Design of Wide-Band (and Narrow-Band) Band-Pass Microwave Filters on the Insertion Loss Basis
Design of Wide-Band (and Narrow-Band) Band-Pass Microwave Filters on the Insertion Loss Basis
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DOI：
10.1109/tmtt.1960.1124801
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发表时间：
1960-11
影响因子：
4.3
通讯作者：
G. Matthaei
中科院分区：
文献类型：
--
作者：
G. Matthaei
描述了一种带通微波滤波器的设计方法，结合图像和插入损耗的观点，给出了一种简单且精度高的近似设计方法。该方法适用于从窄带宽到非常宽带宽（2 到 1 或更多）的滤波器设计。所需的插入损耗特性是通过使用集总元件、切比雪夫或最大平坦（或其他）低通原型来获得的。借助阻抗逆变器的概念，原型被转换为对称（但不同）部分的级联。然后，带通微波滤波器结构的对称部分的图像特性与原型的相应部分的图像特性相关。对于使用短路或开路短截线的滤波器以及使用并联耦合线的滤波器，给出了简单的设计方程。导出的映射函数可以根据原型准确预测微波滤波器的截止特性。计算了多种滤波器设计的响应，并构建并测试了带宽为 2.2 比 1 的切比雪夫滤波器。所有滤波器设计的响应与规定的特性非常一致，并且映射函数的准确性得到了验证。
A method for design of band-pass microwave filters is described that combines the image and insertion-loss points of view to give an approximate design method having simplicity, but also high precision. This method is applicable for filter designs ranging from narrow to very wide bandwidths (2 to 1 or more). The desired insertion loss characteristic is obtained by use of a lumped-element, Tchebycheff, or maximally flat (or other) low-pass prototype. With the aid of the concept of impedance inverters, the prototype is converted into a cascade of symmetrical (but differing) sections. The image properties of symmetrical sections of the band-pass microwave filter structure are then related to those of corresponding sections of the prototype. Straightforward design equations are given for filters using short-circuited or open-circuited stubs, and also for filters using parallel-coupled lines. Mapping functions are derived that permit accurate prediction of the microwave filter cutoff characteristic from that of the prototype. The responses of a number of filter designs were computed, and a Tchebycheff filter with a 2.2 to 1 band-width was built and tested. The reponses of all of the filter designs were in close agreement with the prescribed characteristics, and the accuracy of the mapping functions was verified.