MX2007008690A - Multiple frequency detection system - Google Patents

Abstract

A multiple frequency detection system allows the seamless integration of an almost ideal EAS function with an RFID function. While not being limited to a particular theory, the preferred embodiments integrate EAS technology at, for example, 8.2MHz or 14MHz, and RFID technology at, for example, 13.56 MHz in a common antenna package. The use of standard RFID frequencies as forcing functions will allow for the easy packaging of EAS with RFID and have a true roadmap of a scalable technology.

Description

MULTIPLE FREQUENCY DETECTION SYSTEM DESCRIPTION OF THE INVENTION This invention relates to the electromagnetic field of radiofrequency (F) physics, and in particular, to the prevention of loss and security using radio frequency identification (RFID) and article surveillance technologies electronic (EAS). Current technology uses a high-frequency signal source of 8.2 MHz to create a magnetic field in bandwidth that is adequate to correlate the design tolerance of available targets that become resonant at a single frequency. The basic technology of detection and deactivation has been the same for almost two decades and has reached a worldwide standard. This technology is based on the need to sell a recurring consumable to the customer in the form of a target placed on the merchandise that can be detected by a security system in the perimeter of a protected area with a certain type of alarm that will notify the warehouse personnel if the target has not yet had its physical characteristics changed by a deactivated area, usually integrated in a point of sale (POS). The current technology makes use of a resonant lens of 8.2 MHz (+/- about 4%) that is disposable in the form of a label, or of an enclosure of plastic with certain types of reconnection methods in the merchandise. The disposable objective has the form of a paper type label and has a mechanism by which either the inductor or the capacitor can be disabled. The reusable objective has the form of a discrete purchased capacitor and a coil inductor manufactured without any method to alter any of these physical properties. Currently, there are two different methods to detect targets. Both methods operate by imposing a forced function in a frequency range on a closed-loop antenna structure to induce an almost magnetic field (H). This field hits the target's inductor when the target is close (for example, within a few meters (feet)) of the antenna structure. The impacted field causes a current to flow in the coil (inductor) which, when the field frequency impacted, and the resonant frequency of the objective approach each other, causes a considerable current / voltage oscillation (I / V) to establish on the objective. In the first and most widely used methodology for detecting targets, referred to as FM / AM or Sweep detection method, one door is used as an FM transmitter and another is used as an AM receiver. The FM transmitter is used in a continuous wave (CW) operation in such a way that the receiver sees the response forced and the natural of the objective. This method is inexpensive, is excellent for aisle widths from approximately one point two hundred nineteen meters (four feet) and uses little energy (eg, <100 xuV / m @ 30 m). The receiver detection system can be either based on logic or based on digital signal processing (DSP). The systems close to each other are controlled by RF or use a displacement sweep ratio (FM modulation) to avoid interference. The second methodology for detecting targets, referred to as pulse detection or "pulse listening" method, uses a pulse transmitter coupled with a homodyne AM receiver such as a pair of single gate transceivers. The transmitter offers a randomized uniform distribution of frequencies that transfer energy to the target. The AM receiver is placed on the door to operate quickly after the negative transition of the transmitter pulse. The duty cycle of the transmitter is less than about 10% with a peak radiated power of less than about 1000 μm / m @ 30m. The receiver only responds to the natural function and is exclusively a detection system based on digital signal processor (DSP). Systems physically close to each other (for example, closer than approximately 5 m) need to be synchronized with each other in order to avoid interference. Variations of the mask Transmitter pulse have a modulation level (eg, pulse) that is less than 100% to allow a continuous wave component (CW) to be generated. Unlike the energy dissipation increments, this variation has no effect on the system. A known deactivation system is very similar to that of the second type of sensor impulse transmitter. The method operates on one of three principles, either always active without any receiver; active at low power, detection and alarm, and high power switching; or active in high energy, and detection and alarm if it is not destroyed. The operating frequency band is the same as that of the sensors. The result of peak energy is less than about 1000 μ? / M @ 30 m. This is the current limit set by the Federal Communications Commission (FCC) and is approximately 8 dB less than the European Conformity (CE) limit in Europe. Deactivating the target is almost always immediate, depending on where the transmitter is operating in the frequency cycle. The interconnection with the POS system is provided through an interlock input which causes the transmitter to operate when a closer signal (optical or electrical) is received from the POS system. Various styles and antenna types can be integrated with the POS system either fixed (for example, at a counter) or portable (for example, pocket). The current technology has been installed in hundreds of thousands of various facilities around the world. Several issues have been recurrent with each of the technologies for the various functions (objectives, sensors and deactivators). First, it must be understood that the method of operation of the system is not a communication system as understood in the conventional sense. The system really is a field disturbance function that operates in an unauthorized and unregulated band (for interference) around the world. For example, in EAS systems of the RF type, a transmitter operates to generate power at a predetermined frequency which is transmitted through the transmitter antenna to establish an electromagnetic field within a surveillance zone. Typically, due to manufacturing tolerances within the security labels, the transmitters generate energy that is swept continuously up and down within a predetermined detection frequency range both above and below a selected center frequency in a ratio of Default sweep frequency. For example, if the desired center or label frequency that is transmitted is 8.2 MHz, the transmitter can continuously sweep up and down from approximately 7.5 MHz to 9.0 MHz at a rate of sweep frequency between 60-90 Hz. Several standard RF noise calculations, environmental models and system simulations can not be applied to predict the operation in the real world in an absolute sense. The best that can be achieved with these methods is the design functions of the general system. The current EAS technology limits itself in several areas. Performance is predicted in an "average" noise environment and is based on the most common target size and signal strength. The system, although highly adaptable and well filtered, is vulnerable to environmental resonances (door frames, ceiling cabling, etc.) and therefore in practice needs to have highly trained field service technicians to resolve these resonances. The reliability of the operation of the system and the quality of service (QoS) in the known EAS industry are unsatisfactory, generally because the systems are not operated in truly strong communication systems and functionality. RF has as its main concern the integrity of the alarm, and AM has target deactivation. Both of these problems contribute to causing the target purchases of customers to decline year after year, even when their volume of merchandise grows. A major improvement in the quality of the RF alarm integrity comes with US Patent No. ,510,769 for Kajfez, et al. (after this "Kajfez"), of which its contents are incorporated for reference in the present in its entirety. Kajfez describes an EAS system that detects labels that have two resonant frequencies critically coupled together. This provides a method for using the two critically coupled resonant circuits within the 7.5-9.0 MHz sweep passband of the EAS system. The Kajfez system requires a different relationship between the two resonant frequencies that create a known phase amplitude relationship between the tags. While a label in Kajfez improved the detection reliability of previous EAS systems, the Kajfez system has its limitations. First, any disturbance of the two signals destroys the system. That is, if one of the two signals of a label in Kajfez is not detected, the system does not recognize the label, which makes the system ineffective for its intended purpose. In this way, the system is not immune to localized effects of the label, such as, for example, being near the metal in shopping trolleys, etc. Second, the Kajfez label is formed by two resonant circuits that must be superimposed with a critical fabricated coupling between the two circuits. In other words, the Kajfez label is usually two EAS labels made and superimposed on each other, which greatly increases the cost of the goal. Third, Kajfez is limited to the operation with a sweep-only EAS system. That is, to get a response from a Kajfez tag, the EAS system must sweep through the tag. In other words, the Kajfez system must have a continuous signal that electromagnetically is not discontinuous, meaning that it is always active; and change the frequency and go through and explore through the label to get the answer. RFID technology is considered as a solution to the problems identified above; however, that probably will not prove true. First, the target prices are costs, and will probably remain that way for a predicted future due to the high relative cost of silicon and the wafer for the process of joining the target (for example, antenna). Second, EAS provides a perimeter, or pen-type function. While RFID can simulate this function, the corridor widths for high frequency RFID (HF) are typically too narrow to less than one meter using 2"x 2" size lenses, and for ultra high frequency (UHF) RFID systems they are too unreliable (for example, the de-tuning of the body and the driving structure and the orientation of the target towards the antenna) due to the physics of the RF medium used. Therefore, RFID alone still does not it is the salvation of EAS, since it has too many technical and financial limitations for the predictable future. The use of EAS (electronic article surveillance) tags and RFID (radio frequency identification) tags for a wide variety of reading, tracking and / or detection applications is spreading rapidly. A light connection between the existing functionality of EAS and RFID has been a consistent theme identified by users interested in RFID to allow them to obtain the benefits of RFID while maintaining their investment in EAS technology and its utility to protect lower cost objects in sale that can not justify the higher cost of RFID implementation. However, where identification tags are capable of receiving EAS and RFID frequencies, the conventional manner in which the return of respective RFID EAS signals from these tags is processed shows certain disadvantages or limitations. For example, the reader of these signals comprises an 8.2 MHz EAS transceiver and a 13.56 MHz RFID transceiver in the same packet that drives the separated antenna through the time domain that switches between the two frequencies. The interference between the two technologies is handled by traditional analog signal filtering techniques. By using such configuration without However, it is being questioned since it involves component redundancy (ie, duplication of transceiver components, duplication of antennas, etc.). In addition, the degree of filtration required for such a configuration is large (estimated at 100 dB) due to the very close proximity in frequency (less than 1 octave) and the relative signal amplitude differences admissible for the 2 transmission bands. In addition, the need for two antennas for this configuration results in a much larger structure (for example, approximately twice as much) as for any single deployed technology. Even with these techniques, performance is lower than for any terminology deployed alone. The identification tag used in this EAS and RFID configuration from the related art includes two circuits: an RFID circuit and an EAS circuit, which do not mesh and have nothing to do electromagnetically with each other. As noted above, the system uses time domain switching, by time division multiplexing (TD), between the RFID frequency and the EAS frequency to function as a system for both. However, when switching from one place to another between RFID and EAS, the system combined by definition may not provide as much processing as simple stand-alone RFID and EAS systems. Therefore, the Combined system is not complementary and will not operate as well as simple technology systems, at least because time switching has an equal probability of less individual processing. Traditionally, "pulse listening" methodologies (for example, transmission of a sequence of RF burst signals at different frequencies such that at least one of the frequency bursts falls near a resonant frequency of the RF tag). EAS) have been used in EAS but not in RFID technologies, because such an RFID chip requires a continuous signal emission from the reader to energize the IC of the RFID tag. It may be beneficial to provide a system and method that can simultaneously detect the EAS and RFID identification tag signals while avoiding the disadvantages discussed previously. DEFINITIONS AND ABBREVIATIONS There are a series of variables that can be measured to determine a detection threshold. These variables are measured in the security system or in the target, and can be decomposed into variables that are independent of the forced function and the geometric relationship for the antenna structure and in variables that are dependent. Some exemplary variables are described in the following and will be used for additional descriptions through the document FR: Resonant Frequency Q: TD Bandwidth: Signal duration (TD) in the AT detection zone: Amplitude or Signal Resistance of the TXSNR Objective: Signal to noise ratio of the detection environment TXPWR: Output power of the Transmitter Tss: Signal Strength of Objective Dv: Detection Volume DQ: Detection Quality Doveraii: General Detection Dth: Detection Threshold AT12: Relative Amplitude Differential of GTi2 Objective: Relative Phase Delay between Resonant Frequencies KRI2: Coupling Coefficient FR: Resonant Frequency: In general, FR is defined as the frequency where the electromagnetic impedance of the label is transformed from a positive imaginary value to a negative value by passing instantaneously through only a real value. More than one FR can be present in a system. FR is an independent variable as long as the mutual coupling is negligible between the target and the antenna of the sensor which is only of concern in rare circumstances. For disposable objectives, FR can also be affected by the proximity to conductive and dielectric materials (dependent on the design of the label). Typically, FR is reduced in proximity to these materials. Q: Bandwidth. Q is similar to FR. Q will be reduced (bandwidth will increase) with a direct dependence on Amplitude (A) that also decreases. The effects on bandwidth are usually in the form of bandwidth reduction (broadening) except in some specific physical cases when the target is in a particular (and unusual) proximity to a conductive surface, in some cases the Q signal it is supercharged (along with the signal amplitude). TD: Signal Duration (TD) in the detection zone.

This is a variable with a direct function of the movement through the area of the sensor (for example, door); since such is dependent on the type of function of the transmitter used and the size of the antenna structure. The function here is one of continuity over a minimum (and maximum) time period. AT: Amplitude or Signal Strength of Objective. The Ax function is based on the magnetic volume and Q of the target as well as the proximity of the target to the antenna structure. In a practical sense, the amplitude (AT) of a simple resonant tag can not be used as a single detection method because it is not an independent variable, but it is dependent on the transmission power and the relative position of the target towards the sensor door, therefore other variables must be taken into account directly or indirectly for the detection method. TXS R = The signal to noise ratio of the detection environment. The TXSNR is calculated for each system based on the transmitter output and the threshold level of the detection subsystem. This level establishes a base (for a given detection subsystem) of detection that changes as the environment changes. Depending on the detection method, a system (even a simple pedestal) can have multiple TXSNR values, one possible for each antenna / frequency that is using the gate. TXPWR: Transmitter output power. This value is normally established in the regulatory limit, however, in some cases this can not be optimal. For example, it may be preferable to increase the measure of how well the volume is served by the system by reducing the detection volume. Also, the volume is dependent on the objective signal strength of the targets in a given TXPWR. TSS: Target Signal Strength. TSS is an amount in the effective level of the peak signal that can return a given goal to a controlled setting. For example, current common disposable and reusable objectives have a Tss generally between 0.25 and 9.0 times the measurement of an 8.2 MHz EAS label of 1.5"by 1.5" reference standard. Detection is the key to any EAS system. Two main detection metrics will be discussed through this document. The detection volume (Dv) and the detection quality (DQ). These two metrics are paramount to the client's perception of how well the system works. Dv: Detection Volume, is a measure of how well the system detects a label anywhere in its intended detection zone. This can be measured in the classical method with the three normal carriers of a two-dimensional objective (frontal, plane and lateral) that is transferred through the detection volume in a predetermined matrix. To determine Dv, it is preferable to value the middle third of any aisle width to double the remaining two thirds. For example, for a corridor width of 1,829 meters (six feet), the center 0.61 meters (two feet) should be considered 67% of importance of the general reach. The assumption here is that it is easier to detect a target physically located near the elevator doors than in the middle part of the aisle and that the client will travel to through the central part more frequently. See Figure 1. Dv should preferably be evaluated at a specific noise level, related to a threshold level. This will give a performance prediction function (for a given goal / system combination) at a given level of TXSNR (as measured by the transmitter power control and the threshold level). DQ: Detection Quality, is a measure of how well the volume is served by the system. This measure captures the ability to reject inadvertent alarms when the system is tuned to the maximum Dv. This measure is a measure of stability as well as one in which the customer service engineer 'can judge the risk taken in a given Dv. DQ is measured by having a low Q resonance (less than 30-35) added as a transition target to the environment after the system is tuned and tested at maximum Dv. Again, the evaluation of this must be done at a specific noise level, related to the threshold level of the detection subsystem. DOVERALL: General Detection, is dependent on the two previous variables (Dv and DQ) and provides a value profile and a confidence factor to determine that the stability and functionality of a given system is functioning within the objective and environment as follows: DQVERALL = DQ (TXPWRI DTH, TSS) * DV (TXPWR, DTH, TSS) This detection method can also be used, with some minor modification, for RFID-type systems. The resonance can be used to evaluate the system for interference. In addition, a limit RFID target (detection volume) can be useful for determining the overall functionality of the system in a multi-antenna configuration. The FM / AM (or sweep) detection method detects the forced function and natural function of the target at the exact resonance frequency of the target. This system uses several detection variables, but all are based on detecting the classic subject "S" in the envelope of the FM wave. The leading "projection" is the absorption of energy from the field; the back is the release of energy. Both the resonant frequency FR and the bandwidth Q of the target are measured with this method. Typical modulation functions are a combination of "bucket brigade" filters (eg, analog or digital) and moving average digital filtering (MAV). Because the transmitter has a finite signal-to-noise ratio (TXSN) that is important, especially near the carrier frequency due to phase noise, this FM / AM detection method has a finite base limit in terms of widths of aisle that can be achieved between doors. This limit is inherent in the nature of any active carrier. Also, the F / AM detection systems have an inclination to false alarms induced by noise, because the forced function of the transmitter is always operating. This detection method is not limited to the corridor distance of the TXSNR base effect. It also allows the use of a single pedestal as a transceiver. The pulse detection method uses only the natural function of the target for alarm detection. The detection threshold is usually calculated as the "edge bands" of the sinusoidal FM modulation signal (typically about 7.4 and 9.0 MHz for a classical "sweep" system). Noise is also measured in the presence of the forced function. In fact, noise is measured when the transmitter is not enabled and on the carrier frequency that will be used as the forced function immediately afterwards. This is an advantage in several areas for the quality of detection and volume. The system is extremely immune to external noise that causes false alarms. This is because the noise function and the signal detection function are separated and are random in frame period time to frame period. The preferred embodiments of the present invention specifically refer to a new generation of technologies that will allow the continuous integration of a EAS function almost ideal with an RFID function. While not limited to a particular theory, the preferred embodiments integrate EAS technology into, for example, 8.12 MHz and RFID technology in, for example, 13.56 MHz in a common antenna package. The use of standard RFID frequencies will allow the joint submission phase of EAS with RFID and have a true indicative guidance of a scalable technology. Preferred embodiments of the present invention relate specifically to the fields of security, marketing and retail. Other embodiments of the present invention may be applied to applications that include storage and distribution systems, manufacturing floor environments, people accounting systems, product authenticity systems, supply chain diversion systems, and tamper detection systems. Preferred embodiments include general system design, detection mechanisms, function objective design, and integration to other systems (e.g., RFID). In the end, the need to keep human exposure to near-magnetic field radiation low will become an important issue in the not-so-distant future. The effects of the human central nervous system as well as implantable medical devices will drive a need social towards lower energy, common systems. Preferred embodiments direct this in a number of ways as will be described in greater detail in the following. In accordance with preferred embodiments, the invention includes a multiple frequency detection system having a reader and a resonant tag. The reader emits a pulse interrogation signal at a first frequency. The resonant tag receives the pulse interrogation signal at the first frequency and responds to the pulse interrogation signal by transmitting a first response signal resonating at the first frequency. The resonant tag further transmits a second response signal resonated at a second offset frequency of the first frequency. The reader reads one of the first and second response signals, and optionally reads the other of the first and second response signals to detect the resonant tag. According to preferred embodiments, the invention also includes a multiple frequency band tag having first and second resonant circuits. The first resonant circuit includes a first inductor coil and a first capacitor and is tuned to a resonant frequency in a first frequency band. The second resonant circuit is electromagnetically coupled to the first resonant circuit, and includes a second inductor coil and a second capacitor. The second resonant circuit is tuned to a resonant frequency in a second frequency band displaced from the first frequency band. The tag is adapted to respond to a continuous interrogation signal and a discontinuous interrogation signal. According to preferred embodiments, the invention further includes a method for detecting a resonant tag having a first resonant circuit that is tuned to resonate a first response signal at a first frequency and having a second resonant circuit that is tuned to resonate second response signal at a second offset frequency of the first frequency. The method includes: providing a pulse signal to form an interrogation signal, emitting the interrogation signal to collide on the resonant tag, transmitting the first response signal of the first resonant circuit by resonating at the first frequency in response to the signal of interrogation, transmit the second response signal of the second resonant circuit when resonating at the second frequency, read one of the first and second response signals, and optionally read the other of the first and second response signals to detect the tag resonant In accordance with the preferred modalities, the invention further includes a multiple frequency detection system for detecting a resonant tag having a first resonant circuit that is tuned to resonate a first response signal at a first frequency and having a second resonant circuit that is tuned to resonate a second signal of response on a second offset frequency of the first frequency. The system includes: means for providing an impulse signal to form an interrogation signal, means for emitting the interrogation signal for colliding with the resonant tag, means for transmitting the first response signal from the first resonant circuit by resonating in the first frequency in response to the interrogation signal, means for transmitting the second response signal of the second resonant circuit when resonating the second frequency, and means for reading one of the first and second response signals, and optionally reading the other the first and second response signals to detect the resonant tag. The additional scope of the applicability of the present invention will become apparent from the detailed description given thereafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, and that The invention is not limited to the precise arrangements and instrumentalities shown, since the invention will become apparent to those skilled in the art from this detailed description. BRIEF DESCRIPTION OF THE DRAWINGS The following detailed description of the preferred embodiments of the invention will be better understood when read together with the following drawings, in which like reference numbers designate similar elements and where: Figure 1 shows a percentage of response of typical EAS systems over a width of 1,829 meters (six feet) wide; Figure 2 shows an exemplary spectrum of the transmitter output; Figure 3 shows an exemplary spectrum of the transmitter output for displaced targets, - Figure 4 shows another exemplary spectrum of the transmitter output for displaced targets; Figure 5 shows yet another exemplary spectrum of the transmitter output for displaced targets; Figure 6 is a circuit diagram of an exemplary multifrequency tag according to the preferred embodiments; Figure 7 is an output viewer that shows the double resonant frequencies for a label having circuitry as illustrated in Figure 6; Figure 8 is a circuit diagram of another exemplary multifrequency tag according to the preferred embodiments; Figure 9 shows a simulated transient response to show a descending ring of a label having circuitry as illustrated in Figure 8; Figure 10 illustrates the results of a fast Fourier transform showing the double frequency components of the label's descending ring having circuitry as illustrated in Figure 8; Figure 11 shows an exemplary measurement of a residual RF field once a 13.56 MHz signal is closed; Figure 12 shows an exemplary measurement of residual RF field; Figure 13 shows a transformed Fourier waveform showing the peaks in two different frequency bands; Figure 14 is an exemplary system block diagram according to the preferred embodiments; Figure 15 is an exemplary architecture diagram of a software application layer according to the preferred embodiments; Figure 16 is an exemplary software command and functional diagram according to the preferred embodiments; Figure 17 is a circuit diagram of an exemplary multi-frequency EAS tag according to the preferred embodiments; Figure 18 is a circuit diagram of an exemplary multifrequency EAS and RFID tag according to the preferred embodiments; and Figure 19 is a circuit diagram of another exemplary multifrequency EAS and RFID tag according to preferred embodiments. While not limited to a particular theory, the present invention is described in a system that preferably uses HF type technologies; no UHF. The reason is double. The first is that UHF technologies are easily corrupted by proximity to conductive objects (ie, shielding and de-tuning the body). The second is that the UHF frequencies are still globally harmonized and probably will not be in the near future. While UHF technologies are not preferred, it is understood that the scope of the invention is not limited to HF type technologies and in fact includes UHF technologies. The preferred displaced target uses the Industrial, Scientific and Medical (ISM) band of HF of 13.56 MHz and as a carrier. This carrier could be used with existing RFI systems or alone. The displaced objective of preference is a type of simple resonator which is tuned to a frequency higher or lower than the bandwidth of the carrier. The detection is of the type of impulse that measures the descending ring (exponent) of the envelope of the objective and the signal Q of bandwidth. Deactivation takes place, preferably by a cavity or fuse type structure and a strong overload of a 13.56 MHz signal source. Obviously, this could also be used with other frequencies such as the ISM band of 27.12 MHz. The preference detection methods measure the shifted frequency of the target to ensure that a specific EAS target was measured and not an RFID target. This can be especially important in highly mixed technology environments. The difficulty here is to ensure that the displacement is sufficient to limit the false alarms of the high tuning RFID targets, although it is not high enough to limit the transfer of power to the target. The bandwidth of the ISM band of 13.56 MHz is approximately +/- 7 KHz with an output power of approximately 15,000 uV / m. This important power is sufficient to solve the detection concerns while a certain type of label antidesactivation method as known to one of skill in the art is employee The objective cost and manufacturing capacity of the objective is similar to that of the current EAS production lines. Laser cutting or some other precise frequency control method may be required depending on the process method used. Figure 2 depicts a transmitter output spectrum at approximately 13.56 MHz that shows exemplary results to interrogate a preferred target (eg, labels) "in frequency" within an EAS system using a "zero offset" method. This method provides the benefit of maximizing the transfer of energy to the target. However, any RFID target on that frequency can also alarm the system. The "zero offset" solves this preoccupation of false alarm when activating the alarm; not only in the Frequency and Q, but also in the absence of a response signal (data) of an objective. An alternative to the null shift method is a fixed displacement method. This method provides the advantage of reduced concern to false claims due to RFID objectives. However, the system becomes sensitive to changes in the center frequency. Sensitivity for detection is proportional to the Q of target bandwidth. The higher the Q, the more damaging the response, as shown by the transmitter output spectra of the displaced targets in Figures 3 and 4. With the initial review, the displacement method responses may indicate that a Q target of lower bandwidth can perform better for a energy transfer. However, the target signal strength (TSs) is proportional to the magnetic cross-sectional area and the Q of bandwidth. Therefore, for a given size goal, maximizing Q will maximize TSs · In the detection systems discussed here, there are traditionally concerns about the installation of resonant objects and noise sources (for environmental and co-localized systems). In this way it is beneficial to provide a strong frequency control and Q of bandwidth for the target and corresponding detection methods for both. However, since smaller labels become more prevalent, which is the trend, Q of bandwidth becomes a less controllable factor in the detection of the system. The resonances of the merchandise are aggravated by an increase in transmitter power. In fact, the resonance of the merchandise and other objects can be significantly worse at 13.56 MHz than at 8.12 MHz due to the shorter wavelength involved in the higher frequency. These resonances can be minimized with a Qualification of measure Q of bandwidth, as can be easily understood by someone of experience in the art. The detection volume (Dv) is improved over the current detection systems due to at least an increase of about 23 dB in the peak output power together with a relatively narrow band of detection of the target controlled FR. This increase is managed to perform two activities: to increase DQ under non-inductively coupled noise environments, and to decrease the target package area (with a corresponding decrease in AT and Q). Slavery between the 13.56 MHz and 8.2 MHz detection systems is available since the detection systems are preferably operated on a common single frequency. All transmitter pulses must be at a single frequency and since the FR objective is significantly shifted, cross-system crosstalk is minimal. As noted above, it is understood that the preferred modalities are not limited to a single frequency of 13.56 MHz. For example, an alternative frequency of 27.12 MHz could also be used with slightly lower TXPWR from a regulatory perspective. The inherent benefit of using a system according to preferred embodiments is that only one simple processor controlled transmitter and antenna structure functions for both EAS and RFID objectives, especially with some filtering and an analog receiver for the EAS portion. Filtering for EAS objectives is probably different from filtering for the RFID receiver, but obviously a shared section of DSP can be used. In a similar way, other alternative frequencies could be used for air protocol and RF processing. While not limited to a particular theory, preferential deactivation can take place with a higher power POS system. An interesting note for this system is the transparent detection of the EAS objectives when using the impulse profile of the RFID detection system as the energy sources. This system adds little to no overhead over an RFID design other than a receiver. An exemplary energy budget for a shifted frequency method is shown in the following in Figure 5. This energy budget is based on a tuned ready target and the maximum regulatory limit power output of the 13.56 MHz transmitter. The following equation shows the energy budget equation for a detection system (assuming constant performance algorithms). For this example, Tss is the reference of OdB for a first objective and + 6dB for an automatic application objective. TXPWR is OdB for a reference system of 8.2 MHz and +23 dB for a reference system in the limit of 13.56 MHz. T0FFMAX is based on the possible power transfer of the worst case, for a "frequency" system , which is from OdB.

In the spectrum of the transmitter output shown in Figure 5, T0FFMAX is 13 dB. This provides a DI budget power detection system of 23 dB + 0 dB-13 dB = + 10 dB. This method of the preferred embodiments provides a further and distinct advantage for systems using standard size lenses and smaller lenses. For example, a lens with a size of 2.54 centimeters x 2.54 centimeters (1 inch x 1 inch) could be used instead of a standard 3.81 cm x 3.81 cm (1.5"x 1.5") lens. The preferred objectives are FR objectives of I double resonant frequency that makes resonance in two specific FR bands (for example, FR1 and FR2). The advantage of this system is that the detection quality (DQ) of the system increases without penalty for the detection volume (DV) because the system becomes impenetrable to environmental resonances and inadvertent deactivation due to high energy detection systems of transmitter.

While not limited to a particular theory, one of the frequencies of this system is "carrier" and is preferably used to maximize the transfer of energy to the target. The secondary frequency is selected for system convenience and operational functionality. Most of the examples described herein use a primary resonant frequency (FRi) of 13.56 MHz. The secondary frequency (FR2) is selected to maximize the functionality, DQ and Dv while keeping the cost of the target and the system at a minimum. There are many benefits to this method. It has been found that the integrity of the system alarm is significantly increased by a large factor due to the addition of the coupling coefficient (KR12) between FRi and FR2. A coupling coefficient mechanism KR12 decouples the energy transfer in the target from the partial signal return, as is easily understood by someone skilled in the art. This decoupling means that environmental resonances that are present in FR1 can be ignored, even if they are in motion (as in doors or merchandise that is carried through the system). The receiver preferably detects the presence of FRi as a gate mechanism that can be correlated with the received FR2 to confirm the presence of an EAS target. The communication force of the system increases dramatically by several measurable factors. As mentioned previously, the probability of an environmental resonance with a similar KRi2 is probably high. In addition, there are several variables related to FR2 that provide additional qualification, for example, the frequency of FR2 and Q (Q2). Not so apparent is the differential of relative amplitude between the amplitude of the objective in the two frequencies (for example, AT1 and AT2), after that referred to as AT12, which will always scale the same regardless of the geometric location of the target towards the antenna of sensor. The other variable is the relative phase delay between FRi and FR2, after which referred to as GT12 / which can be measured as a differential between the two envelopes of exponential decay. Of course, the system includes a computer that determines the variables discussed in the present based on the response signals of the objectives. It should be specifically noted that the environmental resonances at FR2 will not be detected by this system, because the secondary frequency FR2 is preferably far enough away in the frequency domain to not be charged by the transmitter power pulse. This makes this system inherently self-installable and very stable in terms of Dv and DQ. The addition of the measurement of KR12, FR2, Q2 and GT12, gives the preferred modalities a quality impressive detection (DQ) over that of the current systems. In empirical terms, each additional variable must at least be half of the number of possible mechanisms to distort the system. In this case there are actually three independent new variables that can be measured, FR2, Q2 and GT12. As long as it is not limited to a particular theory, a target designated according to the preferred modalities could be deactivated in any of the primary or secondary resonances, depending on the regulatory capacity to emit. This is another reason for the preferred secondary frequency FR2, for example, to be approximately 8.2 MHz or 27.2 MHz. The obvious advantage of having it at 8.2 MHz may be the ability to use known equipment that currently exists on the market. The basis of this technology from a detection point of view is similar to current detection systems, but it is scaled for two simultaneous resonances. Detection according to the preferred embodiments may include the additional complexity of calculating the GTi2 variable which is easily performed on the captured data. Another benefit of the preferred modes is that the procedure moves away from false alarms possible due to the presence of RFID 13.56 MHz targets. In addition, no slavery or other synchronization between detection systems because the received signal is significantly different from the transmission frequency. With reference to the preferred objectives, the coupling between the two resonant frequencies in the targets needs to be quite good (> 0.9) in order to facilitate the energy that is transferred to FR2. The mechanism for energy transfer is in the form of the fundamental carrier's degree response (FR1) which acts to "produce a sound" FR2 and cause it to oscillate. The amplitude of this oscillation is substantially lower than the amplitude of the forced function (probably around 10-15 dB). However, this lower amplitude is mitigated by the increase in effective power of approximately +23 dB for an effective signal increase of approximately 8-13 dB. This can be further improved (approximately 6dB) by correlating the variables between the primary and secondary resonances. Another benefit of the preferred modalities is the easy adaptation to standard RFID objectives. The basic RFID target only needs to have this secondary resonance added to it (Figures 18 and 19) to return to an available perimeter EAS detection system. Perimeter detection of RFID targets, even those that only transmit a "bit" of EAS, have maximum aisle widths of no more than 1,219 meters (4 feet). With the Preferred modalities, the REID objective achieves improved EAS functionality in terms of reliability (DQ) and volume (Dv). A re-activatable target can be created according to the preferred embodiments through the use of a cavity that can be reopened by a very strong FR1 signal. In a preferred target, the cavity is restricted to a preferred area that carries a significant amount of primary FR1 circulation current, thereby causing an opening of the cavity at a specific power level. As mentioned previously, the preferred embodiments of this architecture are described using the ISM frequency band of 13.56 MHz. With respect to the double resonant frequency technology, the 13.56 MHz ISM coupling and broadly the standard auxiliary bands (ie 8.2 MHz) is considered beneficial. However, it should be mentioned that 27.12 MHz and higher bands are available for use as well. The basic issue with going well beyond 13.56 MHz for a power transfer frequency is in the areas of the transmitter and antenna design. For example, two known methods for the design of the transmitter power amplifier are a switching power supply and an RF amplifier. Using a switching power supply allows a generation of transmitter current much higher and more efficient as well as a component use at a lower cost (for example, power MOSFET as opposed to RF FET). This also allows for an energy dispersion of efficient driving impulse and rapid evolution of receiver at times. However, since the systems are switched to higher frequencies, the philosophy of the more traditional RF amplifier design becomes beneficial. The components become easier and more efficient for the design and classic RF engineering methods as the frequency rises. The preferred antenna design is linked to the transmitter design type and requires that the self-resonance point of the antenna be higher than the transmitter carrier frequency in order to make an efficient current carrier. Current designs are already running close to the predictable limit at 13.56 MHz and very few designs have self-resonance points in the 20 MHz range. Another method of the preferred embodiments includes the use of multiple secondary detection bands. For example, one secondary band could be used for generic perimeter EAS, while another can work on books, another on DVD / CD. Here this main area may be that the targets could have a primary long-range perimeter detection (relative to other HF systems) and a classification system that is independent of any RFID function that may exist. The preferred modalities provide EAS integration, as a long-term, highly reliable, low-cost function with RFID, as a short-term, highly reliable, higher-cost function. When an RFID target is read, the reliability in terms of false alarms rises extremely. However, the quality of the readings has several limitations due to the RF physics involved. RF RF of 13.56 Hz has two main limitations: reading distance and target acquisition speed in the detection field. The distance, in terms of Dv, refers to the size of a target, the power consumption of the integrated circuit, the design / size of the sensor antenna, and the regulatory emission and exposure limits. All these variables are disputed as RFID moves to the level of the article with the most severe impacts being of the size of the target that becomes smaller and the strict limits on the health and safety impact of human exposure. The 900 MHz UHF RFID also has two distinct limitations: read readability and read distance. The limitations in reading reliability are due to the nature of the electromagnetic properties of the frequency band that is used. The UHF band (and higher bands too) offer excellent properties of the communication system "line of site" (LoS); however, direct line (LOS) communications are also easily interrupted or disrupted by almost any conductive object placed in or near the sensing antenna sensing area. This makes it likely that objectives that need to be detected at any specific point (for example, the perimeter of a warehouse for security reasons) will not be reliable and will in fact be easily fooled. This disturbance effect is also linked to the question of reading distance. The UHF signals, unlike the HF signals, really are a fully formed electromagnetic propagation wave (EM), (HF in fact is still only a magnetic H-flow field) that has the tendency to "ask for a lift" in long drivers and effectively and dramatically increases the detection volume, causing targets to be read at greater distances and causes problems with understanding where exactly the target is. The problem of the extension of reading distance with the UHF signals can be addressed, since it is possible to measure the time of rebound of a question to the objective / response of the objective, which effectively measures the physical distance traveled. The problem is the precision of the measurement since the units of measurement are probably in terms of nano (10 ~ 9) and peak (10 ~ 12) seconds that may not be possible or cost effective given the environmental concerns. By consequently, in view of these limitations, HF physics is preferred when an objective must be specifically identified within a geographically restricted region. This discussion of item level perimeter integration with EAS and RFID technology leads to RFID integration of pallets and boxes. UHF is used as a standard so far in this application due to the apparent benefits of Dv and DQ. However, these benefits are only valid under highly controlled environments. Higher HF objectives (same size as UHF objectives) work at the same level as UHF in both Dv and DQ measurements. In fact, it is likely that HF has better metrics across a wider variety of environments than UHF. In addition, lenses without IC, for a given frequency and sensor antenna design (as well as other parameters that are the same) have a significant advantage in terms of detection volume (Dv). With the proper design of the objective and the communication methodology, the quality of detection (DQ) is equivalent to that of an RFID system. This is valid for any given frequency band used mainly due to the fact that IC does not need to be energized. By using the 13.56 MHz transmission field for RFID and EAS functionality, almost all issues, from the detection volume to the detection quality, they can be handled more easily from a developer, client and integrator perspective. The specific air interface can be either multiplexed by time division (TDM) or superimposed on the RFID read pulses. Detection methods will vary, but a multi-resonant lens has a dramatically improved performance over one of a single resonance. Since objective design and manufacturing is important for the success of any of the aforementioned methods, the requirements and risks involved in the development of each objective are discussed in the following. In any case of the function of the transmitter, or the forced function, the objective will respond with its natural function. It is possible to detect the phase change of the forced function as it is imposed on the target. This phase change is the delay in the energy received back to the antenna from the target on the frequency of the transmitter and the shape of the pulse. In practical terms, this delay is in the order of peak (10 ~ 12) to femto (10 ~ 15) seconds and is difficult to measure. However, for an RFID solution, this delay time can be measured (for example, as a variation of time domain reflectometry (TDR) which is a widely known practice in RF design) when it is in order of micro (10 ~ 6) seconds or a reasonable fraction thereof. This measure is useful to suggest a method to determine if UHF or microwave RFID tags are physically in close proximity to the transceiver antenna. The objective function is best described when the forced function is removed. This can leave only the natural function. The coupling of this to a traditional frequency label is well known. A basic multi-frequency target includes an EAS tag that resonates at one or more other frequencies, and thus also distinguishes the electronic signature of the merchandise target from the store during Pulse Listener detection. In addition, the preferred target includes a form of analog RFID, where different combinations of frequencies can indicate individual serial numbers. Once fabricated, the tag is stimulated at an RF frequency, and then measured for the "natural descending ring" at the two resonant frequencies (or more). While not limited to a particular theory, the preferred label has optimal performance when it is excited at 13.56 MHz, thus taking advantage of the less stringent FCC / CE regulations when operating in ISM bands. An exemplary multi-frequency label is shows schematically in Figure 6. The multi-frequency tag 10 includes a double frequency resonant circuit 12 having two LC circuits 13 and 17. Each LC circuit has a capacitor and an inductor, and such a capacitor 14 (Ci) with an inductor 16 (Lx) forms the first LC circuit 13, and a capacitor 18 (C2) with an inductor 20 (L2) form the second LC circuit 17. The first and second LC circuits 13 and 17 are preferably coupled together in a single plane, but the label is not limited thereto since the planar relationship between the first and second LC circuits is not critical. While not limited to a particular theory, the resonant circuit 12 essentially includes at least one inductor-capacitor (LC) resonant series lead (e.g., the second LC circuit 17) in parallel with a parallel LC circuit (e.g. , the first LC circuit 13). Component values in the capacitors and inductors are preferably selected such that the tag resonates at 8.2 MHz and 13.56 MHz. If desired, the tag 10 can be multiplied to include additional resonant frequencies by adding capacitors and inductors (eg, the capacitor C3 and inductor L3 for resonant frequency FR3, capacitor C4 and inductor L4 for resonant frequency FR4, etc.) it is within the scope of the invention to use printed circuit substrate technology to form label 10. However, a multi-frequency tag 10 could also be formed from known alternative structures, such as discrete inductors and capacitors attached to a cardboard base. In order to integrate the RFID technology, an IC is coupled with the capacitor 14 (Cx) and the inductor 16 (Ll) and provides its ID when it is energized in a detection zone. The capacitor 14 (Ci) and the inductor 16 (Lx) provide the power for the multi-frequency tag 10, and when coupled to another resonant frequency on the tag (eg FR2, FR3, FR3) it provides its symbol of signature . The signature symbol is much faster to respond to a question mark and in response to a distance greater than the IC. Other exemplary multi-frequency tags that incorporate RFID technology are discussed in more detail in the following. As one skilled in the art can readily understand, the design process of the tag 10 requires a reasonable estimate of magnetic coupling between the two inductors 16, 20. Several inductors were wound and tested to establish this coupling factor. The component values of the resonant circuit 12 were selected by considering the effects of this magnetic coupling, and were measured for resonant frequency using an Agilent 8712ET Network Analyzer.

As illustrated in Figure 7, an exemplary label 10 formed with discrete inductors 16, 20 and resonant capacitors 14,18 at approximately 8,003 MHz and approximately 13,562 MHz. Figure 8 depicts a circuit diagram of another multi-frequency label 30. according to the preferred embodiments. The label 30 includes inductors 32, 34 and capacitors 33, 35 which are similar in function to the inductors 20, 16 and capacitors 18, 14 shown in Figure 6. In particular, the inductor 34 and the capacitor 35 form a first circuit of LC having a first resonant frequency, and inductor 32 and capacitor 33 form a second LC circuit having a second resonant frequency. The inductors 32, 34 are modeled as the transformer TX2, to explain the magnetic coupling. The label 30 also includes resistors 36 (Rlow) and 38 (Rhi) that estimate the resistance losses in the inductor wires. The center of the schematic part of the label 30 shows a transformer 40 (TX1) having a pair of inductors and resistors 42 (R6) and 44 (R7), which explain the coupling of the RF energy of the source antenna in the label 30. The label 30 also includes a voltage source 46 (V3) as the voltage source that drives the source antenna. A switch 48 (Ul) opens intermittently at 5 μ sec. to mimic RF with momentum.

Figure 9 shows a transient response that was simulated to search for the "descending ring" of the tag 30 once the switch 48 (Ul) is opened on 5 / iseg. Two distinct sinusoidal components are visible during the exponential descending ring. Figure 10 illustrates the results of a Fast Fourier Transform (FFT) that shows the spectral content. The FFT clearly shows the 8.0 and 13.56 MHz components of the descending ring at peaks 50, 52, respectively. Figures 11-13 illustrate laboratory measurements showing the two frequencies of the descending ring. As a baseline, Figure 11 shows a measure of the residual RF field once the transmitted signal of 13.56 MHz is closed. The measurement, taken by an oscilloscope and probe, shows a rapid transmitter drop, but not the descending ring of the transmitter. the label. An exemplary muiti-frequency tag according to the preferred embodiments was placed in the vicinity of the antenna, and the RF field was again measured with the oscilloscope and the probe. Figure 12 shows the measurement of the residual RF field that has a fast transmitter drop, but with an important tag descending ring at approximately 8.0 and 13.56 MHz. This waveform was transformed into the frequency domain by using the characteristic of FFT on an oscilloscope. The waveform transformed is shown in Figure 13, where obvious peaks are evident at approximately 8.0 and 13.56 MHz. The multi-frequency labels of the preferred embodiments can be manufactured with existing processes, and have a unique electronic signature when compared to warehouse merchandise. Modified algorithms detect the presence of the preferred spectral content of the multi-frequency labels, thereby improving the integrity of the alarm. Detection is improved by hardware modifications in existing transceiver technology, for example, that allow transmission at approximately 13.56 MHz and detection at approximately 8.0 to 8.2 HMz. Figures 14-16 are shown according to the preferred embodiments. In particular, Figure 14 represents a block diagram of the system showing the functional implementation of a sensor / POS device; Figure 15 represents a software architecture diagram of a software application layer; and Figure 16 represents a software command and functional diagram showing the software workflow. The block diagram of the system of Figure 14 shows the review of the implemented functional areas of the preferred detection system. This detection system will also allow any implementation of a system of EAS The limitation is only in the frequency band of the amplifiers and the output filtering characteristics. The direct digital synthesizer allows a flexible multi-band operation, modulation, DS and FH propagation spectrum, etc. The central design of the bandpass filter and the baseband demodulation is the central principle, its entire command set, and the memory handling which is also an internal part of the DSP system. With respect to the high efficiency Class C, D or E Amplifier, the class that is used depends on the linearity, spectral purity and modulation modes, as is well understood by someone skilled in the art. The FPGA allows flexible 10 and integrated uC for higher level application integration. The software application layer diagram in Figure 15 details the command flow and application of the system in terms of (top application and communication layer) to the physical RF interfaces (eg, 8.2 MHz, 13.56). MHz, 27.12 MHz, 58 kHz, etc.). The unique properties of this system allow integration and expansion in almost any RF communication device, including alternative EAS devices and even RFID. The software command and the functional diagram in Figure 16 illustrate the workflows of the physical software implementation of the desired architecture previous. This block diagram of the system represents a preferred embodiment, for example, when the multiple frequency detection system is monitoring tags having two frequencies that are not reasonably close to each other and are still sufficiently excited by a single frequency interrogation signal . An exemplary system monitors labels that have frequencies at 8.2 MHz and 13.56 MHz. It is understood that particular frequencies are being used for ease of discussion and the scope of this example and the invention is not limited to these specific frequencies. In this situation, it is preferred to simultaneously excite the 8.2 MHz and 13.56 MHz signals. With reference to the system shown in Figures 14-16, a software defined procedure is illustrated so that even the transmitter and receiver are fully programmable. When the frequencies are modulated at the same time, the resulting signal has a very complex waveform that is very difficult to correlate from an analogous point of view. It can be an extremely complicated circuit. A preferred circuit includes a broadband amplifier that transmits and passes both signals. The intermodulation distortion can be corrected by predistortion correction or software before transmission, as is easily understood by someone skilled in the art. This linearity of amplifiers requires processors digital signals (DSP) fast enough to be able to do this. Such fast DSPs are known. Accordingly, the preferred system can transmit an interrogation signal on both frequencies at the same time without the signals breaking each other. A software receiver actually receives and digitizes the broadband signal. Then, through the software (or hardware that imitates the software), the receiver allows the system to receive both answering signatures that return. Accordingly, the multiple frequency detection system according to the preferred embodiments may include a 13.56 MHz continuous wave (CW) system that communicates with the RFID tags, and simultaneously drives a 8.2 MHz system to see the response of the combined signature of the objective, which resonates on both frequencies. Figures 17-19 show exemplary circuit diagrams of three variants of the multi-frequency labels according to the preferred embodiments. In particular, each of the circuit diagrams illustrates double frequency labels. Additional frequencies can be added to the tags, for example, by coupling additional resonant circuits (for example, LC circuits) to existing tags. An example of additional resonant circuits coupled to an existing double frequency label to produce a label that resonates in Additional frequencies are shown in Figure 6. Figure 17 is a circuit diagram representing an EAS-only tag 60 having coupled the first and second LC circuits 62 and 64, with each LC circuit resonating at a separate frequency . From an electromagnetic point of view, the tag 60 includes an inductor 66 which is derived at two different points with two different capacitors 68 and 70 to provide an electromagnetically coupled tag. That is, the tag 60 responds similarly to an impacted magnetic signature. Label 60 of only EAS is energized at a first frequency and resonates at the first frequency and a second frequency. Figure 18 is a circuit diagram representing a hybrid tag 80 that is an EAS tag and an RFID, and also includes first and second coupled LC circuits 82, 84. The first LC circuit 82 includes an integrated circuit 86 (IC) and forms an RFID tag circuit 108. The second LC circuit 84 forms an EAS tag circuit. The IC 86 can be easily and electronically mounted to the label 60 shown in Figure 17 during production by adding a belt 88 having the IC and the wires 90, 92 to the label 80 as shown in Figure 18. While not limits a particular theory, label 80 of EAS and RFID is preferably energized in the frequency of the RFID tag circuit 108 to energize and provide power to the IC 86, since an RFID tag typically requires more power than an EAS tag to turn on. As discussed in the above, methodologies of "impulse listening" has traditionally been used in EAS but not in RFID technologies, because the RFID chip requires a continuous signal emission from the reader to provide current to the IC of the RFID tag. However, the invention has found that having a TXPWR transmitter output power is 23dB larger for a reference system at the 13.56 MHz limit than for an 8.2 MHz reference system allows an RFID chip to be energized and respond with your identification. The bandwidth of the ISM band of 13.56 MHz is +/-? KHz with an output power of approximately 15,000uV / m. It should be noted that preferred systems will probably need to periodically switch to CW mode, however, it could also not completely disconnect the 13.56 MHz signal but only advance it (modulation of AM as mentioned previously) to allow RFID tags be energized Like the label in Figure 18, the label represented by a circuit diagram of Figure 19 is a hybrid tag that is an EAS and RFID tag. Without However, the EAS and RFID tag 100 schematized in Figure 19 includes an EAS deactivation circuit 102. Preferably, the deactivation circuit 102 includes a conductive member (e.g., wire 104) that connects an IC 106 of an RFID tag circuit 108 to the EAS tag circuit 110. This wire 104 adds a function in IC 106 which is a switch to the secondary resonant circuit component of the EAS label circuit 110 which can modify the EAS label circuit in such a way that the characteristic resonance no longer falls within the parameters detection. The advantage of this deactivation method (as shown, for example, in Figure 19) is at least double. A first advantage is that the tag 100 could be activated and deactivated several times (such as when an article is returned in a warehouse). A second advantage is the ability to require a code (linked to an ID code in IC 106) to ensure that only authorized applications can deactivate tag 100. An advantage to the objectives represented in Figures 18 and 19 is the structure of The base antenna (as in Figure 17) could be applied to all packets, and the IC (in a carrier arrangement) could be added to only those packets as desired by the user. This can ensure that perimeter security can be available for all packages without the added complexity and cost of RFID IC. The option could be made later in the manufacturing or distribution supply chain to begin identifying the package with the addition of the IC. Another key feature of the preferred embodiments is that the labels 60, 80, 100 shown respectively in Figures 17-19 are retrocompatible. That is, while all the labels shown in Figures 17-19 are double frequency labels, each label can be recognized in an autonomous EAS or RFID system that monitors at a frequency of the label. For example, the label 60 schematized in Figure 17 can be recognized by an EAS system that monitors at any of the frequencies on the label. With respect to labels 80, 100 schematized in Figures 18 and 19, if the RFID tag circuit 108 resonates at a first frequency (eg, 13.56 MHz), and the EAS component (e.g., label circuit 110) ) resonating on a second frequency (eg, 8.2 MHz), then the tags can be recognized by an RFID system that monitors at the first frequency and an EAS system that monitors at the second frequency regardless of whether the RFID and EAS systems they were integrated or autonomous. In this way, preferred embodiments of this invention provide prior and subsequent compatible systems; a true connection technology, which allows a user to exit and came back . The multi-frequency tags of the preferred embodiments include a signature or signature symbol in addition to their identification. While not limited to a particular theory, the signature symbol is based on a specific combination of frequencies for each label that also distinguishes the electronic signature of the label. Since in different frequency combinations they can indicate individual serial numbers, and modified algorithms can detect the presence of the signature, each multi-frequency label has a plurality of indicia (eg, coupled responses) with which it can be identified. That is, in addition to a multi-frequency tag that has its identification number (ID) stored by its IC, the tag has at least a second mark of distinction based on its frequency combinations. In fact, a label can be detected faster and at a greater distance by its signature symbol than by its ID number stored in IC. When a tag enters an interrogation field, the tag is energized by an interrogation signal and responds immediately, so it is detected. The IC on the label does not respond immediately when the label is energized because the IC needs more time to get enough energy from the signal interrogation to turn on and answer with your ID number. In this way, a tag reader captures two coupled responses, the fastest and strongest signature symbol, followed by the tag ID number. Of course, the quality of the ID number, which is preferably digital, is a much higher quality indication of the label since it is much more specific to the label. The preferred system knows the coupled responses and has more than one probability to detect and authenticate each tag. A multiple frequency detection system according to the preferred embodiments as discussed in the foregoing provides the benefit and ability to detect the presence of a label much earlier and under circumstances that a simple frequency detection system might not identify the label. In other words, there are circumstances (for example, interference, insufficient power to charge the IC, without enough time since the tag moved too fast through a detection zone) when an RFID system can not determine the ID number . If the ID number is the only detectable indication of the label, then the system can not determine that a label was present. However, a preferred multiple frequency detection system may determine that a multi-frequency label was present upon detection of the symbol of the label.

Preferred systems can also be used for enhanced authentication of tagged products. Since a multi-frequency tag according to the preferred embodiments provides at least two coupled identification responses, its ID and at least one signature symbol, the tag can be identified much more discreetly than a single frequency tag. . Accordingly, the products associated with the multi-frequency label can be identified much more discreetly than the products associated with single frequency labels. In other words, the preferred embodiments provide the ability to have their signature integrated into the packet. Once an ID is associated with a signature that could be provided on dual technology labels that have schematized circuitry, for example, in Figures 18 and 19, a user can register the signature through either the IC or a base of data. For example, a dual technology label (eg, a 80, 100 hybrid tag) is placed in a pharmaceutical container with an associated signature signed, for example, during manufacture in a database. The signature coupled with an RFID identification number becomes the recipient's fingerprint in such a way that when someone goes and buys the container, or a cash register checks it, or someone of quality control checks it, the detection system can literally check the recipient's fingerprint. Each fingerprint of each individual package can be virtually unique because of how they are attached and the signature and identification are placed on the label. In such a way that each individual resonant frequency, bandwidth value (Q), phase characteristic and tag identification allows a better system for authentication. Therefore, the system can also detect tampering, deviation, copying and even intrusion based on location and tag response. It will be appreciated by those skilled in the art what changes could be made to the embodiments described in the foregoing without departing from the broad inventive concept thereof. For example, the modalities could be modified to operate using other frequencies of the hertz band through the strip band to bands without ionization. Frequencies without ionization can work well as a coupling method differentiated by ionization radiation as opposed to radiation without ionization. It is understood, therefore, that this invention is not limited to particular embodiments described, but it is intended to cover modifications within the spirit and scope of the present invention. Without further elaboration, the foregoing will thus fully illustrate the invention so that others can, by applying current or future knowledge, easily adapt it for use under various conditions of service.

Claims (41)

1. CLAIMS 1. A multiple frequency detection system, characterized in that it comprises: a reader that emits a pulse interrogation signal at a first frequency; and a resonant tag which receives the pulse interrogation signal at the first frequency and responds the pulse interrogation signal by transmitting a first response signal resonating at the first frequency, the resonant tag further transmits a second response signal echoed at a second shifted frequency of the first frequency, the reader further reads one of the first and second response signals, and optionally reads the other of the first and second response signals to detect the resonant tag. The system according to claim 1, characterized in that the reader also emits a second interrogation signal on the second frequency simultaneously with the emission of the pulse interrogation signals on the first frequency, and the resonant tag transmits the second signal resonant at the second frequency in response to receiving the second interrogation signal. 3. The system according to claim 1, characterized in that the system detects the label resonant when reading the first response signal and the second response signal. The system according to claim 1, characterized in that the first response signal has a first amplitude and the second response signal has a second amplitude, and further comprises a computer that determines a differential of relative amplitude between the first amplitude and the second amplitude. The system according to claim 1, further characterized in that it comprises a computer that determines a relative phase delay between the first response signal and the second response signal. The system according to claim 1, characterized in that the resonant tag responds to the pulse interrogation signal by simultaneously resonating both the first frequency and the second frequency. The system according to claim 1, characterized in that the resonant tag is energized by the interrogation signal at the first frequency in order to be able to transmit the second response signal at the second frequency. The system according to claim 1, characterized in that the resonant tag includes a first resonant circuit including a first inductor coil and a first capacitor, the first circuit resonant tuned to resonance at the first frequency, and a second resonant circuit electronically coupled to the first resonant circuit, the second resonant circuit includes a second inductor coil and a second capacitor that is tuned to resonate at the second frequency. 9. The system in accordance with the claim 8, characterized in that the first resonant circuit further includes an integrated circuit to form an RFID tag circuit. 10. The system in accordance with the claim 9, further characterized in that it comprises a deactivation circuit including a conductive member that connects the integrated circuit with the second resonant circuit. The system according to claim 8, characterized in that the first inductor coil and the second inductor coil are combined in a single inductor having a combined coil that is drilled along the combined coil to form the first and second coils inductors. 12. A multiple frequency band tag, characterized in that it comprises: a first resonant circuit including a first inductor coil and a first capacitor, the first resonant circuit tuned to a second frequency in a first frequency band; Y a second resonant circuit coupled electromagnetically to the first resonant circuit, the second resonant circuit includes a second inductor coil and a second capacitor, the second resonant circuit tuned to a resonant frequency in a second offset frequency band of the first frequency band, wherein the tag is adapted to respond to a continuous interrogation signal and a discontinuous interrogation signal. The tag according to claim 12, characterized in that the first resonant circuit further includes an integrated circuit to form an RFID tag circuit. The label according to claim 13, further characterized in that it comprises a deactivation circuit that includes a conductive member that connects the integrated circuit with the second resonant circuit. 15. The tag according to claim 12, further characterized in that it comprises a voltage source and a switch that intermittently opens to mimic a pulse response signal. 16. The label according to claim 12, characterized in that the first coil The inductor and the second inductor coil are combined in a single inductor having a combined coil that is deflected along the combined coil to form the first and second inductor coils. The tag according to claim 12, characterized in that the tag is adapted to respond to an impacted magnetic signature of an external source of the first frequency band by reasoning simultaneously a response signal in the first frequency band by means of the first resonant circuit and a response signal in the second frequency band by the second resonant circuit. 18. The tag according to claim 17, characterized in that one of the first resonant circuit and the second resonant circuit further includes an integrated circuit. 19. The tag according to claim 12, characterized in that the tag is energized by an interrogated signal from an external source in the first frequency band when a response signal is simultaneously echoed in the first frequency band by the first circuit resonant and a response signal in the second frequency band by the second resonant circuit. 20. The label in accordance with the claim 19, characterized in that one of the first resonant circuit and the second resonant circuit further includes an integrated circuit. 21. The tag according to claim 12, characterized in that the second resonant circuit further includes an integrated circuit to form an RFID tag circuit. 22. The label according to claim 21, further characterized in that it comprises a deactivation circuit that includes a conductive member that connects the integrated circuit with the first resonant circuit. 23. A method for detecting a resonant tag having a first resonant circuit that is tuned to resonate on a first response signal at a first frequency having a second resonant circuit that is tuned to resonate on a second frequency response signal displaced from the first frequency, the method characterized in that it comprises: (a) providing a pulse signal to form an interrogation signal; (b) emitting the interrogation signal to hit the resonant tag; (c) transmitting a first response signal of the first resonant circuit when resonating at the first frequency in response to the question mark; (d) transmitting the second response signal of the second resonant circuit when resonating at the second frequency; and (e) reading one of the first and second response signals, and optionally reading the other of the first and second response signals to detect the resonant tag. 24. The method according to claim 23, characterized in that in step (a), further comprises providing the pulse signal at the first frequency. The method according to claim 24, further characterized in that it comprises: (f) providing a second interrogation signal at the second frequency; (g) simultaneously with step (b), emitting the second interrogation signal to collide on the resonant tag, and where step (d), transmits the second response signal in response to the second interrogation signal. 26. The method according to claim 23, further characterized in that it comprises detecting the resonant tag when reading the first and second response signals. 27. The method of compliance with the claim 23, characterized in that the first response signal has a first amplitude and the second response signal has a second amplitude, and further comprises determining a differential of relative amplitude between the first amplitude and the second amplitude. 28. The method of compliance with the claim 23, further characterized in that it comprises determining a relative phase delay between the first response signal and the second response signal. 29. The method of compliance with the claim 23, characterized in that in step (c) and step (d) are simultaneous. 30. The method according to claim 23, further characterized in that it comprises energizing the resonant tag with the interrogation signal at the first frequency in order to be able to transmit the second response signal at the second frequency. 31. The method according to claim 23, characterized in that in step (c), further comprises transmitting the first response signal as an RFID signal. 32. The method according to claim 23, characterized in that in step (d), further comprises transmitting the second response signal as an RFID signal. 33. The method according to claim 23, further characterized in that it comprises deactivating the resonant tag. 34. A multiple frequency detection system for detecting a resonant tag having a first resonant circuit that is tuned to resonate on a first response signal at a first frequency and having a second resonant circuit that tunes to resonate on a second signal response on a second shifted frequency of the first frequency, the system characterized in that it comprises: means for providing a pulse signal to form an interrogation signal; means for emitting the interrogation signal to hit the resonant tag; means for transmitting the first response signal of the first resonant circuit when resonating at the first frequency in response to the interrogation signal; means for transmitting the second response signal of the second resonant circuit when resonating at the second frequency; and means for reading one of the first and second response signal, and optionally reading the other of the first and second response signals to detect the resonant tag. 35. The system according to claim 34, further characterized in that it comprises means for providing the impulse signal at the first frequency. 36. The system according to claim 35, further characterized in that it comprises means for providing a second interrogation signal at the second frequency, means for simultaneously emitting the interrogation signal and the second interrogation signal for colliding on the resonant tag, and means for transmitting the second response signal in response to the second interrogation signal. 37. The system according to claim 34, further characterized in that it comprises means for detecting the resonant tag when reading the first and second response signals. 38. The system according to claim 34, characterized in that the first response signal has a first amplitude and the second response signal has a second amplitude, and further comprises means for determining a differential of relative amplitude between the first amplitude and the second amplitude. 39. The system according to claim 34, further characterized in that it comprises means for determining a relative phase delay between the first response signal and the second response signal. 40. The system according to claim 34, further characterized in that it comprises means for energizing the resonant tag with the interrogation signal at the first frequency in order to be able to transmit the second response signal at the second frequency. 41. The system according to claim 34, further characterized in that it comprises means for deactivating the resonant tag.