The one or more sensors 40 may be disposed in a variety of positions on the object 10, such as the positions described herein, including for instance, one or more sensors 40 in the door panel and one or more other sensors in the B pillar.

The object device 50 and the one or more sensors 40 may be powered via a power bus 120. The power bus 120 may be daisy chained from one device to the next as depicted in the illustrated embodiment of FIG. 4. Alternatively, the power bus 120 may be provided in the form of a star connection with power being supplied from one location to multiple locations via separate connections. Power supply and architecture is not limited to any one type—for instance, power may be distributed via both a daisy chain and star connection configurations.

The system 100 in the illustrated embodiment may be configured to determine location information in real-time with respect to the remote device 20. In the illustrated embodiment of FIG. 1, a user may carry the remote device 20 (e.g., a smartphone). The system 100 may facilitate locating the remote device 20 with respect to the object 10 (e.g., a vehicle) in real-time with sufficient precision to determine whether the user is located at a position at which access to the object 10 or permission for an object 10 command should be granted.

For instance, in an embodiment where the object 10 is a vehicle, the system 100 may facilitate determining whether the remote device 20 is outside the vehicle but in close proximity, such as within 5 feet, 3 feet, or 2 feet or less, to the driver-side door 15. This determination may form the basis for identifying whether the system 100 should unlock the vehicle. On the other hand, if the system 100 determines the remote device 20 is outside the vehicle and not in close proximity to the driver-side door (e.g., outside the range of 2 feet, 3 feet, or 5 feet), the system 100 may determine to lock the driver-side door. As another example, if the system 100 determines the remote device 20 is in close proximity to the driver-side seat but not in proximity to the passenger seat or the rear seat, the system 100 may determine to enable mobilization of the vehicle. Conversely, if the remote device 20 is determined to be outside close proximity to the driver-side seat, the system 100 may determine to immobilize or maintain immobilization of the vehicle.

The object 10 may include multiple object devices 50 or a variant thereof, such as an object device 50 including a sensor 40 coupled to an antenna array 220, in accordance with one or more embodiments described herein. The antenna array 220 may include one or more antennas and may be configured in a variety of ways to facilitate wireless communications. An example embodiment of an antenna array having two orthogonal antennas is depicted in the illustrated embodiment of FIG. 8.

In one embodiment, the object device 50 may be configured to communicate directly with one or more sensors 40 via the communication link 130, which as described herein, may include one or more interfaces, such as both a high frequency (HF) interface 232 and a serial interface 230. The one or more interfaces may be established via one or more physical mediums—for instance, in the case of both a HF interface 232 and a serial interface 230 as depicted in FIG. 4, the HF interface 232 may be established via a physical medium in the form of coax or twisted pair conductors, and the serial interface 230 may be established via a physical medium in the form of twisted pair conductors. As another example, both the HF interface 232 and the serial interface 230 may be established via the same physical medium, which may be a twisted pair of conductors.

In the illustrated embodiment of FIG. 2, the communication link 130 is distributed from one device to another and includes a terminator 132 at each end. The communication link 130 among the devices may be a shared link or a separate link for each device, or a combination thereof. For instance, the communication link 130 may be shared among two or more devices as depicted, and additionally or alternatively, the communication link 130 may be established separately from one device to another device. A device may communicate via more than one separate communications line 130, and may be configured to relay communications from one communication link 130 to another communication link 130.

In addition to or alternative to one or more location techniques described herein, micro-location of the remote device 20 may be determined in a variety of ways, such as using information obtained from a global positioning system, one or more signal characteristics of communications from the remote device 20, and one or more sensors (e.g., a proximity sensor, a limit switch, or a visual sensor), or a combination thereof. An example of microlocation techniques for which the system 100 can be configured are disclosed in U.S. Nonprovisional patent application Ser. No. 15/488,136 to Raymond Michael Stitt et al., entitled SYSTEM AND METHOD FOR ESTABLISHING REAL-TIME LOCATION, filed Apr. 14, 2017—the disclosure of which is hereby incorporated by reference in its entirety.

In the illustrated embodiment of FIGS. 1-3, the object device 50 (e.g., a system control module (SCM)) and a plurality of sensors 40 (each coupled to an antenna array 220 as shown in FIGS. 3-7) may be disposed on or in a fixed position relative to the object 10. Example use cases of the object 10 include the vehicle identified in the previous example, or a building for which access is controlled by the object device 50.

The remote device 20 may communicate wirelessly with the object device 50 via a communication link 140, such as a Bluetooth communication link (e.g., standard Bluetooth, Bluetooth Low Energy (BTLE), or BTLE High Accuracy Distance Measurement (BTLE-HADM)) or an Ultra Wideband (UWB) communication link. The plurality of sensors 40 may be configured to sniff the communications of the communication link 140 between the remote device 20 and the object device 50 as shown in phantom lines 142. The sniff communications or transmissions may correspond to a tone exchange (one-way or two-way) between the object device 50 and the remote device 20. Based on the sniffed communications, a sensor 40 may determine one or more signal characteristics of the communications as described herein, including a phase characteristic of the communications. Additional or alternative signal characteristics include a signal strength, time of arrival, time of flight, angle of arrival, or a combination thereof. The determined signal characteristics may be communicated or analyzed and then communicated to the object device 50 via the communication link 130 separate from the communication link 140 between the remote device 20 and the object device 50.

Additionally, or alternatively, the remote device 20 may establish a direct communication link with one or more of the sensors 40, and the one or more signal characteristics may be determined based on this direct communication link. For instance, the remote device 20 and a sensor 40 may perform a tone exchange as a basis for determining a distance between the sensor 40 and the remote device 20. The tone exchange may form the basis of an analysis of a phase difference in communications, and this phase difference may be a basis for determining a time of flight and therefore range of the remote device 20.

In one embodiment, the direct communication link may be established according to the BTLE protocol; however, the present disclosure is not so limited—the direct communication link may be any type of link or links, including UWB or BTLE-HADM.

It is to be understood that an object 10, such as a vehicle, may include a number of sensors 40 that can be greater than or less than the number shown in the illustrated embodiment of FIGS. 1 and 2. Depending on the implementation, some number of sensors 40 may be integrated in a vehicle.

As described herein, one or more signal characteristics, such as a phase characteristic, a signal strength, time of arrival, time of flight, and angle of arrival, may be analyzed to determine location information about the remote device 20 relative to the object 10, an aspect of the object 10, or the object device 50, or a combination thereof. For instance, a phase rotation of a tone transmission, and optional re-transmission, or a phase characteristic indicative of a phase rotation may form the basis for determining a distance between an object device 50 or a sensor 40 and the remote device 20. Additional examples of signal characteristics include time difference of arrival or the angle of arrival, or both, among the sensors 40 and the object device 50 may be processed to determine a relative position of the remote device 20. The positions of the one or more antenna arrays 220 relative to the object device 50 may be known so that the relative position of the remote device 20 can be translated to an absolute position with respect to the antenna arrays 220 and the object device 50.

Additional or alternative types of signal characteristics may be obtained to facilitate determining position according to one or more algorithms, including a distance function, trilateration function, a triangulation function, a lateration function, a multilateration function, a fingerprinting function, a differential function, a time of flight function, a time of arrival function, a time difference of arrival function, an angle of departure function, a geometric function, or any combination thereof.

II. System Device Overview

In the illustrated embodiment of FIG. 3, the object device 50 is shown in further detail. The structure and configuration of the object device 50 may be incorporated into the object device 50, so the sensor 40 is also referenced as the object device 50 in the illustrated embodiment. Likewise, the structure of the sensor 40′, 40″, 400, and 400′ in the illustrated embodiments of FIGS. 4-7 may be incorporated into an object device 50′, 50″, 500, 500′ and so the sensors are referenced accordingly in the illustrated embodiments.

The object device 50 in the illustrated embodiment of FIG. 3 includes several components, one or more of which may be provided in a commercial embodiment. The object device 50 in some instances may be described as an anchor disposed on the object 10.

The object device 50 may include RF circuitry 204 operable to control transmission and reception of HF signals. The RF circuitry 204 may be operably coupled to an antenna array 220, which may include one or more antennas. An example configuration of an antenna array 220 is depicted in the illustrated embodiment of FIG. 8, with a plurality of antennas 221A, 221B. The plurality of antennas 221A, 221B, optionally more than two, may provide spatial diversity such that they do not receive the same waves. For instance, each of the plurality of antennas may be disposed at different locations to provide spatial diversity. As another example, the plurality of antennas may have different slant polarizations (e.g., circular polarization with lead or lag relative to each other).

The RF circuitry 204 may be configured to supply or receive high-frequency signals from the antenna array 220 via filter circuitry 206 and a HF switch 208. The filter circuitry 206 may condition the signal output from the RF circuitry 204 for driving the antenna array 220. Conversely, the filter circuitry 206 may condition a signal received from the antenna array 220 for processing by the RF circuitry 204. The HF switch 208 may selectively direct input and output of HF signals, including HF supplied to and received from the antenna array 220.

In one embodiment, the RF circuitry 204 may be configured according to one embodiment to transmit and receive signals via HF interface 232 of the communication link 130. Transmission and reception of HF signals in one embodiment may enable an object device 50 to communicate via a physical medium according to a communication protocol that is the same or similar to the one utilized by the antenna array 220 in the RF circuitry 204. For instance, the object device 50 may transmit and receive communications via a physical medium defined by the HF interface 232 that correspond to the BTLE communications, while also transmitting and receiving communications via the antenna array 220 that correspond to BTLE communications.

The HF switch 208 may selectively direct output from the RF circuitry 204 to the HF interface 232 of the communication link 130, and selectively direct input from the HF interface 232 of the communication link 130 to the RF circuitry 204. In one embodiment, the HF interface 232 may be a single ended configuration, such as a coaxial conductor arrangement. Alternatively, the HF interface 232 may be differential, and optionally include conditioning circuitry 214, 216 (e.g., a balun and/or an impedance transformer) for translating between a single ended output from the HF switch 208 and a differential output of the HF interface 232.

In the illustrated embodiment, the object device 50 is configured to transmit and receive communications via separate HF interfaces 232 provided by separate communication links 130. In other words, the two communication links 130 in the illustrated embodiment are isolated from each other, such that communications received on one communication link 130 are not inherently transmitted or seen on the other communication link 130. As discussed herein, the object device 50 may be configured to relay communications from one of the communication links 130 to the other of the communication links 130. For example, communications received via one high-frequency interface may be directed to the RF circuitry 204, and may be relayed to the other high-frequency interface via the RF circuitry 204. The HF switch 208 may be configured to transition from one state to another state to facilitate relaying of such communications. It is to be understood, however, that in one or more embodiments described herein, communications transmitted via one of the communication links 130 may inherently pass to the other of the communication links 130.

The object device 50 may include a main controller 200 and may be configured to direct operation of the RF circuitry 204, as described herein. In one embodiment, the main controller 200 may control communications with the remote device 20 and optionally obtain one or more sensed characteristics with respect to such communications to be used as a basis for ranging the remote device 20. Additionally, or alternatively, the object device 50 may sniff communications between a sensor 40 and the remote device 20 and obtain one or more sensed characteristics with respect to the sniffed communications.

The main controller 200 may further direct transmission and reception of communications via the HF interface 232 of the one or more communication links 130. As an example, the main controller 200 may direct transmission and reception of BTLE communications via the HF interface 232 of the communication link 130. Information transmitted via the HF interface 232 of the communication links 130 may relate to one or more signal characteristics obtained with respect to communications received and/or transmitted via the antenna array 220. As an example, the information transmitted via the communication link 130 may be indicative of a sensed characteristic determined with respect to communications received and/or transmitted via the antenna array 220.

Additionally, or alternatively, the main controller 200 may utilize the high-frequency interface of the communication links 130 for time synchronization purposes. A sensed characteristic of communications may be based at least in part on a time reference of the device. And because time is translatable to distance (and conversely distance to time) with respect to electromagnetic waves, controlling the reference time of the sensor 40 may facilitate enhancing accuracy with respect to determining the distance between the remote device 20 and the object device 50.

The object device 50 may include a clock 202 that operates an oscillator for the sensor 40 and generates one or more timing signals for operation of aspects of the object device 50, including the main controller 200 and the RF circuitry 204.

In one embodiment, the main controller 200 may be configured to initially synchronize one or more timing signals provided by the clock 202 based on synchronization related communications received via the high-frequency interface of the communication links 130. To provide an example, in the context of the sensor 40 including the main controller 200 and the clock 202, the object device 50 may transmit synchronization related communications to the sensor 40 to facilitate substantially synchronizing timing signals between the object device 50 and the sensor 40. This way, sensed characteristics determined by the sensor 40 and the object device 50 may be compared or related to each other against substantially the same time reference.

In the illustrated embodiment, the object device 50 may include first and second transceivers 210, 212 coupled respectively to serial interfaces of the communication links 130. The transceivers 210, 212 may be CAN transceivers, but the present disclosure is not so limited. The transceivers 210, 212 may facilitate any type of serial or non-serial communications via the communication links 130, including but not limited to RS-485, LIN, Vehicle Area Network (VAN), FireWire, I2C, RS-232, RS-485, and Universal Serial Bus (USB).

The first and second transceivers 210, 212 may enable communications among devices (e.g., the object device 50 and a sensor 40) for information that is less time sensitive. For instance, the object device 50 may transmit to a sensor 40, via the serial interface of the communication link 130, connection parameters for the communication link 140 to enable the sensor 40 to sniff or monitor communications between the object device 50 and the remote device 20. A sensor 40 may receive such communications via the first transceiver 210 and relay the communications to another device (e.g., another sensor 40) via the second transceiver 212.

Optionally, the object device 50 may include a communication link 130 configured with a serial interface without the high-frequency interface or a high-frequency interface without the serial interface. Communications described herein with respect to one interface and not the other may be communicated via the interface provided by the communication link 130. For instance, the communication link 130 may include a high-frequency interface without the serial interface, and communications described in connection with the serial interface may be transmitted via the high-frequency interface.

The main controller 200 may include electrical circuitry and components to carry out the functions and algorithms described herein. Generally speaking, the main controller 200 may include one or more microcontrollers, microprocessors, and/or other programmable electronics that are programmed to carry out the functions described herein. The main controller 200 may additionally or alternatively include other electronic components that are programmed to carry out the functions described herein, or that support the microcontrollers, microprocessors, and/or other electronics. The other electronic components include, but are not limited to, one or more field programmable gate arrays (FPGAs), systems on a chip, volatile or nonvolatile memory, discrete circuitry, integrated circuits, application specific integrated circuits (ASICs) and/or other hardware, software, or firmware. Such components can be physically configured in any suitable manner, such as by mounting them to one or more circuit boards, or arranging them in other manners, whether combined into a single unit or distributed across multiple units. Such components may be physically distributed in different positions in the object device 50, or they may reside in a common location within the object device 50. When physically distributed, the components may communicate using any suitable serial or parallel communication protocol, such as, but not limited to, CAN, LIN, Vehicle Area Network (VAN), FireWire, I2C, RS-232, RS-485, and Universal Serial Bus (USB).

As described herein, the main controller 200 may be configured to determine a location or range of a portable device 20 relative to an object 10. The main controller 200 may include a locator, module, model, or generator, or a combination thereof, operable to determine the location or range based on one or more signal characteristics. For instance, a model for determining a range or location, in one embodiment, may include one or more core functions and one or more parameters that affect output of the one or more core functions. Aspects of the model may be stored in memory of the main controller 200, and may also form part of the controller configuration such that the model is part of the main controller 200 that is configured to operate to receive and translate one or more inputs and to output one or more outputs. Likewise, a module or a generator are parts of the main controller 200 such that the main controller 200 is configured to receive an input described in conjunction with a module or generator and provide an output corresponding to an algorithm associated with the module or generator.

The main controller 200 of the object device 50 in the illustrated embodiment of FIG. 3 may include one or more processors that execute one or more applications (software and/or includes firmware), one or more memory units (e.g., RAM and/or ROM), and one or more communication interfaces, amongst other electronic hardware. The object device 50 may or may not have an operating system that controls access to lower-level devices/electronics via a communication interface. The object device 50 may or may not have hardware-based cryptography units—in their absence, cryptographic functions may be performed in software. The object device 50 may or may not have (or have access to) secure memory units (e.g., a secure element or a hardware security module (HSM)).

The main controller 200 in the illustrated embodiment of FIG. 3 is not dependent upon the presence of a secure memory unit in any component. In the optional absence of a secure memory unit, data that may otherwise be stored in the secure memory unit (e.g., private and/or secret keys) may be encrypted at rest. Both software-based and hardware-based mitigations may be utilized to substantially prevent access to such data, as well as substantially prevent or detect, or both, overall system component compromise. Examples of such mitigation features include implementing physical obstructions or shields, disabling JTAG and other ports, hardening software interfaces to eliminate attack vectors, using trusted execution environments (e.g., hardware or software, or both), and detecting operating system root access or compromise.

For purposes of disclosure, being secure is generally considered being confidential (encrypted), authenticated, and integrity-verified. It should be understood, however, that the present disclosure is not so limited, and that the term “secure” may be a subset of these aspects or may include additional aspects related to data security.

The communication interface of the main controller 200 may facilitate any type of communication link, including any of the types of communication links described herein, including wired or wireless. The communication interface may facilitate external or internal, or both, communications. For instance, the communication interface may be coupled to the RF circuitry 204 to enable communications via one or more of the antenna array 220 and the HF interface 232 of the communication link 130.

As another example, the communication interface of the main controller 200 may facilitate a wireless communication link with another system component in the form of the remote device 20, such as wireless communications according to the WiFi standard or UWB, or any combination thereof. As another example, the communication interface of the main controller 200 may include a display and/or input interface for communicating information to and/or receiving information from the user.

In one embodiment, the object device 50 may be configured to communicate with one or more auxiliary devices of a type different from the remote device 20 or the sensor 40. In other words, the auxiliary device may be configured differently from the object device 50. For instance, the auxiliary device may not include a processor, and instead, may include at least one direct connection and/or a communication interface for transmission or receipt, or both, of information with the object device 50. The auxiliary device may be a solenoid that accepts an input from the object device 50, or the auxiliary device may be a sensor (e.g., a proximity sensor) that provides analog and/or digital feedback to the object device 50.

One or more alternative embodiments of the object device 50 and sensor 40 are depicted in the illustrated embodiments of FIGS. 4-7, and generally designated 40′, 40″, 400, 400′ and 50′, 50″, 500, 500″. The object device and sensor in the illustrated embodiments of FIGS. 4-7 are similar in many respects to the object device 50 and sensor 40 of FIG. 3, with similar components having the same reference numeral and potentially arranged or connected in a different manner.

For instance, in the illustrated embodiment of FIG. 4, the object device 50′ is substantially similar to the object device 50 with the exception of having one transceiver 210 instead of two transceivers 210, 212. In this configuration, serial communications may inherently pass between the serial interfaces of both communication links 130.

In the illustrated embodiment of FIG. 4, the object device 50′ includes a serial interface 230 disposed between the transceiver 210 and the physical medium of the communication link 130. (The serial interface 230 may be present in the object device 50.) The serial interface 230 may provide a direct conductive connection between the transceiver 210 and conductors of the physical medium of the communication link 130. For instance, with the physical medium in the form of a differential pair, the serial interface 230 may provide respective direct connections between the transceiver 210 and each of the differential pairs. In an alternative embodiment, the serial interface 230 may provide a galvanically isolated coupling between the transceiver 210 and the serial interface of the communication link 130.

In the illustrated embodiment of FIG. 5, an object device 50″ is shown in a configuration substantially similar to the object device 50′, with the exception of having HF frequency 232″ and conditioning circuitry 214″ operable to inherently pass or transfer communications from one communication link 130 to the other communication link 130. The conditioning circuitry 214″ may be coupled to the HF switch 208 in a manner similar to the construction described in conjunction with FIGS. 3 and 4, including enabling the RF circuitry 204 to receive and transmit communications via the HF interface 232″ (e.g., through the conditioning circuitry 214″) of the communication link 130.

The conditioning circuitry 214″ may be similar to the conditioning circuitry 214, 214′, described herein. For instance, the conditioning circuitry 214″ may be configured to operate as a balun and/or a splitter. The conditioning circuitry 214″ may be passive circuitry, e.g., with RLC circuitry operable to split and route signals to the HF switch 208 and the communication links 130 depicted in the illustrated embodiment. The passive circuitry may be provided 1) in the form of discrete components assembled on a printed circuit board, 2) structures (e.g., RF structures) defined by the construction of the printed circuit board and inherent to the printed circuit board, 3) a packaged balun and/or splitter component, or 4) a combination thereof. The conditioning circuitry 214, 214′ may be configured in a similar manner.

The HF interface 232″ of the communication link 130 in the illustrated embodiment may be single ended or differential, depending on the configuration. For instance, a physical medium used by the HF interface may 232″ be coaxial wire configured for single ended operation. As another example, the physical medium for the HF interface 232″ may be twisted pair conductors configured for differential operation.

Although described in conjunction with two communication links 130, it is to be understood that the object device 50, 50′, 50″, 500, 500′ may include more than two communication links 130, and that circuitry of the HF interface 232, 232′, 232″, such as the conditioning circuitry 214, 214′, 214″, may be configured accordingly (e.g., two-way, three-way, four-way) as split and route signals for communicating with the RF circuitry 204.

Turning to the illustrated embodiments of FIGS. 6 and 7, the object device 500, 500′ may be similar to the object device 50, 50′, 50″ described in conjunction with the illustrated embodiments of FIGS. 3-5. The object device 500, 500′ may include one or more communication links 130′ configured such that the serial interface 230 and the HF interface 232 share a physical medium. For instance, the physical medium of the communication link 130 may be a pair of conductors (e.g., a twisted pair) operable for differential communication, and both serial communications and high-frequency communications may be transmitted via the pair of conductors.

In the illustrated embodiment of FIG. 6, the object device 500 includes a serial interface 230 and a HF interface 232, each operably coupled to the communication interface 130′ for transmission and reception of communications. The HF interface 232 may include circuitry similar to the conditioning circuitry 214, 214′, 214″, including for example one or more of a balun, splitter, and transformer. The HF interface 232 may include a single ended input or output to transfer signals to the HF switch 208, whereas the coupling to the communication link 130′ provided by the HF interface 232 may be differential.

The serial interface 230 may provide a direct or indirect coupling between the transceiver 210 and the communication link 130. For instance, in the case of the communication link 130 including a differential pair, the serial interface 230 may provide direct connections to each of the conductors of the differential pair. As another example, with the communication link 130 including a differential pair, the serial interface 230 may include a transformer operable to couple signals between the communication link 130 and the transceiver 210. Additionally, or alternatively, the serial interface 230 may include optical isolation components configured to isolate one or more signals provided to the serial interface 230 from one or more signals output from the serial interface 230.

As described herein, the communication link 130 may be configured similar to the communication link 130′, including for instance a physical medium for shared use of the HF interface 232 and the serial interface 230.

In the illustrated embodiment of FIG. 7, the object device 500′ is similar to the object device 500 with a communication link 130′ providing a shared configuration for both the HF interface 232 and the serial interface 230. In the illustrated embodiment, the object device 500′ includes first and second communication links 130′ such that communications received and transmitted via one communication link 130′ are not inherently seen or transmitted to the other of the communication links 130′. Communications received via one interface of a communication link 130′ may be redirected or relayed to an interface of the other communication link 130′.

The HF interface 232′ in the illustrated embodiment of FIG. 7 may be similar to the HF interface 232 of FIG. 6, but is shown with additional conditioning circuitry in accordance with one embodiment. Specifically, the HF interface 232′ of FIG. 7 includes conditioning circuitry 216 operable to condition signals between the high-frequency interface and the HF switch 208. The conditioning circuitry 216 may facilitate translating a single ended connection between the HF switch 208 and the HF interface 232′ to a differential output of the communication link 130′.

III. HF Frequency Circuitry for RF communications

High frequency circuitry including aspects of the RF circuitry 204 in accordance with one embodiment is shown in FIGS. 9 and 10. The RF circuitry 204 is shown coupled to an antenna array 220, which is shown, for purposes of disclosure, to represent a single ended connection for the RF circuitry 204. The antenna array 220 may be replaced with any type of single ended connection, including the conditioning circuitry 216 for a high-frequency interface that provides a differential connection. The HF switch 208 is shown optional in phantom lines to indicate it may be present and that connections in addition to the antenna array 220 may be provided, including a connection to a HF interface 232 and the antenna array 220. The filter circuitry 206 in the illustrated embodiment is a bandpass filter, and may be varied depending on the configuration.

Multiple components of the RF circuitry 204 in the illustrated embodiment are coupled to an output from the clock 202, which includes a crystal 242 (e.g., a 32 MHz crystal) and a clock distribution system 244. In one embodiment, additional components of the object device 50 or sensor 40 may be coupled to the clock distribution system 244.

The RF circuitry 204 in the illustrated embodiment includes an output mixer stage and an input mixer stage. The RF circuitry 204 may include conditioning circuitry 240 (e.g., a switch and/or balun) and may be configured to selectively couple the single ended interface 205 of the RF circuitry 204 to the output mixer stage or the input mixer stage of the RF circuitry 204. The conditioning circuitry 240 in the illustrated embodiment may be configured to provide a single ended output to the input mixer stage, and to receive a differential input from the output stage.

Both the input and output stages of the RF circuitry 204 may be coupled to the same phase lock loop (PLL) 248. Optionally, the input and output stages of the RF circuitry 204 may be coupled to separate phase locked loops 248, 248O.

The RF circuitry 204 may include one or more timers 246 coupled to aspects of the input and output stages.

Turning to the output stage of the RF circuitry 204, a processor 250 may be configured to receive or generate a message or communication for transmission via the single ended interface 205 of the RF circuitry 204. The processor 250 may supply the communication for transmission to a protocol engine 252, which is operable to translate the communication according to a protocol defined with respect to high-frequency transmissions between devices. The output from the protocol engine 252 may be supplied to a Gaussian frequency shift keying (GFSK) modulator 254, which provides quadrature components (e.g., IQ form) corresponding to the form of the transmission output from the protocol engine 252. The quadrature components provided by the GFSK modulator 254 may be in a digital form that can be translated to an analog form and filtered by the D-to-A Converter 256 (e.g., a D-to-A Converter and low pass filter). The analog form of the quadrature components may be mixed or modulated in accordance with an oscillator output of the PLL 248. The oscillator output 249 (e.g., RF clock) may be selectable and correspond to a frequency of transmission within a frequency range, such as any frequency between 2.4 GHz and 2.48 GHz.

In the illustrated embodiment of FIG. 9, the oscillator output 249 can be mixed with the quadrature components of the transmission via a mixer 253 (e.g., an up converter). The output from the mixer 253 may be supplied to a power amplifier 251 and directed to the conditioning circuitry 244 output to the single ended interface 205.

Reception and processing of signals received via the single ended interface 205 may be directed along the input stage of the RF circuitry 204, as depicted in the illustrated embodiments of FIGS. 9 and 10. The conditioning circuitry 240 may switch to direct input from the single ended interface 205 to a receiver mixer stage 260, which may include a low noise amplifier 261 and a mixer 263. The mixer 263 may receive the oscillator output 249 from the PLL 248 (or alternatively receive an oscillator output from the optional separate PLL 248O). The mixer 263 may operate as a quadrature demodulator operable to demodulate the received high-frequency signal into quadrature components (e.g., IQ form or in-phase and quadrature phase signals). The quadrature components of the received signal may be directed to conditioning circuitry 262 (e.g., bandpass filter circuitry, low pass filter circuitry, amplification circuitry, or a combination thereof), with conditioned outputs of the quadrature components provided to an A-to-D converter 264. In the illustrated embodiment of FIGS. 9 and 10, the conditioning circuitry 262 may operate as a baseband filter, optionally with a low pass filter configuration or a bandpass filter configuration. The output of the A-to-D converter 264 in IQ form can be used as a basis for determining a signal characteristic of the received signal. Zero IF may yield PCTA and PCTB, respectively at each receiving device.

The outputs from the A-to-D converter 264 may correspond to the digital form of the quadrature components of the received signal, and may be supplied to demodulation circuitry 266 and a protocol engine 268 to yield a message or communication corresponding to the received signal.

IV. HF Interface Configurations

A HF interface in accordance with one embodiment is depicted in FIG. 11 and generally designated 1000. The HF interface 1000, or aspects thereof, may be incorporated into any of the device configurations described herein in place of the HF interfaces described in conjunction with those configurations, including the HF interfaces 232, 232′, 232″.

The HF interface 1000 in the illustrated embodiment is configured for a physical medium 1090 in the form of a differential pair of conductors over which both high frequency communications and lower frequency, serial communications are transmitted. Alternatively, the lower frequency, serial communications and associated circuitry may be absent from the HF interface 1000.

The HF interface 1000 may include a serial coupler 1010 and a HF coupler 1020, respectively operable to receive and/or transmit serial communications and HF communications. The serial coupler 1010 may include a serial transceiver 1012 operable to transmit and receive serial communications via direct electrical connections to the physical medium 1090. For instance, the serial coupler 1010 may include electrical stub connections to the differential pair of conductors.

The HF interface 1000, in the illustrated embodiment, includes a HF coupler 1020 operable to receive and/or transmit HF communications via the physical medium 1090. The HF coupler 1020 may include a transformer-based coupler 1024 and a balun 1022 configured to facilitate HF communications via the physical medium 1090.

A HF interface in accordance with an alternative embodiment is depicted in FIG. 12 and generally designated 1000′. The HF interface 1000′ is similar in many respects to the HF interface 1000, and may similarly be incorporated into any of the device configurations described herein in place of the HF interfaces described in conjunction with those configurations, including the HF interfaces 232, 232′, 232″.

The HF interface 1000′ includes a serial coupler 1010′ and a HF coupler 1020′, similar to the serial coupler 1010 and the HF coupler 1020 described herein, with the exception of the serial coupler 1010′ including a transformer-based coupler 1014′ configured to couple communications to the physical medium (e.g., a differential pair of conductors). The transceiver 1012′, the balun 1022′, and the transformer-based coupler 1024′ may be configured in a manner similar to elements of the HF interface 1000 with the same reference number without the ′.

Although the serial couplers 1010, 1010′, as well as the HF interfaces 232, 232′, 232″, are depicted in some embodiments as including a transceiver (e.g., a serial transceiver), it is to be understood that the transceiver may be separate from the serious coupler and the HF interface.

A HF interface in accordance with one embodiment is depicted in FIG. 13 and generally designated 1100. The HF interface 1100 is configured for coupling single-ended communications (e.g., communications received via an antenna or a single-ended physical interface, such as coax) to a differential configuration, or coupling differential signals to a single-ended configuration, or both. The HF interface 1100 in the illustrated embodiment includes a plurality of connectors 1190-1, 1190-2, 1192. One or more of these connectors 1190-1, 1190-2, 1192 may be differential (e.g., connectors 1190-1, 1190-2), and one or more of these connectors 1190-1, 1190-2, 1192 may be singled ended (e.g., connector 1192). The HF interface 1100