High-power pulse low-frequency antenna based on Tesla coil

Abstract

The low-frequency electromagnetic wave has the characteristics of high penetrability and low signal attenuation, and can be widely applied to the fields of underground communication, underwater communication and the like. Most existing low-frequency transmitting antennas are electrically small antennas, have the problems of large size, complex equipment, short transmission distance and the like, and are difficult to meet actual requirements. The invention relates to a high-power pulse low-frequency antenna based on a Tesla coil. The high-power pulse low-frequency antenna is a high-power pulse transmitting antenna composed of a solid-state double-resonance Tesla circuit, a transformer, a primary coil and a secondary coil. The antenna adopts a high-voltage pulse generated by a Tesla circuit for feeding, and meanwhile, a transformer type impedance matching network is combined, so that the feed power is maximized. The radiation coil selects a primary and secondary nested coupling structure, the working frequency is accurately adjusted to be the output frequency of the Tesla circuit by respectively connecting resonant capacitors in series to the primary and secondary coils, and effective amplification of radiation signals is realized based on a magnetic coupling effect. The size of the coil is in the sub-cubic meter level and is within one thousandth of the working wavelength. Aiming at the antenna design difficulty in long-wave communication, the antenna has the advantages of high input power, long-distance transmission and small physical size, and has potential application value in the fields of cross-medium communication, emergency management communication and the like.

Description

Technical Field

[0001] This invention belongs to the field of low-frequency communication, and particularly relates to a high-power pulse low-frequency antenna based on a Tesla coil. Background Technology

[0002] Low-frequency electromagnetic waves, with their significant advantages such as long wavelength, high penetration, and low loss, can penetrate complex media layers, such as soil, rock, and seawater, to achieve long-distance, stable, and reliable signal transmission, showing great application potential in key areas such as underground emergency communication, submarine communication, and positioning and timing. However, traditional electrically small antennas face many challenges in low-frequency applications. To ensure signal transmission distance, the minimum size of traditional electrically small antennas usually needs to be greater than one-tenth of the operating wavelength. Since the wavelength of low-frequency electromagnetic waves often reaches the kilometer level, this results in an antenna physical size of over 100 meters. Such a large antenna size significantly reduces the flexibility, portability, and safety of low-frequency antennas. In complex scenarios such as underground mines, tunnel construction, and search and rescue in collapsed ruins, the confined space and harsh environmental conditions place extremely high demands on antenna deployment, severely limiting the effective application of low-frequency antennas in these scenarios. Therefore, researching low-frequency antennas with miniaturized design and long transmission distance is of extremely important strategic significance for ensuring the safety of underground and underwater development operations.

[0003] In low-frequency antenna design, the Tesla coil operates based on the principle of magnetic resonance, exhibiting unique advantages in improving transmission efficiency. When the Tesla coil is in a resonant state, the energy exchange between its inductance and capacitance reaches a dynamic balance, achieving efficient coupling and transmission of pulse signals. This high-pulse characteristic gives it powerful energy at the moment of signal transmission, effectively enhancing signal strength and overcoming more complex dielectric losses, ensuring long-distance signal transmission. The Tesla coil offers a possibility for balancing miniaturization and long-distance transmission in low-frequency antennas. By optimizing the coil's structure and parameters, efficient magnetic resonance can be achieved within a relatively small volume, significantly reducing the antenna's physical size while maintaining signal radiation intensity. This provides a new approach and technological direction for solving the challenges faced by traditional low-frequency antennas. Summary of the Invention

[0004] This invention provides a high-power pulse low-frequency antenna based on a Tesla coil, aiming to improve the problems of large size, complex impedance matching, and short transmission distance of existing low-frequency antennas by combining Tesla coils with low-frequency antennas, and to promote the application of low-frequency antennas in cross-medium communication, emergency management communication and other fields.

[0005] The key points of this invention are as follows:

[0006] (1) Innovative design of low-frequency transmitting antenna: The high-power pulse low-frequency antenna based on Tesla coil consists of Tesla circuit signal source, transformer and coupling coil.

[0007] (2) Innovative integration of Tesla circuits: The antenna signal source is innovatively designed based on dual resonant solid-state Tesla coils. By utilizing the low loss, high power and integrated characteristics of Tesla circuits, high power output in the low frequency band is achieved through reasonable design of circuit parameters. Compared with the traditional signal generator-power amplifier combined power supply method, the volume occupied is greatly reduced while ensuring signal strength.

[0008] (3) Optimized application of impedance matching: A transformer-type impedance matching network was adopted. By using the transformer principle and reasonably designing the turns ratio of the transformer, the equivalent impedance of the radiation coil is matched with the output impedance of the signal source, thereby maximizing the feed power and improving the signal transmission strength.

[0009] (4) Enhancement scheme for coupled resonance: The radiation coil is selected with a primary and secondary nested coupling structure. Resonant capacitors are connected in series with the primary and secondary coils respectively. The value of the series capacitors is accurately determined according to the output frequency of the signal source to achieve resonance of the signal source, primary coil and secondary coil. At the same time, the transmitted signal is effectively amplified by using the principle of magnetic coupling resonance, which significantly improves the transmission distance and coverage of low frequency signals.

[0010] (5) Miniaturization of the transmitting antenna: The size of the transmitting coil is controlled at the sub-cubic meter level, that is, the coil diameter is less than 1m and the coil size is less than one-thousandth of the working wavelength. This enables the transmitting antenna to achieve miniaturization while meeting radiation performance requirements, thereby improving portability and flexibility. Attached Figure Description

[0011] Figure 1 System schematic diagram of a high-power pulse low-frequency antenna based on a Tesla coil

[0012] Figure 2 Equivalent circuit diagram of a high-power pulse low-frequency antenna based on a Tesla coil

[0013] Figure 3 Transmit signal spectrum with or without coupling coil

[0014] Figure 4 Actual received signal diagram Detailed Implementation

[0015] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described below with reference to the accompanying drawings and embodiments. The present invention includes, but is not limited to, the following embodiments:

[0016] Example 1

[0017] This embodiment provides a high-power pulse low-frequency antenna based on a Tesla coil, illustrating the basic architecture and working mechanism of the antenna's core components.

[0018] like Figure 1 As shown, the high-power pulse low-frequency antenna based on a Tesla coil proposed in this invention consists of a Tesla circuit signal source 1, a transformer 2, and a coupling coil 3. Its working principle is as follows: the Tesla circuit signal source 1 generates a high-power pulse signal of a specific frequency. The transformer 2 achieves matched transmission between the signal source and the transmitting coil. The matched signal drives the primary coil to generate a time-varying magnetic field. The secondary resonant coil and the primary coil form a coupling coil 3, which amplifies the magnetic field signal and radiates it in a near-field manner.

[0019] The equivalent circuit diagram of a high-power pulse low-frequency antenna based on a Tesla coil is shown below. Figure 2 As shown. The signal source module is designed based on the principle of a solid-state dual-resonant Tesla circuit. Its inverter module can generate a 200kHz AC signal, which, controlled by an arc suppressor, achieves high-power pulse output. The capacitors in the primary and secondary circuits, along with the transmitting coil, form an RLC resonant circuit. This circuit includes coil inductors L1 and L2, capacitors C1 and C2, and copper wire resistors R1 and R2. Its resonant frequency needs to be tuned to 200kHz to achieve resonance with the signal source, i.e.:

[0020]

[0021] At the resonant frequency, the equivalent impedance of the coupling coil is a fixed value R. out The output resistance of the signal source is R. in R in With R out The difficulty in direct matching limits the signal input power, severely restricting its radiation capability. To address this issue, a transformer is introduced as an impedance matching device to match the characteristic impedance of the signal source with the impedance of the coupling coil, thereby maximizing the input power. The relationship is as follows:

[0022]

[0023] Where n1 and n2 are the number of turns in the primary and secondary windings of the transformer, respectively.

[0024] To increase radiation intensity, a secondary coil is coupled inside the primary coil, utilizing the magnetic coupling amplification effect to effectively amplify the signal. In this design, the currents I1 and I2 in the primary and secondary coils can be expressed as:

[0025]

[0026] Where M is the mutual inductance between the two coils, and Z1 and Z2 are the impedances of the primary and secondary coils, respectively. The magnetic field signal is generated by the alternating current in the circuit. As can be seen from equation (3), the intensity of the secondary current after the coupling coil is introduced is significantly greater than the intensity of the primary current without the coupling coil (I1>I2), that is, the intensity of the transmitted signal can be significantly increased after the coupling secondary coil is introduced. Figure 3 The image shows the antenna radiation spectrum measured at a distance of 3 m with and without a coupled secondary coil. The results show that loading a coupled resonant coil within the operating frequency band can significantly improve the signal radiation intensity, increasing the peak signal strength from -5.5 dBm to 17.9 dBm, an increase of up to 200 times.

[0027] Example 2

[0028] This embodiment provides a high-power pulse low-frequency antenna based on a Tesla coil, which is used to illustrate the selection of specific structural parameters of the antenna.

[0029] For a coil uniformly wound along its axis, if its number of turns is n, its length is H, and its radius is R, then its inductance can be expressed as:

[0030]

[0031] Based on equations (1) and (4), the coupling coil structure was designed to achieve a resonant frequency of 200kHz. Specific coil structure parameters are shown in Table 1. The resonant capacitor is a high-voltage film capacitor with a withstand voltage of over 3000V, and Litz wire is used as the conductor for the secondary coil, effectively reducing the internal resistance of the conductor caused by the skin effect at high frequencies.

[0032] The experiment measured the impedance of the coupling coil at 200kHz to be 7000Ω and the output resistance of the signal source to be 2Ω. Based on this, by combining equation (2) to adjust the number of turns of the primary and secondary windings of the transformer to 3 and 180 respectively, the characteristic impedance of the signal source and the impedance of the coupling coil were effectively matched, ensuring the maximum input power of the signal.

[0033] Table 1 Selection of coil structure parameters

[0034] parameter primary coil Secondary coil Number of turns 10 34 wire diameter / mm 1.5 8.0 Turn spacing / mm 3 0.1 Coil radius / mm 350 330 Resonant capacitance / nF 4.4 0.7

[0035] Example 3

[0036] This embodiment provides a high-power pulse low-frequency antenna based on a Tesla coil, used to verify the transmission performance of the high-power pulse low-frequency antenna.

[0037] A communication system is built using the high-power pulse low-frequency antenna based on a Tesla coil proposed in this invention as the transmitter, and the receiver is a loop antenna and a lock-in amplifier, which can separate and process signals at 200kHz.

[0038] Figure 4 The image shows the actual received signal measured at a distance of 4m using a lock-in amplifier near 200kHz. The received pulse signal amplitude is stable, without significant distortion, and the pulse intervals are clearly distinguishable, meeting the requirements for low-frequency communication. Furthermore, with the antenna operating at its maximum power (800W), effective signal reception can be achieved at a communication distance of 400m. Compared to a similarly sized loop low-frequency antenna, which can only achieve low-frequency communication within 200m, this solution offers a much longer communication range.

Claims

1. A high-power pulse low-frequency antenna based on a Tesla coil, characterized in that... It consists of a Tesla circuit signal source, a transformer, and a coupling coil.

2. The high-power pulse low-frequency antenna based on a Tesla coil according to claim 1, characterized in that, An antenna signal source design based on a dual-resonant solid-state Tesla coil was adopted. Utilizing the low-loss, high-power, and integrated characteristics of the dual-resonant solid-state Tesla coil, high-power output of signals at a specific operating frequency was achieved through reasonable circuit parameter design. Compared to the traditional signal generator-power amplifier combined feeding method, this significantly reduces the footprint while ensuring signal strength.

3. The high-power pulse low-frequency antenna based on a Tesla coil according to claim 1, characterized in that, A transformer-type impedance matching network was adopted. Based on the transformer principle, by rationally designing the transformer's turns ratio, the equivalent impedance of the radiating coil was matched with the output impedance of the signal source, thereby maximizing the feed power and improving the signal transmission strength.

4. The high-power pulse low-frequency antenna based on a Tesla coil according to claim 1, characterized in that, A secondary coil is coupled onto the primary radiating coil, and resonant capacitors are connected in series with both the primary and secondary coils. The value of the series capacitors is precisely determined based on the output frequency of the signal source, achieving resonance between the signal source, the primary coil, and the secondary coil. Simultaneously, utilizing the principle of magnetic coupling resonance, the transmitted signal is effectively amplified, significantly improving the transmission distance and coverage of low-frequency signals.

5. The high-power pulse low-frequency antenna based on a Tesla coil according to claim 1, characterized in that, The size of the transmitting coil is controlled to the sub-cubic meter level, meaning the coil diameter is less than 1 meter and the coil size is less than one-thousandth of the operating wavelength. This allows the transmitting antenna to be miniaturized while meeting radiation performance requirements, improving portability and flexibility.

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