High-performance direct terahertz modulator based on resonance mode transformation for high-speed wireless communication

Abstract

The developing terahertz wireless communication demands higher performance modulators. In this Letter, a mechanism of resonance mode transformation for a high-speed terahertz direct amplitude modulator with rather low insertion loss and high modulation depth is presented. By embedding an H-shaped resonance structure, which consists of a fin-line and two flip-flopped GaAs Schottky diodes, into the E-wall of a waveguide, the fed terahertz waves are modulated by the inductive-capacitive (LC) resonance transformation of the structure. Based on this mechanism, a modulator working in the frequency band around 140 GHz is fabricated and packaged. Thanks to the LC resonance transformation, the presented modulator exhibits a low insertion loss of 1.8 dB at 138 GHz, a large modulation depth higher than 99% at 148 GHz, and high modulation speeds up to 30 Gbps at 146 GHz. Accordingly, the presented mechanism paves a promising route to develop high performance terahertz direct modulators, which is of great significance for terahertz high-speed wireless communication.

Low terahertz frequency on-chip multi-functional modulator with amplitude and phase modulation

“…Numerous remarkable studies have proposed terahertz amplitude and phase modulation techniques [12,13], including quasi-optical [14][15][16][17][18][19][20][21] and on-chip devices [22][23][24][25][26][27]. However, they still suffer from the following problems: first, they can only realize single modulation of amplitude and phase, which requires designing multiple devices if we want to manipulate amplitude and phase in frequency division multiplexing systems, increasing the design and processing costs.…”