Dielectric Fibres for Low-Loss Transmission of Millimetre Waves and its Application in Couplers and Splitters
- PDF / 196,888 Bytes
- 7 Pages / 439.37 x 666.142 pts Page_size
- 100 Downloads / 162 Views
Dielectric Fibres for Low-Loss Transmission of Millimetre Waves and its Application in Couplers and Splitters Christian Jördens & Kin Lien Chee & Ibraheem A. I. Al-Naib & Ioachim Pupeza & Sören Peik & Gerhard Wenke & Martin Koch
Received: 20 March 2009 / Accepted: 12 August 2009 / Published online: 2 September 2009 # Springer Science + Business Media, LLC 2009
Abstract We present a dielectric fibre and two splitters made of polyethylene, which are well suited for the guidance of millimeter waves. A successful construction of a 3-dB coupler and a 1×4 splitter is reported. The fibre has a diameter of 3 mm and offers a very low absorption of 0.03 dB/cm at a frequency of 70 GHz. Since the radiation is guided mainly inside the fibre, the waveguide is insensitive to mechanical contact. The fibre has been tested to work effectively for frequencies up to 300 GHz. Therefore, such fibres and derived devices are relevant for practical applications such as endoscopes and fibre arrays. The use of fibre arrays can for example increase the measurement speed in continuous wave imaging. Keywords Dielectric waveguide . Splitter . 3-dB coupler
1 Introduction The recent advances in terahertz (THz) technology have been accompanied by a growing demand for suitable waveguides. The choice of the geometry and the material of a waveguide strongly affect its fundamental properties including attenuation, dispersion, coupling efficiency as well as fabrication and handling issues. Often, the fulfilment of one design criterion is achieved at the expense of another. There has been considerable work in the field for the construction of waveguides with low attenuation and low dispersion C. Jördens (*) : I. A. I. Al-Naib : M. Koch Institut für Hochfrequenztechnik, TU Braunschweig, Schleinitzstr. 22, 38106 Braunschweig, Germany e-mail: [email protected] K. L. Chee : S. Peik : G. Wenke Fachbereich Fakultät Elektrotechnik und Informatik, Hochschule Bremen, Neustadtswall 30, 28199 Bremen, Germany I. Pupeza Max-Planck-Institute of Quantum Optics, Hans-Kopfermann-Str. 1, 85748 Garching bei München, Germany
J Infrared Milli Terahz Waves (2010) 31:214–220
215
employing different techniques [1–6]. An overview about the chronological development is given in [7]. However, such waveguides impose strong challenges in the coupling efficiency and the handling for real life applications. The later one is dominant for approaches where most of the radiation is guided outside the waveguide [3,4]. For many practical applications as endoscopes [8] or non-destructive testing and security inspection [9] continuous wave (cw) or narrowband THz radiation is employed. In these cases, dispersion is almost irrelevant, whereas coupling efficiency and practical handling are of major importance. In this work we demonstrate that a 3 mm thick rod-like polyethylene fibre is very well suited as a low-loss single-mode waveguide for millimeter continuous wave radiation. The employed waveguide is insensitive to touching and therefore very attractive for practical applications. A
Data Loading...
