Wideband Circularly Polarized Millimeter Wave Hemispherical Dielectric Resonator Antenna

Area of Science:

• Electromagnetics and Antenna Design
• Microwave Engineering
• Materials Science in RF Applications

Background:

• Dielectric resonator antennas (DRAs) are widely used for their desirable radiation characteristics.
• Achieving wide axial ratio (AR) bandwidth in circularly polarized (CP) antennas remains a design challenge.
• Existing CP antenna designs often face limitations in bandwidth and manufacturing complexity.

Purpose of the Study:

• To propose and validate a novel design for a CP hemispherical DRA with enhanced AR bandwidth.
• To investigate the impact of an additional dielectric substrate on antenna performance.
• To address practical fabrication and assembly issues in DRA integration.

Main Methods:

• A hemispherical DRA was designed with an additional dielectric substrate placed between the antenna and the ground plane.
• A lower feeding substrate was used in conjunction with a microstrip line for excitation.
• An integrated hemispherical DRA and perforated substrate configuration was employed to optimize effective permittivity.

Main Results:

• The proposed design achieved a wide axial ratio (AR) bandwidth of approximately 18%.
• The addition of the extra dielectric substrate provided an additional design parameter for bandwidth enhancement.
• The integrated configuration facilitated optimal effective substrate permittivity and simplified assembly.

Conclusions:

• The novel approach successfully enhances the AR bandwidth of CP hemispherical DRAs.
• The design offers a practical solution for wideband CP antenna applications.
• Experimental measurements closely matched simulation results, validating the proposed design.