School of Electrical and Electronics Engineering, College of Engineering, Chung-Ang University, 84 Heukseok-ro, Dongjak-gu, Seoul 06974, Korea.
Sensors (Basel). 2019 Mar 3;19(5):1081. doi: 10.3390/s19051081.
In this paper, we propose a switchable band-pass/band-stop filter using liquid metal alloy as a fluidic switch. The filter is designed based on the Chebyshev response and implemented using a three-stage quarter-wavelength resonant structure. The fluidic switch is realized by injecting eutectic gallium⁻indium (EGaIn) in the microfluidic stubs, engraved in the polydimethylsiloxane (PDMS) material. When the fluidic switch selects the short stub using a micro-pump and microprocessor for switching, the filter acts as a bandpass filter (BPF) with the short stubs. When the fluidic switch selects the open stub, the filter acts as the bandstop filter (BSF) with the open stubs. At the BPF mode, the center frequency is 2.5 GHz and the 1-dB bandwidth is 1.75⁻3.07 GHz. The insertion loss is 0.5-dB ± 0.4-dB. At the BSF mode, the 15-dB bandstop bandwidth is 2.4⁻2.65 GHz with 2.5 GHz center frequency.
在本文中，我们提出了一种使用液态金属合金作为流变体开关的可切换带通/带阻滤波器。该滤波器基于切比雪夫响应设计，采用三级四分之一波长谐振结构实现。流变体开关通过在微流道短截线中注入共晶镓-铟（EGaIn）来实现，该短截线刻蚀在聚二甲基硅氧烷（PDMS）材料中。当流变体开关使用微泵和微处理器选择短截线进行切换时，滤波器作为带通滤波器（BPF），使用短截线工作。当流变体开关选择开路短截线时，滤波器作为带阻滤波器（BSF），使用开路短截线工作。在 BPF 模式下，中心频率为 2.5 GHz，1-dB 带宽为 1.75-3.07 GHz。插入损耗为 0.5-dB±0.4-dB。在 BSF 模式下，15-dB 带阻带宽为 2.4-2.65 GHz，中心频率为 2.5 GHz。
