Project: PN-IV-P7-7.1-PED-2024-0949 / 81PED ⁄ 2025
Contractor: National Institute of Materials Physics (NIMP)
Project manager: Dr. Lucian Trupina
Project type: Program 5.7 - Partnership for Innovation, Subprogram 5.7.1 - Demonstration experimental project (PED)
Start date: 05/05/2025
End date: 04/05/2027
Contracting Authority: UEFISCDI
Project summary
The “Adaptable Compact Microwave Antenna Based on Phase Change Materials” (ANCOSM) project focuses on developing innovative solutions to improve the performance of microwave antennas based on multifunctional materials. The main features of these antennas are low power consumption, easy integration into compact devices, low cost, and, most importantly, the ability to operate over a wide frequency range, covering multiple bands of the electromagnetic spectrum.
Achieving such an antenna requires the development of new integration strategies correlated with the intrinsic properties of the materials, in order to identify the optimal solution that enables the targeted performance. Within the project, a microwave antenna based on multifunctional phase-change material (PCM) thin films is designed and implemented by exploiting the metal–insulator transition (MIT) of VO₂. The integration of the antenna elements with phase-change-based components enables dynamic tuning of the operating center frequency and meets current requirements for highly reconfigurable, integrated, reliable, efficient, and low-power devices. This approach represents an ideal solution for covering multiple user channels in microwave standards and constitutes a first step toward the development of innovative, efficient, and market-oriented devices.
INCDFM Romanian InSpace Engineering (RISE)
Dr. Lucian Trupina (director proiect) Claudiu Cherciu (responsabil RISE)
Dr. Marian Gabriel Banciu Dr. Claudiu Dragusanu
Dr. Liviu Nedelcu Mugurel Bălan
Eng. Geambasu Dragos Cezar Ionela-Alexandra Gâză
Dr. Lucia Leonat
Dr. Luminita Hrib
Dr. Cristina Besleaga Stan
Dr. Marius-Cristian Cioangher
Results – Phase I
In the current phase, the activities required to consolidate the scientific and technical basis for the development of a reconfigurable microwave antenna, based on phase-transition materials—specifically vanadium dioxide (VO₂)—were successfully completed. These activities addressed both the electromagnetic design of the radiating structure and the fabrication and characterization of the active material, ensuring appropriate conditions for integration into a future functional prototype.
On the RF design side, a coplanar waveguide (CPW) antenna architecture on an Al₂O₃ (alumina) substrate was defined. This choice was justified by the substrate’s high relative permittivity and low dielectric losses, which are key enablers for compact and efficient microwave devices. Electromagnetic simulations performed in HFSS investigated two configurations corresponding to the ON and OFF states of a switch integrated into one of the radiating arms. The results revealed a significant shift in the resonance frequency between the two states, from 2.23 GHz to 3.71 GHz, together with a marked change in the surface current distribution. These findings confirm the direct impact of the geometric discontinuity on the effective electrical length and validate the proposed reconfiguration mechanism.
For the implementation of the switching element, thin VO₂ films were deposited on Al₂O₃ substrates by RF reactive sputtering. Structural and morphological characterization by XRD, Raman spectroscopy, and SEM/AFM confirmed the formation of the monoclinic M1 phase, the presence of characteristic vibrational modes, and a compact, granular morphology with controlled roughness. Temperature-dependent electrical measurements (R–T) demonstrated a well-defined metal–insulator transition (MIT) occurring at approximately 66 °C, with a resistance change spanning six orders of magnitude, thereby confirming the suitability of the VO₂ films for fast and reliable switching applications.