Satellite Reception Underway


Satellite Reception Underway

Liquid-crystal antenna allows stable satellite-broadcast reception in vehicles

Satellite-television reception and stable Internet links to earth satellites have thus far demanded employment of stationary antennae. However, a doctoral candidate at the Technische Universität Darmstadt has developed a space-saving, inexpensive, and extremely rapidly, electronically redirectable antenna that should allow automobiles, ships, and aircraft to maintain stable radiocommunications with earth satellites.

Onur Hamza Karabey gewann mit seinem Konzept den Ideenwettbewerb der TU Darmstadt. Bild: Katrin Binner – © Kartin Binner
Onur Hamza Karabey won the TU-Darmstadt’s “New Idea” award with his development. Image: Katrin Binner

The LCD-matrix developed by Karabey, working in collaboration with Prof. Dr. Rolf Jakoby and Dr. Felix Goelden, at the TU-Darmstadt’s Department of Electrical Engineering and Information Technology utilizes voltages to delay the incidence of radiowaves on the antenna. The lengths of those delays depend upon the applied voltages, which allows amplifying radiofrequency signals coming from a particular direction and enables the matrix to virtually collect the radiofrequency irradiation incident on its entire surface area. Working in collaboration with Atsutaka Manabe of Merck KGaA, Darmstadt, Karabey has built a prototype of four LCD-cells as a demonstration of his antenna’s principle of operation and, together with another collaboration partner, is currently developing and constructing a larger, 16-cell-by-16-cell matrix having a total surface area of around 10 square centimeters.

The directions from automobiles or aircraft to the satellite whose broadcasts they are to receive constantly change while they are underway. Their antennae have to be redirected to the particular satellite involved as they change their location if reception of satellite broadcasts is to remain stable. Electronically redirectable antennae (“phased-array antennae”) of the current generation are either very expensive or only sluggishly redirectable. However, an idea by Onur Hamza Karabey, a doctoral candidate at the TU-Darmstadt, promises to open up broad application areas. Taking LCD-technology as a basis, Karabey has developed an antenna that consists of a matrix of liquid crystals, has no moving parts and is capable of detecting and tracking a source of radiowaves and amplifying the received radiofrequency signals.

Redirectable within milliseconds and inexpensive to manufacture

Funktionsweise der Phased-Array-Antenne. Bild: Infotext – © Infotext
Mode of operation of the phased-array antenna. Image: Infotext

Karabey remarked that, “Our objective is developing an ultralow-cost, phased-array antenna whose performance will be adequate for satellite reception.” The major benefit of LCD-antennae is that they may be manufactured in the same manner as LCD-monitors and TV-screens. The 28-year-old graduate student therefore expects that such antennae will sell for less than 600 Euros. Another benefit is that they have no moving parts and thus can be aligned on satellites within milliseconds. Furthermore, they are only around 5 mm thick and thus may be readily incorporated into automobiles’ roofs, without being conspicuous. Rolf Jakoby added that, “Such antennae may even be partially transparent, which gives product designers considerable leeway in meeting buyers’ needs.”

Prototyp aus vier LCD-Zellen. Bild: Katrin Binner – © Katrin Binner
The prototype is built up of four LCD-cells. Image: Katrin Binner

Karabey, who won the TU-Darmstadt’s 2011 “New Idea” award with his development of the antenna, views its ideal application area as stable reception of radio, television, Internet, and other telecommunications transmissions in automobiles, ships, aircraft, and other types of vehicles. The next goal of Karabey’s group is founding a consortium that would include a supplier of satellite-broadcast services and other institutions and/or private companies, who would work on optimizing antenna configuration and design the associated electronics, along with a liquid- crystal manufacturer and an end user, e.g., an automobile manufacturer.

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