Transforming Linear to Circular Polarization on Horn Antennas by Using Multiple-Layer Frequency Selective Surfaces.

Area of Science:

• Electromagnetics and Antennas
• Microwave Engineering
• Metamaterials

Background:

• Pyramidal horn antennas are widely used but have limitations in polarization control.
• Frequency-selective surfaces (FSS) offer a method for manipulating electromagnetic wave properties.

Purpose of the Study:

• To present a technique for transforming the polarization of a pyramidal horn antenna.
• To achieve dual orthogonal electric field components with equal magnitude and 90° phase shift.

Main Methods:

• Adding multiple layers of frequency-selective surfaces (FSS) with skewed lambda/2 dipoles in front of the horn aperture.
• Combining the horn's radiated field with the FSS's scattered field, inspired by Yagi-Uda array design principles.

Main Results:

• Achieved a near-unit axial ratio, indicating excellent polarization purity.
• Demonstrated a 3 dB increase in gain compared to a conventional horn antenna.
• Validated the concept through simulations and measurements.

Conclusions:

• The proposed FSS-enhanced horn antenna effectively transforms polarization with improved gain and axial ratio.
• This technique offers a low-cost solution for applications in maritime satellite communication and direction-of-arrival sensing.