In the weakly guided case, the power propagation in the core and the cladding of a left-handed material fiber is obtained by solving Maxwell’s equations. The wave-guide efficiency is analyzed at cutoff and far from c...In the weakly guided case, the power propagation in the core and the cladding of a left-handed material fiber is obtained by solving Maxwell’s equations. The wave-guide efficiency is analyzed at cutoff and far from cutoff. Far from cutoff, the wave-guide efficiency equals to 1. At cutoff, for m=0, 1, the wave-guide efficiency equals to zero; for m=2, the wave-guide efficiency approaches to infinite; for m>2, the wave-guide efficiency is less than zero, but its absolute value is larger than 1. Those are novel characteristics of left-handed material fiber.展开更多
A tunable dual-broad-band branch-line coupler (BLC) utilizing composite right/left-handed (CRLH) transmission lines is presented. Two λ/4 segments consisting of CRLH transmission lines are added to each port to broad...A tunable dual-broad-band branch-line coupler (BLC) utilizing composite right/left-handed (CRLH) transmission lines is presented. Two λ/4 segments consisting of CRLH transmission lines are added to each port to broaden the dual bands of the branch-line coupler. Numerical simulation and optimal design of the novel coupler are presented. The dual bands of the novel coupler are tunable and broad. The 1-dB bandwidth of each pass band is more than 16% of the central frequency.展开更多
基金This work was supported by National Nature Science Foundation of China (60277025)Shanghai Leading Academic Discipline Project (T0102)
文摘In the weakly guided case, the power propagation in the core and the cladding of a left-handed material fiber is obtained by solving Maxwell’s equations. The wave-guide efficiency is analyzed at cutoff and far from cutoff. Far from cutoff, the wave-guide efficiency equals to 1. At cutoff, for m=0, 1, the wave-guide efficiency equals to zero; for m=2, the wave-guide efficiency approaches to infinite; for m>2, the wave-guide efficiency is less than zero, but its absolute value is larger than 1. Those are novel characteristics of left-handed material fiber.
基金Project (No. 2004CB719802) supported by the National Basic Re-search Program (973) of China
文摘A tunable dual-broad-band branch-line coupler (BLC) utilizing composite right/left-handed (CRLH) transmission lines is presented. Two λ/4 segments consisting of CRLH transmission lines are added to each port to broaden the dual bands of the branch-line coupler. Numerical simulation and optimal design of the novel coupler are presented. The dual bands of the novel coupler are tunable and broad. The 1-dB bandwidth of each pass band is more than 16% of the central frequency.
