Phased array antenna HF post. Microwave phased array antenna

The second part of the article is devoted to ways to see what is beyond the horizon.
After reading the comments to, I decided to talk in more detail about VSD communications and radars based on the principles of the “heavenly beam”; about radars operating on the principles of the “earth beam” will be in the next article, if I talk about it then I’ll talk about it sequentially.

Over-the-horizon radars, an engineer’s attempt to explain the complex in simple terms. (part two) "Russian Woodpecker", "Zeus" and "Antey".

INSTEAD OF A FOREWORD

In the first part of the article, I explained the basics necessary for understanding. Therefore, if suddenly something becomes unclear, read it, learn something new or refresh something forgotten. In this part, I decided to move from theory to specifics and tell the story based on real examples. For examples, in order to avoid stuffing, misinformation and inciting the farts of armchair analysts, I will use systems that have been in operation for a long time and are not secret. Since this is not my specialization, I am telling you what I learned when I was a student from teachers in the subject “Fundamentals of Radiolocation and Radio Navigation,” and what I dug up from various sources on the Internet. Comrades are well versed in this topic, if you find an inaccuracy, constructive criticism is always welcome.

"RUSSIAN WOODPECKER" AKA "ARC"

"DUGA" is the first over-the-horizon radar in the union (not to be confused with over-the-horizon radars) designed to detect ballistic missile launches. Three stations of this series are known: Experimental installation “DUGA-N” near Nikolaev, “DUGA-1” in the village of Chernobyl-2, “DUGA-2” in the village of Bolshaya Kartel near Komsomolsk-on-Amur. At the moment, all three stations have been decommissioned, their electronic equipment has been dismantled, and the antenna arrays have also been dismantled, except for the station located in Chernobyl. The antenna field of the DUGA station is one of the most noticeable structures in the exclusion zone after the building of the Chernobyl nuclear power plant itself.

Antenna field "ARC" in Chernobyl, although it looks more like a wall)

The station operated in the HF range at frequencies of 5-28 MHz. Please note that the photo shows, roughly speaking, two walls. Since it was impossible to create one sufficiently broadband antenna, it was decided to divide the operating range into two antennas, each designed for its own frequency band. The antennas themselves are not one solid antenna, but consist of many relatively small antennas. This design is called a Phased Array Antenna (PAR). In the photo below there is one segment of such a PAR:

This is what one segment of the "ARC" HEADLIGHTS looks like, without supporting structures.

Arrangement of individual elements on the supporting structure

A few words about what PAR is. Some asked me to describe what it is and how it works, I was already thinking about starting, but I came to the conclusion that I would have to do this in the form of a separate article, since I need to tell a lot of theory for understanding, so an article about phased array will be in the future. And in a nutshell: the phased array allows you to receive radio waves coming at it from a certain direction and filter out everything that comes from other directions, and you can change the direction of reception without changing the position of the phased array in space. What is interesting is that these two antennas, in the photographs from above, are receiving, that is, they could not transmit (radiate) anything into space. There is a mistaken opinion that the emitter for the "ARC" was the nearby "CIRCLE" complex, this is not so. The VNZ "KRUG" (not to be confused with the KRUG air defense system) was intended for other purposes, although it worked in tandem with the "ARC", more about it below. The arc emitter was located 60 km from Chernobyl-2 near the city of Lyubech (Chernigov region). Unfortunately, I could not find more than one reliable photograph of this object, there is only a verbal description: “The transmitting antennas were also built on the principle of a phased antenna array and were smaller and lower, their height was 85 meters.” If anyone suddenly has photographs of this structure, I would be very grateful. The receiving system of the "DUGA" air defense system consumed about 10 MW, but I cannot say how much the transmitter consumed because the numbers are very different in different sources, but I can say offhand that the power of one pulse was no less than 160 MW. I would like to draw your attention to the fact that the emitter was pulsed, and it was precisely these pulses that the Americans heard on their air that gave the station its name “Woodpecker”. The use of pulses is necessary so that with their help it is possible to achieve more radiated power than the constant power consumption of the emitter. This is achieved by storing energy in the period between pulses, and emitting this energy in the form of a short-term pulse. Typically, the time between pulses is at least ten times longer than the time of the pulse itself. It is this colossal energy consumption that explains the construction of the station in relative proximity to a nuclear power plant - the source of energy. This is how the “Russian woodpecker” sounded by the way on American radio. As for the capabilities of the "ARC", stations of this type could only detect a massive rocket launch during which a large number of torches of ionized gas were formed from the rocket engines. I found this picture with the viewing sectors of three “DUGA” type stations:

This picture is correct partly because it only shows the viewing directions, and the viewing sectors themselves are not marked correctly. Depending on the state of the ionosphere, the viewing angle was approximately 50-75 degrees, although in the picture it is shown at a maximum of 30 degrees. The viewing range again depended on the state of the ionosphere and was no less than 3 thousand km, and in the best case it was possible to see launches right beyond the equator. From which it could be concluded that the stations scanned the entire territory of North America, the Arctic, and the northern parts of the Atlantic and Pacific oceans, in a word, almost all possible areas for launching ballistic missiles.

VNZ "CIRCLE"

For correct operation of the air defense radar and determination of the optimal path for the sounding beam, it is necessary to have accurate data on the state of the ionosphere. To obtain this data, the “CIRCLE” station for Reverse Oblique Sounding (ROS) of the ionosphere was designed. The station consisted of two rings of antennas similar to HEADLIGHTS "ARC" only located vertically, there were a total of 240 antennas, each 12 meters high, and one antenna stood on a one-story building in the center of the circles.

VNZ "CIRCLE"

Unlike "ARC", the receiver and transmitter are located in the same place. The task of this complex was to constantly determine the wavelengths that propagate in the atmosphere with the least attenuation, the range of their propagation and the angles at which the waves are reflected from the ionosphere. Using these parameters, the path of the beam to the target and back was calculated and the receiving phased array was configured in such a way as to receive only its reflected signal. In simple words, we calculated the angle of arrival of the reflected signal and created in this direction maximum sensitivity PAR.

MODERN air defense systems "DON-2N" "DARYAL", "VOLGA", "VORONEZH"

These stations are still on alert (except for Daryal), there is very little reliable information on them, so I will outline their capabilities superficially. Unlike "DUGI", these stations can record individual missile launches, and even detect cruise missiles flying at very low speeds. In general, the design has not changed; these are the same phased arrays used for receiving and transmitting signals. The signals used have changed, they are the same pulsed ones, but now they are spread evenly across the operating frequency band, in simple words This is no longer the knock of a woodpecker, but a uniform noise that is difficult to distinguish from the background of other noise without knowing the original structure of the signal. The frequencies also changed; if the arc operated in the HF range, then “Daryal” is capable of operating in HF, VHF and UHF. Targets can now be identified not only by gas exhaust but also by the target carcass itself; I already talked about the principles of detecting targets against the background of the ground in the previous article.

LONG LONG VHF RADIO COMMUNICATION

In the last article I briefly talked about kilometer waves. Maybe in the future I’ll do an article on these types of communications, but now I’ll briefly tell you using the examples of two ZEUS transmitters and the 43rd communications center of the Russian Navy. The title SDV is purely symbolic, since these lengths fall outside the generally accepted classifications, and systems using them are rare. ZEUS uses waves with a length of 3656 km and a frequency of 82 hertz. A special antenna system is used for radiation. A piece of land with the lowest possible conductivity is found, and two electrodes are driven into it at a distance of 60 km to a depth of 2-3 km. For radiation, a high-voltage voltage is applied to the electrodes with a given frequency (82 Hz), since the resistance of the earth’s rock is extremely high between the electrodes, electric current you have to go through the deeper layers of the earth, thereby turning them into a huge antenna. During operation, Zeus consumes 30 MW, but the emitted power is no more than 5 Watts. However, these 5 Watts are completely enough for the signal to travel completely through the entire globe; the work of Zeus is recorded even in Antarctica, although it itself is located on the Kola Peninsula. If you adhere to the old Soviet norms, "Zeus" works in ELF (extremely low frequencies) range. The peculiarity of this type of communication is that it is one-way, so its purpose is to transmit conditional short signals, upon hearing which, submarines float to a shallow depth to communicate with the command center or release a radio buoy. Interestingly, Zeus remained secret until the 1990s, when scientists at Stanford University (California) published a number of intriguing statements regarding research in the field of radio engineering and radio transmission. Americans have witnessed an unusual phenomenon - scientific radio equipment located on all continents of the Earth regularly, at the same time, records strange repeating signals at a frequency of 82 Hz. The transmission speed per session is three digits every 5-15 minutes. The signals come directly from the earth's crust - researchers have a mystical feeling as if the planet itself is talking to them. Mysticism is the lot of medieval obscurantists, and the advanced Yankees immediately realized that they were dealing with an incredible ELF transmitter located somewhere on the other side of the Earth. Where? It is clear where - in Russia. It looks like these crazy Russians have short-circuited the entire planet, using it as a giant antenna to transmit encrypted messages.

The 43rd communications center of the Russian Navy presents a slightly different type of long-wave transmitter (radio station "Antey", RJH69). The station is located near the town of Vileika, Minsk region, Republic of Belarus, the antenna field covers an area of ​​6.5 square kilometers. It consists of 15 masts with a height of 270 meters and three masts with a height of 305 meters, elements of the antenna field are stretched between the masts, the total weight of which is about 900 tons. The antenna field is located above wetlands, which provides good conditions for signal radiation. I myself was next to this station and I can say that just words and pictures cannot convey the size and sensations that this giant evokes in reality.

This is what the antenna field looks like on Google maps; the clearings over which the main elements are stretched are clearly visible.

View from one of the Antea masts

The power of "Antey" is at least 1 MW, unlike air defense radar transmitters, it is not pulsed, that is, during operation it emits this same mega watt or more, all the time it is working. The exact information transmission speed is not known, but if we draw an analogy with the German captured Goliath, it is no less than 300 bps. Unlike the Zeus, communication is already two-way; submarines for communication use either many-kilometer towed wire antennas, or special radio buoys that are released by the submarine from great depths. The VLF range is used for communication; the communication range covers the entire northern hemisphere. The advantages of VHF communication are that it is difficult to jam it with interference, and it can also work in conditions of a nuclear explosion and after it, while higher frequency systems cannot establish communication due to interference in the atmosphere after the explosion. In addition to communication with submarines, "Antey" is used for radio reconnaissance and transmitting precise time signals of the "Beta" system.

INSTEAD OF AN AFTERWORD

This is not the final article about the principles of looking beyond the horizon, there will be more, in this one, at the request of readers, I focused on real systems instead of theory.. I also apologize for the delay in the release, I am not a blogger or a resident of the Internet, I have a job that I love and who periodically “loves” me very much, so I write articles in between times. I hope it was interesting to read, because I am still in trial mode and have not yet decided what style to write in. Constructive criticism is welcome as always. Well, and especially for philologists, an anecdote at the end:

Matan teacher about philologists:
-...Spit in the face of anyone who says that philologists are tender violets with sparkling eyes! I am begging you! In fact, they are gloomy, bilious types, ready to tear out the tongue of their interlocutor for phrases like “pay for water”, “it’s my birthday”, “there is a hole in my coat”...
Voice from the back:
- What's wrong with these phrases?
The teacher adjusted his glasses:
“And on your corpse, young man, they would even jump.”

The invention relates to the field of radio engineering, namely to antenna technology and can be used as a broadband antenna system with a controlled radiation pattern when providing radio communications with ionospheric waves in the HF and VHF ranges. The purpose of the invention is to develop an antenna system that, with one standard size, ensures the operation of wide-range transmitters that require high quality matching with the antenna. A phased array antenna (PAA) consists of identical flat elements, each of which is formed by a pair of orthogonal coplanar vibrators of length L with triangular arms 1 (the value of L is equal to the minimum wavelength in the operating range). The central element and connected to it by means of a short circuit. conductors and 2 peripheral elements form an orthogonal pair of low-frequency range vibrators. All peripheral elements, including those included in the low-frequency vibrator, form the high-frequency phased array. Excitation of the antenna system is separate for horizontal (g-g") and (v-v") vibrators, but it is also possible to be combined in order to realize circularly polarized radiation. The phased array provides operation in a 40-fold range at a BEV level of at least 0.5. 6 ill.

The invention relates to the field of radio engineering, namely to antenna technology and, in particular, can be used as a transceiver underground or creeping antenna system for operating ionospheric waves in the HF and VHF ranges. Known underground and surface antennas of the HF and VHF ranges (Sosunov B.V. Filippov V.V. Fundamentals of calculation of underground antennas. L. VAS, 1990). Multi-section underground analogue antennas are made in the form of a group of parallel in-phase isolated vibrators. To increase the gain, several such groups are used, placed one after another and phased accordingly. The disadvantages of the known analogs are a narrow range of operating frequencies due to sudden changes in input impedance, a limited beam scanning sector, and large dimensions. To ensure operation in the required range and given directions, it is necessary to have several standard sizes. The closest in its technical essence to the claimed phased array antenna (PAR) is the well-known SGDP 3.6/4 RA PAR (Eisenberg G.Z. et al. Short-wave antennas. M. Radio and Communications, 1985, pp. 271-274, Fig. 13.11.). The prototype antenna consists of a group of flat elements (PE) made of metal conductors. Each PE is a radiator in the form of a symmetrical vibrator made of two triangular arms, the outer ends of which are connected by a short-circuit. conductors. All elements are united by a common feeder path and form an in-phase or phased (if phasing devices are included in the feeder path) array. The elements are located coplanarly within the rectangle that limits the aperture of the phased array and are suspended vertically on the masts of the phased array. Thanks to the use of elements consisting of emitters with triangular arms, it has a wide range of operating frequencies and better matching. However, the prototype has disadvantages. The operating range overlap coefficient (the ratio of the maximum operating frequency to the minimum) of the SGDP 3.6/4 RA antenna array is equal to 2.14, which is significantly less than the value of this parameter for modern transmitters and does not allow one standard size to be used when providing communications on different distances. The control sector of the radiation pattern (DP) in the horizontal plane, equal to 60 o, limits the capabilities of this antenna when operating in a radio network. In addition, the antenna has large dimensions and low security, and does not provide independent operation with vertical and horizontal polarization or a circularly polarized wave. The objective of the invention is to create a broadband phased array intended for use as a surface or underground antenna of the HF and VHF ranges, providing control of the radiation pattern in the entire upper half-space while reducing the size of the radiating surface. The task is achieved by the fact that in a known phased array containing a group of PEs, each of which includes a pair of triangular emitters installed coplanarly within the rectangle limiting the aperture of the phased array and connected to the feeder path, an additional pair of identical emitters installed coplanarly and orthogonal to the first. All PEs are located horizontally within the semiconducting medium or on its surface. The outer ends of the triangular emitters belonging to the PEs adjacent to each other are electrically connected. The outer ends of the triangular emitters belonging to the peripheral PEs are connected along the perimeter of the phased array aperture by additional short circuits. conductors. The outer ends of the triangular emitters, adjacent on both sides to the large diagonals of the phased array, are electrically isolated, and the outer ends of the remaining triangular emitters are connected by short-circuited conductors. The feeder path of the LF channel is connected to the tops of the triangular emitters of the PE located in the center of the phased array. The tops of the triangular emitters of the remaining PEs are connected to the feeder path of the RF channel. Orthogonal emitters in each PE are powered independently, i.e. can excite either each separately with linear polarization, or with a shift of 90 o, thereby achieving circularly polarized radiation. With such a phased array scheme, the same elements are used twice to operate in both the LF and HF ranges (with an overlap coefficient of 5.33 and 7.5, respectively) with matching at the BV level of at least 0.5. In general, the proposed phased array operates in a range with 40-fold overlap. Moreover, at the resonant frequency, the area of ​​its emitting surface is 1.6 times less than that of the prototype. In fig. 1 shown general form PAR; in fig. 2 flat element; in fig. 3 four- and three-shunt PE; in fig. 4 feeder system; in fig. 5, 6 - results of experimental studies. The phased array shown in Fig. 1, consists of N (for example, N 9 is taken) identical PEs. An embodiment of the PE is shown in Fig. 2. Each PE is formed by an orthogonal pair of flat vibrators z-g" and b-v" of length 2L 1 with arms in the form of equilateral triangles 1. The adjacent ends of the triangular emitters of neighboring PEs are electrically connected ( lines m-m"). The peripheral ends of the triangular emitters PE are connected short-circuit by conductors 2 (Fig. 3), with the exception of the triangular emitters adjacent on both sides to the large diagonals c-c" and p-p", i.e. these emitters are electrically isolated (Fig. 3). Under this condition, the central PE short circuit. conductors no less (Fig. 2). The ends of the triangular emitters c-c" and d-g", located on the outer edges of the phased array, are additionally connected by conductors 3 (in this case, each conductor 3 together with two conductors forms a closed circuit, which can be filled with additional conductors or replaced with a solid metal plate of the same forms). Each PE has transverse and longitudinal dimensions 2L= min (where min is the minimum wavelength in the operating range), and in general the phased array is a square with a side . The phased array feeder system shown in FIG. 4, consists of two identical groups feeding horizontal y-y" And vertical in-in"PE emitters. Fig. 1 shows the feeder group of horizontal emitters. It includes feeder 4 of the LF vibrator and (N-1) feeders of 5 HF vibrators. Screen shells 6 of feeders 4, 5 are electrically connected to the tops of the left triangular emitters of horizontal vibrators, and the central conductors 7 of these feeders are connected in the same way to the right triangular emitters. Feeder 4 of the LF element is connected directly to the transmitter (receiver). Feeders 5 of the HF elements to ensure phasing of the antenna array and interface with the output of the transmitter are connected through controlled delay lines (ULZ) 8 and a divider power 9 (when receiving a 1:8 coupling device). The proposed device operates as follows: When an excitation voltage is applied through the feeder 4 k points y-y"(for a vertical vibrator b-c"), the current from the indicated points flows along the rhombic-shaped arms formed by interconnected triangular emitters 1 of the central and side PE, as well as from points E and E" through conductors 2 to points H and H" orthogonal triangular emitters of peripheral PEs, then along them in the transverse direction to points K and K", from each of which there are pairs of conductors 2 located on the outer side of the phased array (or plates replacing them). To operate the phased array in the HF range, the transmitter power in the divider 9 is divided by 8 identical channels, in each of which the required phase shift is created with the help of ULZ 8, and then the PE is excited through feeders 5. When excitation voltage is applied to the input of one of the vibrators (horizontal or vertical) of each PE, the other vibrator together with the conductors forms a .3 jumper connecting the ends of the excited emitter, thereby achieving improved matching in the lower part of the range.Experimental studies of the proposed phased array were carried out on a prototype designed to operate in the range of 1.5-60 MHz, made of sheet steel 2 mm thick. The layout dimensions are 15 x 15 m2, the soil is dry (=5, =0.001 S/m). The HF PAR feeder system was made of coaxial cables RK-75-9-12 with a length of (140-0.1) m, excitation of the LF elements was carried out via cables RK-75-17-12 with a length of (120-0.1) m. the circuit included a 1:8 transformer power divider and an 8-channel 4-bit controlled delay line formed by sections of fluoroplastic-insulated coaxial cable with lengths of 0.66 m, 1.32 m, 2.64 m and 5.28 m. As a transmitter The device used the Fakel-N1 product (operating frequency range 1.5-60 MHz, power up to 4 kW). During the research, the input impedances of low-frequency elements, high-frequency elements separately and as part of a phased array were measured, from which the BEF values ​​and such dynamic radiation patterns at various frequencies were calculated. The values ​​of KBV, low-frequency element, individual high-frequency element and phased array as a whole, shown in Fig. 5, confirm the high quality of matching over the entire operating range. The dynamic radiation patterns of the phased array in the lower, middle and upper parts of the range are shown in Fig. 6 (graphs a, b, c, respectively). The solid line shows the calculated patterns, the crosses show the measurement results. It can be seen that, over the entire range, the phased array ensures the formation of a maximum radiation in a given direction.

Claim

A phased array antenna containing a group of flat elements, each of which includes a pair of triangular emitters installed coplanarly within a rectangle delimiting the aperture of the phased antenna array, and connected to the feeder path, characterized in that the flat elements are located horizontally within the semiconducting medium or on it surface, a second pair of identical emitters is inserted into each flat element, installed coplanarly and orthogonally to the first, the outer ends of triangular emitters belonging to adjacent flat elements are electrically connected, and the outer ends of triangular emitters belonging to peripheral flat elements are connected along the perimeter of the phased aperture antenna array with additional short-circuiting conductors, and the outer ends of the triangular emitters adjacent on both sides to the large diagonals of the phased antenna array are electrically isolated, and the outer ends of the remaining triangular emitters are connected by short-circuiting conductors, while the feed path of the low-frequency channel is connected to the tops of the triangular emitters of the flat element, located in the center of the phased antenna array, and the tops of the triangular emitters of the remaining flat elements are connected to the feeder path high frequency channel, and the orthogonal triangular emitters in each flat element are powered independently.

HF antenna-feeder devices: transmitting antennas

Specifications

• Operating frequency range from 3.0 to 9.0 MHz
  • Nominal input impedance – 2x150 Ohm (balanced path)
  • VSWR in the operating frequency range – no more than 2.0
  • The azimuthal pattern at an elevation angle of 45º is close to circular with unevenness no more than ±1.5 dB
  • Radiation is provided in the sector of elevation angles from 45 to 90º in the frequency band from 3 to 6 MHz and in the sector of elevation angles from 40 to 65º in the frequency band from 6 to 9 MHz with unevenness no more than ±3 dB
  • The polarization of the emitted AZI-PRD waves is elliptical. The ability to remotely control the direction of polarization rotation is provided
  • The AZI-PRD BUP is powered from a three-phase network alternating current V (50±1.5) Hz
  • The remote control is powered from a single-phase alternating current network V (50±2.5) Hz
  • Power consumed by the PSU from the network, no more than 250 VA

The antenna radio transmitting device based on the VGDSH UAR-Sh is intended for use as a radio transmitting antenna as part of radio stations in the UHF range

Specifications

• Operating frequency range from 8.0 to 24.0 MHz
• KBV at the USS-Sh input when connected to the output of a symmetrical matched load of 200 Ohms in an operating frequency range of at least 0.6
• The characteristic impedance of the F-50 feeder is 50 Ohms
• KBV at the input of the F-50 feeder when operating at a matched load in the operating frequency range of at least 0.8

AKAR

Specifications

EAR-V

Specifications

KARB-V, KARB-G

KARB-V

CARB-G

Specifications

• Nominal output impedance - 75 Ohm
• Azimuthal pattern - directional
• Long-term continuous operation without constant presence of maintenance personnel

Active receiving antennas

Active receiving protected antenna APZ with triorthogonal vibrators is intended for use as a receiving antenna in protective shelters for equipment of stationary objects of the VHF radio communication system
Specifications

• Operating frequency range from 1.5 to 30.0 MHz
• The azimuthal APZ pattern in the mode of receiving waves of horizontal or elliptical polarization at an elevation angle of 45° is close to circular with an unevenness of no more than ± 3 dB
• Power - no more than 300 VA
• Long-term continuous operation without constant presence of maintenance personnel

Active receiving small-sized antenna APM with triorthogonal vibrators is intended for use as a receiving antenna for equipment of stationary objects of a radio communication system in the UHF range
Specifications

• Operating frequency range from 1.5 to 30.0 MHz
• Nominal input impedance – 75 Ohm
• The azimuthal pattern in the mode of receiving waves of horizontal or elliptical polarization at an elevation angle of 45° is close to circular with an unevenness of no more than ± 3 dB. Reception is provided in the sector of elevation angles from 45 to 90°. In the mode of receiving vertically polarized waves, reception is ensured in a sector of elevation angles from 10 to 55° with an uneven elevation pattern (in the specified sector) of no more than ± 3 dB
• Long-term continuous operation without constant presence of maintenance personnel
• Automated and manual control
• Power - 30 VA

Receiving active phased array antennas

Fast deployment active ring antenna array AKAR
AKAR is designed to receive signals in the operating frequency range from 2.4 to 29.8 MHz, and is used in emergency situations when antennas in any direction fail, as well as the need to quickly organize radio communications with a correspondent in whose direction there is no radio communication.
The product is used both as part of HF radio communication receiving centers and in a quickly deployed version to provide communications on routes of 400 - 7000 km.

Specifications

• AKAR operating frequency range from 2.4 to 29.8 MHz
• The nominal impedance of AKAR outputs is 75 Ohm
• The directional pattern (DP) of the AKAR in the horizontal plane is directional
• The beam width of the radiation pattern at level 0.7 in the vertical plane at an elevation angle of 45° is no more than 55° at a frequency of 2.4 MHz and no more than 20° at a frequency of 29.8 MHz
• Polarization of waves received by AKAR - vertical
• Power consumed by ACAR from the power supply network, no more than 250 VA
• AKAR provides the possibility of long-term continuous operation without the constant presence of maintenance personnel

The AKAR design is a phased array of 32 active modules, placed evenly around a circle with a radius of 16 m. The suspension height of the active vibrators is 5 m. This structure allows the antenna to be deployed in an open area by a crew of four people in a time not exceeding 3 hours.
The operating temperature range is from minus 50 to plus 50 °C.
AKAR provides simultaneous independent operation of four radio receiving devices (RPU). For each of the four RPUs, 16 independent azimuthal patterns are formed with a discrete azimuth step of 22.5 degrees. To select the required azimuth there is a remote control located in the TZ.
AKAR provides the ability to switch any of the four receivers for reception from any of the 16 free (not occupied by other receivers) azimuth directions.

EAR-V, KARS-V, KARS-G, KARS-V2G

Stationary elliptical antenna array with vertical vibrators EAR-V designed for use as a receiving antenna to provide radio communications on routes from 0 to 50 and from 700 to 10,000 km.

• The stationary ring antenna array with vertical vibrators KARS-V is intended for use as a receiving antenna to provide radio communications on routes from 0 to 50 and from 700 to 10,000 km.
• The stationary ring antenna array with horizontal vibrators KARS-G is intended for use as a receiving antenna to provide radio communications on routes from 50 to 1000 km
• The stationary ring antenna array with triorthogonal (two horizontal and one vertical) vibrators KARS-V2G is intended for use as a receiving antenna to provide radio communications on routes from 0 to 10,000 km.

Specifications

• Switching of each of 64 receivers is provided for reception from any of 16 azimuth directions with a discrete azimuth step of 22.5 degrees. Switching control is carried out by the operator using the user terminal. The server provides operation for up to 64 user terminals, with monitoring results displayed on each user terminal.
• Operating frequency range: from 1.5 to 30.0 MHz, with the exception of EAR-B (from 6.0 to 24.0 MHz)
• Polarization of received radio waves – vertical (KARS-G – horizontal)

KARS-V2G: linear vertical; linear horizontal in the direction corresponding to the “zero” azimuth of the antenna system (G1); linear horizontal in the direction perpendicular to the “zero” azimuth of the antenna system (G2); elliptical with the right direction of rotation of the plane of polarization (EP); elliptical with the left direction of rotation of the plane of polarization (EL). KARS-V2G provides remote control type of polarization.

• Azimuthal pattern - directional
• Power from the power supply network - no more than 1000 VA
• Long-term continuous operation without constant presence of maintenance personnel
• Nominal output impedance - 75 Ohm

KARB-V, KARB-G

Quick-deployment ring antenna array with vertical vibrators KARB-V is intended for equipping mobile DCM radio communication systems as a receiving antenna, while providing radio communication on routes from 0 to 50 and from 700 to 10,000 km.

Quick-deployment ring antenna array with horizontal vibrators CARB-G is intended for equipping mobile DCM radio communication systems as a receiving antenna when providing radio communication on routes from 50 to 1000 km.

The KARB-V and KARB-G designs make it possible to deploy antennas in open areas with a crew of three people in a time not exceeding 1.5 hours (taking into account the time for marking the site).

Specifications

• Operating frequency range from 1.5 to 30.0 MHz
• Polarization of received radio waves – vertical
• Nominal output impedance - 75 Ohm
• Azimuthal pattern - directional
• Power consumed from the power supply network, no more than 100 VA
• Long-term continuous operation without constant presence of maintenance personnel
• Switching of any of four receivers for reception from any of 16 free (not occupied by other receivers) azimuth directions
• Power supply is provided from a single-phase alternating current power supply system with a voltage of 220 V and a frequency of (50±2) Hz

Protected antennas

OKTAVA-KR, OKTAVA-KP

The appearance of a protective shelter that provides protection for the APZ from a shock wave when it is placed in a well or fortification structure

"Octava-KR" And "Oktava-KP"— APZ protected active underground antennas, developed and manufactured in the interests of the Special Communications Service of the Federal Security Service of Russia, passed State tests and were accepted for supply to the above-mentioned department. Designed for use as HF transmitting antennas as part of equipment for special facilities.

They provide the ability to simultaneously operate two radio receiving devices (RPUs) tuned to different frequencies, creating greater opportunities for organizing independent signal reception.

APZ capabilities allow you to work in adaptive automated networks DCMV radio communication, including in communication systems with frequency frequency control. They have seismic resistance and resistance to shock waves as part of a protected object.

Polarization adaptation allows both automatic and manual modes achieve the best signal reception.

Control of operating modes and type of received polarization is carried out using a control and coordination unit (CCU).

APZs have minimal dimensions and weight and occupy a small area. On an unprotected site they can be installed in any unsuitable places. They have a short deployment time.

Triorthogonal receiving active antenna module

The triorthogonal receiving active antenna module is designed to receive signals in the UHF range. The scope of application is the reception of radio signal energy and its transmission through three channels to the inputs of digital signal processing equipment, the construction of a universal receiving antenna array based on it for use as part of promising complexes of technical means of the DCM. The product can also be used as a single receiving antenna.
Together with the control and coordination unit (CCU), it ensures the reception of waves of linear horizontal (in two orthogonal planes), linear vertical and elliptical (with different directions of rotation) polarization.
The triorthogonal receiving active antenna module consists of crossed symmetrical vibrators - two vertical and one horizontal, each 2 m long, connected to receiving antenna amplifiers (RAA), in the form of a shielded block of antenna amplifiers (BAU). To increase the input capacitance, each arm of the vibrator is made in the form of a bicone based on a system of bimetallic conductors.

Specifications

• Operating frequency range from 3.0 to 30.0 MHz
• Electromagnetic isolation between orthogonal TAE vibrators in the absence of closely located poles, wires, trees, etc. not less than 20 dB
• Each receiving antenna amplifier (RAA) as part of the TAE has:
• gain at least 8 dB
• dynamic range of at least 95 dB relative to 1 µV

The utility model relates to the technology of microwave antennas and can be used in radio-electronic systems as an active phased array antenna, in particular, in airborne and shipborne locators and radio countermeasures systems.

The technical result is to increase the reliability of beam control through the use of a plasma reflector.

The essence of the utility model is that the antenna is made in the form of a Helmholtz coil consisting of a vacuum chamber, an irradiator, a linear cathode and an anode, while a layer of plasma is applied to the coil from which the signal is reflected. Ill.1.

The utility model relates to the technology of microwave antennas and can be used in radio-electronic systems as an active phased array antenna, in particular, in airborne and shipborne locators and radio countermeasures systems.

Among the latest developments in the field of creating phased arrays, carried out in the EU countries, is a multifunctional radar with phased arrays, designed for installation on a ship. The radar on the TWT transmitter operates in the C-band wavelengths. The target detection range reaches 180 km. The antenna array rotates in azimuth at speed. 60 rpm Phase control of the beam is performed in the elevation plane.

A spatial transceiver phased antenna array is known. Patent 2287876 Russia, MPK H01Q 3/36, 2006. The array is made in the form of a matrix and contains a master mixer, to which the signals of the master frequencies f and f are supplied, the output signals of the service frequencies f 1 =f and f 2 =f-f through the corresponding phase shifters are supplied respectively to the rows and columns of the matrix; at the intersection points of the rows and columns of the matrix, mixers are located, the output of each of which is connected to the corresponding circulator connected through the corresponding receiving amplifier.

A passive-active phased array antenna for the microwave range is also known. RF patent 2299502, 2006 (prototype). The array consists of n radiating elements, n transmit-receiver modules (RTM) and a distribution system, while the TRP includes m active TPMs, each of which contains a power amplifier of the transmitting channel, low-noise amplifiers of the receiving channel, phase shifters and a control and monitoring circuit, and ( n-m) passive PPMs, each of which contains a phase shifter and a phase shifter control circuit.

The disadvantages of both the analogue and the prototype are the low reliability of the beam control system, large dimensions, as well as low accuracy and speed of beam installation.

The purpose of the utility model is to improve the reliability of beam control through the use of a plasma reflector.

This goal is achieved by the fact that the phased antenna array of the microwave range, containing emitting and transmitting elements, power amplifiers of the transmitting and receiving channels, as well as a phase shifter control circuit, is made in the form of a Helmholtz coil consisting of a vacuum chamber, an irradiator, a linear cathode and an anode, with In this case, a layer of plasma is applied to the coil from which the electron scanning beam is reflected, and the plasma layer is created in a vacuum chamber during a gas discharge between the anode plate and the linear cathode, which is a line of elements of a certain address on the two-coordinate grid of the cathode.

In FIG. Shown functional diagram antennas with electronic beam scanning.

It contains:

1 - vacuum chamber;

2 - plasma layer;

3 - irradiator;

4 - Helmholtz coil;

5 - linear cathode;

6 - reflected signal;

In such an antenna electronic control beams are carried out using a plasma reflector.

Plasma with sufficient density has the ability to reflect electromagnetic energy. Moreover, the higher the irradiation frequency, the greater the density of the plasma.

Plasma layer 2 is created in vacuum chamber 1 during a gas discharge between the anode plate 7 and the linear cathode 5, which is a line of elements of a certain address on the two-coordinate grid of the cathode. By changing the position of the linear cathode 5, it is possible to rotate the plasma layer 2 and thereby scan the reflected beam 6 in azimuth. The beam is scanned in elevation by changing the tilt of the plasma reflector by adjusting the magnetic field of the Helmholtz coils. The latter are placed around the reflector so as not to block the microwave signal. The position of the linear cathode 5 and the value of magnetic induction are controlled by a control system (computer).

According to calculations, the accuracy of beam installation in a given direction is 1-2°. The beam reorientation time is about 10 μs.

To form plasma layer 2 in chamber 1, it is sufficient to maintain a vacuum of approximately 15 Pa. The magnetic induction should be about 0.02 Tesla, the current should be about 2 A and the voltage should be 20 kV. The size of the reflector is about 50×50×1 cm. The level of the side lobes is 20 dB.

Among the advantages of the proposed antenna is the ability to quickly and accurately install the beam, which allows you to simultaneously perform search and tracking operations for a group of targets, as well as form different diagrams direction. In addition, such an antenna has a wide frequency band, as a result of which the same plasma reflector can be used with different feeds. The range of the proposed antenna is from 5 to 50 GHz. Unlike conventional reflective antennas, which significantly increase the effective scattering area of ​​the locator when irradiated by radio reconnaissance means of a potential enemy, this parameter in a plasma antenna is small. Thermal radiation from the antenna is also small, since thermal energy is concentrated inside the plasma and is not radiated outward.

A phased array antenna for the microwave range, containing emitting and transmitting elements, power amplifiers of the transmitting and receiving channels, as well as a phase shifter control circuit, characterized in that the antenna is made in the form of a Helmholtz coil, consisting of a vacuum chamber, an irradiator, a linear cathode and an anode, with In this case, a layer of plasma is applied to the coil, from which the electron scanning beam is reflected, and the plasma layer is created in a vacuum chamber during a gas discharge between the anode plate and the linear cathode, which is a line of elements of a certain address on the two-coordinate grid of the cathode.

Similar patents:

The microwave signal power amplifier belongs to the field of electrical engineering and is used to increase the range of information transmission and improve the operation of unmanned radio equipment aircraft(UAV). A distinctive feature of the device is the ability to reduce phase and amplitude dispersion when transmitting information, and maintain stable specifications in the microwave range.

In the previous publication /1/ we showed that in conditions where it is not possible to raise the antenna to a significant height, antennas with vertical polarization and a small radiation angle have an advantage in long-distance communications: vertical curved dipole (Fig. 1), vertical Moxon ( fig.2)

We deliberately do not mention here verticals with a system of counterweights or radials, since these antennas are very inconvenient for placement in summer cottages or in expeditionary conditions.

The vertical Moxon (Fig. 2), although a good directional antenna with a small radiation angle, still has insufficient gain compared to multi-element “wave channels” or “squares”. Therefore, we naturally had a desire to try a phased array of two vertical Moxons, similar to that used by American radio amateurs on an expedition to Jamaica (they called it “2x2”) /2/.
The simplicity of its design and the small space required for its placement make the task easily feasible. The experiment was carried out on the 17 m band (central frequency 18.120 MHz), since we already had one vertical Moxon for this range. Its calculated characteristics (Fig. 3): gain 4.42 dBi, back lobe suppressed by more than 20 dB, maximum radiation at an angle of 17 degrees, almost pure vertical polarization of radiation. And this is with the height of the lower edge of the antenna only 2 m above the real ground.
For each of the antennas you will need a dielectric mast 8 - 10 m high (or a tree of a suitable height) and two (preferably three) dielectric spacers 2.2 m long (wooden slats can be used). Elements - from any copper wire, 1-3 mm in diameter, bare or insulated.
During the experiment, a set of fiberglass pipes from RQuad with a total height of 10 m was used as a mast, and plastic water pipes with a diameter of 20 mm were used as spacers. The elements are made from vole wire. Guys are made of 3 mm polypropylene cord. The result is the design shown in Fig. 4.

Fig.3. Design characteristics of Moxon vertical antenna.

The wire is passed through the holes near the ends of the spacers and secured to them using electrical tape or plastic clamps. To prevent the spacers from bending under the weight of the antenna, their ends are stretched with fishing line. To maintain the straightness of the active element, which is disrupted due to the weight of the cable, you can use a third spacer at the level of the middle of the elements, passing the director's wire through the hole in it and securing the connection points of the active element to the cable on it. The cable runs along the spreader to the mast and then down the mast. The cable is equipped with ferrite tubes every 2 m, eliminating the influence of its braid on the antenna characteristics and at the same time balancing the supply currents. The antenna is easily lifted onto a pre-installed mast with a roller on top using a nylon cord.
The characteristics of a horizontal stack of two such antennas, calculated using the MMANA program, are shown in Fig. 5. Best Features in terms of amplification and suppression of the back lobe were obtained at a distance between the antennas of 0.7 wavelengths, i.e. 11.6 m. This antenna can be called "2×MOXON".

Fig.5. Radiation pattern of a phased array of two vertical Moxon antennas.

The summation circuit is classic: since each antenna has an input impedance of 50 Ohms, power cables with a resistance of 75 Ohms, ¾ wavelength long, are used, taking into account the cable shortening factor. At the ends of the cables, the antenna resistance transforms to 100 ohms. Therefore, they can be connected in parallel using a tee, followed by a 50 Ohm power cable of any length. The length of the transforming cables was chosen to be ¾ wavelength, since at a length of ¼ wavelength their lengths are not enough to cover the distance between the antennas.
It took us about two hours to make the second copy of this antenna. The masts were installed with a spacing of 11.6 m (the width of the summer cottage was sufficient).
Each antenna was tuned separately, connecting them via a half-wavelength cable (taking into account shortening), and trimming the ends of the lower bent parts of the elements. To avoid errors in configuration, it is necessary to pay special attention to the suppression of common-mode currents in power cables using chokes placed on the cable. We had to use up to 10 pieces. of snap-on ferrite filters distributed along the length of the 75 ohm cable before the results stabilized. These chokes must also be on transforming cables connected by a tee. It is not necessary to put chokes on the 50 Ohm cable connecting the tee to the transceiver. In the absence of ferrites, the chokes can be replaced with several turns of cable assembled into a coil with a diameter of 15-20 cm, placing them near the antenna feed points and near the tee. To improve the performance of antennas, almost the entire free length of transforming cables can be assembled into choke coils.
After connecting two vertical Moxons into an array, the resonant frequency goes up by about 500 kHz, and the SWR at the center frequency becomes equal to 1.4.
It is impossible to correct the resonance of the system by adjusting the Moxons, because in this case the directional pattern falls apart. Most simple ways system matching - either connecting coils with an inductance of 0.2 μH in series with the inputs of both antennas, or one capacitor 400-550 pF (select the value for the minimum SWR at the center frequency) in series with the input of the tee on the 50 Ohm feeder side. In this case, the band according to the SWR level< 1,2 получается около 200 кГц (рис.6).

Fig.6. SWR from the input after adjustment using 0.2 µH inductors.

Calculated parameters at a height of the lower edge of the antennas 2 m above the real ground:
Gain 8.58 dBi (6.43 dBd),
Elevation angle 17 degrees,
Back lobe suppression >25 dB,
SWR in operating range< 1,2.
The presence of side lobes with a suppression of 10 dB relative to the main one is not, in our opinion, a disadvantage, because allows you to hear stations outside the narrow main beam without turning the antenna.
We are not aware of other antenna designs that have such high parameters with such design simplicity.
Of course, this phased array is stationary and should be installed in the direction of the most interesting DX (to the west, for example). Then turning its diagram to the east will not be difficult: to do this, you need to lower the antennas, rotate them 180 degrees and raise them again to the masts. For us, this operation took no more than five minutes after some training.
A photo of the experimental antenna is shown in Fig. 7.

Fig.7. View of a phased array of two vertical Moxons.

Vladislav Shcherbakov, (RU3ARJ)
Sergey Filippov, (RW3ACQ)
Yuri Zolotov, (UA3HR)

Literature:

1. Vladislav Shcherbakov RU3ARJ, Sergey Filippov RW3ACQ. Symmetrical vertical antennas are the optimal solution for DX communications in field and country conditions. Materials of the Forum of the Festival “Domodedovo 2007”.

2. K5K Kingman Reef DXpedition.
www.force12inc.com/k5kinfo.htm

info - http://cqmrk.ru