RU2783226C1 - Method for satellite communication systems using helical type antennas - Google Patents

Abstract

FIELD: antenna technology.

SUBSTANCE: invention relates to antenna technology, in particular to radio transmission systems of spacecraft using antennas of the helical type. The effect is achieved by the proposed method for satellite communication systems using spiral-type antennas, which consists in installing a transmitting antenna for the transmitter and a receiving antenna for the receiver on the body of the spacecraft, interconnected by the principle of reciprocity, connecting feeders to them, four antenna emitters are wound in a spiral in the form of a cylinder, to which signals are supplied with a phase shift of 0°, 90°, 180°, 270°, characterized in that a second antenna is added to each antenna - receiving and transmitting - through a power shaper, while the first antennas have a wide radiation pattern to the Earth, and the added second antennas - a narrowed radiation pattern in the opposite direction - to the zenith, and all antennas are made of all-metal, and the radiators are powered by a slot-type balancing device.

EFFECT: high reliability and efficient radio communication during the entire period of active existence of the spacecraft.

1 cl, 3 dwg

Description

Purpose

SUBSTANCE: invention relates to receiving and transmitting radio communication systems of space vehicles (SC) using spiral-type antennas, mainly decimeter and centimeter ranges, for transmitting and receiving radio-frequency signals with close to circular (elliptical) polarization.

State of the art

The radio communication process is fundamentally impossible without the use of radio waves and, therefore, antenna-feeder devices (AFD) in the form of a transmitting antenna, which converts the coupled electromagnetic waves coming through the feeder from the output of the radio transmitter (in the feeders, radio frequency signals propagate in the form of guided electromagnetic waves that are associated with charges and currents) into free electromagnetic waves (radio waves) in open space, and a receiver, which converts radio waves into coupled electromagnetic waves coming through the feeder to the input of the radio receiver.

Traditionally, various types of antennas are used as onboard AFUs of spacecraft: helical, vibrator, whip, horn, mirror, printed, etc., including antenna arrays (see Generalov A.G., Gadzhiev E.V., Salikhova MR Application of helical antennas for on-board systems and complexes, Proceedings of the Moscow Aviation Institute, Issue No. 106, Website: http://trudymai.ru/).

Today, a class of helical antennas is widely used, and above all, multi-pass (four-pass) antennas of the helical type (see patent, RF, No. 2208272). The main operating range of the helical antenna is the decimeter and centimeter wave range (see website: https://www.bestreferat.ru/referat-207565.html). The use of a helical antenna in the meter range is possible where the design of the spacecraft allows you to install sufficiently large overall dimensions of the antennas. So, for example, helical antennas of the meter range have found application as part of large spacecraft "Meteor", weighing about 3000 kg (head contractor JSC "Corporation" VNIIEM", Moscow) and spacecraft "Resurs", weighing more than 5000 kg (head contractor RCC "Progress", Samara).

When communicating with moving objects, including satellites, it is advisable to use close to circular (elliptical) polarization, the plane of which is defined as a plane passing through the propagation direction and the electric field strength vector (see V.P. Kubanov. Antennas and feeders - purpose and parameters Samara 2015, p. 31). A four-wire helical antenna makes it possible to form and receive radiation with a polarization close to circular, and provides the formation of a radiation pattern close to hemispherical.

The advantage of a four-way helical antenna is the ability to beam from a needle-shaped axial main lobe to a very wide main lobe covering almost the entire sphere. The chart may also need to have peaks and troughs at certain angles. This is done by excitation of different modes of radiation, axial and/or radial.

In a four-way helical antenna, four spaced emitters are used, excited by signals with phases of 0°, 90°, 180° and 270 (see patent, RF, No. 2142183). The length of the emitters is typically equal to an integer multiple of a quarter wavelength at the operating frequency of the communication device. Radiation patterns are usually adjusted by changing the emitter pitch, the emitter length (in whole multiples of a quarter of the wavelength), and the diameter of the cylindrical helix. The lengths of the emitters are an integer multiple of a quarter wavelength at the desired resonant frequency. Ideally, the power circuit should create incident waves with a phase shift of 90 degrees and with the same amplitude (see patent, RF, No. 143825).

Onboard AFS are an integral part of the spacecraft and provide one of the main tasks - the exchange of information between the spacecraft and the ground control complex. Control commands (command-program information as part of work programs and one-time commands) are transmitted from the ground control complex via a radio channel, and telemetry information is transmitted from the spacecraft board to the ground control complex via a telemetry channel. Often, transmitting and receiving antennas are used, interconnected by the principle of reciprocity (see website: https://helpiks.org/5-98079.html). Using the reciprocity principle, it can be proved that the antenna parameters in the receive mode remain the same as in the transmit mode, although some parameters change their meaning.

The quality and continuity of communication sessions between the spacecraft and the ground control complex determine the fulfillment of the tasks assigned to the spacecraft and its intended functioning. For use in space communications technology, a four-wire helical antenna has the following advantages:

• broadband;

• required radiation directivity;

• close to circular polarization of the field (this is important because, in some cases, the polarization of the received signal can be random, for example, from objects whose position in space changes or can be arbitrary);

• small dimensions (can function as resonant antennas);

• fairly simple design;

• potential possibility of achieving high reliability and service life during long-term operation in space.

In accordance with GOST R 56526-2015, reliability is a set of properties that characterize the ability of an AFU to ensure, in the process of operation, obtaining the output effect specified in the terms of reference under given conditions and operating modes.

In order to improve reliability, the antenna and feeder must have a certain electrical strength, which excludes mechanical damage to individual elements of the antenna or feeder due to electrical breakdown or thermal overheating. A feeder is understood to mean an electrical circuit and ancillary devices, with the help of which the energy of the radio frequency signal is supplied from the radio transmitter to the antenna or from the antenna to the radio receiver.

In addition, the antenna must remain operational under the influence of various space factors on the spacecraft, for example, local static discharges, the impact of heavy charged particles or high-energy electrons and protons, factors during the passage of the terminator region, which is characterized by adverse effects on the spacecraft, t.to. a significant potential gradient may occur on the surface of the spacecraft due to the non-equalization of the potentials of the illuminated and unlit surfaces of the spacecraft. In the region of the terminator (the "light-shadow" boundary), the so-called differential charging of the surface occurs, which can also arise due to the difference in the secondary emission characteristics of the materials located on the surface, the difference in the conditions for the plasma to hit certain areas of the surface, and the presence of structural inhomogeneities (see Fig. Dorofeev R.Yu. "Improving the energy efficiency of the spacecraft power supply system by using the energy of the electrostatic charge of the spacecraft surface in orbital operating conditions. "Russian Space Systems", Aviamotornaya st., 53, Moscow, 111250, Russia e-mail: myhavkedah@ mail.ru Electronic journal Proceedings of the MAI, Issue No. 68). Along with the technical requirements listed above, other requirements are also imposed on antennas and feeders: manufacturability, convenience and safety of operation.

A known method of satellite communication systems using antennas of a helical type, described in the patent "Four-way helical antenna and power circuit" (patent, RF, No. reciprocity, which are installed on the body of the spacecraft. Four radiators of the antenna are etched on the radiating part of a thin substrate having a cylindrical shape so that the radiators are wound in a spiral. Also on the microstrip substrate, by etching, a power circuit is made to supply signals with phases of 0°, 90°, 180° and 270° to the indicated emitters, which are formed by a stub coupler and power dividers.

The main disadvantage of the prototype is that the emitters made by etching on the emitter section of the microstrip substrate, and the power supply circuit made by etching on the feeder section of this substrate do not have sufficient mechanical strength, temperature stability, and reliability for long-term operation in difficult space conditions under the influence of factors outer space, in the form of local static discharges, heavy charged particles or high-energy electrons and protons, differential surface charging during the passage of the terminator region. In addition, the prototype does not provide optimally sufficient use of rational solutions to improve the reliability and resource of effective radio communication of satellite communication systems in "difficult conditions", which cannot guarantee the achievement of the high requirements put forward today for the active life, for example, more than 10 years for a spacecraft remote sensing of the Earth (guaranteed service life of currently known spacecraft is 5-7 years). It should be noted that the duration of one revolution of the orbit of the Earth remote sensing spacecraft is approximately (90-100) minutes, and on each revolution there is a significant temperature drop when moving from the light to the shadow part of the orbit and vice versa (in near-Earth orbit, metal under the direct rays of the sun warms up to 160 degrees Celsius, while objects in the shade cool down to minus 100°C), and there are unfavorable conditions at each orbit when the spacecraft passes through the terminator area.

The purpose of the proposed method of satellite communication systems using spiral-type antennas is to increase the reliability and resource of effective radio communications during the life of the spacecraft during long-term autonomous operation in space.

Disclosure of invention

The proposed method of satellite communication systems using spiral-type antennas consists in the fact that a transmitting antenna for the transmitter and a receiving antenna for the receiver are installed on the body of the spacecraft, interconnected by the principle of reciprocity, feeders are connected to them, while four antenna emitters are wound in a spiral in cylinder shape. The power supply of the radiating elements of the spiral is provided with a phase shift of 0°, 90°, 180°, 270°.

The essence of the invention lies in the fact that the redundancy of the transmitter and receiver is used by connecting them to the antennas through power conditioners, while in orbital flight an antenna with a wide radiation pattern to the Earth and an antenna with a narrowed radiation pattern in the opposite direction (towards the zenith) are used on board the spacecraft. ); at the same time, the antennas are made of all-metal, the radiators are powered by a slot-type balancing device, the upper part of the radiators is attached to the slot-type device, and the lower part is attached to a high-quality dielectric crosspiece, under which a disk is installed that acts as a reflector that contributes to the formation of the required radiation pattern.

An increase in the reliability and resource of effective radio communication is ensured, firstly, by redundant transmitter and receiver, and secondly, by using a wide radiation pattern in antennas directed to the Earth, and a narrowed radiation pattern for antennas directed to the zenith, since this reduces the mutual influence diagrams on top of each other by reducing the zone of their overlap (by moving the zone of their overlap away from the direction to the Earth.)

The reliability and efficiency of radio communications are also positively affected by the use of all-metal antennas (the minimum number of plastic parts) and the use of slot-type balancing devices that provide broadband current balancing.

Graphic illustrations

The invention is illustrated by the figures of FIG. 1, fig. 2 and FIG. 3.

In the graphical figure of Fig. 1 shows an example of the implementation of the proposed method of satellite communication systems using spiral-type antennas, containing components indicated by positions:

• On-board computer (electronic computing device) - 1;

• STM (telemetric information system) - 2;

• FKS (former of command signals) - 3;

• Project 1 (first receiver) - 4;

• SU SHT1 (balancing device of slot-type antenna of the first receiver) - 5;

• CHZUA 1 (four-way antenna of the first receiver) - 6;

• Project 2 (second receiver) - 7;

• SU SHT2 (balancing device of the slot-type antenna of the second receiver) - 8;

• CHZUA 2 (four-way device of the antenna of the second receiver) - 9;

• Per-to 1 (first transmitter) -10;

• SU SHT3 (balancing device of the slot-type antenna of the first transmitter) -11;

• CHZUA 3 (four-way antenna of the first transmitter) - 12;

• Transmitter 2 (second transmitter) - 13;

• SU SHT4 (balancing device of the slot-type antenna of the second transmitter) - 14;

• CHZUA 4 (four-way antenna of the second transmitter) - 15;

• coaxial cable - 16, 17, 18, 19, 21, 22, 23, 24;

• FM 1 (power shaper for receivers) - 20;

• FM 2 (power shaper for transmitters) - 25;

• ZDN (narrowed radiation pattern) - 26

• SDN (wide beam pattern) - 27;

• Ground control complex - 28;

• A 1 (first receiving antenna) - 29;

• A 2 (second receiving antenna) - 30;

• A 3 (first transmitting antenna) -31;

• A 4 (second transmitting antenna) - 32;

• bipolar power dividers - 33-1, 33-2, 35-1, 35-2;

• two-pole power adders - 34-1, 34-2, 36-1, 36-2.

FM 1 and FM 2 each have two inputs (Bx ₁ , Bx ₂ ) and two outputs (Out ₁ , Out ₂ ).

In the block diagram, the ground control complex 28, which is not belonging to the spacecraft, is shown by dashed lines.

The telemetry information from the onboard devices of the spacecraft (TM from the CU) is received at the input of the STM 2 telemetry information system.

In FIG. Figure 2 shows wide non-normalized radiation patterns taken on an experimental prototype of an antenna directed to the Earth.

In FIG. Figure 3 shows narrowed non-normalized radiation patterns taken on an experimental prototype of an antenna directed to the zenith.

Description of the Method for Satellite Communication Systems Using Helical Antennas

Shown in FIG. 1 The on-board computer 1 is the central link in the operation of the spacecraft, including in accordance with the commands of the control unit from the ground control complex 28.

From the ground control complex 28, the command and program information as part of the work programs and one-time commands (KU) received by the receivers (Pr-to 1, Pr-to 2) are transmitted via radio channel to the spacecraft (to the on-board computer 1), while the shaper command signals FCC 3 ensures the interface of the receivers with the on-board computer 1 in the information exchange. From the spacecraft onboard to the ground control complex 28, via telemetry channel with STM 2, telemetry information is transmitted from the onboard devices of the spacecraft (TM from the CU) by transmitters (Per-to 1, Per-to 2), therefore, the exchange of information between the onboard AFU on the SC and the ground control complex in the radio visibility zone (see website: http://aykspace.blogspot.com/2013/08/zrv.html) should be carried out in all possible SC flight modes:

• non-orientated flight of the spacecraft (arbitrary position of the spacecraft in space);

• oriented orbital flight of a spacecraft.

Let us consider the flight modes of a spacecraft using the example of a spacecraft for remote sensing of the Earth (see patent, RF, No. 2722598).

SC flight modes:

• occurs when the spacecraft is separated from the rocket or upper stage, during which the process of calming is carried out, then the process of reduction (combination of the axes of the associated coordinate system of the spacecraft with the axes of the orbital coordinate system) and subsequent stabilization of the spacecraft;

• occurs in the orbital flight of the spacecraft in emergency situations or failures in the operation of the spacecraft attitude control system.

Oriented spacecraft flight modes:

• for spacecraft, in which solar panels are not rigidly fixed on the spacecraft body (see, for example, spacecraft "Kondor-E", the head contractor of JSC "VPK "NPO Mashinostroeniya", Reutov), under the action of drive motors located in it , the solar batteries are set in position relative to the spacecraft body to obtain the maximum possible value of the charging current at the current point of the spacecraft orbit, and the body is not turned for the duration of the target work, which means that the angle of the antenna direction to the Earth does not change;

• in a number of modern spacecraft, the solar array panels are rigidly fixed on the spacecraft body (see, for example, the small spacecraft "Kanopus-V", the head contractor JSC "Corporation" VNIIEM ", Moscow), so they are oriented to the Sun by turning the spacecraft body, including its spin around the direction to the Sun (the “passive” spin mode with the orientation of the solar arrays to the Sun, i.e. the solar orientation mode). solar orientation mode into orbital orientation (for example, the longitudinal axis of the spacecraft, coinciding with the longitudinal axis of the optoelectronic module, is directed to nadir when surveying a sub-satellite point) and maintaining this orientation (active orientation mode), and then, at the end of the target work, the body is turned The spacecraft is again in the "passive" swirling mode with the orientation of the solar panels to the Sun.In this mode, the angle of the antenna's direction to the Earth changes.

To ensure continuous exchange of information between the onboard AFS on the spacecraft and the ground control complex 28 in the radio visibility zone in all modes (non-oriented flight of the spacecraft and oriented orbital flight of the spacecraft), it is advisable to use two antennas, one of which is directed to the Earth, and the other in the opposite direction (in zenith) with directivity diagrams (the dependence of the antenna gain or antenna directivity on the direction of the antenna in a given plane), providing communication with the Earth at any position of the spacecraft in outer space. Therefore, in FIG. 1 shows two transmitting antennas A3 (directed to the Earth) and A 4 (directed to the zenith), respectively, transmitters Per-k 1 (10) and Per-k 2 (13), as well as, interconnected by the principle of reciprocity, two receiving antennas A1 (directed to the Earth) and A 2 (directed to the zenith), respectively, receivers Pr-k 1 (4) and Pr-k 2 (7).

In view of the fact that the spacecraft oriented flight mode (with targeted work) is the main mode in orbit, antennas A 1 and A 3 directed to the Earth use a wide radiation pattern (SDN 27) to ensure reliable radio communication, including, with a change in the angle of direction of the antenna to the Earth when carrying out target work with solar panels rigidly fixed on the body of the spacecraft.

To reduce the mutual influence of antenna patterns (aimed at reducing interference between a pair of antennas by reducing the overlap area of the patterns) directed to the Earth and to the zenith, the pattern to the zenith (ZDN 26) is narrowed, that is, antennas A 2 and A 4 in comparison with antennas A 1 and A 3 have a narrower radiation pattern.

It is known that the most important component of the radio facility is the feeders between the radio transmitter and the transmitting antenna or between the receiving antenna and the radio receiver (see (see V.P. Kubanov. Antennas and feeders - purpose and parameters. Samara 2015, p. 45), which are divided into two separate classes: open and closed.Open feeders are usually two-wire or four-wire balanced transmission lines.Closed feeders are a coaxial cable or a hollow metal waveguide.Open lines are used at frequencies up to 30 MHz, cable - up to 3000 MHz, waveguide - up to 30 GHz.

As an example, consider the decimeter range using an antenna, for example, at an operating frequency f=2067 MHz when it is oriented to the Earth (wavelength λ=0.145 m). The decimeter range is the most optimal for small spacecraft widely used today and in the future with a mass ranging from 500 to 1000 kg.

At a given frequency, a coaxial cable is used as a feeder (in Fig. 1, a coaxial cable is represented by positions 16, 17, 18, 19, 21, 22, 23, 24).

As a coaxial cable, you can use: radio frequency cable brand RK 50-7-47, TU 16-705.109-90 with semi-air insulation of increased heat resistance and low attenuation.

Receiving antennas A 1 (29) and A 2 (30) are connected to the receivers: to Pr-k 1 (4) and to Pr-k 2 (7) through the power conditioner for FM receivers 1 (20), respectively:

• through a two-pole power divider 33-2 and two-pole power adders 34-2, 34-1;

• through a two-pole power divider 33-1 and two-pole power adders 34-2, 34-1,

and transmitters Per-to 1 (10) and Per-to 2 (13) are connected to transmitting antennas A3 (31) and A4 (32) through a power conditioner for FM transmitters 2 (25), respectively:

• through a two-pole power divider 35-2 and two-pole power adders 36-2 and 36-1;

• through a two-pole power divider 35-1 and two-pole power adders 36-2 and 36-1.

This connection provides redundancy of transmitters and receivers, which significantly improves the reliability of the satellite communication system.

Let's consider the reservation process for Per-to 1 (10) and Per-to 2(13).

From the output Per-to 1 (10), the radio signal through the feeder 22 enters the FM 2 (25) to the input of the two-pole power divider 35-2, as a result of which radio signals appear at its two outputs, equal to approximately half the power of the input radio signal that arrives at the antenna A 3 (31) through a two-pole power adder 36-2 through the feeder 21, as well as to the antenna A 4 (32) through a two-pole power adder 36-1 through the feeder 24.

Similarly, the radio signals from the output Per-k 2 (13) are fed to the input of a two-pole power divider 35-1, from the output of which, with a half-powered power through a two-pole power adder 36-2, they go to antenna A 3 (31) and through a two-pole power adder 36 -1 to antenna A 4 (32). Therefore, if the main transmitter fails, for example, Per-to 1 (10), which produces radio signals to antennas A 3 (31) and A 4 (34), then the backup Per-to 2 (13 ), which also outputs radio signals to antennas A 3 (31) and A 4 (32).

Redundancy receivers Pr-1 (4) and Pr-2 (7) as follows.

The radio signal from the antenna A 1 (29) through the feeder 16 enters the FM 1 (20) at the input of the two-pole power divider 33-2, as a result of which radio signals appear at its two outputs, equal to approximately half the power of the input radio signal, which are fed to Pr-k 1 (4) through a two-pole power adder 34-2 through feeder 17, and to Pr-k 2 (7) through a two-pole power adder 34-1 through feeder 18.

Similarly, radio signals from antenna A 2 (30) are fed to a two-pole power divider 33-1, which from its output with half the power through a two-pole power adder 34-2 go to Pr-to 1 (4) and through a two-pole power adder 34 -1 to Pr-k 2 (7).

Therefore, if the main receiver fails, for example, Pr-k 1 (4), then, at the signal of the on-board computer 1, the backup Pr-k 2 (7) is connected.

Two-pole power dividers (adders) 33-1, 33-2, 35-1, 35-2 and two-pole power adders 34-1, 34-2, 36-1, 36-2 are mutual devices (see website: https: //scask.ru/n_book_svf.php?id53), so, for example, PS2-800-2700-75 can be used as bipolar power dividers (adders) (see website: https://kroks.ru/shop/power -splitters/). Two-pole power dividers (adders) are widely used and commercially available products. So, for example, on the site: http://rfcomponents.ru/produktsiya/svch-komponenty/deliteli-moshchnosti-kombajnery.html a wide selection of these devices is given in a wide frequency range with different parameters.

It should be noted that as a power shaper for FM receivers 1 (20) and a power shaper for FM transmitters 2 (25), it is possible to use more complex products manufactured by the industry that are suitable in terms of technical parameters compared to bipolar power dividers (adders) that have two inputs (In ₁ , In ₂ ) and two outputs (Out ₁ , Out ₂ ), for example, a quadrature bridge, (see, for example, a quadrature bridge from the manufacturer Radiocomp LLC, Moscow, website: https://productcenter.ru /products/85355/napravliennyi-otvietvitiel) or, for example, a hybrid ring (see website: https://www.qrz.ru/schemes/contribute/antenns/ew8au/improve.shtml).

In antennas A1 (29), A 2 (30), A3 (31), A4 (32), slot-type balancing devices are used, respectively SU SCHT 1, SU SC 2, SU SC 3, SU SC 4 (see website: https ://studbooks.net/2348850/tehnika/simmetriruyuschie_ustroystva), which makes it possible to obtain broadband balancing of the currents that feed the emitters, which are made in the form of four turns of a helix. At the same time, these slot-type balancing devices are the supporting structure for the spirals, as well as the antenna impedance transformer into the feeder impedance.

JSC "NIIEM" (which is the Applicant of the invention) developed an experimental model of the decimeter range antenna for the operating frequency f=2067 MHz (wavelength λ=0.145 m).

With a minimal difference in design, two samples were obtained:

• An experimental breadboard model of an antenna with a wide radiation pattern directed towards the Earth;

• An experimental breadboard model of an antenna with a narrowed zenith-directed radiation pattern.

In FIG. 2 shows real non-normalized radiation patterns (wide), taken on an experimental prototype of the antenna, for the direction to the Earth, and in Fig. 3 - non-normalized radiation patterns (narrowed) for the direction to the zenith.

The presented radiation patterns were taken on antennas with linear polarization in four planes.

From the presented radiation patterns it can be seen that during oriented flight in the sector of maximum range angles (angle θ≈60°) the gain is increased compared to angles (angle θ from 0° to 50°), where the gain is lower; the influence of the antenna directed to the zenith on the quality of communication is significantly reduced. The difference does not affect the quality of communication during non-orientated flight.

The claimed invention makes it possible to ensure high reliability and efficient radio communication throughout the entire period of the active existence of the spacecraft during long-term autonomous operation in space due to the fact that:

• provide rationally efficient redundancy of radio communication systems;

• use the configuration of the antennas on the spacecraft with the optimization of radiation patterns;

• use all-metal antennas with high strength

• Use slot-type baluns that provide broadband current balun.

Claims (1)

The method of satellite communication systems using spiral-type antennas, which consists in installing on the body of the spacecraft a transmitting antenna for a transmitter and a receiving antenna for a receiver, interconnected by the principle of reciprocity, connecting feeders to them, four antenna emitters are wound in a spiral in the form of a cylinder , to which signals are supplied with a phase shift of 0°, 90°, 180°, 270°, characterized in that a second antenna is added to each antenna - receiving and transmitting - through a power conditioner, while the first antennas have a wide radiation pattern to the Earth, and the added second antennas - a narrowed radiation pattern in the opposite direction - to the zenith, and all the antennas are made of all-metal, and the radiators are powered by a slot-type balancing device.

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