Isolation Transformer Based Very Low Frequency Antenna with Enhanced Radiation Characteristics

Area of Science:

• Electromagnetics
• Antenna Engineering
• Materials Science

Background:

• Very low frequency (VLF) electromagnetic waves offer superior propagation in challenging environments compared to high-frequency waves.
• Traditional VLF antennas face limitations in size, efficiency, and power handling capabilities.
• Effective VLF communication is crucial for applications like underground and underwater data transmission.

Purpose of the Study:

• To propose a compact, efficient, and high-performance VLF loop antenna design.
• To overcome the size, efficiency, and power limitations of conventional VLF antennas.
• To enhance the radiation characteristics of VLF antennas for long-distance communication.

Main Methods:

• Design and implementation of a VLF loop antenna incorporating an isolation transformer.
• Utilization of a high magnetic permeability amorphous/nanocrystalline alloy (Fe73.5Cu1Nb3B9Si13.5) within the isolation transformer.
• Experimental validation of antenna performance, including impedance matching and radiation intensity measurements.

Main Results:

• The proposed antenna achieves compact size with well-matched impedance.
• The isolation transformer enables stable high-current input, enhancing electromagnetic performance.
• Radiation intensity increased over 30 times compared to traditional loop antennas.
• Experimental transmission distance exceeded 340 m at 15 kHz with a 2 m diameter antenna.

Conclusions:

• The isolation transformer-based VLF loop antenna offers significantly improved radiation characteristics.
• The design demonstrates high radiation efficiency, low power consumption, and long-distance transmission capabilities.
• This antenna technology holds substantial promise for underground and underwater communication systems.