高温超导薄膜制作的高阶椭圆函数滤波器兼有低插损、极高选择性的优异性能。目前，为了尽可能减小器件的尺寸，减小制冷机的制冷压力，通常采用耦合交叉线来实现非相邻谐振器之间的交叉耦合。此时，由于超导材料的晶格特性和超导电路加工工艺条件的限制，单元谐振器的结构设计和器件总体结构设计都会受到诸多限制，大大增加了滤波器的设计难度。所加工出来的超导滤波器实物的性能也并不理想，即便采用特殊的加工工艺，产品成品率也不高。 项目拟研究无交叉耦合但具有椭圆函数特性的滤波器新模型，包括对称模型和非对称模型。主要研究单对传输零点、多对传输零点的实现技术和传输零点的任意分布方法。在研究简易综合方法并综合出系列无交叉耦合椭圆函数滤波器低通原型参数基础上，提炼出特殊的传输线平面双耦合结构，并最终完成不同传输零点数和不同传输零点分布的多个高性能高温超导滤波器的研制。

High-order elliptic function filters produced by high temperature superconducting (HTS) thin films have excellent performance on both low insertion loss and high selectivity. In order to realize the miniaturization of device and reduce the pressure of refrigerator, crossing line generally is used to implement cross-coupling between non-adjacent resonators. However, due to the lattices properties of superconducting materials and processing conditions of superconducting circuits, it will become very difficulty to design both the structure of resonators and the layout of device. The performance of the produced devices normally is not satisfacting enough. The product yield is still not good even when the filters are fabricated with special processing technic. The project intends to research new filter models of none cross-couplings while with elliptic function characteristics, including symmetric model and asymmetric model. This project is mainly devoting to study how to realize multiple pairs of transmission zeros and how to distribute transmission zeros arbitrarily. Novel planar double-coupled structures of transmission line will be given based on the filter synthesis of elliptic function filter without any cross-coupling. With the structures, a series of high-performance HTS filters with different number and different distribution of transmission zeros will be designed and fabricated.