Two-Dimensional Beam-Steering Phased-Array Antenna With Compact Tunable Phase Shifter Based on BST Thick Films

This letter presents a novel approach for 2-D electrical beam-steering antennas based on barium-strontium-titanate (BST) thick film at 12 GHz. The phased array consists of 16 microstrip patch antenna elements with individual phase shifters as well as a 1: 16 feeding network. As key components in the circuit, the array is equipped with phase shifters based on concept of the composite right/left-handed transmission line. The phase shifters have compact structure for beam steering of planar arrays, where the antenna elements are arranged over a planar substrate. The phase shifters utilize interdigital capacitor varactors with inkjet-printed BST composite thick films. Furthermore, a simple biasing concept is implemented for controlling the phase shifter. The beam scanning range of the 4 x 4 elements array is +/- 25 degrees in both E-and H-plane as demonstrated by the measurements.