A phased array based on large-area electronics that operates at gigahertz frequency

Large-aperture electromagnetic phased arrays can provide directionally controlled radiation signals for use in applications such as communications, imaging and power delivery. However, their deployment is challenging due to the lack of an electronic technology capable of spanning large physical dimensions. Furthermore, applications in areas such as aviation, the Internet of Things and healthcare require conformal devices that can operate on shaped surfaces. Large-area electronics technology could be used to create low-cost, large-scale, flexible electromagnetic phased arrays, but it employs low-temperature processing that limits device- and system-level performance at high frequencies. Here we show that inductor–capacitor oscillators operating at gigahertz frequencies can be created from large-area electronics based on high-speed, self-aligned zinc-oxide thin-film transistors. The oscillator circuits incorporate frequency locking and phase tuning, which are required for electromagnetic phased arrays. We integrate our phase-tunable oscillators in a 0.3-m-wide aperture, creating a phased array system that operates at ~1 GHz and is capable of beamforming. Phased array systems capable of beamforming at microwave frequencies can be created from large-area electronics based on zinc oxide thin-film transistors.