A Modular 2-bit Subarray for Large-Scale Phased Array Antenna

In this article, we introduce a low-cost and modular microstrip phased-array antenna, which is integrated with a 2-bit phase shifter. This module consists of a 16-element, 2-bit phase resolution, and a cooperative dc control board. The antenna subarray adopts a hexagonal aperture, and these left-handed circular polarization (LHCP) antenna elements are arranged in sparse array. Utilizing the combination of multiple subarrays can lead to a significant increase in gain, while effectively accomplishing the beam scanning process by controlling the “ON” and “OFF” states of p-i-n diodes. The simplicity of our methods stems from the ability to steer beams via a storable dc control sequence. To validate the scanning concept, a prototype consisting of seven subarrays was fabricated and measured. The measured results exhibit good agreement with the simulation one, and these steerable LHCP beams can cover a wide-angle range (about 60°) in the upper hemisphere.