RU2757359C1 - Radiovisor based on millimeter emission receivers with pyramidal horn antennas - Google Patents

Abstract

FIELD: measuring equipment.

SUBSTANCE: invention relates to the field of measuring equipment and pertains to a radiovisor based on millimeter emission receivers with pyramidal horn antennas. The radiovisor comprises a sealed body closed with a transparent window on the front side and with a removable cover on the reverse side. Located inside the body is a dielectric plate foiled on two sides, located whereon are multi-element heat receivers made in metal-glass bodies. Pyramidal weakly directional horn antennas are placed in the covers of the bodies. The pyramidal horns are installed relative to each other, accounting for the contact of the surfaces of the volumes of the directivity patterns thereof, in two perpendicular planes of the electric and magnetic vectors based on the level of the half-power of emission reception, electronic apparatuses of the interface of the measuring system are located on the upper and lower parts of the plate.

EFFECT: structural simplification and provided possibility of the radiovisor operating in the field conditions.

1 cl, 5 dwg, 1 tbl

Description

The invention relates to techniques for radio measurements, in particular to measuring the intensity of sources of electromagnetic radiation, and can be used for express research of the spatial distribution of energy (power), radiation of lens and mirror antennas at wavelengths of 1-3 mm.

Imaging devices are used to analyze pulsed and continuous radiation in the terahertz (THz) range in order to determine the size, configuration, and spatial distribution of radiation energy (power). Metrological support of modern radar and telecommunication systems is impossible without instrumentation. In connection with the active development of sources of terahertz radiation, it becomes urgent to develop devices for visualization and measurement of terahertz radiation, capable of functioning under industrial practice and in the field, providing rapid control of the parameters of this radiation. The lack of commercially available devices for visualizing terahertz radiation required the development of new methods for their registration.

The main problems in the development of radiation visualization devices are: ensuring a high level of sensitivity and its uniformity over the entire visualization field, the need to memorize information, short time for recording and erasing information, ensuring constant sensitivity when the ambient temperature changes.

Known is a device for visual observation and registration of electromagnetic radiation, intended for qualitative observation and quantitative measurements of the spatial distribution of radiation fields. (Radiovisor - a receiver of direct vision of infrared microwave radiation using crystal phosphors / A.P. Bazhulin, E.A. Vinogradov, I.A. ). The receiver operates on the principle of temperature quenching of luminescence, which corresponds to the spatial distribution of the intensity of the investigated field of IR-microwave waves. Local heating of the luminescent screen by the detected radiation leads to significant changes in the intensity of the screen glow caused by ultraviolet excitation (thermographic effect). The image of the distribution of the radiation energy density incident on the device can be observed both visually and by photographing with subsequent photometry or using other methods of registering visible radiation. The screen sensitivity is determined by the characteristics of the phosphor and the radiation power. The visual detection threshold of the device is about 1 mW / cm ² . On the screen of the radio imager, you can see the details of the image with a size of the order of tenths of a millimeter.

However, the device described above has a low sensitivity in the THz range and a short time constant of the device.

Known visualization device for infrared and millimeter radiation in the wavelength range of 0.4-16.67 microns and 2-3 mm (patent RU No. 2687992 IPC G01J 1/02 (2006.01) G01J 5/02 (2006.01) , Published: 05/17/2019 Bull. No. 14), containing a flat case with a support frame located in it in the form of two dielectric rings, and having two windows for recording radiation, while the flat case is fixed on a holder with a stand, a dielectric substrate covered with a structure made of thermochromic material with a hysteresis dependence of the color change on temperature, the case has a removable cover with an entrance window, the support frame is removable, the dielectric substrate is made of mica, covered with a film absorber made of nichrome alloy (Kh20N80), thickness 17-23 nm , on the other side of the substrate there is a thermochromic layer, made in the form of two versions: from Al-VO _x or a layer from black dye - CLC.

The disadvantage of the device is a semi-quantitative assessment of the power (energy) of the visualized radiation according to the color picture of the image (each color corresponds to a certain value of the radiation power (energy) density. For the Al-VO _x film structure, there are 3 gradations of brightness and chromaticity of the image, crystal, respectively, 5 gradations.

A device for visualization and measurement of millimeter radiation is known, consisting of a millimeter radiation receiver, an optical-mechanical scanner, an interface of the measuring system, an information processing program and a laptop. (A.S. Oleinik, V.P. Meshchanov, N.A.

The scanner provides the movement of the receiver along the x and y axes (creates a 2D projection of the radiation intensity distribution over the radio beam cross section). The interface of the measuring system outputs the measuring information to the input of the laptop, where, using the program, the voltage values of the measuring channels of the receiver are converted into the relief of the columns on the laptop screen (the height of each column corresponds to the power density of the corresponding measuring channel). In addition, each column is color-coded, which corresponds to the dependence of the receiver's threshold sensitivity. Information in the form of numerical values of the power density of the measuring channels of the receiver is displayed in parallel. Thus, a graphic, digital and color picture of the distribution of the power density of the radio beam in three dimensions (3D profile on the plane of the receiving area of the receiver) takes place on the laptop screen.

The main limitation of the use of the device is the scanning time (formation of the thermal field of the object). Optical-mechanical scanners, depending on the time of formation of the thermal field Tn, are subdivided: Tn> 20s - low-speed, 0.5s <Tn <20s - medium-speed, Tn <0.5s - high-speed, this limits the formation of the image raster.

Closest to the proposed invention is a passive radio imaging system operating in real time. The system consists of an antenna unit, a receiving matrix of sensors, a multichannel video signal processing unit, an ADC, a scanning system, a thermal stabilization device, a control unit for processing and visualizing a radio image (personal computer).

(Gladun V.V., Kotov A.V., Krivoruchko V.I. et al. Near passive radio imaging system of 3-mm range // Journal of radio electronics, 2010, No. 7 pp. 1-13)

The antenna of the device is made of an elliptical mirror, in the near focus of which there is a line of sensors. The observed object is in the far focus of the antenna. The signals from the line of sensors are fed to the transducer unit, where computer processing takes place and an image is built on the monitor screen. The optical axis of the antenna is deflected from the axis of the installation at a given angle. The sensor array is located in the focal plane with some displacement relative to the installation axis. This position leads to the displacement of the beams in the second focus relative to the axis of the antenna. Synchronization of scanning is carried out by swinging the mirror with a stepper motor. The path of the rays in the scanned area forms a raster of the image. The disadvantage of the system is the need to use an optical-mechanical scanner.

The technical problem of the present invention is to create a simple, compact design of a radio imager that provides visualization of the measurement of energy parameters of millimeter radiation and is capable of operating in the field.

The objective of the present invention is to eliminate the optical-mechanical system of scanning and image formation, to simplify the design and the possibility of its operation in the field.

The essence of the invention is characterized by the fact that a radiovisor based on receivers of millimeter radiation with pyramidal horn antennas consists of a sealed housing with an entrance window transparent for the recorded radiation and a removable back cover, a dielectric plate with double-sided metallization is fixed in front of the window, one or more multi-element receivers of millimeter radiation equipped with pyramidal weakly directional horn microantennas, horns of microantennas are placed from each other with the condition of conjugation of their surfaces of volumes of spatial radiation patterns in two perpendicular planes of electric E and magnetic H vectors at the level of half the radiation receiving power, electronic interface devices are located at free places of the plate surface measuring system.

The directivity of the horns is in the 20-5 range.

The radio imager can contain one multi-element receiver equipped with a pyramidal horn antenna with a directivity factor equal to 5.

The technical result is based on the combination of spatial radiation patterns of pyramidal horn antennas, which provides an increase in the reception area of the radiation object. Inside the waveguides of each of the antennas there is a receiving area of the receiver on which the measuring channels based on the Cr-mica-VO _x film structure are located.

The speed and high sensitivity of the radio imager are due to the use of multi-element receivers of millimeter radiation with pyramidal horn antennas.

Expansion of the radiation reception area of the object is achieved by using an even number of horns and aligning their spatial radiation patterns in the horizontal and vertical planes at the level of half the radiation receiving power.

The proposed invention is illustrated by illustrations, where:

in fig. 1 shows a block diagram of a radio imager;

in fig. 2 shows a longitudinal section of the body of a radio imager connected to a laptop;

in fig. 3 shows the case of a multielement receiver with a pyramidal horn antenna in section and a receiving area of the receiver with measuring channels;

in fig. 4 shows the radiation patterns of pyramidal horn antennas with a gain in the range of 26-2.6;

in fig. 5 shows a diagram of the installation of receivers with pyramidal horn antennas on a dielectric plate inside the housing of the radio imager.

Numbers 1-10 in the drawings denote:

1 - cylindrical body, 2 - window transparent for recorded radiation, 3 - foil-plated dielectric board, 4 - multi-element receivers with horn antennas, 5 - measuring system interface, 6 - removable cover, 7 - holder; 8 - COM port; 9 - rack; 10 - PC.

FIG. 1 shows a block diagram of a radio imager.

Millimeter radiation through the transparent window 2 of the housing 1 of the radio imager irradiates the surfaces of the aperture of the pyramidal horn microantennas 4. Inside the waveguides of the horn antennas there are receiving areas of the receivers, which are uniformly filled with measuring channels in the form of square pixels with a size of 0.15 × 0.15 mm ² based on the Cr- structure mica-VO _x . The gaps between the channels are equal in size to the measuring channels. The interface of the measuring system 5 carries out a sequential interrogation of all measuring channels and transmits information to the personal computer 10. With the help of the information processing program on the PC screen, a graphic, digital and color picture of the distribution of the power (energy) density of the radio beam is displayed in three dimensions (in the form of a 3D profile on the plane receiver pad).

FIG. 2 Longitudinal section of the body, connected to the PC, of the radio imager, where 1 - cylindrical body; 2 - window transparent for radiation; 3 - foil-clad dielectric board; 4 - multi-element receivers with horn antennas; 5 - interface of the measuring system; 6 - removable cover; 7 - holder; 8 - COM port; 9 - rack; 10 - PC.

The inventive device contains a cylindrical body 1, closed on the front side with a transparent window for registered radiation 2 and on the back side with a removable cover 6. Inside the body 1 between the window 2 and the cover 6 there is a dielectric plate with double-sided metallization 3. On the surface of the plate 3 in front of the window 2 there are one or more multi-element receivers of millimeter radiation 4 with pyramidal horn antennas. On the free surface of the plate 3 there are electronic devices of the interface of the measuring system 5. The body 1 is attached to the holder 7, which is connected to the rack 9. Inside the holder 7, there is a COM port 8, which connects the body of the radio imager with the PC 10.

FIG. 3 Sectional view of the receiver coupled with a pyramidal horn antenna: 11 - housing base; 12 - removable cover; 13 - dielectric substrate; 14 - horn antenna; 15 - pixels from Cr; 16 - pixels from VOx with contact pads; 17, 18 - current-carrying leads; 19 - dielectric column; 20 - gold plated leads.

The pyramidal horn microantenna 14 is fixed in the removable cover of the housing 12. Inside the base of the housing 11 there are dielectric pillars 19 on which the dielectric substrate is fixed 13. Inside the waveguide of the pyramidal horn 14 there is a receiver receiving platform on which the measuring channels are located in the form of pixels 0.15 × 0.15 mm ² . The measuring channels are made of a Cr-mica VO _x structure, wherein the Cr 15 pixels are on the front surface of the mica substrate 13, and the VO _x 16 pixels are on its reverse side. Pixels VO _x 16 have current-carrying leads 17, 18. The base of the case is equipped with gold-plated leads 20.

FIG. 4 shows the results of calculating the spatial radiation reception patterns of pyramidal horns conjugated with a rectangular waveguide WR6 (1.6 × 0.8 mm ² ) at a wavelength of 2.99 mm according to the method of work (Belotserkovsky GB Tasks and calculations for the course "Fundamentals radio engineering and antennas ", 1966, Moscow, Mashinostroenie, 197 p .; Voskresenskiy DI, Gostyukhin VL, Maksimov VM, Ponomarev LI Microwave Devices and Antennas / Ed. Voskresensky. 2nd ed., Additional and revised - M .: Radiotekhnika 2006. - 376 p.)

The calculation results are shown in Table 1.

1. Determine the area of the horn opening S _a

Where G is the gain, a 'and b' are the dimensions of the sides of the horn aperture.

2. Determine the dimensions of the sides of the horn opening a 'and b'

3. Determine the length of the horn based on

4. Determine

Calculation of the radiation patterns of pyramidal horn atennas with a gain G in the range of 26-2.6 are shown in Table 1.

Positions 1-6, the radiation reception patterns are presented depending on the antenna gain D _n in the range 26-2.6.

FIG. 5 Arrangement of receivers with horn antennas inside the housing of the radio imager, where 2 is the window, 3 is the dielectric plate, 12 is the receiver body, 14 is the pyramidal horn, 21 is the pattern in the H plane, 22 is the pattern in the E plane.

). Уровень половинной мощности приема излучения определяет расстояние от раскрыва рупора 23 до прозрачного окна 26 корпуса радиовизора 1.A diagram of the installation of receivers 22 with weakly directional pyramidal antennas 23 inside the housing of the radio imager 1 is shown.

). The level of the half power of radiation receiving determines the distance from the opening of the horn 23 to the transparent window 26 of the housing of the radio imager 1.

Example

The radiovisor contains a multi-element terahertz radiation receiver [US Pat. RU No. 2701187, IPC G01J 5/20 Terahertz radiation receiver based on VOx film, publ. 09/25/2019 Bul. No. 27]

The design of a multielement radiation detector based on a Cr - mica - VO _x film structure, including 12 measuring channels with a size of 0.15 × 0.15 mm ^{2, has been} developed. The receiving area of the receiver is 1.6 × 0.8 mm ² , which corresponds to the size of the wide and narrow walls of the rectangular waveguide of the horn microantenna. The waveguide of the horn antenna is in contact with the receiving platform of the receiver, and the horn itself is attached to the removable cover of the receiver body. The receiver is made in a standard metal-glass case 155.15-2 consisting of a base PAYA 4.880.007 and a cover PAYA 7.313007-0 (with a hole) measuring 29.35 × 19.35 × 4.4 mm.

The radio imager provides an express analysis of the distribution of radiation intensity over the cross section of the radio beam and the display on the PC screen of information from the measuring channels of the receivers in the form of columns of different heights and colors in proportion to the radiation energy (power), with parallel digitization of each channel.

Claims (1)

A radio imager based on receivers of millimeter radiation with pyramidal horn antennas, containing a multi-element millimeter radiation receiver, an interface of the measuring system, a personal computer, characterized in that the radio imager contains a sealed housing, closed on the front side with a window transparent for the detected radiation, and on the back side with a removable cover, inside the case between the window and the removable cover there is a dielectric plate foil on both sides, on which there are multi-element heat receivers made in metal-glass cases, in the case covers there are pyramidal weakly directional horn antennas with a directivity factor in the range of 20-10, pyramidal horns are installed between themselves taking into account the contact of the surfaces of the volumes of their directional patterns in two perpendicular planes of the electric and magnetic vectors at the level of half the radiation receiving power, on the upper and lower parts x plates are located the electronic devices of the interface of the measuring system.

Images