Disclosed are novel mesogenic compounds, liquid crystal compositions (liquid-crystalline media) comprising them and suitable for high-frequency technology, and high-frequency devices using them, such as phase shifters, antennas, tunable filters, switching devices, e.g. operated in the microwave region, to a process for preparing the compositions. The liquid crystal compositions have high optical anisotropy, a positive dielectric anisotropy and a wide temperature range of nematic phases.

The present invention relates to liquid-crystalline media comprising one or more chiral compounds and one or more compounds selected from the group of compounds of formulae I, II and III,

##STR00001##

in which the parameters have the meaning indicated in claim 1, and to components comprising these media for high-frequency technology, in particular phase shifters and microwave array antennas.

Liquid-crystalline media are disclosed containing one or more compounds of formula I

##STR00001##

along with components containing these media for high-frequency technology, in particular phase shifters and microwave array antennas.

The present invention relates to a liquid-crystal medium which comprises a component A which consists of one or more compounds selected from the group of the formulae I-M and I-U ##STR00001##
in which the parameters have the respective meanings given in the claims or in the text, and to the corresponding, novel mesogenic compounds and to the preparation thereof. The present invention likewise relates to the use of these liquid-crystal media, in particular in components for high-frequency technology, and to components of this type which contain media according to the invention, and to the production and use of these components. The components according to the invention are suitable, in particular, as phase shifters in the microwave and millimeter wave region, for microwave and millimeter wave array antennae and very particularly for so-called tuneable reflectarrays.

Compounds containing at least one CC triple bond of the formula I
R.sup.1-[A.sup.1-Z.sup.1].sub.m-A.sup.2A.sup.3-[Z.sup.2-A.sup.4].sub.n-[Z.sup.3-A.sup.5].sub.o-R.sup.2I,
which have neutral dielectric anisotropy, to the use thereof for high-frequency components, to liquid-crystalline media comprising the compounds, and to high-frequency components, in particular antennae, especially for the giga- and terahertz region, comprising these media. The liquid-crystalline media serve, for example, for the phase shifting of microwaves for tuneable phased-array antennae.

Disclosed are a liquid crystal (LC) composition and a high-frequency component including the same. The LC composition includes one or more selected from compounds shown in structural formula (I) and one or more selected from compounds shown in structural formula (II): ##STR00001## where R.sub.1 is selected from alkyl with 1 to 10 carbon atoms, alkenyl with 2 to 10 carbon atoms, fluorinated alkyl, fluorinated alkenyl, and cycloalkyl; one of X.sub.1, X.sub.2, and X.sub.3 is methyl or chlorine, and the other two are hydrogen; k, m, n, and p are 0 or 1; and ring A is selected from a benzene ring, cyclohexane, and cyclohexene; ##STR00002## where R.sub.2 and R.sub.3 each are selected from alkyl with 1 to 10 carbon atoms, alkenyl with 2 to 10 carbon atoms, fluorinated alkyl, fluorinated alkenyl, cycloalkyl, halogen, and NCS; and ring A and ring B each are selected from a benzene ring, cyclohexane, and cyclohexene.

Compounds containing at least one CC triple bond within a chain of at least 3 ring systems which have positive dielectric anisotropy, the use thereof for high-frequency components, liquid-crystalline media containing these compounds, and high-frequency components, in particular antennae, especially for the gigahertz region, containing these media. The liquid-crystalline media serve, for example, for the phase shifting of microwaves for tuneable phased-array antennae.

The present invention relates to compounds of the formula I ##STR00001##
where one or more of the radicals A.sup.1-5 denote a 1,4-naphthylene or 1,4- or 9,10-anthracenylene radical, and the other parameters are as defined in Claim 1. The invention additionally includes liquid-crystalline media which comprise the title compounds, and components for high-frequency technology which comprise these media, in particular phase shifters and microwave array antennae.

The present invention relates to a liquid-crystal medium which comprises a component A which consists of one or more compounds of the formula I ##STR00001##
in which the parameters have the respective meanings given in the claims or in the text, and to the corresponding, novel mesogenic compounds and to the preparation thereof. The present invention likewise relates to the use of these liquid-crystal media, in particular in components for high-frequency technology, and to components of this type which contain media according to the invention, and to the production and use of these components. The components according to the invention are suitable, in particular, as phase shifters in the microwave and millimeter wave region, for microwave and millimeter wave array antennae and very particularly for so-called tuneable reflectarrays.

The present invention relates to liquid-crystalline media comprising one or more chiral compounds and one or more compounds selected from the group of compounds of formulae I, II and III,

##STR00001##

in which the parameters have the meaning indicated in Claim 1, and to components comprising these media for high-frequency technology, in particular phase shifters and microwave array antennas.