| 摘要 |
Low-cost, thin-layer liquid crystal (LC) millimeter wave (MMW) phase modulators and phased array antennae are provided based on several types of open transmission strip-line, parallel-line, and ridge-guide configurations in which surface-aligned LCs are modulated reversibly with small applied electrical fields. Incorporated properly in the open transmission lines, the LC layer can modulate the propagating MMW with nearly its full value of birefringence. The modulator comprises: (a) at least one transmission line supported on a first substrate; (b) a dielectric medium comprising a liquid crystal or a liquid crystal composite and contacting the substrate and the transmission line(s), the liquid crystal or a liquid crystal composite (e.g., polymer-dispersed liquid crystal; PDLC) having an electrically controllable dielectric permittivity; (c) a second substrate disposed opposite the first substrate and separated therefrom by a distance to accommodate the LC or LC composite; (d) means for sealing the LC or LC composite between the two substrates; (e) a source of millimeter waves electrically connected to the transmission line(s) for transmission therealong; and (f) means for varying the dielectric permittivity of the LC or LC composite to thereby modulate the transmission.
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