Negative Group Delay Characteristics of Embedded Transmission Line with half-wavelength type F-SIR Structure

Negative group delay is one of the anomalous characteristics of the metamaterial, and can be used to compensate the group delay of systems and is applicable to signal processing devices. In this paper, to achieve negative group delay with not only wide-band characteristics but also low-insertion loss, we newly propose the embedded transmission line with half-wavelength type folded-stepped impedance resonator (F-SIR) structure which has the symmetrical electric-wall at the guide center driven by differential-mode. The characteristics are discussed with numerical simulation. The concept of the proposed TL is based on the combination of resonance and anti-resonance due to open-stub resonator and F-SIR. The negative group delay and slope characteristics are achieved around anti-resonance. The insertion loss is dramatically improved compared with our previous results, which is constructed by gap and F-SIR structure. This study is a successful report that the validity of the proposed embedded TL structure is demonstrated.