RU2813857C1 - Towed floating cable antenna device - Google Patents

Abstract

FIELD: antenna equipment.

SUBSTANCE: invention relates to antenna equipment on underwater objects, including those operating under ice. Technical result is achieved by forming and using the phenomenon of propagation of a side radio wave for a floating cable antenna, which is towed horizontally in a near-surface layer of a conducting medium at the boundary with an electrically less dense medium (air, ice).

EFFECT: providing two-way radio communication in the MW/HF bands and high-precision radio navigation in the MW band of underwater objects, including those operating under ice, using towed floating cable antennae without an end body.

1 cl, 2 dwg

Description

The invention relates to radio engineering, namely, to antenna technology and can be used as a transmitting and receiving antenna for the MF/HF ranges at underwater objects, including those operating under ice.

One of the priority tasks being solved within the framework of the development of the Russian Federation is the development of the country’s northern marine territories. Therefore, the development of systems for stable communication and control of underwater objects located in the northern seas seems to be an important and relevant area.

Currently, in order to transmit information towards the shore, underwater objects operating in the Arctic are forced to look for ice to surface or break the ice. Any of these operations is unsafe, leads to loss of time, and when using autonomous underwater vehicles, also to loss of energy resources. The only antennas that can be used by underwater objects under ice at a safe depth (under the topography of the lower edge of the ice, the height of unevenness of which can exceed 10 m) are towed cable antennas without an end body. The presence of a body with transmitting and receiving antenna elements at the running end of the floating cable inevitably leads to entanglement and breakage of the floating cable in the protrusions of the subglacial relief of sea ice during towing. The use of a floating cable antenna with a flexible three-pole assembly of vertical vibrators at the end [1], designed to receive/transmit a vertically polarized radio signal field, is possible only in conditions of clean (without ice cover) water.

Currently, the following options for constructing cable antennas in the form of a floating cable are known:

- cable receiving antennas in the VLF range [2]

- cable VHF/LW receiving antennas [3];

- modular VHF/LW and HF floating cable antenna and method [4];

- ultra-wideband floating cable antenna element [5].

A common disadvantage of the listed antennas is the one-way nature of their operation - all of these antennas are receiving only.

The possibility of manufacturing a towed antenna device for transmission at frequencies from 2 to 10 MHz is mentioned in [6]. However, neither the structure nor the operating principle of such a device is given in this work.

Work [7] describes a promising cable antenna for two-way satellite communication, the basis of which is made up of slot antenna elements, part of which must protrude above the surface of the water when receiving/transmitting a signal. However, the use of this antenna in the Arctic in conditions of a completely submerged cable and high attenuation of DCV radio signals in the thickness of sea ice is impossible.

The closest analogue of the proposed antenna device is a “Towed floating cable antenna device with a built-in broadband amplifier” [8] of VHF/DV/HF/VHF bands, which contains: a metal end seal, a single-wire floating cable, one end of which is connected to a metal end seal, a built-in wideband amplifier, the input of which is connected to the second end of the single-wire floating cable, and a coaxial floating cable, one end of which is connected to the output of the built-in wideband amplifier.

The disadvantages of the prototype include both the inability to use it in transmission mode and the inability to operate in the MV range. Both disadvantages are associated with the use of a built-in broadband amplifier with filtering circuits for VHF/LW and HF/VHF signals. Meanwhile, the SW range is the most informative for underwater objects operating in the Arctic, where radio communication in the HF range is extremely unreliable due to sudden changes in the electron concentration of the ionized layer of the atmosphere, in the VHF range it has insufficient range, and in satellite channels is impossible due to the large signal attenuation in ice cover of any age. The high attenuation of DCV range signals is also an obstacle to the reception of satellite navigation signals at objects operating under ice. And the root-mean-square error in determining a location using long-wave navigation signals, amounting to hundreds of meters, is unsatisfactory for ensuring the safety of navigation of underwater objects. At the same time, the accuracy of solving navigation problems using signals from medium-wave navigation systems is comparable to the accuracy of satellite systems.

The technical problem solved by the inventive antenna device is the provision of two-way radio communication in the MF/HF bands and medium-wave radio navigation of underwater objects operating in the Arctic, including under ice without breaking the ice and from a safe depth.

The achieved technical result is to provide two-way radio communication in the MF/HF bands and high-precision radio navigation in the MF range of underwater objects, including those operating under ice, when using towed floating cable antennas without an end body.

The essence of the proposed invention is to provide the possibility of forming and using the phenomenon of lateral radio wave propagation for a floating cable antenna towed horizontally in the near-surface layer of a conducting medium at the border with an electrically less dense medium (air, ice), as well as to enable its operation in the CB range.

For this purpose, in the proposed invention - a transmitting and receiving towed floating cable antenna device (hereinafter referred to as the towed floating cable antenna device) of the MF/HF ranges, containing a single-wire floating cable, a coaxial floating cable and a metal end seal, the following are additionally introduced:

- characteristic impedance connected between the end metal seal and one of the ends of the wire of a single-wire floating cable;

- an intermediate metal termination connected to the coaxial shield at one end of the coaxial floating cable; wherein the second wire end of the single-conductor floating cable is connected to the center conductor of the coax at the same end of the coaxial floating cable as the second metal termination.

The proposed device includes:

- end metal seal;

- wave resistance;

- single-wire floating cable;

- intermediate metal seal;

- coaxial floating cable.

Characteristic impedance is a resistance whose value is equal to the characteristic impedance of a single-wire floating cable.

The composition and operation of the proposed towed floating cable antenna device are illustrated by the drawings presented in Fig. 1 and 2.

In fig. Figure 1 shows a block diagram of a transceiver towed floating cable antenna device of the MF/HF ranges and its connection to the equipment of the towing object.

In fig. Figure 2 shows a diagram of towing an antenna device, the process of radio signal propagation in transmission mode, and the antenna radiation pattern.

Accepted notations in Figs. 1 and 2:

1 - end metal seal;

2 - wave impedance;

3 - single-wire floating cable;

4 - intermediate metal seal;

5 - coaxial floating cable;

6 - two-electrode antenna;

7 - connector;

8 - receive/transmit switch;

9 - radio communication device;

10 - radio navigation device;

11 - radio transmitting device.

A single-wire floating cable 3 with characteristic impedance 2, end 1 and intermediate 4 metal seals in contact with sea water forms a two-electrode traveling wave antenna 6 (hereinafter referred to as the two-electrode antenna), and the coaxial floating cable 5 is a high-frequency feeder.

The coaxial floating cable 5 is connected to the equipment of the towing underwater object: to the connector 7 and further, through the receive/transmit switch 8, to the radio receiving devices for communication 9 and navigation 10 or the radio transmitting device 11, respectively.

The maximum efficiency of a towed floating cable antenna device in both operating modes is achieved when the antenna is towed along the interface, since radio waves of the MF/HF ranges quickly attenuate in sea water. This position of the antenna is ensured by the buoyancy of the single-wire and coaxial cables and the choice of towing speed. In this case, the safe depth of travel of the towing underwater object is achieved due to the length of the coaxial floating cable.

The operation of the proposed towed floating cable antenna device is carried out as follows.

In the receiving mode, the horizontal component of the field of the MF/HF radio signal incident on the air-water interface (“ice-water”) induces in the two-electrode antenna 6 the electromotive force of the signal, which is carried along the coaxial floating cable 5 through the connector 7 and the reception switch /transmission 8 is sent to radio receivers for communication 9 and navigation 10.

In transmission mode, the radio signal coming from the radio transmitting device 11 through the receive/transmit switch 8 and connector 7 is transmitted via a coaxial floating cable 5 to the two-electrode antenna 6. As a result of the refraction of waves emitted by the elements of the single-wire floating cable of the two-electrode antenna and coming to the interface with the electrically less dense media (ice, air) at angles no less than critical, lateral waves are formed in the air, propagating along the interface [9-12]. For sea water, ice and air in the MF/HF bands, the critical angle corresponds to the direction of wave propagation from the antenna almost vertically upward. In this case, due to the formation of a traveling wave mode in the antenna using wave impedance and the same speed of propagation in the antenna and air, the waves emitted by all elements of the antenna are added when propagating along the interface in the direction of the end metal seal in phase, and the signal due to superposition waves are amplified (the radiation pattern of the antenna in the air is oriented parallel to the antenna wire in the direction of its end).

The calculation results confirmed the possibility of providing two-way radio communication (reception and transmission) in the MF/HF bands at a depth of 60 m with a feeder length of 500 m and a towing speed of 2 knots; the accuracy of determining the location coordinates when working as part of modern radio navigation systems will be several meters [13].

Thus, the declared technical result has been achieved.

Information sources:

1. US Patent 3599213.

2. M.L. Burrows. ELF Communications Antennas. Lincoln Laboratory Massachusetts Institute of Technology, Lexington, Massachusetts, USA, 1979.

3. The Art of the Possible Communications at Speed and Depth. Underseawarfare/ The Official Magazine of the U.S. Submarine force, Spring 2006, v. 8, n. 3.

4. Patent US 2011/0279336 A1.

5. US Patent 7868833B2.

6. Sea-Air Systems Division Communication Systems Group (Buoyant Wire Antenna System, www.sippican.com).

7. Blair Carlson. Adaptive Beamforming for Submarine-Satellite Communications with the (MBCA) Multielement Buoyant Cable Array Antenna. MIT Lincoln Laboratory, ASAP March 2001.

8. US Patent 4774519.

9. Goldshtein L.D., Zernov N.V. Electromagnetic fields and waves // M.: Soviet radio, 1971.

10. Burrows M.L. On the design of a towered ELF H-field antenna/ M.I.T. Lincoln Laboratory, Lexington, Mass., Tech. Note 1972-34 (DDC AD 754949).

11. King R., Smith G. Antennas in material media // M.: Mir, vol. 1, 1984.

12. A. L. Drabkin, V. L. Zuzenko, A. G. Kislov. Antenna-feeder devices // M.: Soviet radio, 1974.

13. Yu.I. Nikitenko, V.I. Bykov, Yu.M. Ustinov. Ship radio navigation systems // M.: Transport, 1992.

Claims (1)

A towed floating cable antenna device of the MF/HF ranges, containing a single-wire floating cable, a coaxial floating cable and a metal end seal, characterized in that a resistance is introduced into it, the value of which is equal to the characteristic impedance of the single-wire floating cable, included between the metal end seal and one of the ends wires of the single-conductor floating cable, and an intermediate metal termination connected to the coax shield at one end of the coaxial floating cable, wherein the second end of the wire of the single-wire floating cable is connected to the center conductor of the coax at the same end of the coaxial floating cable as the intermediate metal termination, with In this case, the coaxial cable is designed to be connected by means of a connector to a transmit-receive switch, connected, in turn, to radio receivers for communication and navigation and a radio transmitter of the towing object; the single-wire floating cable is configured to emit waves arriving at the interface at angles not less critical, corresponding to the direction of wave propagation from the antenna device almost vertically upward, and when towing the antenna device is placed horizontally in the near-surface layer of the conducting medium at the boundary with an electrically less dense medium.