US20050242964A1 - Miniature radio frequency transceiver - Google Patents

Abstract

The present application describes an electronically powered postage stamp or mailing label and including a radio frequency identification (RFID) device and system mounted between the opposing and facing major surfaces thereof. The RFID device and system includes an integrated circuit transceiver chip which is connected to and powered by a thin flat battery cell and is operated with a thin film RF antenna, all of which are mounted in side-by-side relationship on a thin base or support layer. These thin flat components are mounted in an essentially two dimensional planar configuration well suited for incorporation into the planar structure of a postage stamp or a mailing label. In addition, the RFID transceiver chip may be replaced with an electro-optically operated IC chip using, for example, LEDs or laser diodes for the propagation of light signals to an interrogator.

Description

• This application is a continuation of application Ser. No. 09/481,807 filed Jan. 11, 2000, which is a divisional of application Ser No. 08/934,701 filed Sep. 22, 1997, now U.S. Pat. No. 6,013,949; which is a continuation of application Ser. No. 08/610,236 filed Mar. 4, 1996, now abandoned; which is a continuation of application Ser. No. 08/168,909 filed Dec. 17, 1993, now U.S. Pat. No. 5,497,140; which is a continuation of application Ser. No. 07/928,899 filed Aug. 12, 1992, now abandoned.
TECHNICAL FLED
• This invention relates generally to electrically powered postage stamps and mailing labels which operate to transmit radio frequency (RF) identification signals to an interrogator either at the point of shipment origin, in transit, or upon reaching a point of destination. More particularly, this invention relates to such stamps and labels having an integrated circuit therein powered by a thin flat battery cell.
RELATED APPLICATION AND BACKGROUND ART
• In my co-pending application Ser. No. (71-579) entitled “Radio Frequency Identification Device and Method of Manufacture, Including an Electrical Operating System and Method”, filed Jun. 17, 1992, there are disclosed and claimed new and improved radio frequency identification (RFID) tags which may be affixed to various articles (or persons) so that these articles, when shipped, may be easily tracked from the point of shipment origin, then along a given route, and then readily located upon reaching a point of destination. These RFID tags are constructed within a small area on the order of one inch (1″) square or less and of a thickness on the order of 30 mils. These tags include, among other things, an integrated circuit (IC) chip having transmitter, receiver, memory and control logic sections therein which together form an IC transceiver capable of being powered by either a small battery or by a capacitor charged from a remote RF source. The IC chip including the RF transmitter and receiver sections operates to provide for the RF signal transmission and reception to and from remote sources, and a thin film antenna is also constructed within the above small area. The above novel RFID system operates to receive, store, and transmit article-identifying data to and from the memory within the IC chip. This data is stored within the IC chip memory stage and may be subsequently called up and transmitted to an interrogating party at the above point of origin, points along a given shipment route, and then upon reaching a point of destination. This co-pending application is assigned to the present assignee and is incorporated herein by reference.
• The RFID device disclosed and claimed in my above identified co-pending application represents not only a fundamental breakthrough in the field of RF identification generally, but also represents significant specific advances over the prior art described in some detail in this co-pending application. This prior art includes relatively large hybrid electronic packages which have been affixed to railroad cars to reflect RF signals in order to monitor the location and movement of such cars. This prior art also includes smaller passive RFID packages which have been developed in the field of transportation and are operative for tracking automobiles. These reflective passive RFID packages operate by modulating the impedance of an antenna, but are generally inefficient in operation, require large amounts of power to operate, and have a limited data handling capability.
• The above mentioned prior art still further includes bar code identification devices and optical character recognition (OCR) devices which are well known in the art. However, these bar code identification and OCR devices require labor intensive operation and tend to be not only very expensive, but highly unreliable. However, all of the above mentioned prior art devices described in my above co-pending application are only remotely related to the present invention as will become more readily apparent in the following description thereof.
SUMMARY OF INVENTION
• The general purpose and principal object of the present invention is to provide still further new and useful improvements in the field of radio frequency identification (RFID) generally and improvements which are particularly adapted and well-suited for operation with electrically powered postage stamps and mailing labels. These new and useful improvements are made both with respect to the novel devices and processes described and claimed in my above identified co-pending application, and also with respect to all of the prior art described therein.
• To accomplish the above purpose and object, there have been developed both an electrically powered postage stamp and an electrically powered mailing label, each of which include, in combination, an integrated circuit chip having an RF transceiver constructed therein; a thin flat battery cell connected to the IC chip for providing power thereto; and a thin film RF antenna connected to the IC chip for transmitting data to and from the IC chip. All of the above components are connected in a very thin array and mounted between opposing major facing surfaces of either a postage stamp or a larger mailing or shipping label in a substantially two dimensional planar configuration. These components are operative to store data in the IC chip memory, which data includes such things as the destination address, return address, and descriptions of the contents of the article being mailed or shipped. These components are further operative in a novel system combination to transmit the stored data to an interrogating party upon receipt of RF interrogation signals transmitted to the stamp or label, or to receive data from same.
• Accordingly, it is another object of this invention to provide a new and improved RFID stamp or label of the type described which is uniquely constructed in an essentially two dimensional configuration which is easily scalable to the two dimensional major surface area of either a postage stamp or a mailing label.
• Another object of this invention is to provide a new and improved electronically powered stamp or label of the type described and process for making the stamp or label which employs certain novel, thin film fabrication techniques capable of producing device thicknesses on the order of a fraction of a millimeter. These thicknesses are typically within the range of one to five mils, thereby being extremely well suited and adapted for use with corresponding postage stamp or mailing label thickness dimensions.
• A further object of this invention is to provide a new and improved electronically powered postage stamp or mailing label of the type described including RFID integrated circuitry which is operatively powered by a flat and very thin battery and imparts a high and sophisticated degree of RF communication capability to these stamps or labels without significantly increasing the overall size and volume of the stamps or labels.
• The above brief summary of the invention, together with its various objects, novel features and attendant advantages, will become more readily apparent in the following description of the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
• FIG. 1 is an exploded perspective view of the electrically powered mailing or shipping label embodiment of the invention, including the novel radio frequency identification system mounted on the label base member. However, it should be understood that there is no basic functional difference in the label and stamp embodiments of the invention, and that the label cover and label base members shown inFIG. 1 apply equally as well to the smaller stamp cover or stamp base members which, for sake of brevity, have not been shown in the drawings.
• FIG. 2 is an enlarged perspective view of an RFID device and label or stamp package constructed in accordance with a preferred embodiment of the present invention.
• FIG. 3 is a plan view showing the conductive patterns on the base and cover members used inFIG. 2, including dotted line outlines for the locations of the IC chip and batteries which form theFIG. 2 structure.
• FIGS. 4A through 4D are cross sectional views taken along lines4-4 ofFIG. 3 showing the four (4) major processing steps which are used in constructing the RFID device and system array in accordance with a preferred process embodiment of the invention.
• FIG. 5 is a greatly enlarged perspective view of one suitable, very thin lithium/vanadium-oxide/copper battery or cell useful in the label and stamp embodiments and perspective views shown inFIGS. 1 and 2 above.
• FIG. 6 is a functional block diagram showing the major signal processing stages within the RFID integrated circuit chip described herein and shown inFIGS. 1 and 2 above. These major signal processing stages are also used within the interrogation unit (not shown) which is operative to interrogate the IC chip shown inFIGS. 1 and 2 above.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
• Referring now toFIG. 1, the electrically powered, RF operative label or stamp includes acover member10 and abase member12 upon which a radio frequency identification system has been constructed using thin film deposition techniques of the type described in my above identified co-pending application Ser. No. (71-579) filed Jun. 17, 1992. Functionally speaking, the RFID system14 will include one or more thinflat battery cells16 and18 which are connected in series as indicated byline20 and are both connected vialine22 to drive an integratedcircuit transceiver chip24. TheIC transceiver chip24 will preferably be connected to a dipole antenna consisting of thinfilm antenna strips26 and28, and thedipole antenna26 and28 is operative to both transmit RF signals from theIC chip24 to a controller and to receive incoming RF signals from an external RF source controller and operative to encode this data in IC chip memory in a manner more particularly described below with reference toFIG. 6. This data will typically include information on the article to which the label or stamp are affixed, such as an identification number, the sender's name, point of origin, weight, size, route, destination, and the like. In addition, the RFID system14 may be used to automatically RF communicate with postage meters and with automatic sorting machines to thereby completely eliminate the need for human intervention for such automatic sorting, thereby greatly reducing automatic mail sorting costs while simultaneously greatly increasing the speed and accuracy of the mail sorting process.
• The thinflat battery cells16 and18 can be made of various materials and typically include an anode, a collector, a cathode material, and a battery separator including a polymer and electrolytes of the type described below so as to not exceed a total battery thickness of 1 to 10 mils, while simultaneously being flexible and in some cases rechargeable. Furthermore, imminent commercialization of solid thin flat batteries having useful current levels at low temperatures makes the present invention commercially viable. Thus, since theIC chip24 can also be made of thicknesses of no greater than 8 mils and since the thin film metaldipole antenna strips26 and28 may be held to thicknesses less than 1 to 2 mils, it is seen that the total added thickness between the label cover andbase layers10 and12 will be negligible and not significantly affecting the bulk or the volume of the stamp or label into which the RFID system14 is incorporated.
• Referring now toFIG. 2, there is shown in a perspective view a preferred device embodiment of the present invention wherein the RFID tag includes abase support layer30 upon which an integratedcircuit chip32 is disposed on the near end of thelayer30 and connected to a dipole antenna consisting of a pair ofconductive strips34 and36 extending laterally from thechip32. Theseconductive strips34 and36 will typically be screen printed on the upper surface of thebase support layer30.
• A pair of rectangularly shapedbatteries38 and40 are positioned as shown adjacent to theIC chip32 and are also disposed on the upper surface of thebase support member30. The tworectangular batteries38 and40 are electrically connected in series to power theIC chip32 in a manner more particularly described below. The device or package shown inFIG. 2 is then completed by the folding over of an outer orupper cover member42 which is sealed to the exposed edge surface portions of thebase member30 to thereby provide an hermetically sealed and completed package. When thecover member42 is folded over on the base member, thecontact50 which is attached tobatteries38 and40 using conductive epoxy, provides the back side series electrical connection for the twobatteries38 and40. The integratedcircuit chip32 has transmitter, memory, control, logic, and receiver stages therein and is powered by the twobatteries38 and40 during the transmission and reception of data to and from an interrogator to provide the interrogator with the various above information and identification parameters concerning the article, animal or person to which the RFID tag is attached.
• Referring now toFIG. 3, there is shown a plan view of the geometry of thebase support member30 and thecover member42 which, during the initial manufacturing stage for the RFID device, are joined at an intersectingline44. The dipole antenna strips34 and36 are shown positioned on each side of theIC chip32, and the twoconductive strips46 and48 serve to connect the tops of thebatteries38 and40 into theIC chip32. Aconductive strip50 is provided on the upwardly facing inside surface of thetop cover42, so that when thecover42 is folded by 180.degree. at intersectingline44, its outer boundary52 is ready to be sealed with theouter boundary54 of thebase support member30. Simultaneously, theconductive strip50 bonded by the conductive epoxy to thebatteries38 and40, completes the series electrical connection used to connect the twobatteries38 and40 in series with each other and further in the series circuit with theintegrated circuit chip32 through the twoconductors46 and48.
• Referring now toFIGS. 4A through 4D taken at the4A-4D cross section indicated inFIG. 3,FIG. 4A shows in cross section view theIC chip32 bonded to thebase support member30 by means of a spot or button of conductive epoxy material56. Theconductive strip48 is shown in cross section on the upper surface of thebase support member30.
• Referring now toFIG. 4B, thebattery40 is aligned in place as indicated earlier inFIG. 2 and has the right hand end thereof bonded and connected to the upper surface of theconductive strip48 by means of a spot of conductive epoxy applied to the upper surface of theconductive strip48, but not numbered in this figure.
• Referring now toFIG. 4C, a stiffener material58 is applied as shown over the upper and side surfaces of theIC chip32, and the stiffener material will preferably be an insulating material such as “glob-top” epoxy to provide a desired degree of stiffness to the package and protection for the integrated circuit as completed.
• Next, a spot of conductive epoxy is applied to each end of theconductive strip50, and then thecover layer material42 with the conductive epoxy thereon is folded over onto the batteries38 (ofFIG. 2) and40 and thebase member30 to cure and heat seal and thus complete and seal the package in the configuration shown inFIG. 4D. This figure corresponds to the remainingstations22,24, and26 inFIG. 1.
• Referring now toFIG. 5, there is shown in a greatly enlarged perspective view a lithium/vanadium-oxide/copper battery including alithium anode60 as a top plate for the battery, an intermediate polymerized vanadium oxide electrolyte andseparator layer62 and acopper collector64. However, thelayer62 is not limited to the use of vanadium oxide (V₂O₅or V₆O₁₃), but may use other oxides such as magnesium oxide, MnO₂. Theintermediate layer62 is formed and polymerized on the upper surface of thecopper collector64 and may be obtained from outside manufacturers or vendors as a one piece sheet (62,64) and then assembled in house with lithium top anode sheets. Alternatively, the thin flat battery structure shown inFIG. 5 may be obtained as a completed battery cell from outside vendors or manufacturers. The thickness of these thin flat batteries will typically be in the range of 1 to 10 mils, and as previously indicated may be made as thin as a fraction of a mil. The components are assembled in an argon or other inert dry atmosphere using state of the art thin dry cell fabrication techniques. The use of conductive polymer layers as separators in thin flat battery cells is generally known in the art and is described, for example, in an article by M. G. Kanatzibis entitled “Conductive Polymers”, Chemical and Engineering News—American Chemical Society, Dec. 3, 1990, incorporated herein by reference.
• Referring now toFIG. 6, the rectangularouter boundary66 in this figure defines the active area on the integrated circuit chip (e.g.24 inFIG. 1) in which the novel integrated circuit transceiver has been formed using state of the art MOS planar processing techniques. These MOS planar processing techniques are well known in the art and are, therefore, not described in detail herein. Within the chipactive area66 there is provided anRF receiver stage68 and anRF transmitter stage70, both connected through a common line orconnection72 to an off-chip antenna74 of any planar type. A sleep/wake upcircuit76 is also connected vialine78 to theantenna74 and operates in response to signals received from theantenna74 to activate the necessary remaining circuitry and stages on theIC chip66 described below.
• Thereceiver68 is connected through aline80 to acontrol logic stage82, and afirst output line84 from thecontrol logic stage82 is connected as an input to thememory stage86. Areturn output line88 from thememory stage86 connects back to thecontrol logic stage82, and asecond output line90 from thecontrol logic stage82 connects as a second input to thetransmitter70 for providing memory or stored input data to thetransmitter70 via thecontrol logic stage82. In a data encoding operation, the data received concerning ID number, name, route, destination, size, weight, etc. is processed through thereceiver68 and through thecontrol logic stage82 and encoded into thememory stage86.
• As an example of a data call-up operation, when the RFID package in the above figures is placed on the outside surface of a piece luggage by the airlines or on a package for shipment by the postal service, either the airline agent or the postal worker will transmit information to thereceiver68 via an RF communication link concerning data such as the owner's name ID number, point of origin, weight, size, route, destination, and the like. This information received at thereceiver stage68 is then transmitted overline80 and through the appropriatecontrol logic stage82 which sorts this information out in a known manner and in turn transmits the data to be stored vialines84 into a bank ofmemory86. This data is stored here inmemory86 until such time that it is desired to call up the data at one or more points along the shipment route.
• For example, upon reaching a point of shipment destination, an interrogator may want to call up this data and use it at the point of destination for insuring that the item of shipment or luggage is most ensuredly and efficiently put in the hands of the desired recipient at the earliest possible time. Thus, an interrogator at the destination point will send interrogation signals to theRFID chip66 where they will be received at theantenna74 and first processed by a sleep/wake upcircuit76 which operates to bring theFIG. 6 circuitry out of the sleep mode and allow thereceiver stage68 to process this received data to thecontrol logic stage82 vialine80. At the same time, the requester will be operating an interrogation electronic unit having therein the same circuitry as that shown inFIG. 6, less the sleep/wake upcircuit76.
• With all stages in theFIG. 6 circuitry now awake, thememory stage86 will produce the above six pieces of information relating to the shipped article and generate this data online88 and back through thecontrol logic stage82 into thetransmitter70 so that thetransmitter70 can now transmit this data to the interrogator.
• The receiver andtransmitter sections68 and70 inFIG. 6 will preferably be operated in one of the well known spread spectrum (SS) modes using one of several available SS types of modulation which include: (1) direct sequence, (2) frequency hopping, (3) pulsed FM or chirped modulation, (4) time hopping, or time-frequency hopping used with pulse amplitude modulation, simple pulsed amplitude modulation or binary phase shift keying. The spread spectrum mode of operation per se is generally well known in the art and must conform to the frequency band separation requirements of the FCC Regulations, Part 15, incorporated herein by reference. The circuitry for the interrogation unit (not shown) will be similar to the functional system shown inFIG. 6 as will be understood by those skilled in the art, and therefore the interrogation unit will not be described herein.
• Various modifications may be made in and to the above described embodiment without departing from the spirit and scope of this invention. For example, various modifications and changes may be made in the antenna configurations, battery arrangements (such as battery stacking), device materials, device fabrication steps, and the system block diagram inFIG. 6 without departing from the scope of this invention. In addition, the various off chip components such as the antenna, battery, capacitor, and even inductors can be manufactured on-chip within the claims herein. In the case where RF charging is used, a battery will not be required. Accordingly, these and other constructional modifications are within the scope of the following appended claims.
• In addition, still other modifications may be made in and to the above described cell fabrication and device fabrication procedures without departing from the spirit and scope of this invention. For example, the present invention is not limited to the use of any particular types of thin flat battery cells or materials or cell fabrication processes, nor is it limited to the particular preferred fabrication technique for the RFID system as shown inFIGS. 2, 3, and4 above. Moreover, the present invention is not strictly limited to the use of radio frequency communication and may, in environments where RF signals are not allowed, be modified so that the IC chip transceiver is capable of communicating with light waves using certain state of the art electro-optical coupling techniques which are not described herein, but are clearly within the scope of the following appended claims.
• Finally, it will be understood and appreciated by those skilled in the art that the present invention also includes forming an optical detector on the IC chip as a means of receiving and detecting signals carried by light and also as a means of powering the RFID transceiver as an alternative to using a battery. Accordingly, these and other systems and constructional modifications are clearly within the scope of the broad claims filed herein.

Claims (11)

1-12. (canceled)

13. A process for manufacturing either a postage stamp or mailing or shipping label which is operative in either an RF signal or light signal communication mode which includes depositing one or more thin flat battery cells and an integrated circuit (IC) chip between base and cover members of said stamp or label and connecting said one or more of said thin flat battery cells to power said IC chip.

14. The process defined inclaim 13 wherein said cells and said IC chip are formed to thicknesses less than 30 mils.

15. The process defined inclaim 14 which includes constructing said IC chip as an RF transceiver and connecting a thin film antenna to said IC chip.

16. The process defined inclaim 15 wherein said base and cover members of said stamp or label are initially formed of one piece construction and are then folded one upon another after said cells, IC chip, and antenna have been deposited on one of said base or cover members.

17. The process defined inclaim 16 wherein said thin flat battery cells are constructed of lithium, polymerized vanadium-oxide, electrolyte, and copper.

18. The process defined inclaim 17 wherein said cell thickness is formed so as not to exceed a fraction of a mil.

19. The invention defined inclaim 18 which includes forming receiver, transmitter, control logic, and memory stages on said IC chip.

20. The invention defined inclaim 13 which includes forming an electro-optically light operated source on said IC chip as an alternative to RF communication.

21. The invention defined inclaim 13 which includes forming an optical detector on said IC chip as a means of receiving and detecting signals carried by light.

22. The invention defined inclaim 13 which includes forming an optical detector on said IC chip as a means of powering said RFID transceiver as an alternative to using a battery.

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