椭圆函数低通滤波器及其在微波频综中的应用

Design of Elliptic Function Low-Pass Filter and its Application to Frequency Synthesizer

采用滤波器软件综合的方法,设计了一个椭圆函数低通滤波器。与切比雪夫低通滤波器相比,在相同阶数下,椭圆函数低通滤波器拥有更优良的带外特性和更小的尺寸。此外,还介绍了椭圆函数低通滤波器带外抑制极点的调整方法,并从微波网络入手,由于片式电感器Q值的影响,计算出实际测试的椭圆函数低通滤波器带外抑制发生恶化的程度。这种低通滤波器可广泛用于微波频率合成器和其他微波电路中。

An elliptic function low-pass filter has been designed by using the Ansoft tool of filter synthesis.Comparing with Tchebyshev low-pass filter,the elliptic function low-pass filter has better out-of-band suppression and smaller size in the same order.The adjustment of the out-of-band suppression pole of the elliptic function low-pass filter has been introduced in this paper;and the out-of-band suppression deterioration owing to Q factor of the inductor has been also calculated.The Elliptic Low-Pass Filter can be widely used in microwave frequency synthesizer such as frequency multiplier and down convertor etc..