Terahertz Ultra Wideband High-Speed On-Chip Modulator Based on Cascade Coupling Resonance

In this letter, a terahertz ultra wideband high-speed on-chip modulator based on coupling resonance was proposed. By nesting multiple diodes in the coplanar waveguide to form multiple composite modulation units, the equivalent physical state of meta-units is controlled by external voltage signal, and then control the electromagnetic resonance characteristics of the modulation units to achieve high-speed broadband modulation of terahertz waves. This modulation mechanism simplifies the resonant structure, suppresses the parasitic parameters and improves the modulation rate of the existing terahertz external modulator. The bandwidth is expanded through cascade coupling resonance, thus realizing ultra-wideband amplitude modulation of terahertz waves transmitted in coplanar waveguides. The experimental results show that the high-speed ultra-broadband modulation of terahertz waves is achieved at 110 GHz-160 GHz with a maximum modulation depth of 15dB (97%) and a maximum modulation rate of 30 Gbps, providing a promising prospect for the development and application of the integrated terahertz direct modulation technology.