RU42674U1 - DEVICE FOR PROTECTION AGAINST FORGING AND CONTROL OF THE AUTHENTICITY OF VALUABLE GOODS (OPTIONS) - Google Patents

Abstract

The utility model relates to means of protecting and controlling the authenticity of securities from counterfeiting and can be mainly used to protect against counterfeiting, for example, banknotes. The device includes a passive protective means of a given structure. This structure is made with the possibility of controlling the presence and authenticity of the aforementioned means by a physical analysis method for resonance effects during external exposure to it by probing radiation of a given radio frequency. And also with the possibility of detecting the parameters of certain informative features in a resonant response to the aforementioned external influence, followed by automatic comparison of the recorded parameters of informative features with reference values. The protective agent is made in the form of a metallized at least three-layer resonant filter structure, which includes a strip line 1, consisting of at least two metal microstrips 2, a length equal to half the wavelength (λ / 2) of the radiation propagating in the strip line, induced by probe radiation, which are located with mutual overlap and separated by a dielectric, while the gap S between the microstrips in the overlap zone does not exceed 20 μm; solid metal screen 3; as well as the dielectric layer separating them 4. Moreover, the radioelectric and geometric parameters of the planar strip line 1 are selected in such a way that when it is probed by radiation with a microwave frequency of the microwave range, it is possible to use the characteristic peak values of the frequency response of the direct transmission coefficients in the response of the filter structure and back reflection of the probe radiation by this structure, used in the detection process to compare nii with a given range of reference values of the corresponding parameters stored in the memory of the detection means. 2 n.p.-fs and 6 w.p.-fs, 5 ill.

Description

The utility model relates to means of protecting and controlling the authenticity of securities against counterfeiting and can be mainly used in mass production to protect against counterfeiting, for example, banknotes, credit documents, other securities and to enable the subsequent determination of their authenticity with high reliability.

Currently, direct financial losses of developed countries, due to counterfeiting (unauthorized issuance and large-scale introduction into circulation) of banknotes, credit documents and other securities, amount to significant amounts. This is due to the fact that the current level of development of computing, analytical and multiplying technology allows reproducing with a high degree of identity almost any security in unlimited quantities at relatively low material costs.

This problem is especially acute in cases of mass production of products, for example, bank notes (banknotes), when the costs of their manufacture and protection against counterfeiting should be minimal. In addition, in this case, the protective elements (tags) must be quickly detected by means of inexpensive and affordable for a wide range of users means of control.

Currently, there are various methods and means of protection against counterfeiting of valuable products, in particular, banknotes, credit documents and other securities.

For the selected group of protected products, for example, banknotes, securities, etc., the applied security elements (tags) are usually divided into three groups: prepress, print and postpress.

Prepress protective elements are paper composition, watermarks, metallic thread, fibers colored and glowing in ultraviolet rays, confetti, etc.

Printed security features include:

elements that ensure the implementation of methods for graphic image reproduction, including micro printing, combined and code drawings, etc .;

- elements sold directly by printing methods, including by means of deep, high, flat metallographic and other printing methods;

- elements that provide methods for the implementation (creation) of optical effects;

- used printing inks.

A set of post-print security elements may include embossing, film coating, labeled elements, etc.

A significant part of the known methods and means of protection against counterfeiting are methods and means of protection by means of metal protective marks. Moreover, the label can be formed both by direct application of the label material (for example, in the form of paint) on the protected product, and by applying to the said product a separately manufactured protective equipment, for example, in the form of a strip.

In particular, there is a known method and means of protecting banknotes from counterfeiting, according to which a special image is applied to the banknote as a security element by means of magnetic printing ink. Registration of this tag is carried out by means of a magnetic detector (GB, No. 2079506, class G 07 D 7/00, 1982).

The disadvantages of this means of protecting banknotes from counterfeiting known from the prior art and the method for its implementation include the fact that they can be quite easily reproduced and imitated with a high degree of identity with the original using modern means widely known from the prior art that are available to a wide range of interested parties. Moreover,

printing ink is subject to erasure during the long-term operation of banknotes, and therefore the possibility of recognizing a genuine (original) banknote as false when detecting a security mark is not ruled out.

Individual document protection means are known in the form of perforations, the pattern of which has recognizable irregularities. Perforation is carried out using a laser beam, based on the usual pattern, while the laser is controlled by a computer in such a way that each perforation has an individual irregularity depending on the initial value (DE, application N03628353, CL 44 P 1/12, 1988) .

The disadvantages of this well-known from the prior art means of protection against counterfeiting and the method of its implementation include:

- limited functionality, due to the fact that through such a protective element it is advisable to protect only a small-volume product, due to its low productivity (because the speed of point-by-point laser burning is much lower than the methods of forming marks simultaneously over the entire area of the carrier).

- the need to use expensive technological equipment for the industrial sale of the protective element on the protected product;

A known method of creating a document protected from falsification, according to which the protective equipment is performed in the form of a layer of grains deposited on at least one side of the sheet carrier of the reflective layer, whereby the surface of the reflective layer has a varying reflectivity. Labels formed by groups of grains can be read out by machine (EP, EPO patent N0155982, CL G 07 K 19/05, 1985).

This type of document protection known from the prior art from counterfeiting has a number of significant limitations in terms of its application. In particular, significant technical problems arise in the detection of protective

tags with the necessary resolution due to the aggregation of grains in the process of grinding and applying. And with an increase in their dispersion, the width of the image spectrum in the region of low spatial frequencies increases.

A known method of manufacturing a two-sided storage medium for the protection of valuable products, according to which on the front and back sides of the storage medium by applying a magnetic composition form a protective mark in the form of two images that are located on opposite sides of the base of the medium and in a certain way oriented relative to each other. Detection of the protective mark formed in this way is carried out by means of a semiconductor magnetic sensor that simultaneously reads information from the front and back sides of the information carrier. When detecting, the output signal of the semiconductor sensor is passed through a complex circuit to form a pulse at the boundaries of the images of the magnetic mark. These pulses recognize magnetic information on the medium by comparison with a given (reference) information (JP, application N057-177372, class G 07 D 7/00, 1984).

The disadvantages of this method of protection and means for its implementation should include the fact that to register the presence of such a protective label, it is necessary to use special complex and expensive means of its control (detection), which are not available to the mass user.

A known method of protecting securities from counterfeiting and a device for its implementation according to which a strip of magnetic material is pressed into the paper base of a security. The authenticity of a security is determined by means of a magnetic detector detecting a change (gradient) in the magnetic field strength (EP, No. 005720, class G 07 D 7/00, 1982).

The disadvantages of the data of the method and means of protecting securities against counterfeiting known from the prior art include its insufficient reliability, since the manufacture (fake) of a strip from a magnetic material accessible to a wide range of people does not represent any

technical complexity and does not require significant material costs. Consequently, the degree of probability of counterfeiting securities protected in accordance with the considered method of protection is quite high.

The closest (for the problem being solved and the achieved result) to the claimed object of the invention is a method known from the prior art for protecting against counterfeiting of valuable products, in particular banknotes, securities and documents, as well as a means for its implementation, according to which they use as a means of protection isotope indicator based on the stable isotope osmium-187 ( ¹⁸⁷ Os) or its (stable isotope osmium-187) chemical compound in which (the chemical compound) provides constant stabilization (in time and space ve) the magnetic orientation of the spins (intrinsic angular momenta) of the system of elementary particles that make up the osmium-187 atoms.

A protective tag is formed with the possibility of monitoring the presence of this tag (when detecting) on the protected product by the physical analysis method for isotopic effects, in particular, for the magnetic properties of osmium-187 nuclei by nuclear magnetic resonance / NMR / (RU, patents No. 2074420 and No. 2077072, C. G 07 D 7/00, 1997).

The use (in the considered method of protecting products from counterfeiting) of the stable osmium-187 isotope in the form of a chemical compound of osmium-187 with a ferromagnetic substance allows the use (in the detection process) of the internal magnetic fields of atoms reaching 500 T or more, because when interacting with the magnetic fields of the atoms of a ferromagnet, the magnetic fields of osmium-187 atoms are ordered in space. This allows one to obtain an NMR signal, i.e. the effect of selective absorption of radiation of a certain radio frequency, without exposure to external magnetic fields of high power. A favorable (for the case under consideration) characteristic of osmium-187 is also that its core has a spin equal to 1/2, therefore, there is no electric quadrupole moment, which eliminates electrical disturbances in the process of detecting a protective mark.

To detect the well-known and reproduced according to the aforementioned prior art (see RU, patents No. 2074420 and No. 2077072) on the protected product of the security label is used (also known from the prior art) NMR spectrometer in which superconducting are used to orient the magnetic fields of the atomic nuclei of the material under study magnets creating a magnetic field up to 20 T.

It should be noted that the aforementioned superconducting magnets constitute the dominant (main) part of the cost of the aforementioned NMR spectrometer.

Detection in the case of using a osmium-187 compound with a ferromagnetic substance (material) as a protective mark is also carried out by known methods using means known from the prior art.

In particular, when an π / 2 pulse of radio frequency generated by the detector is superimposed (in antiphase with the magnetic moments of osmium-187 atomic nuclei), the spins of osmium-187 atomic nuclei are “scattered”. At the next pulse π (of the same source of electromagnetic radiation in phase with the magnetic moments of the osmium-187 atomic nuclei), the spins of the osmium-187 atomic nuclei simultaneously return to their main oriented (stabilized by the magnetic influence of the atomic spins of the substances that are the ingredients of the compound under consideration) state. This makes it possible to register by means of a detector (including an NMR spectrometer) the so-called "spin echo" created (generated) by a system of elementary particles that form the osmium-187 atomic nucleus. Detection is carried out by triggering the device only on the osmium-187 nuclei with a resonant frequency of 107.5 MHz.

The disadvantages of the above, closest (in relation to patentable objects of the invention) technical solutions, it is advisable to include the following. Reliable protection of a product protected from falsification (in particular, banknotes, securities or other documents), according to the method and means for its implementation described above, known from the prior art, is provided by using as a protective

labels of unique material, the development of which requires a level of technical means, material and labor costs that can only be provided by a state that has modern nuclear technologies (including methods for the separation of the osmium-187 isotope from rhenium-containing and ultra-poor ores or from poor and ultra-poor waste technological solutions) .

Indeed, the uniqueness of the material and the technology of its production provides a sufficiently high degree of protection for valuable products (including banknotes, credit and other documents, as well as other objects that require, due to their certain value, individual or large-scale protection) from forgery. However, it is the uniqueness and technological complexity of the production of osmium-187 that limits its use in terms of the large-scale protection of products (for example, banknotes) from counterfeiting, since the cost of producing one banknote can be comparable with the nominal value of this banknote, and in some cases it can be significantly above its face value, for example, for small banknotes.

If we take into account the fact that in the current conditions of market relations this unique material (osmium-187) can be acquired by interested parties in pure form in the right amount by purchasing it (including illegally), as well as the fact that the technological process of forming a protective label based on osmium-187 (according to the invention under consideration) does not present any difficulties and does not have technological know-how, and that the minimum amount of osmium-187 necessary to ensure is guaranteed detection of a security label, is 5 μg, it can be concluded that an interested person can reproduce this security label, for example, on banknotes, an unlimited number of times, and each illegally reproduced label will be absolutely identical to the reference one, since the physicochemical properties of osmium-187 , even obtained by various technological methods and from different sources, will be absolutely identical.

The claimed technical solution was based on the task of creating such a device for protection against counterfeiting and authenticity control of valuable products that would allow for low-cost industrial implementation to provide high-quality protection by using technologies known from the prior art for its production, as well as high detection speed (authenticity control of marked products, in particular banknotes) by providing the device with the ability to operate in the microwave range of radio frequencies, p implements high speed radio.

The task according to the first embodiment is achieved by the fact that in the device for protection against counterfeiting and authenticity control of valuable products comprising a passive protective means of a given structure, which is configured to provide control of the presence and authenticity of the said means by the physical method of analysis of resonance effects during external exposure probing electromagnetic radiation of a given radio frequency and detecting the parameters of certain informative of signs in the resonant response of the protective agent to the aforementioned external influence followed by automatic comparison of the recorded parameters of these informative features with the reference values stored in the memory of the detection means according to the invention, the passive protective means is made in the form of a metallized at least three-layer resonant filter structure, which includes a planar strip line consisting of at least two metal microstrips with a floor length of fault wavelength propagating in line stripline radiation induced by the probe radiation, which are arranged with mutual overlap and are separated by a dielectric in said overlap area, wherein the magnitude of the dielectric gap between the microstrips do not exceed 20 microns in the overlap zone; solid metal screen; as well as the dielectric layer separating them; moreover, the radioelectric and geometric parameters of the planar strip line

chosen in such a way that when it is probed by radiation with a microwave frequency of the microwave range, it is possible to use the characteristic peak values of the frequency response of the direct transmission and backward reflection coefficients of the external probe radiation used in the detection process for comparison with a predetermined range of reference values of the corresponding parameters embedded in the memory of the detector sirovany.

Advantageously, said separating dielectric layer is made of lavsan.

It is optimal to place the three-layer resonant filter structure between two additional dielectric layers made, for example, of lavsan.

It is most optimal to use radiation with a frequency from 8 to 12 GHz as probing radiation with a microwave frequency in the microwave range.

The task according to the second embodiment is achieved by the fact that in the device for protection against counterfeiting and authenticity control of valuable products comprising a passive protective means of a given structure, which is configured to provide control of the presence and authenticity of the said means by the physical method of analysis of resonance effects during external exposure probing electromagnetic radiation of a given radio frequency and detecting the parameters of certain informative of signs in the resonant response of the protective agent to the aforementioned external influence followed by automatic comparison of the registered parameters of these informative features with the reference values stored in the memory of the detection means according to the invention, the passive protective means is made in the form of a metallized at least five-layer resonant filter structure, which includes a planar strip line consisting of at least two metal microstrips with a floor length of fault propagation in the wavelength stripline

radiation induced by probing radiation, which are located with mutual overlap and separated by a dielectric in the zone of said overlap, while the dielectric gap between the microstrips in the overlap zone does not exceed 20 μm; solid metal screen; a dielectric layer separating the strip line and the metal screen; an additional dielectric layer and an additional solid metal screen covering it, which are sequentially located on the side of the strip line, the radioelectric and geometric parameters of the plane strip line being selected in such a way that when it is probed with radiation from the microwave frequency, it is possible to use informative signs as resonant the response of the filter structure characteristic peak values of the frequency response coefficient s direct transmission and backscatter this structure, an external probe radiation used in the detecting process for comparison with a predetermined range of reference values corresponding to the parameters laid down in the memory of the detection means.

Advantageously, said dielectric layers are made of lavsan.

In some cases, a five-layer resonant filter structure can be gaplessly placed between two additional dielectric layers made, for example, of lavsan.

It is most optimal to use radiation with a frequency from 8 to 12 GHz as probing radiation with a microwave frequency in the microwave range.

The utility model is illustrated with graphic materials.

Figure 1 - arrangement of metal microstrip in a flat strip line.

Figure 2 - embodiment of a device according to claim 1 of the claims.

Figure 3 is an embodiment of a device according to claim 3 of the claims.

Figure 4 -. an embodiment of the device according to claim 5 of the claims.

Figure 5 -. an embodiment of the device according to claim 7 of the claims.

The device for protection against counterfeiting and authenticity control of valuable products, according to the first embodiment, includes a passive protective means of a given structure. This structure is made with the possibility of monitoring the availability and authenticity of the said means by the physical method of analysis of resonance effects during external exposure to it by probing electromagnetic radiation of a given radio frequency. And also with the possibility of detecting the parameters of certain informative features in the resonant response of the protective agent to the mentioned external influence, followed by automatic comparison of the registered parameters of these informative features with the reference values stored in the memory of the detection means.

The passive protective device is made in the form of a metallized at least three-layer resonant filter structure, which includes a planar strip line 1, consisting of at least two metal microstrip 2 with a length equal to half the wavelength (λ / 2) propagating in the strip line 1 radiation induced by probing radiation, which are located with mutual overlap and are separated by a dielectric in the zone of the said overlap. The value of the dielectric gap (S) between the microstrips 2 in the overlap zone does not exceed 20 μm. In addition, said resonant filter structure includes a continuous metal screen 3; as well as the dielectric layer 4 separating the microstrip line 1 and the said screen 3. The radioelectric and geometric parameters of the planar strip line 1 are selected so that when it is probed by radiation with a microwave frequency of the microwave range, mainly from 8 to 12 GHz, it is possible to use as detectable informative features in the resonant response of the filter structure

characteristic peak values of the frequency response of the direct transmission and backward reflection coefficients of the external probe radiation by this structure. These informative features (i.e., peak values of the frequency response of the transmittance and absorption coefficients) are used in the detection process to compare with the specified range (and not the specific absolute value) the reference values of the corresponding parameters stored in the memory of the detection means.

Advantageously, said separating dielectric layer is made of lavsan.

It is optimal to place the three-layer resonant filter structure between two additional layers 5 and 6 of the dielectric, made, for example, of lavsan. This eliminates damage to the resonant strip line 1 and the metal screen 3 during operation of the protected products, such as banknotes.

The second embodiment of the device for protection against counterfeiting and authenticity control of valuable products is largely similar to the first. Its differences are only in that the passive protective agent is made in the form of a metallized at least five-layer resonant filter structure, which, in addition to the previously listed elements of the three-layer resonant filter structure (according to the first embodiment of the device), contains an additional dielectric layer 7 and a coating its additional solid metal screen 8, which are sequentially located on the side of the strip line 1. As in the first embodiment, a five-layer cut According to the second embodiment, the on-off filter structure can be gaplessly placed between two additional dielectric layers 9 and 10, made, for example, from lavsan.

The physical essence of the principle of operation of the device for protection against counterfeiting and authenticity control of valuable products according to any of the embodiments is almost identical and is as follows.

It is advisable to note that in the development of radio frequency protective labels (protective equipment), the choice of the frequency range and

possible types of modulation of the probe signal. From the point of view of radio engineering, the construction of a tag that provides identification of an object can be implemented in almost the entire spectrum of radio frequencies mastered to date - from a few kilohertz to hundreds of gigahertz. However, the specific requirements for the marks in the protective metal strip impose special requirements on the choice of frequency range and type of modulation.

For a better understanding of the physical nature of the claimed invention, it is advisable to analyze the currently existing construction principles and approaches to the use of radio frequency identification systems.

Radio frequency identification and registration systems (RFID systems) have been widely used since the beginning of the 90s. Compared to existing well-known identification methods (by barcode or magnetic stripe), RFID systems have a number of significant advantages. Namely: the object is identified by a unique digital code emitted by an electronic transponder tag attached to the object; transponders are polled automatically using a transceiver (reader).

Such systems can significantly accelerate the identification process, do not require a special location of the object relative to the reader (as, for example, in systems with a bar code), are more reliable, durable and protected, in relation to systems with a magnetic strip.

Currently, depending on the requirements of the system, both active (powered by a built-in battery) and passive transponders are used. The passive transponder receives the energy necessary for generating a response signal via a radio link from a reader.

The first radio frequency identification and registration system is TIRIS (Texas Instruments Registration and Identification System). Originally developed for warehouse automation, TIRIS has found application in access control systems, car immobilizers, automated trading systems, in paid car parks, gas stations, etc.

Existing RFID systems of various manufacturers, as a rule, differ in the carrier frequency of the signals used, the type of modulation, the radio protocol, and the amount of information returned by the transponder. Recently, attempts have been made to standardize these products. This primarily relates to the carrier frequency of the signals.

Currently, there are three main frequency ranges in which RFID systems operate:

- low-frequency range (up to 150 KHz);

- mid-frequency range (13.56 MHz);

- high-frequency range (850 ... 950 MHz and 2.4 ... 5 GHz). Among the low-frequency range RFID systems widely used in the Russian market, transponders operating at a frequency of 125 kHz should be noted (protocol of the Swiss company EM Microelectronic Marin). These transponders use amplitude modulated signals and a Manchester code. The transponders of Temic, Atmel, and Microchip companies have a similar exchange protocol. The specified standard is significantly inferior to the Texas Instruments RFID system in range (about 20 cm) and noise immunity, however, the low cost of transponders ($ 1.2 ... $ 1.5) and readers ($ 20 ... $ 30) allows you to implement inexpensive access protection systems, accounting systems, etc.

The main disadvantages of low-frequency RFID systems include, first and foremost, the low speed of radio exchange and the technological complexity of manufacturing high-inductance transponder antennas. The low speed of the radio exchange does not allow the reader to distinguish between several transponders simultaneously located in the field of its antenna. This limits the use of low frequency RFID systems to a certain extent. Spiral or magnetic antennas of low-frequency transponders, as a rule, require complex winding equipment and are poorly transported. This leads to high costs for packaging transponders and, ultimately, to their high cost.

The transition to the megahertz frequency range allowed us to get rid of these shortcomings. The standard mid-range for the manufacture of RFID systems is the 13.56 MHz band. The development of transponder microcircuits in this range is available from a number of well-known manufacturers: Philips- MIFARE technology, Microchip, and many others.

The transponders manufactured by Texas Instruments using Tag-It ™ technology are a complete construction consisting of a thin (0.03 mm) plastic substrate, a microcircuit, and a sputter-coated frame antenna. The thickness of the transponder at the location of the chip is 0.3 mm. The transponder contains a unique 32-bit code recorded at the factory and 256-bit user memory (8 pages of 32 bits). The transponder signal is amplitude-modulated, a Manchester code is used for encoding.

The estimated cost of a transponder in Russia is less than one US dollar. The main advantage of Tag-It ™ transponders is the simplicity of their packaging. In the simplest application, the transponder can simply be glued between two sheets of paper or cardboard.

High-frequency transponder devices in the modern RFID market are represented primarily by Amtech and Micro Design ASA products. Texas Instruments High Frequency Active Transponders are designed to US and Canadian standards and are not available on the European market. The transponder contains a high-frequency transceiver inside. All this leads to rather high prices for components of such systems, in particular, the cost of reader equipment is $ 2000 ... 5000, the cost of a high-frequency transponder ranges from $ 30 to $ 100.

It should be noted that the long-wavelength ranges imply significant dimensions of the receiving and transmitting structures, the microwave ranges are quite expensive in terms of the element base and the manufacture of guide structures with extremely tight tolerances.

Thus, a reasonable compromise is required when choosing an operating frequency range. In addition, it must be borne in mind that resonance effects, which are used as the main informative features in

The claimed technical solution is observed at characteristic sizes that are multiples of half the wavelength. Therefore, in theoretical studies (preceding the practical development of the claimed technical solution), a rather wide frequency range was selected - from 2 to 15 GHz (with various types of modulation). We were guided by the following requirements:

- the label must be passive, not contain active elements and nonlinearities in the form of semiconducting structures;

- the label manufacturing technology should be quite simple and well-developed today;

- used devices for generating and receiving radio signals today should be produced in series;

- today there should be serial measuring equipment for monitoring and identification.

As the laws of modulation of the probing signals, at this stage of the work, the following were chosen. Short radio pulse, linear frequency modulation of a continuous signal, continuous signal. Perhaps, at the next stages of the work, the list of modulating laws will be expanded. At the same time, the list taken as a basis practically exhausts the possible options, since in particular cases it can only be a refinement of certain modulation parameters, for example, frequency deviation, repetition period, etc.

When constructing a system for detecting and identifying microwave tags, i.e., protective equipment (in particular, at such objects as banknotes and other securities), the choice and justification of informative features is of great importance. During the development of the claimed invention, it was decided to divide the detection and identification of the microwave tag (protective means) into two independent tasks. This is due to the following:

- firstly, it is necessary to clearly fix the presence of a metallized structure (and this in itself is an informative parameter);

- secondly, for objects of different nominal values (in particular, banknotes), the signal of the label (protective equipment or resonant filter structure) should be different.

Therefore, two tagging techniques are proposed. One is based on spectral differences between transmitted and reflected signals. Another involves binary quantization of labels according to their geometric location.

In the process of developing the claimed technical solution, the process of transmitting a radio pulse through linear filters of various orders was simulated, mathematical models of resonant filter structures of microwave tags on coupled flat strip lines were developed, the influence of geometric dimensions and field polarization on the isolation of the receiving and transmitting paths and on the detection of the label was studied .

The parameters of the probe signal adopted during the simulation are as follows: carrier frequency - 10 GHz (wavelength 3 cm), pulse duration 50 ns. Accordingly, the selected simulation parameters and sampling rates. It seems reasonable to perform a low-order tag filter, since it has a small number of links and can be compact, which is very important when using microwave tags to protect banknotes from counterfeiting. In addition, the implementation of high-order filters may not be feasible in the microstrip embodiment.

The studies show that there is a fundamental possibility of identifying an informative feature (by impulse response) when implementing a label in the form of a resonant microstrip filter. The main difficulty in this construction is the practical limitations of achieving a high quality factor of the label structure.

During the simulation, the reflection coefficient from the studied structure (i.e., labels in the form of a resonant microstrip filter) and the transmission coefficient were evaluated. This set is due to the fact that it is these parameters that can be measured (evaluated) and compared with the reference values of the corresponding parameters in real and with a high degree of reliability in the recording equipment.

Studies show that changing the parameters of the structure chains significantly affects both the reflection coefficient and the transmission coefficient. However, it should be noted that such an effect is observed at significant values of the frequency deviation (the width of the spectrum of the probing signal). This is due, firstly, to the small order of the filter, and secondly, to the low quality factor (large attenuation) of the microstrip line due to the very small thickness of the dielectric (lavsan). Within one octave, no more than 6 different microwave tag structures can be identified. As the frequency range increases to values exceeding an octave, resonances at multiple harmonics appear, which makes identification difficult.

Increasing the order of the filter will lead to an increase in size and failure to comply with the requirement to place 3 marks on the tape. In addition, due to overall limitations (in particular, when using the considered microwave tags on banknotes), there is no possibility of a significant increase in the thickness of the dielectric base.

It is advisable to consider the isolation between the emitter and the receiver of the probe electromagnetic radiation when they are located on the same wall. In this case, it seems most rational to use a slot in the conductive screen as the emitter and receiver.

The isolation between the slot emitters, like all subsequent calculations, was carried out in the electromagnetic simulation environment of the Microwave Office. The achieved level of isolation at the selected sizes was minus 55 dB.

When passing the slots of the protective strip (protective equipment) between the slots, electromagnetic coupling occurs and the decoupling value decreases to minus 19 dB. That is, the signal difference in the absence of a protective band and in its presence is 36 dB, which is a sure sign of the presence of the simplest label (binary detection).

A two-band structure with electromagnetic coupling simulates an exciting filter structure. In this case, the isolation between the emitting and receiving slit is minus 14 - minus 15 dB. The gain in this case is 40 dB.

We proceed to consider structures located in two parallel planes opposite each other. The air gap between the planes simulates a structural gap in which an object protected by a metal strip moves.

When the slots are located opposite each other, a strong electromagnetic coupling arises between the transmitter and receiver. An informative sign in this case may be its violation during the passage of the mark in the gap and an increase in the reflected signal in the transmitter.

The orthogonal arrangement of the slots allows you to weaken the connection between the slots to minus 60 dB. When passing through a metallized strip oriented in the same way as one of the slots, electromagnetic coupling does not occur and the isolation still does not exceed minus 60 dB.

When the protective strip is positioned at an angle of 45 ° relative to the emitting and receiving slots, a strong coupling of the receiving and transmitting channels occurs and the isolation is reduced to minus 7 - minus 8 dB. With an appropriate selection of the geometric parameters (sizes) of the metallization of the strip, the coupling reaches a value of minus 4 dB.

Next, the nature of the electromagnetic coupling during the passage of the metallized strip relative to the receiving and radiating slots was analyzed.

The simulation results show that the maximum electromagnetic coupling occurs only when the metallized strip passes symmetrically through the center of intersection of the emitting and receiving slits. This circumstance allows us to conclude that with an appropriate positional location of a label simple in structure and an appropriate location of the receiver and transmitter in the reading system, reliable detection of the label (strip) is achieved. When using several marks (inclined stripes), it is possible to solve the recognition problem.

The experiments on identifying informative parameters of tags and selecting their reading schemes were performed using standard measuring instruments, in particular, an SWR meter and attenuation P2-59.

The device was used according to the attenuation measurement scheme. That is, an experimental check was made of the transmittance module as the most informative parameter for the filter structure.

In contrast to the standard set of accessories, two coaxial-waveguide transitions and two microstrip slot antennas were included in the measurement scheme. Coaxial waveguide transitions provide a connection to the power node microstrip line, exciting the gap. As power units, transitions E2-116 / 1 directly connected to the antenna and connectors SR-50-270C with pieces of coaxial cable PK50-4-21 were used. The microstrip slot antennas were designed for maximum bandwidth in the instrument operating range and were fabricated on FR4 material.

Calibration of the device was carried out in several stages. Initially, only the waveguide path was calibrated. That is, all non-standard devices were excluded from the circuit. The microwave generator power level was set at which the incident wave detector operates on a quadratic portion of the current-voltage characteristic. This mode provides the characteristics proportional to the power and, therefore, the parameters of the transmission-reflection coefficients. When calibrating the reflected wave detector (in this measurement scheme, it is actually a transmitted wave detector), we achieved the equality of powers and the most flat frequency response on the device screen.

At the next stage, coaxial-waveguide transitions were connected and connected with a special broadband cable. This stage takes into account the frequency characteristics of the coaxial waveguide transitions with cable. The level of the incident wave did not change, but the level of the transmitted wave was corrected. Calibration was carried out in the frequency range 8.3 ... 12.0 GHz.

The unevenness of the frequency response is due to the combination of frequency characteristics of the coaxial waveguide junctions and cable. Its unevenness does not exceed 2.5 dB. This is quite satisfactory not only for qualitative estimates of circuit parameters, but also for quantitative estimates.

Next, we consider the methodology for conducting experiments to identify informative signs of the label. The transmittance module is used as the basis of the informative feature and the same measuring equipment is used.

For a resonant filter structure (protective label), the procedure for calibrating the device is similar to that described above. In this design of the label contact excitation is impossible, only electromagnetic is possible. During the experiment, it was not intended to obtain quantitative values of the frequency response. It is more important to determine the presence of characteristic differences between a resonant filter tag and its counterfeit.

After calibrating the device and connecting the slot emitters, you need to make sure that there is no electromagnetic coupling between the slots. At least the isolation should be at least minus 40 dB.

After making sure that there is a junction, it is necessary to create a guaranteed gap (thickness of a sheet of paper) between the slots and the object under study.

Next, place the object under investigation in such a way that the edges of the object under study are above the emitting and receiving slits, respectively.

Without changing the position of the “calibration” knob, using only the “attenuation” switch, achieve a stable picture and the desired image scale of the frequency response of the object under study on the device screen.

Fix the obtained frequency response.

Delete one investigated object and observe the lack of response.

Without changing the position of the device adjustments, place the second object under investigation similarly to the first object.

Observe the frequency response of the object under study. If necessary, switch the "attenuation" to achieve the desired image scale of the frequency response of the investigated object on the screen of the device.

Fix the obtained frequency response.

Remove the object under investigation and again verify the presence of isolation.

We emphasize once again that the purpose of the experiments was not to obtain quantitative characteristics, we are talking about characteristic physical phenomena that can become informative signs.

A strip line (a conductor 1 mm wide on 0.7 mm thick FR4 material) with a given frequency response was used as a false object.

It should be noted that here the characteristic is very different. Firstly, responses at completely different frequencies. Secondly, due to the higher quality factor of the structure, the peak of the frequency response is substantially narrower.

We proceed to consider another method for exciting a resonant filter structure.

As in the first case, the frequency response has characteristic resonant peaks in the frequency range 8.3 ... 9.6 GHz. However, the response amplitude is somewhat lower. As a test (false) sample, a similar one was used, but with a different type of food. And in this case, a false sample, like the first one, does not give resonant responses, but forms an outlier at a frequency of 9.2 GHz with a larger amplitude than the filter tag.

Thus, with the second type of supply, there is a steady difference between the resonant filter structure (label) and the false sample.

The filter tag has a rather complicated manufacturing technology, requires a two-layer aluminum coating of the lavsan and sophisticated identification equipment. However, the performed experiments confirmed the effectiveness of this type of microwave tags and their resistance to counterfeiting. Thus, a filter type label can be considered the most promising for industrial applications.

Consider the options for constructing equipment for reading tags of this kind. The main informative feature, as experiments have shown, is the frequency response of the direct transmission (transmittance) coefficient module formed by the label. It should be noted that this information is not exhaustive. It is advisable to obtain a frequency

dependence of the reflection coefficient in addition to the direct transmission coefficient (transmittance).

To obtain frequency characteristics, “white” noise and frequency modulation were used as test signals according to a linear or close to linear law.

Consider the structural diagrams of a reader or identifying device on both principles of action.

The scheme using "white" noise, in essence, is an OTDR with a channel of transmitted and reflected waves. Consider the operation of this circuit. The band noise generator (GS) operates in the frequency band of the label, i.e. from 8 to 11 GHz. It can be performed on an avalanche-span diode (LPD) and have a sufficiently low spectral noise power density (SPMSh), of the order of 33 dB.

The generated noise is modulated in amplitude by a sinusoidal signal with a frequency of the order of 100 kHz. From the output of the amplitude modulator, the signal enters the directional coupler of the reflected wave. This coupler generates a signal proportional to the modulus of the reflection coefficient from the first antenna. This antenna emits a modulated noise signal into the working gap through which the tag moves. If there is no label, the signal is received by the second antenna, a set of bandpass filters passes, and is detected by the detector. From the detector output, the signal is amplified in a narrow-band amplifier of intermediate frequency (IF), which is tuned to a modulation frequency of 100 kHz. The envelope detector emits a slowly varying amplitude of the intermediate frequency (IF) signal, which is proportional to that passed through the working gap and bandpass power filters. This channel serves for calibration and formation of reference signal levels.

If there is a mark in the working gap, the signal, propagating in it as in a filter, enters the input of the third antenna and then, as in the calibration channel, is detected and amplified. The signal from the output of the envelope detector and low-pass filter (LPF) is proportional to the direct transmission (transmission) coefficient module.

From the output of the directional coupler, the signal also goes to the detection and amplification circuit. A voltage proportional to the modulus of the reflection coefficient is formed at the output of this channel.

From the outputs of the low-pass filter, the signal is fed to the ADC and processed by the computer. The computer compares the signals of the three measuring channels and decides on the authenticity of the label.

The greatest difficulty in this device is a set of bandpass filters, which in fact is a sensitive device. The number of filters and their passband determine the quality of measurements. The choice of this or that filter is carried out by a computer.

According to the results of the experiments, five bands in the set are enough, which will be switched using p-i-n diode keys.

The scheme using frequency modulation is as follows. The original signal is generated by the oscillating frequency generator (GKCh). The generator can be performed on microwave diodes or transistors. The frequency tuning range is from 8 to 12 GHz. Such a wide tuning range (almost half an octave) significantly complicates the design of the generator.

When performing R&D in the process of creating the claimed technical solutions, the following results were obtained and the following conclusions were made.

There is a fundamental possibility of identifying an informative sign (by impulse response or frequency) when implementing a tag in the form of a resonant microstrip filter (the main difficulty in this construction is the practical limitations of achieving a high quality factor in the structure of the protective tag due to the small thickness of the polyester dielectric).

The parameters of the filter structure circuits significantly affect the reflection and transmission coefficients with a large spectral width of the probe signal. This is due to the small order of the filter and low quality factor (large attenuation) of the microstrip line. Within one octave, identification of no more than 6 different security label structures is possible.

Maximum electromagnetic coupling in a cross-talk system

polarization of the antennas of the receiving and transmitting paths occurs when a metallized band passes symmetrically through the center of intersection of the radiating and receiving slots. With the appropriate positional location of the protective strip relative to the receiver and transmitter in the reading system, reliable detection of the mark is achieved. When using multiple labels, it is possible to solve the recognition problem.

The mathematical and simulation modeling allowed us to develop a topology of the elements of the receiving and transmitting identifier paths and the structure of the microwave tag.

The filter tag has a rather complicated manufacturing technology, requires a two-layer aluminum coating of the lavsan and sophisticated identification equipment. However, the performed experiments confirmed the effectiveness of this type of tags and their resistance to fake.

Currently, mathematical models of various structures of protective microwave filter tags have been developed. Mathematical modeling of the detection and identification process has been carried out. A scheme for conducting experimental studies with an identification mark has been developed. Topological drawings of the transceiver paths of the product model have been developed. Designed and manufactured laboratory model of identification device. A topology was developed and samples of protective microwave filter tags were made. Laboratory studies have been carried out.

Thus, the claimed invention can be widely used for the production and simultaneous protection against unauthorized reproduction (fake) of valuable products and its use is most suitable for industrial use, mainly in large-scale production and authorized reproduction of protected products (for example, such as banknotes and other securities, as well as various types of credit documents) in view of the possibility of operational control of the authenticity of protected products a wide range of users accessible means of control and identification.

Claims (8)

1. A device for protecting against counterfeiting and authenticity control of valuable products, including a passive protective agent of a given structure, which is configured to provide control of the presence and authenticity of said agent by a physical analysis method for resonance effects during external exposure to it by probing electromagnetic radiation of a given radio frequency and detection parameters of certain informative features in the resonant response of the protective agent to the mentioned external influence with after automatic comparison of the recorded parameters of these informative features with the reference values stored in the memory of the detection means, characterized in that the passive protective means is made in the form of a metallized at least three-layer resonant filter structure, which includes a planar strip line consisting of at least of two metal microstrip lengths equal to half the wavelength of the radiation propagating in the strip line of the probe yuschim radiation, which are arranged with mutual overlap and are separated by a dielectric in said overlap area, wherein the magnitude of the dielectric gap between the microstrips do not exceed 20 microns in the overlap zone; solid metal screen; as well as the dielectric layer separating them; moreover, the radioelectric and geometric parameters of the planar strip line are selected in such a way that when it is probed by radiation with a microwave frequency of the microwave range, it is possible to use the characteristic peak values of the frequency response of the direct transmission and backward reflection coefficients of the external probe radiation as the informative features in the resonant response of the filter structure used in the detection process for comparison with a given range reference values of the corresponding parameters stored in the memory of the detection means. 2. The device according to claim 1, characterized in that the said separating dielectric layer is made of lavsan. 3. The device according to claim 1, characterized in that the three-layer resonant filter structure is gaplessly placed between two additional dielectric layers made, for example, of lavsan. 4. The device according to claim 1, characterized in that the radiation with a frequency of from 8 to 12 GHz is used as sounding radiation with a microwave frequency of the microwave range. 5. A device for protecting against counterfeiting and authenticity control of valuable products, including a passive protective agent of a given structure, which is configured to provide control of the presence and authenticity of the said agent by a physical method for analyzing resonance effects during external exposure to it by probing electromagnetic radiation of a given radio frequency and detection parameters of certain informative features in the resonant response of the protective agent to the mentioned external influence with after automatic comparison of the recorded parameters of these informative features with the reference values stored in the memory of the detection means, characterized in that the passive protective means is made in the form of a metallized at least five-layer resonant filter structure, which includes a planar strip line consisting of at least of two metal microstrip lengths equal to half the wavelength of the radiation propagating in the strip line of the probe yuschim radiation, which are arranged with mutual overlap and are separated by a dielectric in said overlap area, wherein the magnitude of the dielectric gap between the microstrips do not exceed 20 microns in the overlap zone; solid metal screen; a dielectric layer separating the strip line and the metal screen; an additional dielectric layer and an additional solid metal screen covering it, which are sequentially located on the side of the strip line, the radioelectric and geometric parameters of the plane strip line being selected in such a way that when it is probed with radiation from the microwave frequency, it is possible to use informative signs as resonant the response of the filter structure characteristic peak values of the frequency response coefficient s direct transmission and backscatter this structure, an external probe radiation used in the detecting process for comparison with a predetermined range of reference values corresponding to the parameters laid down in the memory of the detection means. 6. The device according to claim 5, characterized in that the said dielectric layers are made of lavsan. 7. The device according to claim 5, characterized in that the five-layer resonant filter structure is gaplessly placed between two additional dielectric layers made, for example, of lavsan. 8. The device according to claim 5, characterized in that the radiation with a frequency of from 8 to 12 GHz is used as probing radiation by the microwave frequency of the microwave range.