The wave-field from an array of periodic emitters driven simultaneously by a broadband pulse

Area of Science:

• Physics
• Wave Phenomena
• Acoustics

Background:

• Phased array methods are standard in ultrasonic applications for beam steering.
• Controlling phase variations in narrowband emitters enables focused ultrasonic waves.

Purpose of the Study:

• To present a novel pulsed array approach for generating a two-dimensional wave.
• To demonstrate a method for rapid spatial coverage with a wave-front.
• To explore applications in radar, sonar, and ultrasound.

Main Methods:

• Utilizing a one-dimensional array of alternating polarity emitters pulsed simultaneously.
• Employing emitters with sufficiently wide, controlled bandwidth.
• Developing analytic and finite element models.
• Validating models with experimental ultrasonic wave results in metal samples.

Main Results:

• Achieved a smooth, continuous wave-front emitted over a large solid angle.
• Demonstrated that the wave's frequency varies continuously as a function of angle to the array.
• Observed distinct arrival times and frequencies for scattered or reflected waves.

Conclusions:

• The pulsed array method provides a rapid means for spatial wave coverage.
• The angularly dependent frequency variation is a key characteristic of the emitted wave-front.
• The phenomenon has potential applications across various wave-based detection systems.