Liquid-crystalline media comprising one or more compounds of formula T ##STR00001##
as defined in claim 1, and high-frequency components comprising these media, especially microwave components for high-frequency devices, such as devices for shifting the phase of microwaves, tunable filters, tunable metamaterial structures, and electronic beam steering antennas, e.g. phased array antennas.

A liquid-crystal medium containing a component A of one or more compounds of formula X ##STR00001##
the preparation thereof, and the use of these liquid-crystal media, in particular in components for high-frequency technology, and components of this type which contain the media, and the production and use of these components. The components are suitable for phase shifters in the microwave and millimeter wave region, for microwave and millimeter wave array antennae and for tuneable reflectarrays.

Liquid-crystalline media comprising one or more compounds of formula G ##STR00001##
and one or more compounds selected from the group of compounds of formulae I, II and III, ##STR00002##
in which the parameters have the meaning indicated in claim 1, and components comprising these media, are suitable for use in high-frequency technology, in particular, in phase shifters and microwave array antennas.

A liquid crystal dielectric applicable to high-frequency electromagnetic wave modulation has a clearing point of the liquid crystal dielectric higher than 110° C., a low-temperature storage temperature lower than −20° C., and an optical anisotropy greater than 0.35. The liquid crystal dielectric includes: one or more compounds selected by general formula I, which occupy 30-80% of the total weight of the liquid crystal dielectric, and one or more compounds selected by general formula II and/or general formula III, which occupy 20-70% of the total weight of the liquid crystal dielectric. The liquid crystal dielectric has good low-temperature stability, high dielectric anisotropy, a high phase width, appropriate rotary viscosity, appropriate optical anisotropy, low dielectric loss, and a low loss tangent, exhibits strong high-frequency electromagnetic wave tuning capability, is specifically suitable for electromagnetic wave modulation in microwave or millimeter wave areas, and has a good application prospect in liquid crystal phase shifters. ##STR00001##

The present invention relates to aromatic isothiocyanates of formula U ##STR00001##
as defined in claim 1, to liquid-crystalline media comprising one or more compounds of formula U and to high-frequency components comprising these media, especially microwave components for high-frequency devices, such as devices for shifting the phase of microwaves, tunable filters, tunable metamaterial structures, and electronic beam steering antennas, e.g. phased array antennas.

A film transmission line includes a dielectric layer including at least one of a liquid crystal polymer (LCP) structure or a cyclo olefin polymer (COP) structure, and an electrode line on the dielectric layer. A signal loss level (S21) defined of the film transmission line is −1.5 dB or more at a frequency in a range from 20 GHz to 30 GHz. The film transmission line may be applied to a high frequency thin film antenna and an image display device.

A liquid crystal polyester comprising a repeating unit (A1) represented by the formula (A1) and a repeating unit (A2) represented by the formula (A2). A molar ratio (phenolic hydroxyl groups derived from the repeating unit (A2)/phenolic hydroxyl groups derived from the repeating unit (A1)) is 1 or lower, as calculated by .sup.1H-NMR. A ratio [repeating unit (A2)/repeating unit (A1)] is 1.2 or larger. The number of the repeating unit (A1) is 20% or more and the number of the repeating unit (A2) is 58% or more based on 100% of a total number of all repeating units of the liquid crystal polyester. A flow starting temperature of the liquid crystal polyester is 250° C. or more.

—O—Ar.sup.11—CO—  (A1)

—O—Ar.sup.12—CO—  (A2)

Ar.sup.11 represents a phenylene group and Ar.sup.12 represents a naphthylene group. A hydrogen atom is optionally substituted.

A compound is represented by general formula (I), a liquid-crystal composition contains this compound, and devices are made using this liquid-crystal composition.

##STR00001##

Having a large refractive-index anisotropy Δn and a sufficiently high Tni, highly compatible with liquid-crystal compositions, and exhibiting a high dielectric anisotropy in the radiofrequency range, the compound is a useful material for RF phase shifters, phased-array antennae, image recognition devices, distance meters, liquid-crystal displays, liquid-crystal lenses, and birefringent lenses for 3D image display, among other devices.

The present invention relates to liquid-crystalline media comprising one or more pleochroic compounds, and one or more compounds selected from the group of compounds of formulae I, II and III, ##STR00001##
in which the groups have the meanings as set forth in claim 1,
and to components comprising these media for high-frequency technology, in particular phase shifters and microwave array antennas.

A steerable antenna having a plurality of radiating elements and a plurality of modifier elements configured for shifting phase and/or adjusting amplitude of a signal to be emitted by the radiating elements is disclosed. Each of the radiating elements is coupled to one of the modifier elements, wherein the modifier elements each comprise a liquid crystalline medium and wherein the modifier elements are configured such that the adjustment of the phase and/or amplitude is dependent on a state of the liquid crystalline medium. The steerable antenna further comprises a signal generator connected to the modifier elements and configured for generating a signal suited for dielectric heating of the liquid crystalline media of the modifier elements. Further aspects relate to a method for heating and/or controlling the temperature of the liquid crystalline medium of such a steerable antenna.