Ricerc@Sapienza

A planar antenna radiating twisted beams with different azimuthal order and a consistent beam angle is designed by employing a single uniform circular array embedded in a Fabry–Perot cavity. Circular phased arrays placed in free space are commonly employed to radiate conical beams carrying orbital angular momentum. However, the beam angle depends on both the array radius and the azimuthal order of the beam, thus requiring the use of multiple concentric circular arrays in order to produce beams with different azimuthal order and a common beam angle.

Alow-cost planar leaky-wave antenna (LWA) offering directive antenna beam patterns as well as linear beam scanning through broadside is proposed. The design is based on a one-sided annular slot grating placed on a dual-layer grounded dielectric slab with an integrated TM0 antenna feed system in the bottom ground plane.

A two-dimensional leaky-wave antenna fed by an array of fully integrated sources and able to provide fixed-frequency continuous beam steering through broadside is presented in this contribution. The structure is constituted by a 'bull-eye' leaky-wave antenna fed by a proper arrangement of four surface-wave launchers, whose excitation coefficients are selected to control the beam pointing angle around broadside.

A radar sensor suitable to record carotid wall movements has been developed and tested. The sensor is based on a double-sideband continuous-wave coherent transceiver, operating at 2.45 GHz, and on a bow-tie planar antenna optimized to operate in contact with the neck. Measured transceiver responses on a sliding short load are in good agreement with an analytical model and simulation results. An artificial model of the neck with an embedded pulsatile carotid-artery mockup has been built to test the radar.