Millimeter Wave Measurement of the Low-Loss Dielectric in Vacuum Electronic Devices with Reflection-Type Hemispherical Open Resonator

Autor: J. Su, Li-xuan Wang, Qianshu Zhang, Yuehang Xu, Guoxiang Shu, Yonglan Luo, S. F. Wang
Rok vydání: 2015
Předmět:
Zdroj: Journal of Infrared, Millimeter, and Terahertz Waves. 36:556-568
ISSN: 1866-6906
1866-6892
DOI: 10.1007/s10762-015-0160-x
Popis: Accurate dielectric properties are of great importance for the design and fabrication of the input and output windows in vacuum electronic devices. A reflection-type hemispherical open resonator (RTHOR) was designed through theoretical analysis and numerical simulation and also was utilized to measure the dielectric properties of the windows material sapphire. Compared with the two ports measurement, a simplified measurement system to obtain the dielectric performance was proposed and the RTHOR with only one coupling aperture was directly connected to a W-band vector network analyzer (VNA). The material properties can be easily calculated through the VNA measured port reflection coefficient (S11) resonant curve. Investigation shows that the permittivity and the loss tangent of the measured sapphire, which is used to construct the input and output window, is respectively about 9.40 and 1.80 × 10−4 at room temperature in W-band, which agree well with the reported results. Measured results also show that the simplified measurement system can provide a high accuracy for the measurement of low-loss dielectric in a relatively convenient way.
Databáze: OpenAIRE
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