Wyniki wyszukiwania - BazTech

Ograniczanie wyników

2 Opto-Electronics Review

2 2015

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Sortuj według:

Ogranicz wyniki do:

Liquid crystal dual-mode band-pass filter with improved performance

Torrecilla J., Marcos C., Urruchi V., Sánchez-Pena J. M., Chojnowska O.

Opto-Electronics Review

2015

Vol. 23, No. 2

121-125

Over the last twenty years, there has been a growing interest in the design of tunable devices at microwave frequencies by using liquid crystals technology. In particular, the use of liquid crystals with high dielectric anisotropy allows manufacturing voltage-controlled devices to operate in a wide frequency range. In this work the frequency response of a liquid crystal band-pass filter with dual-mode microstrip structure has been studied in depth by using a simulation software tool. A reshaping of a conventional dual-mode square patch resonator band pass filter with a square notch, studied in the literature, has been proposed with the goal of improving the filter performance. The main features achieved are a significant increase in the return loss of the filter and a narrowing of a 3-dB bandwidth. Specifically, a reduction in the filter bandwidth from 800 MHz to 600 MHz, which leads to a return loss increase from 6 dB to 12.5 dB, has been achieved. The filter centre frequency can be tuned from 4.54 GHz to 5.19 GHz.

Light propagation mechanism switching in a liquid crystal infiltrated microstructured polymer optical fibre

Rutkowska K. A., Milenko K., Chojnowska O., Dąbrowski R., Woliński T. R.

Opto-Electronics Review

2015

Vol. 23, No. 4

252-258

In this work studies on propagation properties of a microstructured polymer optical fibre infiltrated with a nematic liquid crystal are presented. Specifically, the influence of an infiltration method on the LC molecular alignment inside fibre air-channels and, thus, on light guidance is discussed. Switching between propagation mechanisms, namely the transition from modified total internal reflection (mTIR) to the photonic bandgap effect obtained by varying external temperature is also demonstrated.