Piezoelectric-based circuit for modifying functionality of RFID tag

Abstract

The present disclosure provides a radio frequency identification (RFID) tag, the RFID tag comprising: a tag integrated circuit (IC); an antenna coupled to the tag IC; and an impedance tuning circuit coupled to the antenna, where the impedance tuning circuit is configured to tune a circuit impedance of the antenna based on power received by the impedance tuning circuit. The RFID tag also includes a piezoelectric energy harvesting module coupled to the impedance tuned circuit, where the piezoelectric energy harvesting module is configured to supply power to the impedance tuned circuit.

Description

Technical Field

[0001] Exemplary embodiments of the present disclosure relate generally to radio frequency identification (RFID) tags, and particularly to RFID tags having a communication function based on their movement. Background Art

[0002] RFID systems can be used in a wide range of applications, such as, for example, in retail supply chains, postal logistics, healthcare, or manufacturing. For example, RFID systems can be used to help identify and track assets that need to be reliably monitored and / or controlled in a specific environment. The use of RFID in such applications has resulted in a safer, more efficient, and more accurate system for managing assets. RFID systems can be used to trace and track each individual asset from its origin to its destination using its individual identification information.

[0003] Applicants have recognized the many technical challenges and difficulties associated with conventional RFID systems. Summary of the invention

[0004] Various embodiments described herein relate to methods, components, and apparatus for modifying the communication functionality of a radio frequency identification (RFID) tag based on the movement of the RFID tag.

[0005] According to various embodiments of the present disclosure, an RFID tag is provided. In some embodiments, the RFID tag includes: a tag integrated circuit (IC); an antenna coupled to the tag IC; and an impedance tuning circuit coupled to the antenna, wherein the impedance tuning circuit is configured to tune the circuit impedance of the antenna based on the power received by the impedance tuning circuit. In some embodiments, the RFID tag also includes a piezoelectric energy harvesting module coupled to the impedance tuning circuit, wherein the piezoelectric energy harvesting module is configured to supply power to the impedance tuning circuit.

[0006] In some embodiments, the impedance tuning circuit is further configured to control the operation of the antenna and the tag IC by tuning the circuit impedance of the antenna. In some embodiments, the RFID tag also includes a latch switch coupled to the impedance tuning circuit from the piezoelectric energy harvesting module. In some embodiments, the piezoelectric energy harvesting module includes a piezoelectric transducer, a power management module, and an energy storage unit. In some embodiments, the impedance tuning circuit is further configured to tune the circuit impedance of the antenna to match the functional impedance of the tag IC based on the power received by the impedance tuning circuit. In some embodiments, the impedance tuning circuit is further configured to: (i) tune the first circuit impedance of the antenna based on not receiving power from the piezoelectric energy harvesting module, and (ii) tune the second circuit impedance of the antenna based on receiving power from the piezoelectric energy harvesting module. In some embodiments, the first circuit impedance of the antenna includes a non-functional circuit impedance, and the second circuit impedance of the antenna includes a functional circuit impedance. In some embodiments, the non-functional circuit impedance includes an impedance greater than the functional impedance of the tag IC, and the functional circuit impedance includes the functional impedance of the tag IC. In some embodiments, the piezoelectric energy harvesting module is further configured to supply power to the impedance tuning circuit based on the movement of the RFID tag. In some embodiments, the piezoelectric energy harvesting module is further configured to stop supplying power to the impedance tuning circuit based on the non-movement of the RFID tag.

[0007] According to another embodiment, an RFID tag includes: an antenna configured to receive and transmit radio frequency (RF) signals; and a tag integrated circuit (IC) coupled to the antenna, wherein the tag IC includes an input / output (I / O) port, and the tag IC is configured to generate a discrete signal based on an electrical signal received on the I / O port for transmission in the RF signal. In some embodiments, the RFID tag also includes a piezoelectric energy harvesting module coupled to the I / O port, wherein the piezoelectric energy harvesting module is configured to generate the electrical signal to the I / O port.

[0008] In some embodiments, the piezoelectric energy harvesting module is further configured to generate the electrical signal based on the movement of the RFID tag. In some embodiments, the tag IC is further configured to generate the discrete signal based on the movement of the RFID tag. In some embodiments, the tag IC is further configured to generate a high discrete signal based on the RFID tag being in motion. In some embodiments, the tag IC is further configured to generate a low discrete signal based on the RFID tag being in a stationary state.

[0009] The above exemplary invention content and other exemplary objects and / or advantages of the present disclosure and the manner of achieving these objects and / or advantages are further explained in the following detailed description and the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The description of the exemplary embodiments may be read in conjunction with the accompanying drawings. It will be appreciated that, for simplicity and clarity of illustration, the elements shown in the figures are not necessarily drawn to scale unless otherwise described. For example, the dimensions of some of the elements may be exaggerated relative to other elements unless otherwise described. Embodiments incorporating the teachings of the present disclosure are shown and described with respect to the drawings presented herein, in which:

[0011] Figure 1 is an exemplary overview of an architecture that can be used to practice embodiments of the present disclosure;

[0012] Figure 2 An exemplary radio frequency identification (RFID) reader computing entity is shown;

[0013] Figure 3 An exemplary host computing entity is shown;

[0014] Figure 4 shows an exemplary RFID tag according to some embodiments discussed herein;

[0015] Figure 5 shows an exemplary impedance tuning circuit according to some embodiments discussed herein;

[0016] Figure 6 shows an exemplary piezoelectric energy harvesting module according to some embodiments discussed herein; and

[0017] Figure 7 Another example of an RFID tag according to some embodiments discussed herein is shown. DETAILED DESCRIPTION

[0018] Some embodiments of the present disclosure will be described more fully below with reference to the accompanying drawings, which illustrate some, but not all, embodiments of the present disclosure. In fact, these disclosures may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that the present disclosure satisfies applicable legal requirements. Throughout the content, similar reference numerals refer to similar elements.

[0019] As used herein, terms such as "front," "rear," "top," and the like are used for illustrative purposes in the examples provided below to describe the relative positions of certain components or portions of components. Additionally, as will be apparent to one of ordinary skill in the art from this disclosure, the terms "substantially" and "approximately" indicate that the referenced element or associated description is accurate within an applicable engineering tolerance.

[0020] As used herein, the term "comprising" means including but not limited to, and should be interpreted in the manner commonly used in the patent context. It should be understood that the use of broad terms such as "comprising," "including," and "having" provides support for narrower terms such as "consisting of," "consisting essentially of," and "consisting essentially of."

[0021] The phrases "in one embodiment," "according to one embodiment," and the like generally mean that the particular feature, structure, or characteristic following the phrase may be included in at least one embodiment of the present disclosure, and may be included in more than one embodiment of the present disclosure (importantly, such phrases are not necessarily referring to the same embodiment).

[0022] The word “example” or “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any implementation described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other implementations.

[0023] If the specification states that a component or feature "may", "can", "could", "should", "will", "preferably", "likely", "usually", "optionally", "for example", "often", or "might" (or other such language) be included or have a property, the specific component or feature is not required to be included or have that property. Such components or features may optionally be included in some embodiments, or may be excluded.

[0024] Those skilled in the art will appreciate that for certain applications, a longer read range than expected may cause problems. In an exemplary scenario, a radio frequency identification (RFID) reader may be installed in a parcel vehicle to monitor parcels with RFID tags. It may be desirable to monitor only parcels stored in the vehicle and avoid reading RFID tags that are outside the vehicle but may be within the range of the RFID reader. A possible solution to avoid this problem may involve reducing the power of the RFID reader, however, by doing so, the RFID coverage of RFID tags inside the vehicle may be negatively affected.

[0025] In a similar exemplary scenario, a worker with a wearable RFID reader may handle a package, and while handling the package, the wearable RFID may read the RFID tag on the package. However, the wearable RFID reader may also detect and read stray packages near the wearable reader. Such reading of stray packages may be unintentional and will require additional work of repeated reading and isolation of the intended package.

[0026] In a related exemplary scenario, an overhead RFID reader may be installed in a retail store and configured to track merchandise that customers interact with (via RFID tags) and the movement of merchandise. However, in this configuration, in addition to reading RFID tags of merchandise that customers interact with, surrounding stationary / static merchandise with RFID tags may also be read by the overhead RFID reader.

[0027] The above difficulties are due to the limitation that RFID tags are non-intelligent or non-programmable and therefore respond to any read signal from the RFID reader.

[0028] Various exemplary embodiments of the present disclosure overcome such technical challenges and difficulties in RFID systems and provide various technical advances and improvements. According to various examples of the present disclosure, an RFID tag may include a piezoelectric-based circuit configured to modify the communication function of the RFID tag. A piezoelectric-based circuit may include a circuit that generates electricity through mechanical pressure. For example, a piezoelectric-based circuit may convert energy generated by changes in force, acceleration, pressure, or strain.

[0029] In some embodiments, a piezoelectric-based circuit may be coupled to an antenna of an RFID tag to tune the impedance and operation of the antenna based on the physical movement of the RFID tag. For example, the antenna may be tuned to the impedance of the tag integrated circuit (IC) so that when the RFID tag moves, the antenna is operable to respond to RFID read commands (e.g., receive and transmit RF signals). Otherwise, the antenna may be detuned to a high impedance so that when the RFID tag is stationary, the antenna is inoperable and RF signals cannot be received and / or transmitted to the RFID tag. An RFID tag with an antenna that is tunable based on movement may be suitable for use with a wearable RFID reader, as disclosed in the exemplary scenario above, where a user may want to detect a package being handled.

[0030] In some embodiments, a piezoelectric-based circuit may be coupled to an input / output (I / O) port of an RFID tag IC. The RFID tag IC may respond to a read signal of an RFID reader using a discrete signal based on an electrical signal generated from a piezoelectric-based circuit. For example, an RFID tag including an RFID tag IC coupled to a piezoelectric-based circuit may generate various discrete signals based on the movement of the RFID tag. When the RFID tag is in motion, the RFID tag IC may generate a high discrete signal, and when the RFID tag is stationary, the RFID tag IC may generate a low discrete signal. In this way, an RFID reader may identify an asset having an RFID tag with a high discrete signal (indicating movement) and distinguish it from an RFID tag with a low discrete signal (indicating stationary). An RFID tag configured to generate a discrete signal based on movement may be suitable for use in a package vehicle or a retail store, as disclosed in the above scenario, where it may be desirable to read both a mobile RFID tag and a static RFID tag within a vehicle / store, for example.

[0031] Figure 1 1 is a schematic diagram of an exemplary architecture 100 for reading RFID tags. The architecture 100 includes an RFID reader computing entity 106 configured to generate a read signal, receive one or more responses to the read signal from corresponding one or more RFID tags 102, and process the one or more responses locally on the RFID reader computing entity 106 or via the host computing entity 104. For example, the RFID reader computing entity 106 or via the host computing entity 104 may convert the response from the RFID tag 102 into a form that can be subsequently used. In an exemplary embodiment, the RFID reader computing entity 106 may receive a response including encoded data sent from the RFID tag 102 and decode the data for processing by the host computing entity 104. In some embodiments, the RFID reader computing entity 106 may communicate with at least one of the RFID tags 102 using a radio frequency (RF) signal. The RF signal may include a frequency of approximately 125KHz-135KHz, 13.56MHz, 860MHz-960MHz, 2.45GHz, or 5.8GHz, but those skilled in the art will appreciate that other frequencies may be used.

[0032] Figure 2 A schematic diagram of an RFID reader computing entity 106 according to one embodiment of the present disclosure is provided. Figure 2As shown, in some embodiments, the RFID reader computing entity 106 may include or communicate with one or more processing elements 205 (also referred to herein as processors, processing circuits, and / or similar terms used interchangeably) that communicate with other elements within the RFID reader computing entity 106, for example, via a bus. It should be understood that the processing element 205 can be embodied in a variety of different ways.

[0033] For example, processing element 205 may be embodied as one or more complex programmable logic devices (CPLDs), microprocessors, multi-core processors, co-processing entities, application specific instruction set processors (ASIPs), microcontrollers, and / or controllers. In addition, processing element 205 may be embodied as one or more other processing devices or circuits. The term circuit may refer to a complete hardware embodiment or a combination of hardware and a computer program product. Thus, processing element 205 may be embodied as an integrated circuit, an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), a programmable logic array (PLA), a hardware accelerator, other circuits, etc.

[0034] Therefore, it should be understood that the processing element 205 may be configured for specific purposes or configured to execute instructions stored in volatile or non-volatile media or otherwise accessible by the processing element 205. Thus, whether configured by hardware or by a computer program product, or by a combination thereof, when configured accordingly, the processing element 205 may be capable of performing steps or operations according to embodiments of the present disclosure.

[0035] In some embodiments, the RFID reader computing entity 106 may also include or communicate with non-volatile media (also referred to herein as non-volatile storage, memory, memory storage, memory circuits, and / or similar terms used interchangeably). In some embodiments, the non-volatile storage device or memory may include one or more non-volatile memories 210, including but not limited to a hard disk, a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), a flash memory (e.g., serial, NAND, NOR, and / or the like), a multimedia memory card (MMC), a secure digital (SD) memory card, a smart media card, a compact flash (CF) card, a memory stick, a conductive bridging random access memory (CBRAM), a phase change random access memory (PRAM), a ferroelectric random access memory (FeRAM), a non-volatile random access memory (NVRAM), a magnetoresistive random access memory (MRAM), a resistive random access memory (RRAM), a silicon-oxide-nitride-oxide-silicon memory (SONOS), a floating junction gate random access memory (FJG RAM), a millipede memory, a racetrack memory, and / or the like.

[0036] As will be appreciated, non-volatile storage devices or memory media may store databases, database instances, database management system entities, data, applications, programs, program modules, scripts, source code, object code, byte code, compiled code, interpreted code, machine code, executable instructions, etc. The terms "database," "database instance," "database management system," and / or similar terms used interchangeably herein may refer to a collection of records or data stored in a computer-readable storage medium using one or more database models, such as a hierarchical database model, a network model, a relational model, an entity-relationship model, an object model, a document model, a semantic model, a graph model, etc.

[0037] In some embodiments, the RFID reader computing entity 106 may also include or be in communication with volatile media (also referred to as volatile storage, memory, memory storage, memory circuits, and / or similar terms used interchangeably herein). In some embodiments, the volatile storage device or memory may also include one or more volatile memories 215, including but not limited to random access memory (RAM), dynamic random access memory (DRAM), static random access memory (SRAM), fast page mode dynamic random access memory (FPM DRAM), extended data output dynamic random access memory (EDO DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), second generation double data rate type synchronous dynamic random access memory (DDR2SDRAM), third generation double data rate type synchronous dynamic random access memory (DDR3 SDRAM), Rambus dynamic random access memory (RDRAM), two-transistor RAM (TTRAM), semiconductor thyristor RAM (Thyristor RAM, T-RAM), zero capacitor (Z-RAM), Rambus embedded memory module (RIMM), dual in-line memory module (DIMM), single in-line memory module (SIMM), video random access memory (VRAM), cache memory, register memory, etc.

[0038] As will be appreciated, volatile storage or memory media may be used to store at least a portion of a database, database instance, database management system, data, applications, programs, program modules, scripts, source code, object code, byte code, compiled code, interpreted code, machine code, executable instructions, etc., which are executed by, for example, processing element 205. Thus, a database, database instance, database management system, data, applications, programs, program modules, scripts, source code, object code, byte code, compiled code, interpreted code, machine code, executable instructions, etc. may be used to control certain aspects of the operation of RFID reader computing entity 106 with the assistance of processing element 205 and an operating system.

[0039] As noted, in some embodiments, the RFID reader computing entity 106 may also include one or more network interfaces 220 for communicating with various computing entities, such as the host computing entity 104, by transferring data, content, information, and / or similar terms that may be used interchangeably herein, that may be transmitted, received, manipulated, processed, displayed, stored, etc. Such communications may be performed using a wired data transmission protocol, such as Fiber Distributed Data Interface (FDDI), Digital Subscriber Line (DSL), Ethernet, Asynchronous Transfer Mode (ATM), Frame Relay, Data Over Cable Service Interface Specification (DOCSIS), or any other wired transmission protocol. Similarly, the RFID reader computing entity 106 may be configured to communicate via a wireless external communication network using any of a variety of protocols, such as General Packet Radio Service (GPRS), Universal Mobile Telecommunications System (UMTS), Code Division Multiple Access 2000 (CDMA2000), CDMA2000 1X (1xRTT), Wideband Code Division Multiple Access (WCDMA), Global System for Mobile Communications (GSM), Enhanced Data Rates for GSM Evolution (EDGE), Time Division Synchronous Code Division Multiple Access (TD-SCDMA), Long Term Evolution (LTE), Evolved Universal Terrestrial Radio Access Network (E-UTRAN), Evolution Data Optimized (EVDO), High Speed ​​Packet Access (HSPA), High Speed ​​Downlink Packet Access (HSDPA), IEEE 802.11 (Wi-Fi), Wi-Fi Direct, 802.16 (WiMAX), Ultra Wideband (UWB), Infrared (IR) protocol, Near Field Communication (NFC) protocol, Wibree, Bluetooth protocol, wireless Universal Serial Bus (USB) protocol, and / or any other wireless protocol.

[0040] The one or more network interfaces 220 may also include one or more antennas, one or more transmitters (e.g., radio components), and one or more receivers (e.g., radio components) in communication with the processing element 205, which provides signals to the one or more transmitters and one or more receivers and receives signals from the one or more transmitters and one or more receivers, respectively. The signals provided to the one or more transmitters and one or more receivers and the signals received from the one or more transmitters and one or more receivers, respectively, may include signaling information / data according to the aforementioned wireless communication protocols for communicating with the host computing entity 104 and the RFID standards and protocols for communicating with the RFID tag 102.

[0041] Although not shown, the RFID reader computing entity 106 may include or communicate with one or more input elements, such as keyboard input, mouse input, touch screen / display input, motion input, movement input, audio input, pointing device input, joystick input, keypad input, etc. The RFID reader computing entity 106 may also include or communicate with one or more output elements (not shown), such as audio output, video output, screen / display output, motion output, movement output, etc.

[0042] Figure 3 A schematic diagram of a host computing entity 104 according to an embodiment of the present disclosure is provided. Typically, the term computing entity, computer, entity, device, system and / or similar words used interchangeably herein may refer to, for example, one or more computers, computing entities, desktop computers, mobile phones, tablet computers, tablet phones, notebook computers, laptop computers, distributed systems, information kiosks, input terminals, servers or server networks, blade servers, gateways, switches, processing devices, processing entities, set-top boxes, relays, routers, network access points, base stations, etc., and / or any combination of devices or entities suitable for performing functions, operations and / or processes described herein. Such functions, operations and / or processes may include, for example, transmission, reception, operation, processing, display, storage, determination, creation / generation, monitoring, evaluation, comparison and / or similar terms that may be used interchangeably herein. In some embodiments, these functions, operations and / or processes may be performed on data, content, information and / or similar terms that may be used interchangeably herein.

[0043] like Figure 3 As shown, in some embodiments, the host computing entity 104 may include or communicate with one or more processing elements 305 (also referred to herein as processors, processing circuits, and / or similar terms that may be used interchangeably) that communicate with other elements within the host computing entity 104, for example, via a bus. It should be understood that the processing element 305 may be embodied in a variety of different ways.

[0044] For example, processing element 305 may be embodied as one or more CPLDs, microprocessors, multi-core processors, co-processing entities, ASIPs, microcontrollers, and / or controllers. In addition, processing element 305 may be embodied as one or more other processing devices or circuits. The term circuit may refer to a complete hardware embodiment or a combination of hardware and a computer program product. Thus, processing element 305 may be embodied as an integrated circuit, an ASIC, an FPGA, a PLA, a hardware accelerator, other circuit systems, and the like.

[0045] It should therefore be understood that the processing element 305 may be configured for specific purposes or configured to execute instructions stored in volatile or non-volatile media or otherwise accessible by the processing element 305. Thus, whether configured by hardware or by a computer program product, or by a combination thereof, when configured accordingly, the processing element 305 may be capable of performing steps or operations according to embodiments of the present disclosure.

[0046] In some embodiments, the host computing entity 104 may also include or communicate with a non-volatile medium (also referred to herein as a non-volatile storage device, memory, memory storage device, memory circuit and / or similar terms used interchangeably). In addition, the non-volatile storage device or memory may include one or more non-volatile memories 310, including but not limited to a hard disk, ROM, PROM, EPROM, EEPROM, flash memory, MMC, SD memory card, memory stick, CBRAM, PRAM, FeRAM, NVRAM, MRAM, RRAM, SONOS, FJG RAM, millipede memory, racetrack memory, etc.

[0047] As will be appreciated, non-volatile storage devices or memory media may store databases, database instances, database management system entities, data, applications, programs, program modules, scripts, source code, object code, byte code, compiled code, interpreted code, machine code, executable instructions, etc. The terms "database," "database instance," "database management system," and / or similar terms used interchangeably herein may refer to a collection of records or data stored in a computer-readable storage medium using one or more database models, such as a hierarchical database model, a network model, a relational model, an entity-relationship model, an object model, a document model, a semantic model, a graph model, etc.

[0048] In some embodiments, the host computing entity 104 may also include or communicate with volatile media (also referred to herein as volatile storage, memory, memory storage, memory circuits, and / or similar terms used interchangeably). In some embodiments, the volatile storage or memory may also include one or more volatile memories 315, such as, but not limited to, RAM, DRAM, SRAM, FPM DRAM, EDO DRAM, SDRAM, DDR SDRAM, DDR2SDRAM, DDR3 SDRAM, RDRAM, TTRAM, T-RAM, Z-RAM, RIMM, DIMM, SIMM, VRAM, cache memory, register memory, etc.

[0049] As will be appreciated, volatile storage or memory media may be used to store at least a portion of a database, database instance, database management system, data, applications, programs, program modules, scripts, source code, object code, byte code, compiled code, interpreted code, machine code, executable instructions, etc., which are executed by, for example, processing element 305. Thus, a database, database instance, database management system, data, applications, programs, program modules, scripts, source code, object code, byte code, compiled code, interpreted code, machine code, executable instructions, etc. may be used to control certain aspects of the operation of host computing entity 104 with the assistance of processing element 305 and an operating system.

[0050] As noted, in some embodiments, the host computing entity 104 may also include one or more network interfaces 320 for communicating with various computing entities, such as by transmitting data, content, information, and / or similar terms used interchangeably herein that can be transmitted, received, manipulated, processed, displayed, stored, etc. Such communications may be performed using a wired data transmission protocol, such as FDDI, DSL, Ethernet, ATM, Frame Relay, DOCSIS, or any other wired transmission protocol. Similarly, the host computing entity 104 may be configured to communicate via a wireless external communication network using any of a variety of protocols, such as GPRS, UMTS, CDMA2000, 1xRTT, WCDMA, GSM, EDGE, TD-SCDMA, LTE, E-UTRAN, EVDO, HSPA, HSDPA, Wi-Fi, Wi-Fi Direct, WiMAX, UWB, IR protocol, NFC protocol, Wibree, Bluetooth protocol, Wireless USB protocol, and / or any other wireless protocol.

[0051] Although not shown, the host computing entity 104 may include or communicate with one or more input elements, such as keyboard input, mouse input, touch screen / display input, motion input, movement input, audio input, pointing device input, joystick input, keypad input, etc. The host computing entity 104 may also include or communicate with one or more output elements (not shown), such as audio output, video output, screen / display output, motion output, movement output, etc.

[0052] Figure 4 Depicted is an exemplary schematic diagram of an RFID tag that may be used in conjunction with some embodiments of the present disclosure. Figure 4As shown, the RFID tag 102-1 includes a tag IC 402 and an antenna 404 coupled thereto. The antenna 404 may enable the RFID tag 102-1 to receive RF signals from an RFID reader (such as the RFID reader computing entity 106) and to transmit RF signals to the RFID reader in response to the received RF signals. For example, in response to a read signal received from the RFID reader computing entity 106 via the antenna 404, an RF signal may be generated by the tag IC 402 and also transmitted by the antenna 404. In some embodiments, the tag IC 402 may include a digital memory that stores data associated with an underlying object coupled to the RFID tag 102-1. For example, the transmitted RF signal may provide identification information, such as a serial number or an identification number, to the RFID reader computing entity 106.

[0053] In the depicted embodiment, the antenna 404 includes a circuit loop coupled to an impedance tuning circuit 406. The impedance tuning circuit 406 can control the operation of the antenna 404 and the tag IC 402 by tuning the circuit impedance of the antenna 404 (e.g., impedance matching). The impedance tuning circuit 406 is further coupled to a latch switch 408 and a piezoelectric energy harvesting module 410, and can be driven by both. The latch switch 408 may include a switch that, after being actuated, holds an output signal based on an input signal until the latch switch 408 is actuated again or a signal is provided to turn off the latch switch 408. The latch switch 408 can be actuated (e.g., turned on) by the piezoelectric energy harvesting module 410 to provide power from the piezoelectric energy harvesting module 410 to the impedance tuning circuit 406.

[0054] In some embodiments, the functionality of the antenna 404 and the tag IC 402 may be based on the circuit impedance tuned by the impedance tuning circuit 406, wherein the circuit impedance tuned by the impedance tuning circuit 406 may be based on whether power is received from the piezoelectric energy harvesting module 410. Therefore, the ability of the RFID tag 102-1 to receive or transmit RF signals may depend on the circuit impedance tuned by the impedance tuning circuit 406. Specifically, when power is provided to the impedance tuning circuit 406 from the piezoelectric energy harvesting module 410, the impedance tuning circuit 406 may be configured to tune the circuit impedance of the circuit loop of the antenna 402 to match the functional impedance of the tag IC 402, so that the RFID tag 102-1 can receive or transmit RF signals. According to various embodiments of the present disclosure, the circuit impedance tuned by the impedance tuning circuit 406 for the antenna 404 affects the ability of the RFID tag 102-1 to receive power, thereby controlling the reading of an RFID reader (such as an RFID reader computing entity 106). Additionally or alternatively, the circuit impedance tuned by the impedance tuning circuit 406 may determine the level of the modulated backscattered signal that is reradiated to the RFID reader.

[0055] refer to Figure 5 , the impedance tuning circuit 406 includes a circuit including one or more inductors, capacitors, and diodes, which connects the antenna 404 and the tag IC 402 with the output from the latch switch 408. Specifically, when the latch switch 408 is actuated to provide power from the piezoelectric energy harvesting module 410 to the impedance tuning circuit 406, the impedance tuning circuit 406 can tune the circuit impedance of the antenna 404 to match the functional impedance of the tag IC 402. In some embodiments, the impedance tuning circuit 406 can be configured to (i) tune a first circuit impedance of the antenna 404 when power is not received from the piezoelectric energy harvesting module 410, and (ii) tune a second circuit impedance of the antenna 404 when power is received from the piezoelectric energy harvesting module 410. In an exemplary embodiment, the first circuit impedance of the antenna 404 can include a non-functional circuit impedance, and the second circuit impedance of the antenna 404 can include a functional circuit impedance. The non-functional circuit impedance can prevent the antenna 404 from receiving and transmitting RF signals, and the functional circuit impedance can allow the antenna 404 to receive and transmit RF signals. For example, the non-functional circuit impedance may include an impedance greater than the functional impedance of the tag IC 402 , and the functional circuit impedance may include the functional impedance of the tag IC 402 .

[0056] According to various embodiments of the present disclosure, when, for example, a package box with an RFID tag 102-1 is in motion, power from the piezoelectric energy harvesting module 410 can be used to tune the circuit impedance of the antenna 404 to match the functional impedance of the tag IC 402. The movement of the RFID tag 102-1 (and, by extension, the piezoelectric energy harvesting module 410) can cause the latch switch 408 to be actuated by the piezoelectric energy harvesting module 410, thereby transferring power from the piezoelectric energy harvesting module 410 to the impedance tuning circuit 406. The piezoelectric energy harvesting module 410 can use the energy generated by the movement of the RFID tag 102-1 to send power to the impedance tuning circuit 406. When the RFID tag 102-1 becomes stationary (e.g., non-moving), the latch switch 408 can be deactivated by the piezoelectric energy harvesting module 410 to stop supplying power from the piezoelectric energy harvesting module 410 to the impedance tuning circuit 406.

[0057] Figure 6An exemplary piezoelectric energy harvesting module is depicted. The piezoelectric energy harvesting module 410 includes a piezoelectric transducer 602, a power management module 604, and an energy storage unit 606. The piezoelectric transducer 602 may include a device that measures mechanical energy or mechanical force and converts the energy into electrical energy or an electrical signal in a proportional form. The power management module 604 may include an electronic system that manages the storage of electrical energy generated by the piezoelectric transducer 602 (e.g., generated by the movement experienced by the piezoelectric transducer 602) to the energy storage unit 606. In some embodiments, the power management module 604 may be further configured to send a signal to actuate the latch switch 408 when movement of the piezoelectric transducer 602 is detected and to send a signal to deactivate the latch switch 408 when non-movement of the piezoelectric transducer 602 is detected.

[0058] The electrical energy stored in the energy storage unit 606 can supply a continuous and stable power supply to the impedance tuning circuit 406, so that the impedance tuning circuit 406 can maintain the operating impedance. That is, the power supplied by the energy storage unit 606 can be more consistent than the power directly generated by the piezoelectric transducer 602 itself. In this way, the use of the energy storage unit 606 ensures that the operating impedance tuned by the impedance tuning circuit 406 is stable and properly maintains the operation of the antenna 404 and the tag IC 402, such as during the movement experienced by the piezoelectric transducer 602.

[0059] Figure 7 Another exemplary schematic diagram of an RFID tag that may be used in conjunction with some other embodiments of the present disclosure is depicted. Figure 7 As shown, the RFID tag 102-2 includes a tag IC 702 and an antenna 704 coupled thereto. The antenna 704 may enable the RFID tag 102-2 to receive RF signals from an RFID reader (such as the RFID reader computing entity 106) and to transmit RF signals to the RFID reader in response to the received RF signals. For example, in response to a read signal received from the RFID reader computing entity 106 via the antenna 704, an RF signal may be generated by the tag IC 702 and transmitted via the antenna 704. In some embodiments, the tag IC 702 may include a digital memory that stores data associated with an underlying object coupled to the RFID tag 102-2. For example, the transmitted RF signal may provide identification information, such as a serial number or an identification number, to the RFID reader computing entity 106.

[0060] Compared to the antenna 404 of the RFID tag 102-1, the functionality of the tag IC 702 and antenna 704 does not rely on the circuit impedance tuned by the impedance tuning circuit. Specifically, the antenna 704 omits the circuit loop coupled to the impedance tuning circuit and includes a static impedance that matches the operating impedance of the tag IC 702. The RFID tag 102-2 also includes a piezoelectric energy harvesting module 708 coupled to the I / O port of the tag IC 702 via a latch switch 706. The tag IC 702 can convert electrical signals received at its I / O port into discrete signals that can be transmitted in RF signals in response to RFID read signals.

[0061] The electrical signal received at the I / O port of the tag IC 702 may be based on the electrical signal generated by the piezoelectric energy harvesting module 708 from the movement of the RFID tag 102-2 (and, by extension, the piezoelectric energy harvesting module 708). In this way, the tag IC 702 can generate a discrete signal based on the movement of the RFID tag 102-2. For example, the tag IC 702 can generate a high discrete signal when the RFID tag 102-2 is in motion and a low discrete signal when the RFID tag 102-2 is stationary. Therefore, the RFID tag 102-2 can identify whether it is in motion or stationary in its response to the RF read signal from the RFID reader (e.g., the RFID reader computing entity 106). In some embodiments, the RFID reader (e.g., the RFID reader computing entity 106) can identify the first one or more assets and distinguish the first one or more assets from the second one or more assets based on the discrete signals in the response RF signal sent from the RFID tags associated with the first one or more assets and the second one or more assets. For example, each of the first one or more assets is associated with an RFID tag 102-2 that responds with an RF signal including a high discrete signal (indicating movement), and each of the second one or more assets is associated with an RFID tag 102-2 that responds with an RF signal including a low discrete signal (indicating stillness).

[0062] It should be understood that the disclosure is not limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation unless otherwise specified.

Claims

1. A radio frequency identification (RFID) tag, the RFID tag comprising: Tag integrated circuit (IC); an antenna coupled to the tag IC; an impedance tuning circuit coupled to the antenna, the impedance tuning circuit configured to tune a circuit impedance of the antenna based on power received by the impedance tuning circuit; and A piezoelectric energy harvesting module is coupled to the impedance tuning circuit, and the piezoelectric energy harvesting module is configured to supply the power to the impedance tuning circuit.

2. The RFID tag of claim 1, wherein the impedance tuning circuit is further configured to control operation of the antenna and the tag IC by tuning a circuit impedance of the antenna.

3. The RFID tag of claim 1, further comprising a latching switch coupled from the piezoelectric energy harvesting module to the impedance tuning circuit.

4. The RFID tag according to claim 1, wherein the piezoelectric energy harvesting module comprises a piezoelectric transducer, a power management module and an energy storage unit.

5. The RFID tag of claim 1, wherein the impedance tuning circuit is further configured to tune the circuit impedance of the antenna to match a functional impedance of the tag IC based on the power received by the impedance tuning circuit.

6. The RFID tag of claim 1 , wherein the impedance tuning circuit is further configured to: (i) tune a first circuit impedance of the antenna based on not receiving power from the piezoelectric energy harvesting module, and (ii) tune a second circuit impedance of the antenna based on receiving power from the piezoelectric energy harvesting module.

7. The RFID tag of claim 6, wherein the first circuit impedance of the antenna comprises a non-functional circuit impedance, and the second circuit impedance of the antenna comprises a functional circuit impedance.

8. A radio frequency identification (RFID) tag, the RFID tag comprising: an antenna configured to receive and transmit radio frequency (RF) signals; a tag integrated circuit (IC) coupled to the antenna, the tag IC comprising an input / output (I / O) port, and the tag IC configured to generate a discrete signal for transmission in the RF signal based on an electrical signal received at the I / O port; and A piezoelectric energy harvesting module is coupled to the I / O port and is configured to generate the electrical signal to the I / O port.

9. The RFID tag of claim 8, wherein the piezoelectric energy harvesting module is further configured to generate the electrical signal based on movement of the RFID tag.

10. The RFID tag of claim 8, wherein the tag IC is further configured to generate the discrete signal based on movement of the RFID tag.

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