Abstract: This seminar presents the design and analysis of a sinusoidally modulated metasurface antenna for multimode orbital angular momentum OAM beam generation aimed at multiplexing applications. A multi-feed configuration connected to a Butler matrix is introduced. Excitation at different input ports of the Butler matrix produces the required phase shifts at its output ports, which subsequently feed monopole antennas on the metasurface aperture to generate distinct OAM modes.

The critical parameters in the radiation characteristics of various OAM modes are first identified. A continuously varying impedance sheet model, which is computationally efficient, is used to systematically study the impact of key modulation parameters on antenna performance. The effects of surface impedance parameters, specifically the modulation index and modulation impedance, on radiation characteristics, gain, polarization purity, and beam divergence are investigated, and optimal values are determined.

The metasurface is subsequently realized by replacing the continuous impedance sheet with optimized unit cells that implement the required impedance profile. An 8 × 8 Butler matrix is then designed and implemented to enable multimode excitation. The proposed approach results in a fully planar and low-profile aperture antenna for high-capacity wireless communication systems based on OAM multiplexing.

Event Details
Title: Simultaneous Multimode OAM Generation using Sinusoidally Modulated Metasurface Antennas for Multiplexing Applications.
Date: February 23, 2026 at 11:00 AM
Venue: ESB 244
Speaker: Mr. Karthik P Bilichod (EE23D023)
Guide: Dr. Uday K Khankhoje
Type: PHD seminar

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