Lead Niobate-based Tunable Dielectrics for Smart Microwave and Millimeter-wave Systems

微波和毫米波（mm波）频率的电子波束可操纵阵列天线（相控阵或智能天线）对于包括卫星通信、地面移动的通信、雷达、“物联网”、无线电力传输、卫星导航和深空通信的各种无线系统极其重要。传统的天线波束控制是通过机械移动反射面来实现的，其速度慢、体积大且不可靠。集成天线和移相器电路的相控阵是万向抛物面反射器的一种有吸引力的替代方案，因为它们提供了朝向所需目标的快速波束转向和更好的可靠性。移相器是相控阵天线中的关键器件，通过电子控制移相器实现波束控制，利用可调谐介质材料作为天线和电路的单片化材料，可以实现小型、快速、可靠、高频低损耗的移相器，是一个很有前途的研究方向。最近，当我们证明铌酸铅Pyrotechnores PbnNb2O5+n提供任何已知薄膜系统的介电常数，可调谐性和低损耗的最佳组合时，此类材料的突破出现了。将这些上级材料特性转化为实际的器件性能和微波和毫米波段的高性能电子波束可调阵列天线是本项目的主要目标

Electronically beam-steerable array antennas (phased arrays or smart antennas) at microwave and millimetre-wave (mm-wave) frequencies are extremely important for various wireless systems including satellite communications, terrestrial mobile communications, radars, "Internet Of Things", wireless power transmission, satellite navigations and deep-space communication. Traditionally, beam steering of antenna is achieved by moving the reflector mechanically, which is slow, bulky and not reliable. Phased arrays, which integrate antennas and phase shifter circuits, are an attractive alternative to gimbaled parabolic reflectors as they offer rapid beam steering towards the desired targets and better reliability. Phase shifters are critical components in phased arrays as the beam steering is achieved by controlling phase shifters electronically.A promising research direction to create small, fast, reliable phase shifters with low insertion loss at high frequency is the use of tunable dielectric materials due to its potential of monolithic fabrication of array antennas and circuits. A breakthrough in such materials came recently when we demonstrated that Lead Niobate Pyrochlores PbnNb2O5+n gives the best combination of dielectric constant, tunability and low loss of any known thin film system. Translating these superior materials properties into actual device performance and high-performance electronically beam-steerable arrays antennas at microwave and mm-wave bands are the key aims of this project