CEA Leti offers a PhD topic to develop new electronically scanning antennas for efficient data transmission in satellite communications (Satcom). Novel efficient electronically scanning antennas are essential for future satellite communications (Satcom). Electronically reconfigurable flat lens antennas, also known as transmitarrays, are a promising architecture to achieve high scanning performance. Each element of the flat lens introduces an optimized phase shift on the impinging wave emitted by a primary source, to steer and shape the radiation pattern. The phase profile over the lens can be dynamically modified by adding reconfigurable devices in the cells, such as switches (e.g. pin diodes) or varactors. Compared to phased arrays, these antennas attain high-gain beam-steering with a significantly lower power consumption and architectural complexity.
The Ph.D. work aims to propose and experimentally demonstrate novel concepts and design methods for wideband/multi-band electronically beam-steering flat lens antennas. The main research goals are:
. Study of new approaches for designing unit cells with broad radiation patterns, stable performance under oblique incidence and wideband/multiband operation.
. Electrically thin subwavelength cells and Huygens’ radiating elements will be investigated to tailor the angular and frequency response of the cell.
. Novel design solutions to enable a fine electronic control of the phase shift introduced by the cells. Multilayer cells comprising either pin diodes or varactors, or a combination of both, will be analyzed. The trade-offs between phase resolution, bandwidth, power consumption, number of reconfigurable devices and bias lines, will be studied.
. Development of dedicated synthesis procedures to enable the independent control and shaping of the radiation pattern at two or multiple frequencies.
. Experimental demonstration of high-gain dual-band fixed-beam and electronically 2-D beam-steering prototypes achieving extremely wide scan ranges (±60° or greater). The demonstratators will be optimized to work in typical Satcom bands (e.g. around 20 GHz and 30 GHz).