摘要
提出了一个结构紧凑,具有两个传输零点和优良频响特性的四级LTCC低通滤波器,并用场路结合的方法完成其设计。在经典切比雪夫四级低通滤波器的并联电容支路中增加一个电感,并进一步在1、3级串连电感支路之间引入交叉耦合,成功地在滤波器的通带附近产生了两个传输零点,形成了陡峭的衰减曲线。传输零点的位置可以通过改变谐振支路的L、C值或控制1、3级串连电感的间距来灵活移动,实现了通常需要五级椭圆函数低通滤波器才能达到的频响特性。提出的电路结构减少了电路元件的个数和复杂性,降低了滤波器的插入损耗。在分析集总参数等效电路的基础上,最后用电磁场仿真软件完成了整个电路的设计和频响分析。
a novel low temperature co-fired ceramic （LTCC） four-pole lowpass filter with compact size and excellent frequency property is designed in this paper. Two transmission zeros are introduced in its stopband. In the conventional equivalent circuit of a four-pole Chebyshev lowpass filter, an inductor is added to the shunt capacitor to form a series L-C resonator, which produces the first transmission zero nearby the passband and makes a sharp rate of attenuation. The second transmission zero is yield by moving the first and third inductors closer so that cross couplings occur between these two inductors. The positions of the two transmission zeros can be adjusted easily, and a frequency response better than that of a five-pole elliptic filter is obtained with a smaller number of circuit elements, a simpler circuitry, and lower insertion losses. The physical dimensions of the filter and its frequency response are obtained by using a full-wave electromagnetic simulator.
出处
《电波科学学报》
EI
CSCD
北大核心
2005年第5期566-569,共4页
Chinese Journal of Radio Science
基金
国家自然科学基金资助项目(GP60271029)
