Phased Array Antenna

The prototype of our antenna was developed for a satellite-based IoT network in which IoT devices communicate with GEO satellites. The array provides hemispherical beam coverage with a highly directional antenna beam. Instead of expensive phase shifters, our design allows this coverage with a few, cost-effectively implemented phase values.

Innovative element arrangement

There are two degrees of freedom in pointing an antenna beam at a LEO or GEO satellite: the elevation to the satellite, which ranges from the satellite's rise above the horizon to its crossing zenith, and the azimuth angle, which describes the horizontal orientation of an antenna.

Unlike the usual rectangular arrays where the elements are arranged in a regular grid, we arrange the antenna elements in concentric rings and regular sectors. Controlling the phase difference between the rings allows direct control of the elevation angle, while the symmetry and sector repetition in the azimuth direction supports arbitrary alignment of the antenna relative to the satellite.

Optimized phase set

During the design and optimization process, the phase shifters for each ring are adjusted to support a minimum set of discrete phases. Each phase set is usually very small and offers between two and four different phase options. Combined with the optimized arrangement of elements, this provides just enough variability to steer the beam in any required direction. The use of switched delay lines built as part of the array feed network further simplifies the implementation of the phase shifter.

Our compact phased array antenna is primarily designed for satellite-based IoT devices with low energy consumption and low data rates. However, phased array antennas are also in demand in other application areas. Higher data rates can be transmitted by adding additional element rings. This makes the phased-array antenna suitable for further applications in satellite communications, such as satellite internet or satellite links to remote locations.

Even for use in mobile communications antennas, the concept of the phased-array antenna is well-suited. Here, the focus is on downstream digital signal processing and optimization of energy consumption.