Self-Biased Magneto-Electric Antenna for Very-Low-Frequency Communications: Exploiting Magnetization Grading and...

Area of Science:

• Electromagnetics
• Materials Science
• Wireless Communication

Background:

• Magneto-electric (ME) antennas offer compact size and high radiation efficiency.
• Miniaturization of VLF ME antennas is hindered by the requirement for large DC magnetic bias fields.
• Existing VLF systems face challenges in portability and size.

Purpose of the Study:

• To introduce a self-biased ME antenna design for miniaturized VLF communication systems.
• To explore the operating principles and performance of an asymmetric, self-biased ME antenna.
• To demonstrate the communication capabilities of the developed VLF antenna.

Main Methods:

• An asymmetric antenna design using two magneto materials was developed to induce a magnetization grading effect.
• The resonant frequency was reduced through bending, facilitated by the asymmetric design.
• Performance parameters including radiation mechanism, intensity, and driving power were experimentally assessed.
• A custom modulation-demodulation circuit was used to validate communication with 2ASK and 2PSK modulation.

Main Results:

• The self-biased ME antenna demonstrated effective operation as both a transmitter and receiver due to its direct and converse magneto-electric effects.
• At 2.09 mW driving power and 24.47 kHz, the antenna achieved a magnetic flux density of 2.44 pT at 3 meters.
• Communication capability was validated for baseband signals of 10 Hz and 100 Hz using 2ASK and 2PSK modulation.

Conclusions:

• The developed self-biased ME antenna offers a practical solution for lightweight and compact VLF communication systems.
• The asymmetric design and magnetization grading effect effectively reduce the resonant frequency and eliminate the need for external bias.
• This technology holds potential for advancing portable VLF communication devices.