Tilted-Beam Antenna Based on SSPPs-TL with Stable Gain.

Area of Science:

• Electromagnetics and Wave Propagation
• Antenna Theory and Design
• Metamaterials and Plasmonics

Background:

• Surface waves are confined to transmission lines (TLs).
• Spoof surface plasmon polaritons (SSPPs) enable wave confinement on TLs.
• Endfire antennas radiate waves parallel to the antenna axis.

Purpose of the Study:

• To propose a novel titled-beam antenna.
• To achieve steerable beam angles using a simple metallic plate.
• To demonstrate stable radiation patterns and gain over a wide frequency band.

Main Methods:

• Utilizing a parallel spoof surface plasmon polaritons (SSPPs) transmission line (TL) as the core radiating structure.
• Periodically introducing tapered stubs along the SSPPs-TL to form backward endfire beams.
• Employing a large metal plate positioned below the endfire antenna to tilt the radiation beams.
• Steering the beam tilt angle by adjusting the distance between the metal plate and the antenna.

Main Results:

• The proposed antenna successfully generates tilted beams with steerable angles.
• Constant radiation pattern shapes are maintained over the 5.7 GHz to 7.0 GHz frequency band.
• A stable gain of approximately 12 dBi is achieved.
• A 1-dB gain bandwidth of 20% is demonstrated.
• Experimental validation confirms the simulation and design principles.

Conclusions:

• The proposed titled-beam antenna based on SSPPs-TL offers a viable solution for steerable beam applications.
• The integration of a metal plate provides an effective and simple mechanism for beam tilting.
• The antenna exhibits robust performance with stable gain and radiation patterns over a significant bandwidth.