RU136241U1 - INFORMATIVITY NONLINEAR TRANSITION DETECTOR - Google Patents

Abstract

A detector of non-linear transitions of increased information content, comprising a probe signal transmitter, receivers tuned to double and triple the frequency of the probe signal, a processing unit, an indication unit, an antenna unit and a control unit that controls all components and units of the device except the antenna unit, where the output of the probe signal transmitter connected to the input of the antenna unit (transmitting antenna), the output of the antenna unit (receiving antenna) is connected to the inputs of the receivers, the outputs of which are connected to the input of the processing unit, which includes the addition of a broadband receiver, a block of narrow-band filters and a field strength indicator connected by two-way connections to the control unit, where the input of the broadband receiver is connected to the output of the antenna unit, the output of the antenna unit is connected to the input of the narrow-band filter unit, the output of which is connected to the indicator input field strength, and the output of the field strength indicator is connected to the display unit.

Description

The utility model relates to technical means for special purposes and can be used to search for radio-controlled explosive devices (RVU).

To search for radio-controlled explosive devices, nonlinear radars (NRL) are used [1]. Their principle of operation is based on the irradiation of the studied objects with short radio frequency pulses and the reception of response signals (re-emitted signals) at the frequencies of the second and third harmonics of the probe radiation.

The response signals at the frequencies of the second and third harmonics of the probe radiation appear as a result of spectral conversion of the probe signal on elements with a non-linear current-voltage characteristic. This characteristic is possessed by semiconductor elements that are part of electronic devices.

When irradiating electronic devices in the spectrum of the re-emitted signal, as a rule, even harmonic components of the probe radiation predominate (2nd harmonic).

The contacts of metal objects, especially those subjected to corrosion, also have semiconductor properties. When such objects are irradiated, in the spectrum of the reradiated signal, as a rule, the odd harmonic components of the probe radiation predominate (3rd harmonic). By the ratio of the levels of response signals at the frequencies of the second and third harmonics of the sounding frequency, it is possible to distinguish objects containing electronic circuits with semiconductor elements from objects made of metal.

The well-known non-linear transition detector NR-900EK consists of a probe signal transmitter, two receivers tuned to double and triple the signal frequency of the transmitter, control unit, processing unit, display unit and antenna unit (receiving and transmitting) (Fig. 1). [2, 3]

The monoharmonic probe signal generated by the transmitter is supplied to a directional transmitting antenna and is radiated in the direction of the object being examined. On non-linear (semiconductor) elements of the object under examination, the probing signal is converted to polyharmonic and re-emitted.

The re-emitted signal is received by the receiving antenna and fed to the inputs of the receivers, which emit the signals of the second and third harmonics of the sounding frequency. After processing the received signals in the processing unit, their levels are displayed on the indicator of the display unit. The control unit controls the operation of the transmitter of the probe signal, two receivers, the processing unit and the display unit, connecting and disconnecting nodes and units to ensure the operation of the tool. The decision on the type of object is made by the ratio of the levels of the response signals at the frequencies of the second and third harmonics of the sounding frequency.

The disadvantage of the NR-900 EK is its high sensitivity to artificial interference, characteristic of the locations (bookmarks) of radio-controlled explosive devices (RVU). Such interference includes semiconductor devices elements left in place by performers, metal parts having special galvanic coatings or traces of corrosion, rust, elements and materials having non-linear characteristics. These obstacles reduce the pace of intelligence by engineering units of the federal forces by about three times, and, consequently, the effectiveness of military missions. [2]

The purpose of creating a utility model is to increase the efficiency of the search for the HLR.

To achieve this goal, the problem is solved - the creation of a detector of nonlinear transitions of increased information content.

One of the ways to increase the information content of the NRL is to determine the resonant frequency of the oscillatory circuit, which is part of the RVU transceiver.

To determine the resonant frequency of the oscillatory circuit, a parametric location is successfully used [1]. However, the use of parametric locations in the NRL will significantly increase its complexity and cost.

The studies showed that during irradiation of the transceiver with a monoharmonic probe signal in the oscillatory circuit of the DFD receiver (transmitter), the oscillatory circuit is excited and the signal is re-emitted in the form of a response at the resonant frequency of the oscillatory circuit.

This phenomenon occurs as follows. Under the influence of a probe pulse, energy is stored in the oscillatory circuit, under the influence of which forced damped oscillations are excited at the resonant frequency of the circuit. The decay rate of these oscillations depends on the quality factor of the oscillatory circuit (the higher the quality factor, the longer the self-oscillation). [four]

Improving the efficiency of the search using the detector of nonlinear transitions consists in the possibility of determining the presence of the oscillatory circuit, which is part of the RVU transceiver. Thus, the information content and noise immunity of the nonlinear detector during the search are increased.

To increase the information content and noise immunity of the nonlinear transition detector, it is proposed to supplement the existing device with a broadband receiver, a block of narrow-band filters, and an indicator of the radio frequency signal.

The invention is illustrated by drawings, where:

- figure 1 presents the structural diagram of the detector NR-900EK [2, 3];

- figure 2 is a structural diagram of the proposed detector of nonlinear transitions.

The proposed device consists of a transmitter 1 of the probing signal, receivers 2 and 3, tuned to double and triple the frequency of the signal of the transmitter 1, respectively, control unit 4, processing unit 5, display unit 6, antenna unit 7, broadband receiver 8, narrow-band filter unit 9 and indicator 10 of the radio frequency signal.

The transmitter 1 of the probing signal at the command of the control unit 4 generates short probing radio frequency pulses that are fed to the directional transmitting antenna of the unit 7 of the antennas and radiated in the direction of the object being examined.

Receivers 2 and 3 are designed to amplify the response signal received from the antenna and to extract its even and odd harmonics. Receiver 2 is tuned to isolate from the received signal response equal to twice the frequency of the transmitter signal (2nd harmonic), and receiver 3 is tuned to triple the frequency of the transmitter signal (3rd harmonic). From the outputs of the receivers 2 and 3, the received signals are fed to the processing unit 5.

The control unit 4 controls the operation of all blocks and nodes of the detector of nonlinear transitions, except for block 7 antennas (receiving and transmitting). The control units of the control unit set the radiation power and the attenuation value of the input signals of the receivers 2 and 3. It has two-way communication with the transmitter 1, broadband receiver 8 and block 9 of narrow-band filters.

The processing unit 5, using the attenuation coefficients set by the control unit, processes the signals from the receivers and determines their levels with the subsequent display of these levels on the indicators of the display unit 6.

The display unit 6 has two signal level indicators that display the levels of the signals coming from receivers 2 and 3, and an indicator of the field strength of the signal coming from block 8 if there is an oscillating circuit in the detection object.

Block 7 antennas consists of a receiving and transmitting antennas located in one housing coaxially. The transmitting antenna is connected to the transmitter 1 of the probe signal and is intended for directional emission of a monoharmonic signal in the direction of the object being examined. The receiving antenna of the antenna unit 7 is designed to receive response signals from objects irradiated with a sounding signal.

Broadband receiver 8 is designed to receive signals in the frequency band where the transmit-receive devices used to control explosive devices work.

Block 9 narrow-band filters is used to filter the probing signal of high-frequency oscillations of the first carrier frequency, the second and third harmonics of the response from nonlinear transitions.

The field strength indicator 10 is designed to measure and display the field strength level of a signal that has passed through a broadband receiver 8 and a narrow-band filter unit 9.

The device operates as follows.

The monoharmonic probe signal generated by the transmitter 1 of the probe signal is supplied to the transmitting antenna of the antenna unit 7 and is radiated in the direction of the surveyed object. The control unit 4 controls the operation of the transmitter 1 of the probing signal, receivers 2, 3 and 8, the processing unit 5 and the indication unit 6. On non-linear (semiconductor) elements and the oscillatory circuit (if any) of the object under examination, the probe signal is converted to a polyharmonic signal and re-emitted.

The re-emitted signal is received by the receiving antenna of the antenna unit 7 and is fed to the inputs of receivers 2 and 3, which emit the signals of the second and third harmonics of the sounding frequency, as well as to the input of the broadband receiver 8, which receives a signal from the object’s oscillatory circuit arising from the influence of the probe signal nonlinear transition detector. According to the ratio of signal levels of the 2nd and 3rd harmonics, objects are distinguished that contain electronic circuits with semiconductor elements and objects made of metal, and the presence of a resonant frequency in the signal from block 8 concludes that there is an oscillatory circuit in the detection object and the nature of the detected object. From the output of this receiver, the signal enters block 9 of narrow-band filters. The narrow-band filter unit 9 filters out the sounding frequency of the transmitter at the first, second and third harmonics. After processing the signals received by the receivers 2 and 3 in the processing unit 5, their levels are displayed on the indicator of the display unit 6. Also on the indicator of the display unit displays the frequency of the signal from the oscillatory circuit, if any, highlighted by the indicator of the radio frequency signal from the received response processed by the receiver 8. The combination of all signals allows the operator to determine the presence of an oscillatory circuit in the detection object and to draw a conclusion about the nature of the detected object.

The proposed utility model allows to increase the informativeness and noise immunity of the detector of nonlinear transitions when performing the tasks of reconnaissance of the terrain (objects) for the presence of an IED by fixing the presence of an oscillatory circuit in the survey object and, therefore, to increase the efficiency of the search for an IED.

LIST OF USED LITERATURE

1. Dikarev VI, Methods and means of detecting objects in covering environments / V.I. Dikarev, V.A. Zarenkov, D.V. Zarenkov. - St. Petersburg: Science and Technology, 2004. - 280 p.

2. Portable detector of nonlinear transitions "NR-900EK" / Operation manual. UTDN 468165003 RE. - CJSC “Protection Group - UTTA”.

3. Website http://www.detektor.ru

4. Yavorsky BM, Handbook of Physics / B.M. Yavorsky, A.A. Detlaf // 2-ed., Rev. - M .: Nauka, 1985 .-- 512 p.

5. Pat. 2424024 Russian Federation, IPC ⁷ H01P 1/00. Narrow-band filter / V.P. Razinkin, V.N. Udalov, D.S. Matveev. - No. 2009115096/07; declared 04/20/2009; publ. 10/27/10. - 3 ill.

Claims (1)

A detector of non-linear transitions of increased information content, comprising a probe signal transmitter, receivers tuned to double and triple the frequency of the probe signal, a processing unit, an indication unit, an antenna unit and a control unit that controls all components and units of the device except the antenna unit, where the output of the probe signal transmitter connected to the input of the antenna unit (transmitting antenna), the output of the antenna unit (receiving antenna) is connected to the inputs of the receivers, the outputs of which are connected to the input of the processing unit, which includes the addition of a broadband receiver, a block of narrow-band filters and a field strength indicator connected by two-way connections to the control unit, where the input of the broadband receiver is connected to the output of the antenna unit, the output of the antenna unit is connected to the input of the narrow-band filter unit, the output of which is connected to the indicator input field strength, and the output of the field strength indicator is connected to the display unit.

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