CN118233019A - Magnetic transmission technique for low frequency radio waves for submarine communication - Google Patents

Abstract

A magnetic emission technology for low-frequency radio waves for submarine communication, wherein the last-stage alternating current of a radio transmitter (1) is output to an LC circuit, electromagnetic resonance is generated in the LC circuit, an alternating magnetic field is generated in a magnetic core (4) of an inductor (3), the magnetic core (4) excites an alternating magnetic field (5) in the air, the alternating magnetic field (5) excites an alternating electric field (6), and … then electromagnetic waves are radiated outwards. Compared with the traditional emission mode (electric emission), the emission mode does not need a huge antenna array and a complicated ground network, does not need high voltage or ultrahigh voltage, and has obvious advantages: 1. the device is low in cost and small in volume, and can be conveniently arranged on a ship to realize direct communication between the ship and a submarine. 2. Has strong directivity. 3. Is less affected by bad weather. 4. Is suitable for the emission of radio waves of medium wave, long wave, very long wave, ultra-long wave and the like. The lower the frequency of the radio wave, the larger the wavelength, and the more pronounced the advantage.

Description

Magnetic transmission technique for low frequency radio waves for submarine communication

Technical Field

The invention relates to radio electronic technology, in particular to magnetic emission technology of low-frequency radio waves mainly used for submarine communication.

Background

The submarine utilizes the water layer to shield for concealing activities, has larger self-supporting force, endurance and operational radius, and the self-supporting force of the conventional submarine is generally about tens of days, and the nuclear submarine can reach hundreds of days. Therefore, the submarine can independently fight in a longer time and a larger ocean area even deeper into the sea area of the enemy, can lay underwater mines, launch torpedoes and missiles, attack the offshore targets or the onshore targets of the enemy or even the aerial targets, and can implement sudden attack on the enemy;

The submarine is shielded by the water layer, has good concealment and is not easy to be found by enemy. However, the seawater has strong attenuation effect on radio waves, and the conventional communication mode is not suitable for communication in water, so that the submarine is not easy to realize bidirectional, timely and long-distance communication;

however, the attenuation of the radio wave by seawater is related to the frequency of the radio wave, and the lower the frequency of the radio wave, the lower the attenuation. This suggests that if lower frequency radio waves are used, effective communication with the submarine in the sea can be achieved. The working frequency of communication radio stations for conventional submarines in various countries in the world is mostly between 10 and 30kHz, and the working frequency of the radio stations for nuclear submarines is lower.

The radio wave is generated by modulating the useful signal with low frequency to the carrier signal with higher frequency to form modulated wave, the transmitter of the radio station amplifies the modulated wave and feeds the modulated wave to the open circuit formed by the antenna wire to be transmitted, namely, the radio wave required by us is generated, and the modulated wave is received, amplified and demodulated by the receiver to obtain useful information for us;

this way of transmitting radio waves with the earth, which is first excited between the earth by a varying electric field, is generally referred to as the electric transmission of radio waves. Most of the radio waves are emitted in this way;

Transmitting radio waves in this way requires a higher carrier frequency, since the radiated power is proportional to the fourth power of the frequency, i.e. the higher the carrier frequency, the easier it is to transmit; meanwhile, the geometric dimension of the transmitting antenna is related to the wavelength of the carrier wave, for example, a vertical straight wire is used as the antenna, the height of the antenna is between 1/4λ (λ: the wavelength of radio waves) and 1/2λ, the frequency of the medium wave is lower, the wavelength is longer, and the height of the antenna is tens of meters to hundreds of meters, namely, a higher transmitting antenna is needed; the lower the frequency, the higher the required antenna. And the final stage of the transmitter requires high or ultra high pressure;

that is, radio wave transmission with a low frequency (long wavelength) is difficult, and refers to an electric transmission technique for transmitting radio waves.

Whether or not we can change the idea to send radio waves with lower frequencies, instead of conventional electric transmission techniques, to use magnetic transmission? This is what the invention is to describe.

Disclosure of Invention

In our environment, various radio waves are filled, and the radio waves are received, selected and demodulated by specific devices, so that useful information such as sound (radio) and image (television) needed by us can be restored;

Taking a medium wave broadcasting station as an example, the broadcasting station modulates a sound signal with a lower frequency onto a carrier signal with a higher frequency to form a modulated wave, and a broadcasting transmitter of the broadcasting station amplifies and feeds the modulated wave to a ground wire to be transmitted, namely, a radio wave required by people is generated, and the sound is received, amplified and demodulated by a radio, namely, the sound can be heard.

We briefly describe the principle of radio wave emission, as shown in fig. 2 (a), a high-frequency carrier signal generated by a radio transmitter is fed to an LC circuit to make the LC circuit form electromagnetic oscillation, at this time, electric field energy and magnetic field energy are continuously converted into each other in the LC circuit, and due to the constraint of a capacitor plate and a magnetic core being closed, electromagnetic energy leaks little in this case, and radio waves cannot be propagated outwards;

if we increase the capacitance plate spacing, as shown in FIG. 2 (B), some of the electric field can be dispersed into the air;

if we further use the antenna and the ground line as the two poles of the capacitor, as shown in fig. 2 (C), an open circuit is formed, the antenna and the ground line are the two poles of the capacitor of the open circuit, and a variable electric field is excited in the space between the antenna and the ground line, and the variable electric field further excites a variable magnetic field, and the variable magnetic field further excites a variable electric field …, so that electromagnetic waves are radiated to the outside, and thus, the radio waves required by us are generated;

it follows that the radio waves are emitted in a heaven-earth fashion, with a varying electric field being first excited between the heaven-earth, which we generally refer to as the electric emission of radio waves. Most of the radio waves are emitted in this way.

Transmitting radio waves in this way requires a higher carrier frequency, since the radiated power is proportional to the fourth power of the frequency, i.e. the higher the carrier frequency, the easier it is to transmit; meanwhile, the geometric dimension of the transmitting antenna is related to the wavelength of the carrier wave, for example, a vertical straight wire is used as the antenna, the height of the antenna is between 1/4λ (λ: the wavelength of radio waves) and 1/2λ, the frequency of the medium wave is lower, the wavelength is longer, the height of the broadcasting antenna is tens of meters to hundreds of meters, that is, the higher the transmitting antenna is needed, the lower the frequency is, and the higher the required antenna is; and the final stage of the transmitter requires high or ultra high pressure;

In a long wave band (low frequency LF, frequency 30kHz-300kHz, wavelength 1000m-10000 m) with lower frequency than the medium wave, the low frequency is not easy to emit; the wavelength is long, huge antenna equipment is needed, and high voltage or ultrahigh voltage is needed for the final stage, so that broadcasting stations in China do not adopt long-wave band broadcasting;

Very long wavelength bands (very low frequency LVF, frequency 3kHz-30kHz, wavelength 10000m-100000 m) with lower frequencies than long waves are less prone to transmit due to the lower frequencies; because the wavelength is longer, the antenna needs to be normally transmitted, a huge antenna array and a complicated grounding grid are needed, and the final stage needs ultrahigh voltage;

That is, the emission of these radio waves of lower frequencies (longer wavelengths) is difficult for long and very long waves.

Why do we have to pay a great effort to build, since radio waves of lower frequencies (longer wavelengths) are difficult to send? Due to their excellent transmission characteristics;

When radio wave with long wavelength propagates, the phenomena of abrupt change of the receiving intensity and abrupt interruption of communication are avoided, the influence of ionosphere disturbance is small, the stability is good, and the acting distance can reach thousands to tens of thousands kilometers. The optimal characteristic is that it can spread in sea water, it can be drilled into water from the air, the attenuation in water is smaller, the frequency is lower, the depth of penetrating sea water is deeper, so that the submarine submerged under water can receive the electric wave sent from the shore.

The low-frequency radio wave propagates in the sea water, the depth of the radio wave penetrating through the sea water is related to the power of a transmitting station, the transmitting distance and the receiving sensitivity of a receiver, and when the conditions are given, the lower the frequency of the radio wave is, the deeper the depth of the radio wave penetrating through the sea water is;

FIG. 1 is a graph showing the relation between the depth of penetration of radio waves into seawater and frequency

If the radio wave frequency penetrates the sea water to a depth of 10-20m in the very long band (very low frequency VLF), the depth of penetration of the sea water in the long band (low frequency LF) is only a few meters; and the depth of penetrating seawater in an extremely long wave band (extremely low frequency ELF) can reach 100-200m.

In summary, lower frequency radio waves have excellent propagation characteristics, and are extremely important in applications, but are difficult to transmit. Radio wave transmission difficulties of lower frequencies (longer wavelengths) refer to the use of electric transmission techniques to transmit radio waves;

whether or not we can change the idea to send radio waves with lower frequencies, instead of conventional electric transmission techniques, to use magnetic transmission? This is what the invention is to describe.

Drawings

Fig. 1: the depth of penetration of radio waves into sea water as a function of frequency

Under certain conditions, the penetration depth of the radio wave frequency into the seawater in a long wave band (low frequency LF) is 0-10m; the depth of penetration of seawater in the very long wavelength band (very low frequency VLF) is 10-20m, and the depth of penetration of seawater in the very long wavelength band (very low frequency ELF) can reach 100-200m.

Fig. 2: a radio wave electric emission schematic diagram in which: FIG. 2A, closed magnetic circuit, closed circuit unable to generate electromagnetic waves; FIG. 2B, a closed magnetic circuit, semi-open circuit, capable of generating a small amount of electromagnetic waves; fig. 2C, closed magnetic circuit, open circuit, produces electromagnetic waves.

Fig. 3: closed electrical circuit, open magnetic circuit, can also generate electromagnetic waves wherein: 1. the final stage of the transmitter of the radio station is designed as a current output type; 2. capacitance, capacitance C;3. inductance, inductance L. LC should resonate at the frequency of the radio wave emitted by the station, if the frequency of the radio wave emitted by the station is f: f=1/(2pi_lc); 4. an inductive core, open. Ferrite for the material of the magnetic core (4) when the frequency of radio wave is high; when the frequency of radio waves is very low, such as when operating at Extremely Low Frequency (ELF), the magnetic core (4) material is an oriented silicon steel sheet. 5. Describing the magnetic field lines (first chain) of an alternating magnetic field; 6. the electric lines of force (first chain) describing the alternating electric field; 7. describing the magnetic field lines (second chain) of the alternating magnetic field; 8. the electric lines of force (second chain) describing the alternating electric field; 9. and (3) winding the coil of the inductor (3) by insulating enameled wires.

Fig. 5: magnetic antenna schematic diagram of medium wave radio

Wherein: 10. a magnetic rod; 11. a primary coil; 12. a variable capacitance; 13. and a secondary coil.

Fig. 4: simulation experiment device diagram

Wherein: 14. a low frequency signal generator; 15. millivoltmeter; 16. a transmitting inductance; 17. and receiving the inductance.

Detailed description of the preferred embodiments

As shown in fig. 3, an LC circuit is formed by a capacitor (2) and an inductor (3), and resonates at the frequency of radio waves emitted by a radio station, and the final stage of the radio station transmitter (1) is designed as a current output type;

when the radio station works, alternating current generated by the transmitter (1) is output to an LC circuit, electromagnetic oscillation is generated in the LC circuit, mutual conversion of electric field energy and magnetic field energy is continuously carried out in the LC circuit, the electric field energy is not leaked due to the constraint of a capacitor plate, a magnetic core (4) of the inductor (3) is open, when the alternating current passes through the inductor (3), an alternating magnetic field is generated in the magnetic core (4) of the inductor (3), two ends of the magnetic core (4) excite an alternating magnetic field (5) in the air, the alternating magnetic field (5) excite an alternating electric field (6), the alternating electric field (6) excite an alternating magnetic field (7), the alternating magnetic field (7) further excite an alternating electric field (8), and … radiate electromagnetic waves outwards;

this way of emitting radio waves, which is first excited in air, is an alternating magnetic field, and therefore we refer to as magnetic emission of radio waves.

The radio wave magnetic emission mode is suitable for the transmission of radio waves with lower frequencies, such as medium waves (medium frequency MF), long waves (low frequency LF), very long waves (very low frequency VLF), ultra-long waves (ultra-low frequency ULF), very long waves (ultra-low frequency SLF) and very long waves (very low frequency ELF), without high voltage and complex antenna and ground wire systems, compared with the traditional radio wave radio emission mode. The lower the frequency of the emitted radio wave, the longer the wavelength, the more pronounced the advantage;

Because the transmitting mode does not need high voltage and a very complex antenna and ground wire system, a radio station adopting a magnetic transmitting design can be miniaturized, is conveniently arranged on various ships and is convenient for sending instructions to nearby submarines. Meanwhile, if insulation is treated, can be emitted in water? If the device can emit in water, the device can be miniaturized, and can be installed on a submarine to realize bidirectional interaction between the submarine and a base station;

Because the transmitting mode does not need a very complex antenna and ground wire system, the construction cost is low; the high voltage is not needed, the insulation requirement is reduced compared with that of a ground wire transmitter, and the manufacturing cost is reduced. Therefore, the overall cost of the emission mode is lower;

In the conventional mode of emitting radio waves by using the antenna and the ground wire, normally, vertical polarized waves are emitted, and in order to enable the radio waves emitted by the magnet to be compatible with the existing receiver, a magnetic core (4) (a magnetic rod) of an emitting inductor (3) is horizontally arranged, and the excited electromagnetic waves are also vertical polarized waves, so that the compatibility of the emitted radio waves is ensured;

When the magnetic core (4) (magnetic bar) of the inductor (3) is placed horizontally, the electric field excited in the axial direction is weak, but the electric field excited in the direction perpendicular to the magnetic bar is strongest, so that when the radio wave is emitted by the magnetic emission mode, the direction perpendicular to the magnetic core is directed in the direction in which the radio wave is to be emitted in practical application.

The traditional mode of emitting radio waves by using the antenna and the ground wire is higher, and is easily influenced by bad climates such as thunder and lightning, but the influence of the bad climates is small when the magnetic-emission radio waves are used.

Pattern of excess 1

Fig. 5 (a) shows a schematic diagram of a magnetic antenna of a medium wave radio, in which a magnetic rod (10) receives a radio wave in space, induces an alternating current in a primary coil (11) and is coupled to a secondary (13) for later use, which is used as a magnetic antenna of the radio. According to the principle of reciprocity of the antenna, if the primary coil (11) inputs alternating current from the a and B terminals, the magnetic rod will emit radio waves outwards as shown in fig. 5 (B).

Pattern of excess 2

As shown in fig. 4, the output end of the low-frequency signal generator (14) is connected with the transmitting inductor (16), the receiving inductor (17) is connected with the input end of the millivoltmeter (15), and the output level and frequency of the low-frequency signal generator (14) are adjusted to read from the millivoltmeter (15). The transmitting inductor (16) and the receiving inductor (17) are arranged in parallel and are 13.5cm apart, and no resonance capacitor is added. The experimental results are shown in the following table

Number of experiments	Frequency (kHz)	Output level (v)	Millivoltmeter reading (mv)
				1	0.3	2	25
2	3	2	28
				3	30	2	82
4	63	2	1.5v

An interesting phenomenon also appears in the experiment, when the frequency is adjusted to 63kHz, millivolts represent the maximum number, and the frequency reaches surprisingly 1.5v, and a certain inductance and a distributed capacitance are likely to generate resonance;

from experiments it has been demonstrated that magnetic emission of radio waves is indeed possible.

Imagine

The frequency range from the Extremely Low Frequency (ELF) section to the Very Low Frequency (VLF) section is 30Hz-30kHz, the frequency response of the amplifier is close to that of an audio power amplifier, and the frequency response of the high-fidelity power amplifier is 20Hz-20kHz, so that the amplifier can be used as a transmitter of a low-frequency radio station, and the long direct transmitting inductor in the patent can be used for replacing a loudspeaker, so that low-frequency radio waves can be transmitted;

i have not studied their feasibility further in an intensive experiment, mainly involving frequency use problems, and have used a certain frequency for experiments, which may interfere with the facilities that are using it when its radiated power is too great, which is not permissible. However, the personal application frequency is extremely difficult, and the frequency can not be known to be idle and can be used, so that the personal does not further increase the power experiment;

A civil 100w power amplifier core, about one hundred yuan, if use corps level things, estimate can control in one thousand yuan, namely about ten yuan of every watt, it is presumed that, make 1Mw radio station by this patent technology, the cost is expected to control in ten million yuan magnitude, compare with construction cost of the conventional radio station much smaller;

The volume of the 100w power amplifier together with the power supply is almost equal to that of a desktop computer, and the power supply is supposed to be equal to that of a kilowatt-level radio station manufactured by the technology of the patent, and the volume of the radio station is not very large, so that the radio station can be conveniently arranged on a ship, and the ship can directly send instructions to a protected submarine, namely, the ship and the submarine can directly communicate;

If the transmitter is arranged on a ship, the transmitter can send instructions to submarines outside 100km under the assumption that the transmitting power is 0.1kw, the efficiency is equivalent to that of the transmitter with the land transmitting power of 1Mw for sending instructions to submarines outside 10000km, and the influence of the curved surface of the earth and the climate is not considered yet;

If the transmitter can be arranged on a ship, the significance is very great. In China, 3 aircraft carriers are in service, when the aircraft carriers are in ocean to execute tasks, the huge and huge seakeeping formation is carried out, the nuclear submarines are the best to serve the seakeeping tasks, but at present, the connection between the aircraft carriers and the formation needs to be transferred through a land transmitter station, and if the transmitter (radio station) is arranged on the formed ships, the ships can directly command the seakeeping submarines, so that timely and effective communication among the ships can be ensured.

The magnetic emission of radio waves is truly feasible, but there are many things to do to put into practice, assuming that the station is operating at a certain frequency, what material is required for the core to achieve a certain emission power, how large the cross section is, how long the two ends are shaped, how the transmitter is cascaded with the emission inductance, etc., all require sufficient theory and experimentation.

The following words: electromagnetic waves have been found and applied for a hundred years, and from the beginning of the discovery, the electric and magnetic densities are known to be indistinguishable, so people have been under scrutiny to study the antenna and ground wire emission (electric emission) technology of radio waves to manufacture antennas of various shapes, and the theory is also quite sufficient, so that the antenna is applicable to high-frequency radio waves. However, the emission of low-frequency radio waves is always a difficult problem, and the radio wave magnetic emission mode clearly provides a brand new idea.

Claims (4)

1. A magnetic transmission technique for low frequency radio waves for submarine communication, characterized by: with this transmission mode, an alternating magnetic field is first excited in the air; suitable for the transmission of radio waves with lower frequencies, such as the transmission of medium waves (medium frequency MF), long waves (low frequency LF), very long waves (very low frequency VLF), very long waves (ultra low frequency ULF), very long waves (ultra low frequency SLF) and very long waves (very low frequency ELF).

2. A magnetic transmission technique for low frequency radio waves for submarine communication according to claim 1, characterized by: an LC circuit is formed by a capacitor (2) and an inductor (3), and the LC circuit resonates with the frequency of radio waves emitted by a radio station; wherein the capacitor (2) is closed; the magnetic core (4) of the inductor (3) is open and is a long and straight magnetic core (such as a magnetic rod); the direction perpendicular to the core points in the direction in which radio waves are to be emitted.

3. A magnetic transmission technique for low frequency radio waves for submarine communication according to claim 1, characterized by: the radio station designed by the technology has low cost and small volume, can be conveniently arranged on a ship, and can be directly communicated with a submarine.

4. A magnetic transmission technique for low frequency radio waves for submarine communication according to claim 1, characterized by: ferrite for the material of the magnetic core (4) when the frequency of radio wave is high; when the frequency of radio waves is very low, such as when operating at Extremely Low Frequency (ELF), the magnetic core (4) material is an oriented silicon steel sheet.