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Millimeter-wave (mm-Wave) technology is a promising solution to meet ever-increasing demand in wireless data transmission capacity thanks to the availability of large bandwidths at mm-Wave frequencies, where the choice of dielectric materials is one of important issues because the high water absorption at mm-Wave frequencies restricts remarkably the choice. Liquid crystal polymer (LCP) is one of materials available for mm-Wave applications and is able to provide cost-effective solution. In this paper, features of LCP will be introduced for applications at V-band (60 GHz) and E-band (70 GHz, 80 GHz) in terms of dielectric constant, feasible structure, process and reliability. Some LCP-based devices such as transmission line, mode transition between different transmission-lines, antenna and filter will be reviewed. It is demonstrated that LCP-based devices actually have shown good performance and LCP is especially suitable for consumer applications that require high reliability and cost-effectiveness.

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High energy-resolution electron energy-loss spectra were obtained from barium titanate (BaTiO3) nanocrystals (BTNCs), which were synthesized by chemical vapor deposition using inductively coupled plasma. Onset energies of spectral intensities were 3.2 eV for 34 nm BTNCs and 3.5 eV for 6 nm BTNCs. This indicates an increase in the bandgap energy of BaTiO3 with a decrease in crystal sizes. Those onset energies obtained from 90 nm specimen areas showed an excellent agreement with those estimated by previously reported optical measurements. Volume plasmon peaks were observed at 26.5 eV for 34 nm BTNCs and 25 eV for 6 nm BTNCs. Dielectric functions of the BTNCs were derived from loss-functions by Kramers–Kronig analysis using the refractivity of bulk BaTiO3 (=2.4). The peaks of O 2p→Ti 3d (t2g) transitions in the imaginary part of dielectric function (ε 2) were observed at 3.3 eV for 34 nm BTNCs and 3.8 eV for 6 nm BTNCs. Those of O 2p→Ti 3d (eg) transitions were at 7.8 eV for 34 nm BTNCs and 6.6 eV for 6 nm BTNCs.

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