Experimental Characterization of 2 x 2 Electronically Reconfigurable 1 Bit Unit Cells for a Beamforming Transmitarray at X Band

This paper proposes a reconfigurable unit cell for a transmitarray operating at the X band. The unit cell consists of an active patch, a passive patch, and a phase shifter. The active patch has two PIN diodes that change the phase of 180 degrees of the transmitted waves. The passive and active patches both have circular slots to enhance the bandwidth of the transmitted wave. We also propose a new type of experimental characterization technique to measure the performance of the unit cells at the X band without fabricating the entire transmitarray. Instead of a 1 unit cell as described in the literature, we propose 2 x 2 unit cells to measure the performance of unit cells using the X band waveguide. The waveguide consists of a WR-90 section and a rectangular to square waveguide transition section that can be fit to our proposed structure. A good agreement between simulated and measured results was found.

Automated summary

This paper proposes a reconfigurable unit cell for a transmitarray operating at the X band, consisting of an active patch, a passive patch, and a phase shifter. The unit cell utilizes PIN diodes to change the phase of transmitted waves and circular slots to enhance bandwidth. A new experimental characterization technique is also introduced to measure unit cell performance without fabricating the entire transmitarray.