Terahertz space phase modulator based on high electron mobility transistor

Abstract

The invention discloses a terahertz space external phase modulator based on a high electron mobility transistor. The phase modulator combines the quick response type high electron mobility transistor with a novel artificial electromagnetic medium resonant structure, so as to be able to conduct quick phase modulation on terahertz waves transmitted in free space. The phase modulator is composed of a semiconductor material substrate, an HEMT epitaxial layer, a periodical artificial metal electromagnetic resonant structure and a muff-coupling circuit. The concentration of two-dimensional electron gas in the HEMT epitaxial layer is controlled through loaded voltage signals, so that the electromagnetic resonance mode of the artificial electromagnetic medium resonant structure is changed, and then phase modulation of terahertz waves is achieved. Over-90-degree phase modulation depth can be realized within a large bandwidth, and the maximum phase modulation depth can be about 140 degrees. Furthermore, the phase modulator is simple in structure, easy to machine, high in modulation speed, convenient to use and easy to package.

Description

technical field [0001] The invention belongs to the technical field of electromagnetic functional devices, focusing on fast dynamic functional devices in the terahertz band. Background technique [0002] As one of the most critical core technologies in terahertz communication systems, terahertz wave dynamic functional devices—terahertz external modulators have become the focus of terahertz science and technology research. Since the size required for functional devices in the terahertz band is on the order of microns or even nanometers, communication devices in the microwave band cannot be directly applied to the terahertz band. Since 2004, a number of articles on terahertz wave external modulators have been published in top international natural science journals such as Nature / Science, including materials based on doped silicon, gallium arsenide, phase change materials, and graphene. Combined with artificial electromagnetic media (Metamaterials), the modulation of terahertz...

AI Technical Summary

Problems solved by technology

Since the required size of functional devices in the terahertz band is on the order of microns or even nanometers, communication devices in the microwave band cannot be directly applied to the terahertz band.

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