Abstract: Aircraft-mounted antennas are central to modern airborne communication, radar, and other surveillance systems. These airborne antennas demand wide-angle/selective coverage, with high gain, yet to be a low-profile, light weight, and reliable system under extreme environmental conditions. Conventional omnidirectional antennas, like monopoles and dipoles, are inadequate due to platform-induced electromagnetic effects that distort radiation patterns and create significant nulls, particularly in the elevation plane. Additionally, high-power AESA elements must function in high moisture without electrical breakdown, necessitating improved power-handling in a compact, robust design. This work addresses these challenges using advanced conformal and cavity-backed antenna architectures for airborne platform. The first part focuses on direct air-to-ground communication and aerial surveillance data-link applications. A frustum-shaped conformal circular array with eight radiating elements is proposed for 360° azimuth coverage at shallow elevation angles, operating in the C-band range of 4.4–5.0 GHz. This design improves elevation-plane coverage by utilizing both direct and reflected rays, resulting in minimal gain variation under 5 dB across the elevation plane. The second stage introduces an active switchable-beam array that uses a switch matrix for selective sector activation, enhancing gain while reducing power requirements and complexity, ideal for high-speed, multi-sensor surveillance platforms. 3D printing simplifies the realization of frustum geometry, also addressing key challenges such as material selection and the curing and metallization processes required for a solid, conductive design. Moving from communication and data-link antennas to radar front ends, the work extends the study to aircraft-mounted AESA applications. This study explores various feeding methods for a fixed cavity geometry, including a dielectric-loaded coaxial probe, microstrip patch on solid dielectric, and microstrip patch on ridged dielectric. The latter reduces dielectric volume while maintaining stiffness. For L-band antennas, this approach decreases peak electric field intensity, improves power-handling capability by 64.57%, and reduces feed mass by 49% compared to solid dielectric while maintaining performance from 1.03–1.09 GHz. High-power testing at 64 dBm pulse power confirms its effectiveness, which is further validated for S-band antennas at 55.1 dBm continuous power. This work explores advanced aircraft-mounted antenna solutions, including conformal wide- coverage arrays for air-to-ground communication, switchable-beam data-link architectures, and high-power cavity-backed slot antennas for AESA systems. These innovations enhance coverage, power efficiency, structural integration, mass reduction, and reliability for next- generation airborne platforms.

Event Details
Title: A Progressive Study on Class of Aircraft-Mounted Antennas: Conformal Wide-Coverage Arrays, Switchable-Beam Antenna for Data-Links, and High-Power Element for AESA Array
Date: August 03, 2026 at 3:00 PM
Venue: ESB244
Speaker: Ms. Masoom Verma (EE20D058)
Guide: Dr. David Koilpillai
Type: PHD seminar

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