This article presents a novel waveguide-based terahertz (THz) variable attenuator, integrated with a piezoelectric motor, to achieve precise and fine step values of signal attenuation. A low-resistivity silicon slab, coated with a thin layer of titanium metal, is inserted inside a waveguide that absorbs some of the electromagnetic waves traveling through the guide. Impedance matching is achieved by gradually perforating the silicon slab and thus, creating variable impedance needed for matching. The amount of signal absorbed by the slab is determined by the sheet resistance value of the metal coating and the position of the slab in the waveguide. A miniature nanometer-scale precision piezoelectric motor is used for precise control of the signal attenuation. In this article, we present the attenuator design for a frequency band of 500–750 GHz where up to 40 dB of signal attenuation was achieved, using a 1.75 mm long silicon slab with a 25 nm titanium metal coating. The presented variable attenuator design offers compactness, scalability, and easy integration with THz sources and receivers. Furthermore, the compact size and low power consumption open up possibilities for implementation on CubeSat/Smallsat/Drone-based platforms, further expanding its potential space applications.

中文翻译：

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适用于太赫兹应用的基于波导的可变衰减器

本文提出了一种新型的基于波导的太赫兹（THz）可变衰减器，与压电电机集成，以实现精确且精细的信号衰减步进值。将涂有一层薄薄的钛金属的低电阻率硅板插入波导内，吸收部分穿过波导的电磁波。阻抗匹配是通过逐渐对硅板穿孔来实现的，从而产生匹配所需的可变阻抗。板吸收的信号量由金属涂层的薄层电阻值和板在波导中的位置决定。采用微型纳米级精密压电电机来精确控制信号衰减。在本文中，我们介绍了针对 500–750 GHz 频段的衰减器设计，使用带有 25 nm 钛金属涂层的 1.75 mm 长硅板，实现了高达 40 dB 的信号衰减。所提出的可变衰减器设计具有紧凑性、可扩展性，并且易于与太赫兹源和接收器集成。此外，紧凑的尺寸和低功耗为在基于 CubeSat/Smallsat/Drone 的平台上实施提供了可能性，进一步扩展了其潜在的空间应用。