Ultra-Wideband Tunable Thin-Film Lithium-Niobate-on-Insulator Microwave Photonic Filter

To meet the growing demand for high-frequency and broadband wireless communications, extending microwave frequencies to the millimeter-wave range is essential. Microwave photonic filters (MPFs), as key components in microwave photonic systems, are used to select target signals and reduce channel interference. However, achieving MPFs with a tuning range beyond 40 GHz remains challenging due to the limited bandwidth of electro-optical devices and optical filters. In this study, we demonstrate a reconfigurable integrated MPF based on a thin-film lithium-niobate-on-insulator platform. The MPF achieves the widest operational range from 2 to 62 GHz and a tunable frequency resolution from 0.7 to 3 GHz. Additionally, the filter enables channel selection for Gbit/s data rates in high-frequency wireless communication, offering a practical and scalable solution for future applications.