Plasma-Based Beamforming Antennas

In this article, beamforming methodologies for antennas are first reviewed, highlighting the pros and cons of each method. It is observed that each method offers unique advantages and limitations. Some of the key technologies used to provide beamforming antennas are also compared with consideration of complexity, beamwidth, price, scanning angle, frequency range, beamforming speed, and accuracy. It is shown that beamforming using plasma offers flexibility compared to other techniques while remaining relatively cost-efficient. Moreover, using plasma components, it is possible to conceal the entire antenna or parts of it. Based on these advantages, this study presents a low-complexity, low-cost plasma-based antenna for beamforming. This novel antenna combines an axial mode helical antenna surrounded by circular arrays of plasma elements, forming plasma cups around the helix. The plasma cups are used to control the direction and width of the radiated beam of the helix. Activation of a plasma cup enhances the beamwidth of the helix, while asymmetrically activated configurations allow for steering the end-fire beam pattern up to ±27°. A prototype of the proposed antenna structure has been fabricated, and measurements for different configurations of the plasma reflectors have been carried out. The concept and computational results have been validated by the strong agreement between the simulation and measurement results. The proposed antenna offers a cost-effective solution for scanning and target acquisition in space communications and radar systems.