介电可调薄膜材料及压控微波器件研究

Investigations of Tunable Dielectric Thin Film Materials and Voltage-Controlled Microwave Devices

利用介电可调薄膜材料的调谐特性研制的介质压控微波器件高频特性好、功率容量大、响应速度快,还有易集成、功耗小、成本低、可靠性高的特点,相比半导体管、铁氧体以及MEMS器件有明显的优势。该文系统介绍了近年来国内外介电可调薄膜材料及压控微波器件的研究进展,并结合作者的工作评述了介电可调薄膜材料和压控微波器件的应用情况。除研究最为集中的钛酸锶钡BaxSr1-xTiO3(BST)材料,还介绍了具有较高调谐率的铋基焦绿石铌酸铋镁Bi1.5MgNb1.5O7(BMN)薄膜材料,该材料介电损耗低(约0.002),介电常数适中(约86),温度系数小,是一种极具发展前景的微波介电可调材料。

Voltage-controlled devices based on tunable dielectric thin film materials are attractive for microwave applications for their excellent high frequency performance, power handling capability, and fast tuning speed. Dielectric voltage-controlled microwave devices offer advantages over semiconductor varactor diodes, ferrite, and MEMS devices with potential integration with microelectronic circuits, small power consumption, low cost, and high reliability. In this paper, based on the recent work of the authors, the recent development of tunable dielectric thin film materials and voltage-controlled microwave devices is introduced. Besides the intensively investigated BaxSr1-xTiO3 （BST） thin films, the alternative tunable Bi1.5MgNb1.5O7 （BMN） thin films with cubic pyrochlore structure are introduced due to relatively high tunability, low loss dielectric loss （-0.002）, moderate permittivity （-86）, and small temperature coefficient. BMN thin films may be one of potential tunable materials for microwave applications.