A Biomimetic Miniaturized Microphone Array for Sound Direction Finding Applications Based on a Phase-Enhanced...

Area of Science:

• Acoustics and Bio-inspired Engineering
• Electrical Engineering and Signal Processing

Background:

• Traditional sound direction finding often relies on mechanical structures to enhance intensity differences, leading to larger device footprints.
• The Ormia Ochracea fly's auditory system provides inspiration for novel sound localization mechanisms.

Purpose of the Study:

• To develop a miniaturized two-element sensor array for enhanced sound direction finding.
• To leverage an electrical coupling network for improved phase difference detection and signal-to-noise ratio.
• To reduce the required sensor separation distance for accurate angle of arrival determination.

Main Methods:

• Proposed a miniaturized two-element sensor array utilizing an electrical coupling network with lumped elements.
• Replaced conventional mechanical coupling with an electrical circuit to enhance phase differences.
• Designed, fabricated, and experimentally validated a prototype in an anechoic chamber.

Main Results:

• Achieved a significant phase enhancement of 110 degrees at a 90-degree incident angle.
• Demonstrated a normalized power level of -2.16 dB at output ports, with received power 3 dB higher than transformer-type systems.
• Reduced sensor separation to 0.1 wavelength (3.43 mm) at 10 kHz, enabling miniaturization.
• Confirmed a wide and tunable operation bandwidth from 8 kHz to 12 kHz.

Conclusions:

• The proposed bio-inspired electrical coupling network effectively enhances phase differences for sound direction finding.
• The miniaturized sensor array offers advantages in terms of low power loss, design flexibility, and broad operational bandwidth.
• This technology holds promise for the development of compact sonar and radar systems.