A Monolithically BST-Integrated $K_{a}$ -Band Beamsteerable Reflectarray Antenna

A 5 × 9 beamsteering reflectarray operating at K
_a
-band is presented in this paper. Continuous beamsteering is achieved through the use of barium strontium titanate (BST) technology. BST is monolithically integrated into each unit cell using clean room fabrication techniques. With the application of dc bias voltage, an integrated tunable capacitor is realized. The unit cell design utilized in this reflectarray is analyzed and multiple biasing schemes are assessed. The reflectarray is designed to scan in the E-plane only, and is evaluated using full-wave simulations and measurements. An appropriate feeding structure is designed and fabricated using a fused filament deposition 3-D printer, with micrometer stages used to make fine adjustments for final alignment. Overall a gain of 8.3 dBi, with a 1-dB bandwidth of 2% and continuous beamscanning from 0° to 25° at 32 GHz is demonstrated.