Design of a Mechanically RIS Unit Cell with Prephased States at 26 GHz Baena-Molina, Marcos Palomares-Caballero, Ángel Padilla, Pablo Valenzuela-Valdés, Juan F. Mechanical reconfiguration millimeter-wave frequencies reconfigurable intelligent surface (RIS) unit cell A prephased 1-bit mechanically reconfigurable unit cell for a reconfigurable intelligent surfaces (RIS) is presented. In the proposed RIS unit cell design, a geometric translation of the element has been implemented, obtaining two different pairs of RIS unit cell each with a 1-bit mechanical reconfiguration. The electromagnetic (EM) behavior is analyzed using the reflection coefficient for normal and oblique incidence, demonstrating its suitable operation in the n258 band of 5G. A 10 × 10 mechanically RIS is designed using the two pairs of unit cells and its radiation performance is compared to a conventional 1-bit RIS at 26 GHz. It is shown how a 1-bit configuration with pseudo-randomization for mechanically RIS enhances the radiation pattern performance while maintaining the simplicity of 1-bit reconfiguration. 2026-02-17T12:31:16Z 2026-02-17T12:31:16Z 2025-05-21 conference output M. Baena-Molina, Á. Palomares-Caballero, P. Padilla and J. F. Valenzuela-Valdés, "Design of a Mechanically RIS Unit Cell with Prephased States at 26 GHz," 2025 19th European Conference on Antennas and Propagation (EuCAP), Stockholm, Sweden, 2025, pp. 1-4, doi: 10.23919/EuCAP63536.2025.10999514. https://hdl.handle.net/10481/111107 10.23919/EuCAP63536.2025.10999514 eng embargoed access European Conference Antennas and Propagation (EurAAP)