Extended aperture sample reception method for high-order orbital angular momentum vortex beam mode number measurement

Area of Science:

• Electromagnetics and Wave Propagation
• Antenna Theory and Design
• Signal Processing

Background:

• Traditional phase gradient methods for measuring orbital angular momentum (OAM) number in vortex beams are limited by a spatial sampling phase aperture span restricted to π radians.
• This restriction hinders the versatility and completeness of OAM reception and measurement techniques in radio frequency (RF) applications.

Purpose of the Study:

• To introduce a novel extended aperture sampling reception (EASR) method for RF applications.
• To overcome the π radian spatial sampling phase aperture span limitation of traditional OAM measurement techniques.
• To enhance the flexibility and versatility of OAM mode number reception and measurement.

Main Methods:

• The proposed EASR method converts higher-order OAM modes to lower-order OAM modes.
• This conversion effectively extends the spatial phase aperture span between adjacent receiving sampling points.
• Comprehensive theoretical analysis and numerical simulations were employed to validate the method.

Main Results:

• The EASR method successfully breaks through the π radian restriction of traditional methods.
• Numerical simulations demonstrated the effective reception and measurement of OAM mode numbers for high-order mode vortex beams using EASR.
• Theoretical analysis and simulation results showed excellent agreement, confirming the method's validity.

Conclusions:

• The EASR method provides a more complete and versatile approach to OAM mode number reception and measurement in RF applications.
• This technique offers significant advantages over traditional phase gradient methods by overcoming aperture span limitations.
• The EASR method holds promise for advancing vortex beam characterization and applications in RF systems.