A Wideband Array Antenna With 1-Bit Digital-Controllable Radiation Beams

In this paper, we propose a 4 × 4 low-profile wideband patch array antenna with radiation pattern agility. The digital-controllable antenna element is composed of a square driven patch, a 2×2 parasitic patch array, and two switchable feeding ports, which are connected to a designed single-pole double-throw switch. Due to the symmetrical structure, individual excitation at the two feeding ports produces a 1800 phase difference, giving rise to two basic digital elements of “0”and “1,”respectively. By switching the feeding ports for all antenna elements using a micro-controller unit, the radiation beam of the 4×4 array antenna can be dynamically reconfigured. To validate the proposed concept, a prototype operating at 5.7 GHz with an overall size of 3.42λ0 × 3.42λ0 × 0.069λ0(λ0 is the free-space wavelength at 5.7 GHz) was fabricated and measured. The measured 10-dB return loss bandwidths for all the states cover the frequency band of 5.12-6.32 GHz. The simulated and measured results show close agreement, which proves the powerful dynamical beam manipulation capability of the proposed array antenna.