X-Band Reflectarray Antenna With Switching-Beam Using PIN Diodes and Gathered Elements

An electronically switching-beam reflectarray antenna to be used in X-band has been designed, manufactured and tested, using PIN diodes as switching device. The antenna has 244 elements arranged in a circular aperture. With the aim of saving electronic devices and reducing both manufacturing complexity and cost, the phase control has been implemented at sub-array level, using aperture-coupled patches gathered by pairs to a common delay line. The antenna was designed to switch the beam between ±5
^°
, in a scanning plane tilted 18.3
^°
with respect to the YZ plane. Each state was obtained by forward biasing one half of the diodes, while the other half remains in reverse biasing. A third state with the beam pointing to 0
^°
was obtained when all the diodes are in reverse biasing. The concept has been demonstrated by manufacturing and testing a breadboard. The measured radiation patterns fulfill the design requirements.