Design of wideband high and low impedance metatransmission lines

The modeling and design of metamaterial composite right/left handed transmission lines (CRLH-TL) is usually based on the assumption that its unit cell is small in terms of the host TL wavelength (d 0). However, it was also shown that this assumption is not required for most CRLH-TL applications and difficult to meet for balanced CRLH-TLs in particular cases. Thus, a more general design strategy, free of this assumption, has been implemented. In this letter, we further develop this second approach to show that it allows designing CRLH-TLs whose impedance is much beyond the range achievable in the case where d 0, for a given technology and fabrication tolerances. The use of the presented concept is illustrated by means of a quartz-integrated CRLH-TL exhibiting a low-impedance (20 ). Measured results are in good agreement with the theory and satisfactory performances are observed on a bandwidth covering almost the entire Ku band. Potential applications of the presented results are also discussed in a dedicated section. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1926-1929, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22628