On the Relation between Composite Right-/Left-Handed Transmission Lines and Chebyshev Filters. (13th January 2010)

• Record Type: Journal Article
• Authors: Liu, Changjun; Menzel, Wolfgang
• Other Names: Yazdandoost Kamya Yekeh Academic Editor.
• Is Part Of: International journal of microwave science and technology. Volume 2009(2009)
• Publication Date: 2010-01-13
• Subjects: Radio frequency -- Periodicals; Microwave circuits -- Periodicals; Radiofréquences; Circuits pour micro-ondes; Microwave circuits; Radio frequency; Periodicals; Electronic journals; 621.3813
• DOI: 10.1155/2009/184895
• Languages: English
• ISSNs: 1687-5826

Abstract

Abstract : Composite right-/left-handed (CRLH) transmission lines have gained great interest in the microwave community. In practical applications, such CRLH sections realized by series and shunt resonators have a finite length. Starting from the observation that a high-order Chebyshev filter also exhibits a periodic central section of very similar structure, the relations between finite length CRHL transmission lines and Chebyshev filters are discussed in this paper. It is shown that a finite length CRLH transmission line in the balanced case is equivalent to the central part of a low-ripple high-order Chebyshev band-pass filter, and a dual-CRLH transmission line in the balanced case is equivalent to a low-ripple high-order Chebyshev band-stop filter. The nonperiodic end sections of a Chebyshev filter can be regarded as matching sections, thus leading to an even better amplitude and phase response. It is also shown that, equally to a CRHL transmission line, a Chebyshev filter exhibits negative phase velocity in part of its passband. As a consequence, an improved behavior of finite length CRLH transmission lines may be achieved adding matching sections based on filter theory; this is demonstrated by a simulation example.