A 340-GHz thin film polarisation converter. Issue 4 (3rd April 2019)

• Record Type: Journal Article
• Authors: Zhang, Meng; Wang, Xuetian; Yuan, Xueqi; Gao, Hongmin; Ma, Shiqi
• Is Part Of: International journal of electronics. Volume 106:Issue 4(2019)
• Page Start: 634
• Page End: 647
• Publication Date: 2019-04-03
• Subjects: THz device -- polarisation converter -- flexible film device -- metamaterial -- transmission line theory; Electronics -- Periodicals; Electronic control -- Periodicals; 621.381
• DOI: 10.1080/00207217.2018.1545927
• Languages: English
• ISSNs: 0020-7217

Abstract

ABSTRACT: This paper introduces a 340-GHz polarisation converter. The polarisation converter consists of a bilayer metamaterial, which is processed by the flexible thin film lithography method. Two-dimensional metamaterial offer such advantages over traditional quarter-wave-plates as compactness, low profile and simple fabrication process, but the insertion loss is comparably high. In order to lower the insertion loss, the 10-μm ultrathin polyimide substrate and a bilayer structure separated by a quarter wavelength air impedance match layer are adopted. After the horn antenna's far-field test by vector network analyser and the Gaussian beam test based on Terahertz time-domain spectroscopy (THz-TDS), the results show that in the band of 325–350 GHz, the transmission loss is less than 2 dB, and the axial ratio is less than 3 dB; besides, simulation and test insertion loss performance difference is less than 1 dB, which indicates that the method we adopt is effective. In addition, based on transmission line theory, we analyse its working principle and the influence from the fabrication error.