RU2301429C2 - Passive transceiver - Google Patents

Abstract

FIELD: radio detection and ranging, applicable for transmission of signals of identification of the object of transmission and messages from the external information sources via and active radar to the consumer.

SUBSTANCE: the passive transceiver has an antenna, modulator, detector, solver, power source, identification code generator, synchronizer, lines of transmission of synchronizing pulses to the external information sources, modulator control unit, lines of transmission of messages from the external information sources.

EFFECT: expanded information potentialities of the passive transceiver due to the increase of the quantity of the transmission carrier frequencies and the quantity of the information sources participating in the transmission.

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Description

The invention relates to radar and is intended for transmission of identification signals of the transmission object and messages from external information sources through an active radar to the consumer. It can be used in navigation systems, in air traffic control systems, in security systems of remote objects, in communication systems and in other areas.

From US patent No. 5,247,305 of FIG. 1, a passive transceiver is known for receiving interrogation signals and transmitting response signals in a moving object recognition system. It contains an antenna, a rectifier, a modulator and an identification code generator. In a passive transceiver, a request signal from the interrogator (active radar) is received by the antenna and fed to the input of the rectifier and to the input-output of the modulator. Part of the request signal is absorbed by the rectifier and converted by it into a constant voltage. DC voltage from the output of the rectifier is supplied to the input of the identification code generator. The identification code generator has a memory in which identification information is stored. When a constant voltage is applied to the input of the code generator, an identification code is read from its memory. The identification code from the output of the code generator is fed to the input of the modulator. Simultaneously with the identification code, another part of the request signal is input to the output of the modulator. In it, it is modulated by an identification code so that the request signal is converted into a response signal. The response signal includes identification information. The modulator reflects the signal and returns it back to the antenna. The antenna emits a response signal to the interrogator.

A disadvantage of the passive transceiver shown in US Pat. No. 5,247,305 in FIG. 1 is that it is powered by the rectifier converting a portion of the electromagnetic energy of the interrogation signal. This leads to disruption of the information transmission channel in interference conditions.

Of the known passive transceivers closest to the claimed technical essence is a passive transceiver for receiving interrogation signals and transmitting response signals in a system for identifying moving objects, is shown in US patent No. 5247305 on Fig and described on page 13. It contains: antenna 1; modulator 2; detector 3; solver 4; power source 5; identification code generator 6. The input of the modulator 2 is connected to the output of the identification code generator 6, and its input-output is connected to the antenna 1 and to the input of the detector 3. The output of the detector 3 is connected to the first input of the resolver 4. The second input of the resolver 4 is connected to the first output of the source power 5. The output of the deciding device 4 is connected to the first input of the identification code generator 6. The second input of the identification code generator 6 is connected to the second output of the power source 5.

Passive transceiver operates as follows. The request signal from the interrogator (active radar) is received by the antenna 1 and fed to the input-output of the modulator 2 and the input of the detector 3. A part of the request signal received by the detector 3 is absorbed and detected by it. As a result, the voltage of the envelope of the request signal is generated at the output of the detector 3, which is then fed to the first input of the resolver 4. The voltage from the first output of the power supply 5 is supplied to the second input of the resolver 4. The solver 4 compares the voltage of the envelope of the request signal with a threshold voltage and on its basis it generates control signals for the identification code generator 6. From the output of the resolving device 4, control signals are supplied to the first input of identification nnogo code generator 6. The second entry identification code generator 6 is supplied voltage from the second output power source 5. The identification code generator 6 comprises a memory for storing identification information. When it receives control signals from the output of the deciding device 4 at its first input, the code generator 6 is turned on and generates an identification code based on information read from the memory. The identification code from the output of the code generator 6 is fed to the input of the modulator 2. Simultaneously with the identification code, the second part of the request signal is supplied to the input-output of the modulator 2. Under the action of the identification code, the modulator 2 changes the output impedance so that the request signal is converted into a response. The response signal contains identification information. Modulator 2 reflects the response signal and returns it back to antenna 1. Antenna 1 emits a response signal towards the interrogator (active radar).

A disadvantage of the passive transceiver shown in US Pat. No. 5,247,305 to FIG. 14 is the ability to transmit messages only from the built-in identification code generator and only at the carrier frequency of the interrogation signal. This significantly limits his information capabilities.

The aim of the invention is to expand the information capabilities of a passive transceiver by increasing the number of carrier frequencies and the number of information sources involved in the transmission.

This goal is achieved by the fact that in a known passive transceiver containing a series-connected antenna 1 and a modulator 2, a series-connected detector 3 and a resolver 4, a power source 5 and an identification code generator 6, the second input of which is connected to the second output of the power source 5, connected to the first an output to the second input of the resolving device 4, introduced the synchronizer 7, the transmission line of the synchronizing pulses to external sources of information 8, the transmission line of messages from external sources information 9 and the control unit of the modulator 10. The first input of the synchronizer 7 is connected to the output of the deciding device 4, and its second input is connected to the second output of the power source 5. The first group of outputs of the synchronizer 7 is connected to the first group of inputs of the identification code generator 6, and the second group of it outputs connected to the transmission lines of the synchronizing pulses to external sources of information 8. The group of outputs of the identification code generator 6 is connected to the first group of inputs of the control unit of the modulator 10. Co w A line of messages from external information sources 9 is connected to a different group of inputs of the control unit of the modulator 10. The third input of the control unit of the modulator 10 is connected to the third output of the power source 5. The group of outputs of the control unit of the modulator 10 is connected to the second group of inputs of the modulator 2 connected to the output of the detector 3.

Figure 1 presents the structural diagram of a passive transceiver.

2 shows voltage plots illustrating the principle of operation of a passive transceiver.

A passive transceiver for transmitting identification signals of a transmission object and messages from external information sources through an active radar to a consumer comprises an antenna 1, a modulator 2, a detector 3, a resolver 4, a power supply 5, an identification code generator 6, a synchronizer 7, transmission lines of synchronizing pulses to external information sources 8, transmission lines of messages from external information sources 9, the control unit of the modulator 10.

The antenna 1 of the passive transceiver is, for example, a Luneberg spherical lens. Its design and principle of operation are described, for example, in [2] on p.272-273. Antenna 1 is connected to the first input-output of modulator 2. As a modulator 2 in a passive transceiver, for example, a discrete reflective phase shifter on p-in diodes is used, providing a phase change of the reflected signal in the range from 0 to 360 ° with a resolution of, for example, 22, 5 ° and containing m = 17 pin diodes (diode sections). The number of inputs of the second group of inputs of modulator 2 is m. The specified phase shifter is described, for example, in [3] on S. 349-350. The output of the modulator 2 is connected to the input of the detector 3. The detector 3 is, for example, an amplitude detector assembled on a semiconductor diode. It is a consistent load. The output of the detector 3 is connected to the first input of the resolver 4. The solver 4 is made, for example, according to the Schmitt trigger scheme on the comparator. Its structure and principle of operation are described, for example, in [4] on p.223. The second input of the deciding device 4 is connected to the first output of the power source 5. As a power source 5 in the passive transceiver, for example, batteries are used. The output of the solver 4 is connected to the first input of the synchronizer 7. The second input of the synchronizer 7 is connected to the second output of the power source 5. The synchronizer 7 is, for example, a multiphase clock generator shown in [5] in Fig.5.78 and described on p.119. The first N of its outputs form the first group of outputs, and the remaining (N + 1) ÷ (N + K) belong to the second group of outputs. The first group of outputs of the synchronizer 7 is connected to the same group of inputs of the identification code generator 6, and the second group of outputs of the synchronizer 7 is connected to the transmission lines of synchronizing pulses to external information sources 8. As transmission lines of synchronizing pulses to external information sources in a passive transceiver, for example, coaxial cables. The identification code generator 6 is, for example, read-only memory on the KM1608PT1 chip. It stores identification information. The outputs of the KM1608RT1 microcircuit form the group of outputs of the identification code generator 6. They are connected to the first group of inputs of the control unit of the modulator 10. The second group of inputs of block 10 is connected to the message transmission lines from external information sources 9. As the message transmission lines 9 in a passive transceiver, for example, coaxial cables. The control unit of the modulator 10 is, for example, a multi-channel pulse distributor. The number of its channels is equal to the number of inputs in the first and second groups of inputs of block 10. As a channel of a multi-channel pulse distributor in block 10, for example, the circuit shown in [6] in Fig. 9.8 and described on p.123 is used. Its input through a differentiating RC circuit is connected to the corresponding input of unit 10. The differentiating circuit generates a short trigger pulse of the distributor channel, which coincides with the leading edge of the signal received at the input of block 10. The outputs of the same name on all channels of the multi-channel pulse distributor are interconnected and loaded onto the same circuit control pin diodes. A variant of the control circuit of the p-i-n diode is given, for example, in [7] in Fig. 5.14 and described on p.169-170. The number of pin diode control circuits is equal to the number of outputs in the group of outputs of block 10 and matches the number of pin diode sections of modulator 2. Power supply to the control unit of modulator 10 is provided through its third input, which is connected to the third output of power supply 5. The group of outputs of the control unit of modulator 10 is connected to the second group of inputs of modulator 2.

External sources of information for a passive transceiver are, for example, optoelectronic detectors of object radiation (see [8] p. 530), contact sensors of alarm systems (see [9] p. 273), sensors of technical condition monitoring systems on-board equipment, etc. To the input of each sensor, a normally closed or normally open relay contact, a self-resetting button, etc., the same-name transmission line of synchronizing pulses 8 is connected, and the output of each of them is connected by the same-name message transmission line 9 to the second group of inputs of the modulator 10 control unit.

и их длительность Δt задаются исходя из требуемой величины смещения Δf несущей частоты ответного сигнала относительно частоты запросного сигнала f₀. Согласно [10] (см.фиг.2,к),Passive transceiver operates as follows. The antenna 1 of the passive transceiver receives a request signal from the interrogator (see figure 2, a). From the input of the antenna 1 through the modulator 2, the request signal is fed to the input of the detector 3. At the time of the request signal to the input of the detector 3 (time, for example, t ₁ in figure 2, a) pin diodes of the modulator 2 are in the off state. For this reason, most of the power of the interrogation signal is absorbed by the detector 3, and its smaller part is reflected towards the interrogator. The detector 3 selects the envelope of the request signal (see Fig. 2, b) and brings the envelope voltage to the first move of the resolver 4. The _solver 4 (Schmitt trigger on the comparator) has two comparison thresholds U _{por. 1} and U _por. 2 (cm .ig. 2, b). When the voltage exceeds the envelope of U _{pore 1, the} Schmitt trigger is transferred from the state of logical zero at its output to the state of the logical unit (see _figure 2, c). The state of the logical unit at the output of the solver 4 is maintained until the envelope voltage of the request signal exceeds the voltage U _p . 2 of the Schmitt trigger. From the output of the solver 4, the pulsed logic signals are fed to the first input of the synchronizer 7. The synchronizer 7 distributes the pulses obtained from the packet of request signals, so that the pulses with numbers 1,2, ... N are applied to the same numbers of outputs of the first group of outputs of the synchronizer 7, and the pulses with numbers (N + 1), (N + 2), ..., (N + K) are fed to the numbers of the pins 1,2, ... To the second group of outputs of the synchronizer 7, respectively. Pulse logical signals through the first group of outputs of the synchronizer 7 are fed to the first group of inputs of the identification code generator 6 and then to the address inputs of the same name and the resolution input of the KM1608RT1 microcircuit. A read-only memory device generates an identification code from them, which represents pulses with amplitudes of a logical unit or zero, combined in time with the same request signals (see Fig. 2, c, d). The identification code through the group of outputs of the code generator 6 is supplied to the first group of inputs of the control device of the modulator 10. The signals from the second group of outputs of the synchronizer 7 through the transmission lines of the synchronizing pulses 8 are fed to the inputs of the same external information sources. Each external source of information generates a pulse at its output with the amplitude of a logical zero or one (see figv, d) in accordance with its current state. From the outputs of external information sources, these pulses are fed to the second group of inputs of the modulator 10 control unit. Block 10 generates pin diode control signals only when a pulse with an amplitude of a logical unit arrives at one of the inputs of the first or second group of its inputs. In this case, the differentiating chain forms a short trigger pulse from the input signal (see Fig. 2, e), which coincides with the leading edge of the input signal. According to the start pulse, the channel of the same name of the pulse distributor during the action time of the request signal τ _u sequentially generates control pulses of duration Δt at its m outputs (see Fig. 2, e-i). Number of control pulses

and their duration Δt are set based on the desired offset value Δf of the carrier frequency of the response signal relative to the frequency of the request signal f ₀ . According to [10] (see Fig. 2, k),

where T is the time interval of the phase change of the request signal from 0 to 360 ° in modulator 2, moreover, in accordance with [3] (see pages 349-350)

во временных интервалах

mΔt (см.фиг.2,к). Сложение дискрет высокочастотного сигнала с различными фазами в фазовращателе приводит к формированию единицы в разряде информационного сообщения (ответного сигнала) на несущей частоте (см.фиг.2,л)Δφ - discrete phase shift of the request signal; λ is the wavelength in the phase shifter; L is the distance between the pin diodes in the phase shifter. The control pulses from the outputs of the distributor channel are fed to the pin diode control circuit and then through the group of outputs of block 10 to the second group of inputs of modulator 2. In the modulator 2, the control pulses sequentially transfer the pin diodes of the phase shifter from off to on and back. As a result of this, the modulator 2 reflects the interrogation signal with phase additions (m-1)

in time intervals

mΔt (see Fig. 2, k). Adding a discrete of a high-frequency signal with different phases in the phase shifter leads to the formation of a unit in the category of information message (response signal) at the carrier frequency (see figure 2, l)

where the sign of the offset Δf is specified by the direction of switching p-i-n diode sections.

The constant maintenance of one of the pin diodes of modulator 2 in the on state when transmitting a unit in the discharge of a discrete message significantly increases the power of the signal reflected towards the radar (see Fig. 2, l interval t ₂ ≤t≤t ₃ ). This leads to a significant reduction power leaking to the input of the detector 3 through the modulator 2, and, therefore, to reduce the amplitude of the envelope of the request signal in the time interval t ₂ ≤t≤t ₃ (see figure 2, b). To exclude the influence of the envelope amplitude on the operation of the passive transceiver, its decision device 4 is made according to a two-threshold scheme.

The logical zero signal in the category of an information message, received at any of the inputs of the first or second groups of inputs of the control unit of the modulator 10, does not change its state. For this reason, all pin diodes of the modulator 2 are in the off state. The request signal passes through the modulator to detector 3 (matched load), where most of it is absorbed, and a small part is reflected and returns at the carrier frequency f ₀ in the direction of the interrogator (see Fig. 2, a-l), i.e. zero in the discharge of the information message is transmitted by a passive transceiver on the carrier frequency of the interrogation signal of low power.

Modern radars, as a rule, contain several receiving channels, which allows them to transmit request and response signals at different carrier frequencies in their normal operating mode. Then the presence at known time instants of a response signal from a passive transceiver at the output of a threshold device of a known radar channel can be considered as a unit transmission in the category of an information message, and its absence as a zero transmission.

Information sources

1. US patent No. 5247305 MKI ⁵ G01S 13/74.

2. Kocherzhevsky G.N. Antenna feeder devices. - M.: Communication, 1972.

3. Antennas and microwave devices. Phased Antenna Design: A Textbook for High Schools / V.S. Filippov, L.N. Ponamorev, A.Yu. Grinev et al. / Ed. D.I.Voskresensky - 2nd ed., Ext. and reslave. - M .: Radio and communications, 1994.

4. Gutnikov B.C. Integrated electronics in measuring devices. - L .: Energoatomizdat, 1988.

5. The use of integrated circuits in electronic computing: a Handbook / R.V. Danilov, S.A. Eltsova, Yu.P. Ivanov, etc. / Ed. B.N. Fayzulaeva, B.V. Tarabrina. - M.: Radio and Communications, 1986.

6. Goroshkov B.I. Radio-electronic devices: Reference. - M.: Radio and Communications, 1984.

7. Khizh G.S., Vendik I.B., Serebryakova E.A. Microwave phase shifters and switches: Features of creation on p-i-n diodes in integrated design. - M.: Radio and Communications, 1984.

8. Miroshnikov M.M. The theoretical basis of optoelectronic devices. - L .: Engineering, 1983.

9. The reference book of the amateur radio designer: in 2 books. Book 1. A.A. Bokunyaev, N.M. Borisov, E.B. Gumel et al. / Ed. N.I. Chistyakova - M.: Radio and Communications, 1993.

10. Maksimov E.R. The spectrum of the signal at the output of a discrete phase shifter. - Radio engineering, 1990, No. 2, p. 73-76.

Claims (1)

A passive transceiver comprising a series-connected antenna and a modulator, a series-connected detector and a resolver, a power source and an identification code generator, the second input of which is connected to a second output of a power source connected by a first output to a second input of a resolver, characterized in that a synchronizer is inserted into it , the first input of which is connected to the output of the deciding device, and the first group of outputs - with the first group of inputs of the identification code generator, l transmitting synchronizing pulses to external information sources connected to the second group of outputs of the synchronizer, a modulator control unit, the first group of inputs of which is connected to the group of outputs of the identification code generator, and the group of outputs - to the second group of inputs of the modulator, connected by the output to the detector input, and the transmission line messages from external sources of information connected to the second group of inputs of the control unit of the modulator, the third input of which is connected to the third output of the source pi anija connected to the second output to the second input of the synchronizer.

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