
     Example Ex5 
     The hearing device system according to one or more of Ex2 to Ex4, wherein the master processor is configured to steer the antenna array pattern in a direction that increases or maximizes a signal-to-noise ratio of a received radio frequency signal while concurrently nulling a radio frequency noise source or a multipath null contributor. 
     Example Ex6 
     The hearing device system according to one or more of Ex1 to Ex5, wherein the memory is configured to store phase parameters tabularized as a function of spatial steering direction, and the processor is configured to adjust the phase shift of each of the phase shifters by sequentially applying the tabularized phase parameters. 
     Example Ex7 
     The hearing device system according to Ex6, wherein the phase parameters stored in the memory account for head-loading effects on the antenna array pattern. 
     Example Ex8 
     The hearing device system according to one or more of Ex1 to Ex7, wherein the transceiver and the antenna arrangement are configured to transmit and receive radio frequency signals within a 2.4 GHz ISM frequency band. 
     Example Ex9 
     The hearing device system according to one or more of Ex1 to Ex8, wherein the antenna arrangements of the first and second hearing devices comprise first and second phased array antenna arrangements, the first and second phased array antenna arrangements comprise a plurality of antennas each coupled to one of a plurality of phase shifters, and the master processor is configured to cause the first and second hearing devices to operate the first and second phased array antenna arrangements as the phased array antenna arrangement. 
     Example Ex10 
     A hearing device system comprising a first hearing device and a second hearing device adapted to be worn at first and second ears of a wearer, the system comprising a first hearing device and a second hearing device each comprising a housing configured to be supported at, on or in the wearer&#39;s ear, a processor coupled to memory, the processor and memory disposed in the housing, a radio frequency transceiver coupled to the processor and disposed in the housing, and an antenna arrangement disposed in or on the housing and coupled to the transceiver and the processor, the antenna arrangement comprising an antenna coupled to a phase shifter and a variable gain amplifier, the processor configured to adjust a phase shift of the phase shifter and adjust a gain of the variable gain amplifier. The system includes a clock synchronization link between the transceivers, a second link configured to communicate received signal information between the transceivers, and a master processor defined by the processor of the first or second hearing device, the master processor configured to cause the first and second hearing devices to operate the antenna arrangements as a phased array antenna arrangement via the clock synchronization link and the second link. 
     Example Ex11 
     The hearing device system according to Ex10, wherein the master processor is configured to coordinate adjustment of the phase of the phase shifters to steer an antenna array pattern of the phased array antenna arrangement, and adjust a gain of the variable gain amplifier to one or more of reduce a side lobe of the antenna array pattern, change a location of the side lobe, and adjust a width of a main lobe of the antenna array pattern. 
     Example Ex12 
     The hearing device system according to Ex11, wherein the master processor is configured adjust the phase of the phase shifters to steer a main lobe of the antenna array pattern in a direction of a desired radio frequency signal source that increases or maximizes a signal-to-noise ratio of a radio frequency signal received from the radio frequency signal source. 
     Example Ex13 
     The hearing device system according to Ex11 or Ex12, wherein the master processor is configured to steer a main lobe of the antenna array pattern in a direction that increases or maximizes a signal-to-noise ratio of a received radio frequency signal on a per channel frequency basis. 
     Example Ex14 
     The hearing device system according to one or more of Ex11 to Ex13, wherein the master processor is configured to steer the antenna array pattern in a direction that increases or maximizes a signal-to-noise ratio of a received radio frequency signal while concurrently nulling a radio frequency noise source or a multipath null contributor. 
     Example Ex15 
     The hearing device system according to one or more of Ex10 to Ex 14, wherein the memory is configured to store phase parameters and gain parameters tabularized as a function of spatial steering direction, and the master processor is configured to adjust the phase shift of each of the phase shifters and a gain of each of the variable gain amplifiers by sequentially applying the tabularized phase and gain parameters. 
     Example Ex16 
     The hearing device system according to Ex15, wherein the phase and gain parameters stored in the memory account for head-loading effects on the antenna array pattern. 
     Example Ex17 
     The hearing device system according to one or more of Ex10 to Ex16, wherein the transceiver and the antenna arrangement are configured to transmit and receive radio frequency signals within a 2.4 GHz ISM frequency band. 
     Example Ex18 
     A method implemented by a hearing device system comprising a first hearing device and a second hearing device each adapted to be worn at, on or in an ear of a wearer, the method comprising providing, at the first and second hearing devices, an antenna arrangement coupled to a radio frequency transceiver and a processor, the antenna arrangement comprising an antenna coupled to a phase shifter, adjusting a phase shift of the phase shifters by the processors of the first and second hearing devices, and causing the first and second hearing devices to operate the antenna arrangements as a phased array antenna arrangement by a master processor defined by the processor of the first or second hearing device. 
     Example Ex19 
     The method according to Ex18, comprising steering, under control of the master processor, a main lobe of an antenna array pattern of the phased array antenna arrangement in a direction that increases or maximizes a signal-to-noise ratio of a received radio frequency signal. 
     Example Ex20 
     The method according to Ex18, comprising steering, under control of the master processor, a main lobe of an antenna array pattern of the phased array antenna arrangement in a direction that increases or maximizes a signal-to-noise ratio of a received radio frequency signal on a per channel frequency basis. 
     Example Ex21 
     The method according to Ex18, comprising steering, under control of the master processor, a main lobe of an antenna array pattern of the phased array antenna arrangement in a direction that increases or maximizes a signal-to-noise ratio of a received radio frequency signal while concurrently nulling a radio frequency noise source or a multipath null contributor. 
     Example Ex22 
     The method according to one or more of Ex18 to Ex21, wherein the antenna arrangements each comprise a variable gain amplifier coupled to the phase shifter and the antenna, and the method comprises adjusting, under control of the master processor, the phase shift of each of the phase shifters to steer an antenna array pattern of the phased array antenna arrangement, and adjusting, under control of the master processor, a gain of each of the variable gain amplifiers to one or more of reduce a side lobe of the antenna array pattern, change a location of the side lobe, and adjust a width of a main lobe of the antenna array pattern. 
     Example Ex23 
     The method according to one or more of Ex18 to Ex22, comprising transmitting and receiving radio frequency signals communicated on a per channel basis via the phased array antenna arrangement. 
     Example Ex24 
     A hearing device system comprising a first hearing device and a second hearing device adapted to be worn at first and second ears of a wearer, the system comprising a first hearing device and a second hearing device each comprising a housing configured to be supported at, on or in the wearer&#39;s ear, a processor coupled to memory, the processor and memory disposed in the housing, a radio frequency transceiver coupled to the processor and disposed in the housing, and an antenna arrangement disposed in or on the housing and coupled to the transceiver and the processor, the antenna arrangement comprising an antenna coupled to a phase shifter, the processor configured to adjust a phase shift of the phase shifter. The system includes a clock synchronization link between the transceivers, and a master processor defined by the processor of the first or second hearing device, the master processor configured to cause the first and second hearing devices to operate the antenna arrangements as a phased array antenna arrangement in a coherent transmit mode by phase-locking the transceivers via the clock synchronization link. 
     Example Ex25 
     The hearing device system according to Ex24, wherein, for each of the first and second hearing devices, the antenna is coupled to the phase shifter and a variable gain amplifier, and the processor is configured to adjust the phase shift of the phase shifter and adjust a gain of the variable gain amplifier. 
     Example Ex26 
     A hearing device system comprises a first hearing device and a second hearing device adapted to be worn at first and second ears of a wearer, the system comprising a first hearing device and a second hearing device each comprising a housing configured to be supported at, on or in the wearer&#39;s ear, a processor coupled to memory, the processor and memory disposed in the housing, a radio frequency transceiver coupled to the processor and disposed in the housing, and an antenna arrangement disposed in or on the housing and coupled to the transceiver and the processor, the antenna arrangement comprising an antenna coupled to a phase shifter, the processor configured to adjust a phase shift of the phase shifter. The system includes a clock synchronization link between the transceivers, a second link configured to communicate received signal information between the transceivers, and a master processor defined by the processor of the first or second hearing device, the master processor configured to cause the first and second hearing devices to operate the antenna arrangements as a phased array antenna arrangement in a coherent receive mode by phase-locking local oscillators of the transceivers via the clock synchronization link and the second link. 
     Example Ex27 
     The hearing device system according to Ex26, wherein for each of the first and second hearing devices, the antenna is coupled to the phase shifter and a variable gain amplifier, and the processor is configured to adjust the phase shift of the phase shifter and adjust a gain of the variable gain amplifier. 
     Example Ex28 
     A hearing device system comprising a first hearing device and a second hearing device adapted to be worn at first and second ears of a wearer, the system comprising a first hearing device and a second hearing device each comprising a housing configured to be supported at, on or in the wearer&#39;s ear, a processor coupled to memory, the processor and memory disposed in the housing, a radio frequency transceiver coupled to the processor and disposed in the housing, and an antenna arrangement disposed in or on the housing and coupled to the transceiver and the processor, the antenna arrangement comprising an antenna coupled to a phase shifter, the processor configured to adjust a phase shift of the phase shifter. The system includes a clock synchronization link between the transceivers, a second link configured to communicate received signal information between the transceivers, and a master processor defined by the processor of the first or second hearing device, the master processor configured to cause the first and second hearing devices to operate the antenna arrangements as a phased array antenna arrangement in a coherent transmit mode by phase-locking the transceivers via the clock synchronization link, and operate the antenna arrangements as the phased array antenna arrangement in a coherent receive mode by phase-locking local oscillators of the transceivers via the clock synchronization link and the second link. 
     Example Ex29 
     The hearing device system according to Ex28, wherein for each of the first and second hearing devices the antenna is coupled to the phase shifter and a variable gain amplifier, and the processor is configured to adjust the phase shift of the phase shifter and adjust a gain of the variable gain amplifier. 
       FIG. 1A  illustrates a hearing device system  100  adapted to be worn at left and right ears  111 A,  111 B of a wearer&#39;s head  109 . The hearing device system  100  includes a left hearing device  100 A supported at, on or in the wearer&#39;s left ear  111 A, and a right hearing device  100 B supported at, on or in the wearer&#39;s right ear  111 B. Among other components, the left and right hearing devices  100 A,  100 B include an RF transceiver  103 A,  103 B operably coupled to at least one antenna  105 A,  105 B. Although single antennas  105 A,  105 B are shown in  FIG. 1A , it is understood that the left and right hearing devices  100 A,  100 B can include a multiplicity of antennas. 
     The RF transceivers  103 A,  103 B are configured to be synced together via a communication link  113  (e.g., a clock synchronization link) which enables the antennas  105 A,  105 B of the left and right hearing devices  100 A,  100 B to operate cooperatively as a phased array antenna arrangement  107 . A second link  113 ′ is used to communicate received signal information between the RF transceivers  103 A,  103 B during a receive mode. The received signal information link  113 ′ can be a continuous link (present during transmit and receive modes) or a discontinuous link (present only during the receive mode). In some implementations, one or both of the clock synchronization link  113  and the received signal information link  113 ′ can be a non-RF link (e.g., a non-BLE link), such as a magnetic link (e.g., an NFMI link). In other implementations, one or both of the clock synchronization link  113  and the received signal information link  113 ′ can be an RF link that uses a frequency different from that used by the RF transceivers  103 A,  103 B. The phased array antenna arrangement  107  comprises antenna  105 A of hearing device  100 A and antenna  105 B of hearing device  100 B which together cooperate to create a beam of radio waves that can be electronically steered to point in a desired direction (e.g., towards a target external device  130 ) without moving the antennas  105 A,  105 B. It is understood that the phased array antenna arrangement  107  includes other components of the left and right hearing devices  100 A,  100 B, including RF transceivers  103 A,  103 B, clock synchronization link  113 , and received signal information link  113 ′. The antennas  105 A,  105 B can also be electronically steered to point in a desired direction when receiving radio waves from an external source  130  or to avoid external sources of interference  140 . 
       FIG. 1B  illustrates a hearing device system  100  comprising a first hearing device  100 A and a second hearing device  100 B each adapted to be worn at, on or in an ear of a wearer in accordance with any of the embodiments disclosed herein. Each hearing device  100 A,  100 B shown in  FIG. 1B  includes a housing  102 A,  102 B configured to be supported at, on or in the wearer&#39;s ear. Disposed within the housing  102 A,  102 B is a processor  104 A,  104 B coupled to memory  106 A,  106 B. The processor  104 A,  104 B can include or be implemented as a multi-core processor, a DSP, an audio processor or a combination of these processors. In some embodiments, the hearing device  100 A,  100 B includes a microphone  120 A,  120 B mounted in or on the housing  102 A,  102 B, which can be a single microphone or multiple microphones (e.g., a microphone array). The microphone  120 A,  120 B can be coupled to a preamplifier (not shown), the output of which is coupled to the processor  104 A,  104 B via an analog front end. A speaker or receiver  122 A,  122 B of the hearing device  100 A,  100 B is coupled to an amplifier (not shown) and the processor  104 A,  104 B. The speaker or receiver  122 A,  122 B is configured to generate sound which is communicated to the wearer&#39;s ear. A power source  124 A,  124 B, such as a rechargeable battery, provides power for the components of the hearing device  100 A,  100 B. 
     A radio frequency transceiver  108 A,  108 B is coupled to the processor  104 A,  104 B and disposed in the housing  102 A,  102 B. An antenna  112 A,  112 B is disposed in and/or on the housing  102 A,  102 B and coupled to the RF transceiver  108 A,  108 B via a phase shifter  114 A,  114 B. The antennas  112 A,  112 B may be implemented according to any antenna topology (e.g., bowtie, dipole, patch, PIFA, chip). As will be described below in greater detail, the processors  104 A,  104 B are configured to cooperatively adjust a phase shift of the phase shifters  114 A,  114 B to facilitate electronic steering of an antenna array pattern of the phased array antenna arrangement  107  comprising antennas  112 A,  112 B. It is understood that, in addition to antennas  112 A,  112 B, the phased array antenna arrangement  107  shown in  FIG. 1B  includes other components of the left and right hearing devices  100 A,  100 B, including RF transceivers  108 A,  108 B, phase shifters  114 A,  114 B, and clock synchronization link  113  and received signal information link  113 ′ supported by resident NFMI transceivers  115 A,  115 B or functionally equivalent communications (referred to herein collectively as NFMI transceivers). 
     The processors  104 A,  104 B are configured to cooperatively adjust the phase shift of the phase shifters  114 A,  114 B to electronically steer the antenna array pattern in one or both of an azimuth plane  116  and an elevation plane  118  as shown in  FIG. 1C . The antenna array pattern can be steered when the phased array antenna arrangement  107  operates in a transmit mode and in a receive mode. In some embodiments (see, e.g.,  FIGS. 3A and 3B ), the hearing devices  102 A,  102 B include a multiplicity of antennas  112 A,  112 B and a corresponding multiplicity of phase shifters  114 A,  114 B. In such embodiments, the processors  104 A,  104 B are configured to cooperatively adjust the phase shift of each of the multiplicity of phase shifters  114 A,  114 B to facilitate electronic steering of the antenna array pattern. 
     Each of the radio frequency transceivers  108 A,  108 B is coupled to an NFMI transceiver  115 A,  115 B. The NFMI transceivers  115 A,  115 B support a clock synchronization link  113  and a received signal information link  113 ′ (e.g., a high frequency magnetic link) between the RF transceivers  108 A,  108 B. The clock synchronization link  113  facilitates synchronization between the RF transceivers  108 A,  108 B needed to operate antennas  112 A,  112 B cooperatively as a phased array antenna arrangement  107 . More particularly, the clock synchronization link  113  allows the synthesizers of the RF transceivers  108 A,  108 B (e.g., synthesizers of BLE transceivers) to be phase-locked to provide for coherent transmission, and the received signal information link  113 ′ is provided for the local oscillators in receive mode. The clock synchronization link  113  and the received signal information link  113 ′ also enables the transceiver synthesizers to modify the phase output between the two RF transceivers  108 A,  108 B. This allows for the overall radiation pattern of the phased array antenna arrangement  107  to be shifted based on the phase shift between the two RF transceivers  108 A,  108 B. This also enables the output powers of each hearing device  100 A,  100 B to be modified coherently as well, which can also impact the overall radiation pattern of the phased array antenna arrangement  107 . This is especially useful for steering a null of the phased array antenna arrangement  107 . 
     According to any of the embodiments disclosed herein, one of the hearing devices (e.g., hearing device  100 A) serves as a master and the other hearing device (e.g., hearing device  100 B) serves as a slave. In such embodiments, one of the processors  104 A,  104 B is configured to control phase shift adjustments of the phase shifters  114 A,  114 B to steer the overall radiation pattern of the phased array antenna arrangement  107 . The clock synchronization link  113  between the two hearing devices  100 A,  100 B is used to communicate the coherent receiver output (preferably the Intermediate Frequency-IF) of one receiver (e.g., the receiver of RF transceiver  108 A) to the second receiver (e.g., the receiver of RF transceiver  108 B). The clock synchronization link  113  can be implemented using NFMI on a separate channel from the reference clock information, for example. The two receiver outputs can then be coherently combined prior to detection/demodulation to effectively function as one receiver coupled to the phased array antenna arrangement  107  defined by antennas  112 A,  112 B. The phase shifting can be done at the IF level if desired. 
     As was previously discussed, the antennas  112 A,  112 B can also be electronically steered to point in a desired direction when receiving radio waves from an external source  130  or to avoid external sources of interference  140 . In a transmit mode, radio frequency current generated by the RF transceivers  108 A,  108 B is fed to the antennas  112 A,  112 B with the correct phase relationship via the phase shifters  114 A,  114 B so that the radio waves from the separate antennas  112 A,  112 B add together to increase the radiation in a desired direction, while canceling to suppress radiation in undesired directions. By changing the phase of the phase shifters  114 A,  114 B, the master processor  104 A or  104 B can quickly change the angle or angles of the beam and null(s) of the antenna array pattern. For example, the master processor  104 A or  104 B can adjust the phase of the phase shifters  114 A,  114 B to cause the antenna array pattern to be directed at a desired angle (e.g., an azimuth angle  116  or an elevation angle  118  shown in  FIG. 1C ) or angles (an azimuth angle  116  and an elevation angle  118 ) relative to the axis  117  of the phased array antenna arrangement  107 . For purposes of illustration, a representative antenna pattern on the azimuth plane is shown in  FIG. 1D . A representative antenna pattern on the elevation plane is shown in  FIG. 1E .  FIG. 1F  shows a representative antenna pattern which includes a main lobe  150  (having a length, L, and direction, d), side lobes  152 , and a null  154 . 
     Antenna array pattern nulls are often many tens of dB, whereas peaks in antenna gain are often several dB above the average antenna gain. In environments with one or more high-power sources of RF interference  140 , it may be advantageous to steer the antenna null toward one of these RF interferers  140 , rather than steering the beam toward the external target device  130 . Steering the antenna null toward one of these RF interferers  140  can substantially improve the signal-to-noise (SNR) ratio of the wireless link (e.g., 2.4 GHz link) with the external target device  130 . Generally, however, a steering methodology that involves a combination of steering the antenna null toward an RF interferer  140  and steering the beam toward the external target device  130  (with the weighting toward reducing the noise over increasing the desired signal) is particularly useful in scenarios where the noise level is quite high. 
     In environments with minimal RF interference, the antenna array pattern of the phased array antenna arrangement  107  can be steered such that the beam is directed toward the external target device  130  to increase (e.g., optimize) the SNR of the wireless link with the external target device  130 . The external target device  130  can be a device in the wearer&#39;s pocket (e.g., an ear-to-pocket wireless link) or an off-body accessory (e.g., an ear-to-off body wireless link). An improvement in SNR can allow lowering of the hearing devices&#39; transmitter power, which can significantly reduce current drain, extend battery life, and/or provide for a more robust wireless link for a given transceiver power level. 
       FIG. 2  illustrates a hearing device system  200  comprising a first hearing device  200 A and a second hearing device  200 B each adapted to be worn at, on or in an ear of a wearer in accordance with any of the embodiments disclosed herein. Each hearing device  200 A,  200 B shown in  FIG. 2  includes a housing  202 A,  202 B configured to be supported at, on or in the wearer&#39;s ear. Disposed in the housing  202 A,  202 B is a processor  204 A,  204 B coupled to memory  206 A,  206 B. According to any of the embodiments disclosed herein, one of the hearing devices (e.g., hearing device  200 A) serves as a master and the other hearing device (e.g., hearing device  200 B) serves as a slave. The processor  204 A,  204 B can include or be implemented as a multi-core processor, a DSP, an audio processor or a combination of these processors. In some embodiments, the hearing device  200 A,  200 B includes a microphone  220 A,  220 B, which can be a single microphone or multiple microphones (e.g., a microphone array). The microphone  220 A,  220 B can be coupled to a preamplifier (not shown), the output of which is coupled to the processor  204 A,  204 B via an analog front end. A speaker or receiver  222 A,  222 B is coupled to an amplifier (not shown) and the processor  204 A,  204 B. The speaker or receiver  222 A,  222 B is configured to generate sound which is communicated to the wearer&#39;s ear. A power source  224 A,  224 B, such as a rechargeable or conventional battery, provides power for the components of the hearing device  200 A,  200 B. 
     A radio frequency transceiver  208 A,  208 B is coupled to the processor  204 A,  204 B and disposed in the housing  202 A,  202 B. An antenna  222 A,  222 B is disposed in and/or on the housing  202 A,  202 B and coupled to the RF transceiver  208 A,  208 B via a phase shifter  224 A,  224 B and a variable gain amplifier (VGA)  217 A,  217 B. As previously described, the processors  204 A,  204 B (typically via a master processor  204 A or  204 B) are configured to cooperatively adjust a phase shift of the phase shifters  224 A,  224 B to electronically steer an antenna array pattern of the phased array antenna arrangement  207  defined by antennas  222 A,  222 B. It is understood that, in addition to antennas  222 A,  222 B, the phased array antenna arrangement  207  shown in  FIG. 2  includes other components of the left and right hearing devices  200 A,  200 B, including RF transceivers  208 A,  208 B, phase shifters  224 A,  224 B, VGAs  217 A,  217 B, and clock synchronization and received signal information links  223 ,  223 ′ (described previously) supported by NFMI transceivers  215 A,  215 B. It is noted that the dashed box labeled phased array antenna arrangement  207  is shown in  FIG. 2  to encompass only antennas  222 A,  222 B for purposes of clarity. 
     The antenna array pattern can be steered when the phased array antenna arrangement  207  operates in a transmit mode and in a receive mode. In some embodiments (see, e.g.,  FIGS. 3A and 3B ), the hearing devices  202 A,  202 B include a multiplicity of antennas  222 A,  222 B and a corresponding multiplicity of phase shifters  224 A,  224 B and VGAs  217 A,  217 B. In such embodiments, the processors  204 A,  204 B (typically via a master processor  204 A or  204 B) are configured to cooperatively adjust the phase shift of each of the multiplicity of phase shifters  224 A,  224 B to electronically steer the antenna array pattern. 
     The processors  204 A,  204 B (typically via a master processor  204 A or  204 B) are also configured to cooperatively adjust the gain of the VGAs  217 A,  217 B to provide for improved phased array antenna performance, as is discussed below. 
     Each of the radio frequency transceivers  208 A,  208 B is coupled to an NFMI transceiver  215 A,  215 B. As previously discussed, the NFMI transceivers  215 A,  215 B support a clock synchronization link  223  and a received signal information link  223 ′ between the RF transceivers  208 A,  208 B which facilitates synchronization between the RF transceivers  208 A,  208 B needed to operate antennas  222 A,  222 B cooperatively as a phased array antenna arrangement  207  (see discussion above regarding  FIG. 1B ). 
     The embodiment shown in  FIG. 2  provides for improved phased array antenna performance by using non-uniform excitation amplitudes provided to each of the antennas  222 A,  222 B by variable gain amplifiers  217 A,  217 B. In general, the processors  204 A,  204 B (e.g., as controlled by the master processor  204 A or  204 B) cooperate with the phase shifters  224 A,  224 B and the VGAs  217 A,  217 B to feed variable phase and amplitude to their respective antenna  222 A,  222 B of the phased array antenna arrangement  207 . In some embodiments, the VGAs  217 A,  217 B are configured to feed antennas  222 A,  222 B of the phased array antenna arrangement  207  with different power levels. The processors  204 A,  204 B (e.g., as controlled by the master processor  204 A or  204 B) can be configured to vary the gain of the VGAs  217 A,  217 B in a manner which reduces the side lobes of the antenna array pattern, changes the location of the side lobes, and/or changes the beam widths of the side lobes. In addition, or alternatively, the processors  204 A,  204 B (e.g., as controlled by the master processor  204 A or  204 B) can be configured to vary the gain of each of the VGAs  217 A,  217 B to modify the width of the main beam of the antenna array pattern. In addition, or alternatively, the processors  204 A,  204 B (e.g., as controlled by the master processor  204 A or  204 B) can be configured to vary the gain of each of the VGAs  217 A,  217 B to modify the null levels, locations, and widths. In some cases, the VGAs  217 A,  217 B can have unity gain. In other cases, the VGAs  217 A,  217 B can provide for attenuation of excitation amplitudes provided to each of the antennas  222 A,  222 B. 
     In accordance with any of the embodiments disclosed herein, it may be desirable for the phase shifters  224 A,  224 B to perform their function at lower amplitudes, with the output of the phase shifters  224 A,  224 B being amplified by the VGAs  217 A,  217 B before being feed to each antenna  222 A,  222 B. If all the gains of the VGAs  217 A,  217 B were equal (but greater than 1), then this approach would effectively be consistent with the phase-shift only approach shown in  FIG. 1B . 
       FIGS. 3A and 3B  illustrate a hearing device system  300  comprising a first hearing device  300 A and a second hearing device  300 B each adapted to be worn at, on or in an ear of a wearer in accordance with any of the embodiments disclosed herein.  FIG. 3A  shows the circuitry in a transmit mode, while  FIG. 3B  shows the circuitry in a receive mode. Each of the hearing devices  300 A,  300 B includes a phased array antenna arrangement  302 A,  302 B. The first and second hearing devices  300 A,  300 B are configured to cooperate communicatively such that the phased array antenna arrangements  302 A,  302 B operate as a combined phased array antenna arrangement  307 . 
     It is understood that, in addition to antennas  304 A, the phased array antenna arrangement  302 A shown in  FIGS. 3A and 3B  includes other components of the first hearing device  300 A, including RF transceiver  314 A, power splitter/combiner  308 A, phase shifters  306 A, and VGAs  305 A. It is also understood that, in addition to antennas  304 B, the phased array antenna arrangement  302 B shown in  FIGS. 3A and 3B  includes other components of the second hearing device  300 B, including RF transceiver  314 B, power splitter/combiner  308 B, phase shifters  306 B, and VGAs  305 B. It is noted that the dashed boxes labeled phased array antenna arrangements  302 A,  302 B are shown in  FIGS. 3A and 3B  to encompass only antennas  304 A,  304 B, respectively, for purposes of clarity. The combined phased array antenna arrangement  307  also includes a clock synchronization link  319  and a received signal information link  319 ′ supported by devices  316 A,  316 B. 
     The following discussion provides details concerning individual operation of the phased array antenna arrangements  302 A,  302 B of the first and second hearing devices  300 A,  300 B. Following this discussion, details are provided concerning the operation of the combined phased array antenna arrangement  307  by cooperation between the first and second hearing devices  300 A,  300 B. 
     Each of the phased array antenna arrangements  302 A,  302 B comprises a plurality of antennas  304 A,  304 B. Although four antennas  304 A,  304 B are shown in  FIGS. 3A and 3B  for illustrative purposes, it is understood that the number of antennas  304 A,  304 B can vary (e.g., any number of antennas from  2  to  8  antennas). The antennas  304 A,  304 B can be implemented according to any topology (e.g., bowtie, dipole, patch, PIFA, chip). Each of the antennas  304 A,  304 B is coupled to a VGA  305 A,  305 B, and each VGA  305 A,  305 B is coupled to a phase shifter  306 A,  306 B. As was discussed previously, non-uniform excitation amplitudes can be provided to each of the antennas  304 A,  304 B by controlling the gain of individual VGAs  305 A,  305 B by the processor  320 A,  320 B. In some cases, the VGAs  305 A,  305 B can have unity gain. In other cases, the VGAs  305 A,  305 B can provide for attenuation of excitation amplitudes provided to each of the antennas  304 A,  304 B. It is noted that, according to some embodiments, the transceiver/antenna circuitry of the first and second hearing devices  300 A,  300 B can exclude the VGAs  305 A,  305 B (see, e.g.,  FIG. 1B ). 
     A power splitter/combiner  308 A,  308 B includes a first port  310 A,  310 B coupled to an RF transceiver  314 A,  314 B and a plurality of second ports  312 A,  312 B. The power splitter/combiner  308 A,  308 B can be a Wilkinson power splitter/combiner/divider, for example. Each of the second ports  312 A,  312 B is coupled to a corresponding phase shifter  306 A,  306 B. The RF transceiver  314 A,  314 B is coupled to a reference clock  316 A,  316 B, such as a phase lock loop. The RF transceiver  314 A,  314 B can be configured to operate in the 2.4 GHz band. 
     Each of the phase shifters  306 A,  306 B and VGAs  305 A,  305 B is coupled to a processor  320 A,  320 B. The phase of the phase shifters  306 A,  306 B and the gain of the VGAs  305 A,  305 B are controlled by the processor  320 A,  320 B. Each of the processors  320 A,  320 B is coupled to a memory  322 A,  322 B configured to support a phase parameter table  324 A,  324 B and a gain parameter table  326 A,  326 B. Phase and gain parameters can be tabularized and stored electronically as a function of desired spatial steering direction in the phase parameter table  324 A,  324 B and the gain parameter table  326 A,  326 B. For example, in a linear, uniformly excited array, the main beam can be steered away the perpendicular “broadside” pattern by the same angle as the phase delay. So, if each antenna from left to right has a delay of 30 degrees, for example, the antenna array pattern will move 30 degrees down to the right. A phased-weighting scheme can be implemented by the processors  320 A,  320 B to steer the antenna array pattern such that the direction of maximum reception is in a desired direction. 
     In some embodiments, the phase and gain parameters stored in the phase parameter table  324 A,  324 B and the gain parameter table  326 A,  326 B can account for head-loading effects (e.g., of an average head) on the antenna array pattern. It is known that an antenna can be substantially affected by the presence of human tissue, which may degrade the antenna performance. The presence of human tissue can also reduce the efficiency of an antenna. Such effect is known as head loading and can make the performance of the antenna when the hearing device is worn (referred to as “on head performance”) substantially different from the performance of the antenna when the hearing device is not worn. The phase parameters stored in the phase parameter table  324 A,  324 B that account for head-loading effects on the antenna array pattern can be determined during development of the hearing device system and/or via a machine learning algorithm that customizes the phase parameters for each user. 
     The antenna array pattern (main lobe or null) of each phased array antenna arrangement  302 A,  302 B can be spatially steered by each processor  320 A,  320 B, which accesses the phase and gain parameters stored in the phase parameter table  324 A,  324 B and the gain parameter table  326 A,  326 B. For example, each processor  320 A,  320 B can be configured to step through tabularized phase and gain parameters sequentially, with the processors  320 A,  320 B feeding phase parameters to each of phase shifters  306 A,  306 B and gain parameters to each of the VGAs  305 A,  305 B. As was discussed previously, the processors  320 A,  320 B can be configured to feed phase parameters to the phase shifters  306 A,  306 B to steer the antenna array pattern in a desired direction, and feed gain parameters to the VGAs  305 A,  305 B to modify the width of the main beam, modify one or more of a magnitude, location, and beam width of the side lobes, and/or modify the null levels, locations, and widths. Various methodologies for steering the antenna array pattern of the phased array antenna arrangements  302 A,  302 B by the processors  320 A,  320 B are described hereinbelow. 
     In some embodiments, the transceiver/antenna circuitry of the first hearing device  300 A shown in  FIGS. 3A and 3B  can be implemented on a single RF IC. Similarly, the transceiver/antenna circuitry of the second hearing device  300 B shown in  FIGS. 3A and 3B  can also be implemented on a single RF IC. Additional details concerning the configuration and operation of the phased array antenna arrangements  302 A,  302 B are provided in copending U.S. Ser. No. 16/059,779 filed on Aug. 8, 2018 under Attorney Docket No. ST0763US1/SLI.024.A1, which is incorporated herein by reference. 
     The following discussion provides details concerning the operation of the combined phased array antenna arrangement  307  by cooperation between the first and second hearing devices  300 A,  300 B. The processes described below are preferably coordinated by a master processor defined by the processor  320 A of the first hearing device  300 A or the processor  320 B of the second hearing device  300 B. The other processor  320 A or  320 B serves as a slave to the master processor. The first and second hearing device  300 A,  300 B communicate via a clock synchronization link  319  and a received signal information link  319 ′ to coordinate operation of the phased array antenna arrangements  302 A,  302 B as the combined phased array antenna arrangement  307  under the control of the master processor  320 A or  320 B. 
     According to various embodiments, the RF transceivers  314 A,  314 B are UHF (ultra-high frequency) transceivers, and the PLLs  316 A,  316 B are UHF PLLs. Each hearing device  300 A,  300 B includes an NFMI transceiver (TX/RX)  317 A,  317 B that cooperate to support an ear-to-ear clock synchronization link  319  and an ear-to-ear received signal information link  319 ′ (e.g., high frequency magnetic links). The clock synchronization link  319  and received signal information link  319 ′ allow the UHF synthesizers of the RF transceivers  314 A,  314 B to be phase locked to provide for two coherent UHF transmitters and two coherent UHF receivers. Phase-locking the UHF synthesizers of each hearing device&#39;s UHF transceiver  314 A,  314 B to the NFMI transceiver&#39;s frequency reference, which in turn has one NFMI transceiver&#39;s frequency reference phase-locked to the second NFMI transceiver&#39;s frequency reference, leads to two coherent UHF transmitters which may then be used as a distributed phased array antenna/transceiver system. 
     Just as reciprocity applies to the antenna system (assuming that the direction of the variable gain amplifiers is reversed as shown in  FIG. 3B ), so too does the phase-locking of the first transceiver&#39;s frequency synthesizer(s) to the second transceiver&#39;s frequency reference via the NFMI signal sent between the hearing devices  300 A,  300 B. This technique enables coherent down-conversion of the received signal to be processed, either nearly in real-time via combined processing of received information from the second receiver via the NFMI link  319 ′ or post-processed/non-near-real-time via a similar, time-delayed, flow. 
     Alternatively, MIMO (Multiple Input/Multiple Output), or alternately Rake-Receiver (at the antenna level), techniques can be used to utilize and/or combat multipath fading. In the later case, phase and gain adjustments can be made to the received signal from each antenna in the array to effectively coherently add multipath components. This can be done on a per hearing device basis or in combination with the techniques described in the preceding paragraph. It is noted that an additional NFMI “channel” can be included for the Intermediate Frequency of one UHF Receiver (the receiver portion of a transceiver) to be sent to the other hearing device&#39;s receiver for coherent combination/processing prior to detection/demodulation. 
     For an antenna array, the overall pattern is dependent on the distance between the two elements. This is because the wave construction and destruction are dependent on the phase differences (or distances traveled from the sources) between the two waves. Because people have variable head sizes, this distance may need to be calibrated for each person who wears the set of hearing devices. This can be accomplished by using the acoustics capabilities of the hearing device to emit and record an ultrasonic pulse, or by a locking technique that determines the delay using BLE after synchronizing the two hearing devices. The issue with both of these approaches is that the signal does not travel through the head, but around it. This incurs additional delay that may result in an overestimate of the true distance between the two hearing devices. However, it may be possible to not require the distance between devices at all. If a scanning algorithm is designed to sweep phase and amplitude settings until it finds the best setting, this would account for the different distances between antennas. 
       FIG. 3C  is a block diagram of a VGA  305  shown in  FIGS. 3A and 3B  with accompanying switching circuitry in accordance with any of the embodiments disclosed herein. The VGA circuitry shown in  FIG. 3C  allows the VGA  305  to function in both a transmit mode and a receive mode by the addition of switching circuitry. The switching circuitry includes a first switch  330  coupled to an input  307  of the VGA  305  and a second switch  332  coupled to an output  309  of the VGA  305 . The first switch  330  is coupled to a phase shifter  306 , and the second switch  332  is coupled to an antenna  304 . The first and second switches  330 ,  332  can be implemented as single-pole-double-throw (SPDT) RF switches. As shown, the first and second switches  330 ,  332  are set for operation in a transmit mode. In a receive mode, the first and second switches  330 ,  332  would be set for operation as indicated by the dashed lines. 
     In a transmit (TX) mode, RF signals pass from the phase shifter  306  to the TX throw of the first switch  330 , and from the pole of the first switch  330  to the input  307  of the VGA  305 . Variable gain is applied to the RF signals passing through the VGA  305 . The RF signals pass from the output  309  of the VGA  305  to the pole of the second switch  332 , and from the TX throw of the second switch  332  to the antenna  304 . In the receive (RX) mode, RF signals are communicated from the antenna  304  to the RX throw of the first switch  330 , and from the pole of the first switch  330  to the input  307  of the VGA  305 . Variable gain is applied to the RF signals passing through the VGA  305 . The RF signals pass from the output  309  of the VGA  305  to the pole of the second switch  332 , and from the RX throw of the second switch  332  to the phase shifter  306 . 
       FIG. 3D  is a block diagram of a VGA arrangement with accompanying switching circuitry for use in the hearing device circuitry shown in  FIGS. 3A and 3B  in accordance with any of the embodiments disclosed herein. The switching circuitry includes a first switch  340  having a pole coupled to a phase shifter  306 , a TX throw coupled to an input of a first VGA  305   a , and an RX throw coupled to an output of a second VGA  305   b . The switching circuitry also includes a second switch  342  having a pole coupled to an antenna  304 , a TX throw coupled to an output of the first VGA  305   a , and an RX throw coupled to an input of the second VGA  305   b . In the embodiment shown in  FIG. 3D , the first VGA  305   a  is used during a transmit mode, and the second VGA  305   b  is used during the receive mode. The first VGA  305   a  is preferably designed for efficiency and high-power output. The second VGA  305   b  is preferably a Low Noise Amplifier (LNA). The relative gains can be set similarly for both the first and second VGAs  305   a ,  305   b  (relative to gains of other pairs of first and second VGAs  305   a ,  305   b  of the hearing device circuitry shown in  FIGS. 3A and 3B ). 
       FIG. 4  illustrates a method of operating a phased array antenna arrangement formed from antennas of two hearing devices in accordance with any of the embodiments disclosed herein. The method shown in  FIG. 4  involves providing  402 , at first and second hearing devices, an antenna arrangement coupled to a radio frequency transceiver and a processor, the antenna arrangement comprising an antenna coupled to a phase shifter. The method also involves adjusting  404  a phase shift of the phase shifters by the processors of the first and second hearing devices. The method further involves causing  406  the first and second hearing devices to operate the antenna arrangements as a phased array antenna arrangement by a master processor defined by the processor of the first or second hearing device. 
       FIG. 5  illustrates a method of operating a phased array antenna arrangement from antennas of two hearing devices in accordance with any of the embodiments disclosed herein. The method shown in  FIG. 5  involves providing  502 , at first and second hearing devices, an antenna arrangement coupled to a radio frequency transceiver and a processor, the antenna arrangement comprising an antenna coupled to a phase shifter and a variable gain amplifier. The method also involves adjusting  504  a phase shift of the phase shifters and a gain of the VGA by the processors of the first and second hearing devices. The method further involves causing  506  the first and second hearing devices to operate the antenna arrangements as a phased array antenna arrangement by a master processor defined by the processor of the first or second hearing device. The method of  FIG. 5  involves adjusting  508 , under the control of the master processor, the phase shift of each of the phase shifters to steer an antenna array pattern of the phased array antenna arrangement, such as in one or both of an azimuth plane and an elevation plane. The method also involves adjusting  510 , under the control of the master processor, a gain of each of the variable gain amplifiers to one or more of reduce a side lobe of the antenna array pattern, change a location of the side lobe, and adjust a width of a main lobe of the antenna array pattern. 
       FIG. 6  illustrates a method of operating a phased array antenna arrangement formed from antennas of two hearing devices in accordance with any of the embodiments disclosed herein. The method shown in  FIG. 6  involves producing  602  a phased array antenna arrangement using antennas of two hearing devices, each antenna coupled to a phase shifter and a variable gain amplifier. The method involves storing  604 , in memory coupled to the processor of each hearing device, phase parameters and gain parameters tabularized as a function of spatial steering direction. The method also involves incrementing  606 , under control of a master processor of the two hearing devices, the phase and gain parameters to change the steering direction of an antenna pattern of the phased array antenna arrangement, such as in one or both of an azimuth plane and an elevation plane. 
     A check  608  is made to determine if the desired received signal is present. If not, the phase and gain parameters are incremented  606  under control of the master processor to change the steering direction of the antenna array pattern. If the desired received signal is present  608 , the spatial antenna scan is halted  610  by the master processor and the SNR of the desired signal is measured. A check  612  is made to determine if the SNR of the desired received signal is above a threshold. The threshold can be established based on the transceivers&#39; modulation type/protocol and the use-case for the data sent/received. Each transceivers&#39; modulation type/protocol and the use-case for the data sent/received will determine the bit error rate (BER) required for proper system performance. This BER has an associated SNR. For an FSK system, for example, typically a 12 dB to 14 dB SNR would be a suitable SNR. The threshold could be set for this SNR level. In other implementations, a suitable SNR threshold may be 3 dB. If above the threshold, the current steering direction of the antenna array pattern is maintained and the SNR of the desired received signal is measured  610 . If the SNR of the desired received signal is below the threshold  612 , the phase and gain parameters are incremented by the master processor to change the steering direction of the antenna array pattern  606 . The processes of blocks  606 - 612  are repeated to steer the antenna array pattern in a direction that increases or maximizes the SNR of the desired received signal. 
     According to various embodiments, the antenna array pattern of a phased array antenna arrangement formed by antennas of two hearing devices can be spatially steered by a master processor of the hearing device system to increase or maximize the SNR of a received signal of interest. For example, an RSSI (Received Signal Strength Indicator) measurement can be made by the master processor of the hearing device without a signal present (e.g., on-channel receives noise). An RSSI measurement can be made by the master processor with the desired signal present. The master processor can calculate the SNR of the desired signal. Various methodologies can be implemented by the master processor of the hearing device system to maintain adequate SNR of the desired received signal. Five example embodiments for steering an antenna array pattern of a phased array antenna arrangement formed from antennas of two hearing devices are summarized below. Additionally or alternatively, even if the SNR threshold is significantly exceeded for a given/selected phased array antenna steering direction, the direction could be slightly dithered in multiple directions to find a local maximum of SNR, all the while operating without error in the TX/RX output. 
     Example 1 
     A spatial antenna scan is performed and the SNR of the desired received signal is measured incrementally as a function of spatial directions of the desired received signal, such as in a manner discussed previously. The phased array antenna array pattern can be steered to the direction of the centroid of measured directions which yields an adequate SNR (e.g., an SNR above a preset threshold). This antenna array pattern direction is maintained until the SNR falls below the threshold, at which point the scan and SNR measurement process is repeated. 
     Example 2 
     According to this example embodiment, the methodology of Example 1 is performed in a successive approximation manner for faster operation. According to this example, gross directional resolution sampling of the SNR of the desired received signal is performed, followed by successively reducing the resolution of the spatial steering/sampling. A spatially coarse (quick) sampling of the SNR can be subsequently refined by operating on the highest SNR sampled direction, while moving halfway over to adjacent spatial directions (e.g., effectively doubling the spatial resolution in the area about the maximum) while operating the transceiver-to-transceiver data all the while. This process further involves moving to the new maximum and repeating the refinement procedure. 
     Example 3 
     According to this example embodiment, if the measured SNR of the desired received signal at the currently steered spatial direction is above a threshold (e.g., a pre-set threshold), the antenna array pattern direction is maintained. If the measured SNR of the desired received signal at the currently steered spatial direction is below the threshold, a spatial antenna scan is performed as previously described (e.g., by incrementing or decrementing the spatial directions in a sequential manner) until an SNR of the desired received signal is measured above the threshold. A local versus global region of acceptable SNR may be chosen with this example embodiment. While not optimal, the steering methodology of this example embodiment is faster than other example embodiments while still providing an adequate SNR of the desired received signal. 
     Example 4 
     This example embodiment provides a methodology for steering a phased array antenna arrangement for frequency hop systems. According to this example embodiment, any of the embodiments of Examples 1-3 can be performed on a per channel frequency basis, with the antenna array pattern “hopping”/steering with each channel frequency. This example embodiment is particularly useful for mitigating multipath effects. For example, a dynamic antenna array pattern adjustment can be performed on each Bluetooth-like hop frequency to maximize SNR as needed for each frequency. This can be performed as part of an advanced adaptive frequency hopping (AFH) methodology. 
     Example 5 
     This example embodiment provides a methodology for steering a phased array antenna arrangement for servicing multiple independent (e.g., BLE) sessions. According to this example embodiment, the phased array antenna arrangement can be sequentially servicing multiple independent sessions. For example, the phased array antenna arrangement can be sequentially steered on a per session basis. 
       FIG. 7  is a block diagram of a hearing device system  700  which includes a pair of hearing devices  702 A,  702 B whose antennas operate cooperatively as a phased array antenna arrangement in accordance with any of the embodiments disclosed herein. The block diagram of  FIG. 7  shows various components of a first hearing device  702 A of the hearing device system  700 . At least these components are included in a second hearing device  702 B of the hearing device system  700 , but are not shown for purposes of simplicity of explanation. The hearing devices  702 A,  702 B shown in  FIG. 7  represent generic hearing devices for purposes of illustration. It is understood that the hearing devices  702 A,  702 B may exclude some of the components shown in  FIG. 7  and/or include additional components. The components of the hearing devices  702 A,  702 B can be the same or different. 
     The hearing device  702 A includes several components electrically connected to a circuit board  703 A (e.g., flexible, non-flexible, or rigid-flex combination). A battery  705 A is electrically connected to the circuit board  703 A and provides power to the various components of the hearing device  702 A. One or more microphones  706 A are electrically connected to the circuit board  703 A, which provides electrical communication between the microphones  706 A and a digital signal processor (DSP)  704 A. Among other components, the DSP  704 A can incorporate or is coupled to audio signal processing circuitry. In some embodiments, a sensor arrangement  720 A (e.g., a physiologic or motion sensor) is coupled to the DSP  704 A via the circuit board  703 A. One or more user switches  708 A (e.g., on/off, volume, mic directional settings) are electrically coupled to the DSP  704 A via the circuit board  703 A. 
     An audio output device  710 A is electrically connected to the DSP  704 A via the circuit board  703 A. In some embodiments, the audio output device  710 A comprises a speaker (coupled to an amplifier). In other embodiments, the audio output device  710 A comprises an amplifier coupled to an external receiver  712 A adapted for positioning within an ear of a wearer. The hearing device  702 A incorporates a communication device  707 A coupled to the circuit board  703 A and to an antenna  709 A directly or indirectly via the circuit board  703 A. The antenna  709 A can be a single antenna or a phased array antenna arrangement comprising a plurality of antennas. Although not shown in  FIG. 7 , the antenna  709 A is coupled to a phase shifter and, in some embodiments, to a VGA. The communication device  707 A can be a Bluetooth® transceiver, such as a BLE (Bluetooth® low energy) transceiver or other transceiver (e.g., an IEEE 802.11 compliant device). The communication device  707 A can be configured to communicate with one or more external devices, such as those discussed previously. 
     The hearing devices  702 A,  702 B also include a non-RF communication device  715 A,  715 B, such as an NFMI transceiver. The NFMI transceivers  715 A,  715 B support a communication link  719  (e.g., a high frequency magnetic link) between the communication devices  707 A,  707 B of the two hearing devices  702 A,  702 B. As previously discussed, the communication link  719  facilitates synchronization between the communication devices  707 A,  707 B of the two hearing devices  702 A,  702 B needed to operate antennas  709 A,  709 B cooperatively as a phased array antenna arrangement  711 . 
     A hearing device system which provides a phased array antenna arrangement using antennas of two disparate hearing devices can be implemented to provide electronic steering of an antenna array pattern for wirelessly communicating with a variety of external devices located at a variety of positions relative to the hearing device system. For example, the external device can be located in the wearer&#39;s hand, in a pocket of a garment worn by the wearer, or at a position spaced apart from the wearer&#39;s body. The external device can be a smartphone, which may be in the wearer&#39;s hand, in a pocket, or off body, and the hearing device can be configured to receive audio and/or streaming data from the smartphone. The external device can be a remote microphone, which may be on or off body, and the hearing device can be configured to receive and/or stream data to/from the remote microphone. The external device may be a TV streamer located off body, and the hearing device system can be configured to receive audio from the TV streamer. The external device can be a remote control, which may be located on or off body, and the hearing device system can be configured to transmit and receive streaming data to/from the remote control. The external device can be a multi-functional accessory (e.g., a wireless bridge between the hearing device(s) and another wireless device(s), such as a smartphone or TV/audio streamer), which may be located on or off body, and the hearing device system can be configured to stream audio and/or data to/from the multi-functional accessory. 
     Although reference is made herein to the accompanying set of drawings that form part of this disclosure, one of at least ordinary skill in the art will appreciate that various adaptations and modifications of the embodiments described herein are within, or do not depart from, the scope of this disclosure. For example, aspects of the embodiments described herein may be combined in a variety of ways with each other. Therefore, it is to be understood that, within the scope of the appended claims, the claimed invention may be practiced other than as explicitly described herein. 
     All references and publications cited herein are expressly incorporated herein by reference in their entirety into this disclosure, except to the extent they may directly contradict this disclosure. Unless otherwise indicated, all numbers expressing feature sizes, amounts, and physical properties used in the specification and claims may be understood as being modified either by the term “exactly” or “about.” Accordingly, unless indicated to the contrary, the numerical parameters set forth in the foregoing specification and attached claims are approximations that can vary depending upon the desired properties sought to be obtained by those skilled in the art utilizing the teachings disclosed herein or, for example, within typical ranges of experimental error. 
     The recitation of numerical ranges by endpoints includes all numbers subsumed within that range (e.g. 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5) and any range within that range. Herein, the terms “up to” or “no greater than” a number (e.g., up to 50) includes the number (e.g., 50), and the term “no less than” a number (e.g., no less than 5) includes the number (e.g., 5). 
     The terms “coupled” or “connected” refer to elements being attached to each other either directly (in direct contact with each other) or indirectly (having one or more elements between and attaching the two elements). Either term may be modified by “operatively” and “operably,” which may be used interchangeably, to describe that the coupling or connection is configured to allow the components to interact to carry out at least some functionality (for example, a radio chip may be operably coupled to an antenna element to provide a radio frequency electric signal for wireless communication). 
     Terms related to orientation, such as “top,” “bottom,” “side,” and “end,” are used to describe relative positions of components and are not meant to limit the orientation of the embodiments contemplated. For example, an embodiment described as having a “top” and “bottom” also encompasses embodiments thereof rotated in various directions unless the content clearly dictates otherwise. 
     Reference to “one embodiment,” “an embodiment,” “certain embodiments,” or “some embodiments,” etc., means that a particular feature, configuration, composition, or characteristic described in connection with the embodiment is included in at least one embodiment of the disclosure. Thus, the appearances of such phrases in various places throughout are not necessarily referring to the same embodiment of the disclosure. Furthermore, the particular features, configurations, compositions, or characteristics may be combined in any suitable manner in one or more embodiments. 
     The words “preferred” and “preferably” refer to embodiments of the disclosure that may afford certain benefits, under certain circumstances. However, other embodiments may also be preferred, under the same or other circumstances. Furthermore, the recitation of one or more preferred embodiments does not imply that other embodiments are not useful and is not intended to exclude other embodiments from the scope of the disclosure. 
     As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” encompass embodiments having plural referents, unless the content clearly dictates otherwise. As used in this specification and the appended claims, the term “or” is generally employed in its sense including “and/or” unless the content clearly dictates otherwise. 
     As used herein, “have,” “having,” “include,” “including,” “comprise,” “comprising” or the like are used in their open-ended sense, and generally mean “including, but not limited to.” It will be understood that “consisting essentially of” “consisting of,” and the like are subsumed in “comprising,” and the like. The term “and/or” means one or all of the listed elements or a combination of at least two of the listed elements. 
     The phrases “at least one of,” “comprises at least one of,” and “one or more of” followed by a list refers to any one of the items in the list and any combination of two or more items in the list.