RU2669203C1 - Energy-independent transponder - Google Patents

Abstract

FIELD: security systems; electrical equipment.

SUBSTANCE: invention relates to the field of protected and specially protected objects with increased requirements to their safety ensuring remote identification and control. For this, the energy-independent transponder contains the transceiver antenna connected to the delay line on the surface acoustic waves, common input / output converter and reflective elements. Reflective elements are made in the form of interdigital transducers, to which terminals the m threshold or analog sensors are connected for the protected object state monitoring. Input / output converter consists of n bi-directional interdigital transducers connected by slanted potential buses. Input / output converter is made compatible with the external wave path and is connected to the transceiver antenna by the coaxial cable.

EFFECT: technical result is the energy-independent transponder development with the protected object state monitoring sensors and increase in its operation range.

3 cl, 3 dwg

Description

The invention relates to the field of remote identification and control of protected and specially protected objects with increased requirements for ensuring their safety.

Known transponder systems based on semiconductor large integrated circuits (LSI), widely used, for example, when working with ATMs. However, such systems do not provide resistance to such destabilizing factors as ionizing radiation.

Also known transponder, proposed for use in an automated system for monitoring objects [1]. This device contains a piezoelectric transducer based on surface acoustic waves (SAW) and a reflective delay line (OLZ), made on the same substrate, and control sensors connected to the piezoelectric transducer. A significant drawback of the presented transponder is the method of connecting control sensors that are connected to the piezoelectric (input) transducer and upon triggering of which energy will be redistributed to the OLC, which will lead to an increase in the uneven amplitude of the pulses of the information signal and, in turn, will complicate its processing. In addition, the number of sensors will be limited by the number of piezoelectric transducers, which in case of shunting will reduce the information capacity of the transponder and reduce the transmission range of information. Since the sensors are connected directly to the piezoelectric (input) transducer, the design of this transponder is difficult to implement without using an external power source.

The closest in technical essence to the proposed technical solution is a transponder (prototype) [2, 3] for the detection and identification of an object.

The transponder contains a solid-state repeater based on a multi-tap SAW delay line. The main disadvantage of the transponder selected as a prototype is the insufficient range of information transmission, since this delay line is made in a unidirectional version, which leads to a loss of 50% of energy. To register the controlled parameters, the taps of the output interdigital transducers are switched by external electric circuits, which, when the sensor is triggered, will redistribute energy in the reflective delay line and increase the unevenness of the amplitudes of the pulses of the information signal.

The technical result of the invention is the creation of a non-volatile transponder with sensors for monitoring the status of the protected object and increasing the range of its operation, which will remotely receive information about its condition during and after exposure to critical destabilizing factors.

The technical result is achieved in that in a non-volatile transponder containing a solid-state repeater made on the basis of a delay line on surface acoustic waves and a transceiver antenna, a solid-state repeater is made on the basis of a multi-channel reflective delay line, which includes a common input / output converter and reflective elements. Reflective elements are made in the form of interdigital transducers, to the terminals of which m threshold or analog sensors of monitoring the state of the protected object are connected. The input / output converter consists of n bidirectional interdigital converters connected by inclined potential buses. The input / output converter is made consistent with the external wave path and connected by a coaxial cable to the transceiver antenna.

The technical result is achieved by the fact that in the non-volatile transponder the reflective elements are made in a unidirectional version.

The technical result is achieved by the fact that in the non-volatile transponder in front of the reflective elements additional reflective reflectors are installed, which are a metallized strip located perpendicular to the direction of propagation of surface acoustic waves.

In FIG. 1 shows a diagram of the implementation of the proposed non-volatile transponder based on a multi-channel SIR for SAW, which shows: 1 - transceiver antenna, 2 - coaxial cable connecting the transceiver antenna with the input / output converter of a multi-channel OSS, 3 - input / output converter of a multi-channel OSS, 4 - reflective elements made in the form of IDT, 5 - reflective reflectors, 6 - threshold or analog sensors connected to the IDT conclusions, 7 - transponder case, W - IDT aperture.

In FIG. Figure 2 shows an information signal in which 8, 9 are pulses responsible for recording destabilizing factors acting on an object (pulse amplitudes are equal to logical “0”), and the remaining pulses are identifying this object.

In FIG. Figure 3 shows an information signal in which 10, 11 are pulses signaling that the sensors detected facts that threshold values of destabilizing factors were exceeded (pulse amplitudes are logical “1”).

The transponder operates as follows.

The transponder uses the energy of the initiating radio pulse to form an information encoded signal from the controlled object. The transponder 1 transceiver antenna receives a short initiating radio pulse, which is transmitted through a coaxial cable 2 to the input / output transducer 3, converting it into a surface acoustic wave propagating from it in both directions, each in its own acoustic channel. SAW, having reached the reflective elements 4, 5, is reflected from them and reaches the input / output converter 3, which converts it into a response radio pulse containing an information package including the identification number of the protected object and information about the status of threshold or analog sensors 6. Input / output transducer 3, reflective elements in the form of IDT 4, reflective reflectors 5 and sensors 6 are located in the transponder housing 7. Threshold or analog sensors 6 can be placed inside the protected area object, in places exposed to critical loads or in places of special control of changes in physical parameters and located both inside the transponder body 7 and outside it. The metallization coefficient of the reflecting elements 4 is selected in such a way that when the sensor is triggered, the corresponding IDT closes (or opens), as a result of which the SAW reflection coefficient changes to the minimum (or maximum) value, thereby changing the pulse amplitudes 8, 9, which change (pulses 10, 11) it is possible to draw conclusions about the state of the protected object.

To increase the range of the remote identification system (transmitting an information signal) in the proposed transponder, the amplitude coding of the information signal is used. Reducing the attenuation of the pulses of the information signal is an important technical task. As can be seen from the radar equation

where D is the identification range, λ is the operating wavelength, K ₁ is the gain of the antenna of the transmitter, K ₂ is the gain of the antenna of the transponder, P _per is the pulsed radiation power of the transmitter, P _pr is the maximum sensitivity of the receiver, m is the discrimination coefficient selected from conditions for ensuring the probability of correct identification, σ _olz is the attenuation of the pulses of the information signal, with a decrease in the attenuation of the information signal (i.e., with an increase in the amplitudes of the pulses), the transmission range of the transponder information increases derom.

An additional advantage of the invention is the possibility of matching the input / output converter with the external wave path at the stage of designing the topology of the multichannel OLS transponder, which eliminates the use of matching circuits and elements and, thus, increases the resistance of the product to destabilizing factors, simplifies the design, reduces its cost and significantly increases the range of identification of an object with a transponder installed on it (or in it).

As was shown in [4], the most effective connection scheme for a multi-channel OLS is a series-parallel connection of a single IDT of an input / output converter with a relatively short information signal delay time (from 2 to 50 μs). This is because the active component of the radiation resistance at the center frequency has the form [5]

where G _a (ω _c ) is the active component of the radiation conductivity, ω _c is the center frequency, C _t is the static capacitance of a single IDT.

The static capacity of a single IDT is calculated by the formula:

, а/р - коэффициент металлизации; N_p - число пар электродов; W - апертура ВШП; P_ν(cosΔ) - полином Лежандра, v=-1/S_e; ε_p - диэлектрическая проницаемость пьезоэлектрика.where γ = 1, 4/3, 2 for S _e = 2, 3, 4, respectively - the number of electrodes per one period;

, and / p is the metallization coefficient; N _p is the number of pairs of electrodes; W - IDT aperture; P _ν (cosΔ) is the Legendre polynomial, v = -1 / S _e ; ε _p is the dielectric constant of a piezoelectric.

As was shown in [6], for the best conversion of the initiating radio pulse into a SAW, the aperture W of a single IDT of an input / output converter must satisfy the condition:

where λ is the SAW length, x is the distance from the IDT of the input / output converter to the farthest reflective element, β is the anisotropy parameter.

Thus, the value of R a (ω _c ) can be corrected by the switching circuit of single IDTs of the input / output transducer and the selection of their optimal aperture W, which will make it possible to refuse to use matching circuits in the transponder and, at the same time, reduce the attenuation of the information pulse amplitudes signal.

The implementation of the potential input / output converter buses with a slope allows part of the surfactant energy reflected from them during its passage through the acoustic channel to deviate from the direction of the pure mode (coinciding with the crystallographic axis of the piezoelectric substrate), thus eliminating additional parasitic reflection of the surfactant, which allows to simplify the processing of the information signal generated by the transponder.

Reflective IDTs made in a unidirectional version most effectively reflect the incoming surfactant [7], which makes it possible to increase the pulse amplitudes of the information signal.

In the proposed transponder, the maximum number of monitored parameters (the number of installed monitoring sensors) is equal to twice the number of single IDTs that form the input / output converter. In addition, the information capacity of the transponder can be increased by placing in front of the reflective elements made in the form of IDT additional reflective reflectors, and the encoding of the information signal can be carried out as a topological method, i.e. the inclusion or exclusion of a reflective reflector from the topology of a multichannel OLS on a surfactant, and bypassing of reflective elements.

As a result of the use of the proposed technical solutions when creating a non-volatile transponder based on a multichannel OLS on a surfactant, it is possible to achieve an identification range of more than 15 m, the obtained identification range allows you to remotely receive information about the state of the protected object during exposure to critical destabilizing factors (for example, in the process fire).

Implementation of the proposed transponder will simplify and increase the information content of the state of the controlled object in case of emergency situations.

Literature

1. Patent No. 2495489 IPC G06K 7/00 (2006.01), G08B 25/10 (2006.01). Automated system for remote monitoring of objects in stationary storages / Verezhansky V.Yu., Knyazev I.A., Kostyukevich ON, Yuferev V.I. // Publ. 10/10/2013 Bull. No. 28.

2. Patent No. 2133482 of the Russian Federation IPC G01S 13/00. Transponder / Bakhirev G.G., Kiselev V.K., Pozdeev A.N., Tremasov N.Z., Yakovlev V.V. // Publ. 07/20/1999.

3. Patent No. 2126980 of the Russian Federation IPC G01S 13/75, 13/76. A method for detecting and identifying an object / Bakhirev G.G., Kiselev V.K., Pozdeev A.N., Tremasov N.Z., Yakovlev V.V. // Publ. 02/27/1999.

4. Patent No. 2610415 IPC Н03Н 9/30 (2006.01). Multichannel reflective delay line / Dorokhov S.P., Salov A.S. // Publ. 02/10/2017. Bull. Number 4.

5. D. Morgan "Devices for processing signals on surface acoustic waves", M .: "Radio and communications", 1990.

6. S.P. Dorokhov, V.A. Kozlov. The effect of crystal anisotropy of 1 lMuS on the change in the surfactant phase velocity / Physics and Technical Applications of Wave Processes: Abstracts of the XIV International Scientific and Technical Conference: Appendix to the journal “Physics of Wave Processes and Radio Engineering Systems” / Ed. V.A. Neganova. - Kazan: LLC "16PRINT", 2016.- 123 s.

7. Karapetyan G.Ya. Studies of unidirectional and slightly apodized interdigital transducers of surface acoustic waves and the development of frequency selection devices based on them. The dissertation of the candidate of technical sciences: 05.27.01 Veliky Novgorod, 2011. Link to the abstract: http://www.dissercat.com/content/issledovaniya-odnonapravlennykh-i-slaboapodizovannykh-vstrechno-shtvrevykh-preobrazovatelei-.

Claims (3)

1. Non-volatile transponder containing a transceiver antenna connected to a delay line on surface acoustic waves, including an input / output transducer and reflective elements made in the form of interdigital transducers, to the terminals of which m threshold or analog sensors of monitoring the state of the protected object are connected, which differs in that the input / output converter consists of n bidirectional interdigital converters connected to each other and connected to nym potential busbars, furthermore, the input / output converter is matched to the external wave path. 2. Non-volatile transponder according to claim 1, characterized in that the reflective elements are made in a unidirectional version. 3. The non-volatile transponder according to claim 1, characterized in that additional reflective reflectors are installed in front of the reflective elements, which are a metallized strip located perpendicular to the direction of propagation of surface acoustic waves.

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