Design of Wideband High-gain Multi-beam THz Antennas Based on Modified Luneberg Lens and Magneto-electric Dipoles

Description

To support the growth of high-speed and low-latency data transmission through wireless channels, radio-frequency communication systems operating at terahertz frequencies have been proposed and aroused much interest in academia and industry. Among all the techniques for realizing multibeam and steerable-beam antennas operating at microwave and millimeter-wave frequencies, the Luneburg lens was found to have the advantages of wide bandwidth and wide scanning angular range. Also, no expensive phase shifters are required, which is an attractive feature for THz applications. Luneburg lens antennas operating at terahertz frequencies are preferable to have a planar structure for ease of integration with feed antennas. This can be achieved through the transformation optics technique. Its bandwidth performance at terahertz frequencies will be enhanced using efficient optimization algorithms including novel machine-learning approaches. In parallel, efficient fabrication processes and low-loss materials for realizing the antennas will be explored. The magneto-electric dipole will be employed as the lens antenna feeds owing to its excellent radiation characteristics including wide bandwidth, low cross-polarization radiation, low backside radiation, symmetrical radiation pattern, and stable gain and beamwidth over the operating bandwidth when compared with conventional antennas such as dipoles, slots, and microstrip antennas. Efficient ME dipole antenna structures for ease of fabrication between 100 to 200 GHz will be investigated. ME dipoles designed for free-space radiation may not be matched well for Luneburg lens excitation especially when the lens is made of high dielectric constant materials. We will investigate ways to improve the matching performance by modifying innovatively the antenna structures by adding appropriate matching layers. The success of this project will help to improve significantly the performance and production costs of future wireless systems operating at terahertz frequencies.