Novel one-bit digital coding broadband transmitarray antenna

Abstract

In this paper, a novel broadband transmitarray (TA) design based on one-bit digital coding. The double-layer transmitarray element is composed of a notched square ring patches which is etched the upper layer of the dielectric substrate, and the lower layer is the same metal slit having the same shape as the notched square ring patch, but the notch direction is rotated by 180°. By changing the physical dimensions of the notched square ring element, a phase coverage of about 360° can be achieved. To realize the coding transmitarray, the phase compensation is fuzzified. Two kinds of elements with 0 and π phase responses to represent “0” and “1” elements for 1-bit digital coding are introduced. Theoretical rules of phase compensation fuzzified and a broadband transmitarray antenna are designed by coding unit cell. We design, manufacture and measure a digital coding transmitarray antenna by using the proposed element. The measured results show that the transmitarray has the 1-dB gain bandwidth of 25% (8.4 GHz - 10.8 GHz). The proposed digital coding transmitarray antenna has a wide gain bandwidth. The measured results agree with the simulated results well, which verifies the feasibility and correctness of the proposed structure.