摘要
基于微带SIR的特性,提出了一种紧凑的微带多耦合带通滤波器结构,介绍了通过控制微带SIR谐振器的阻抗比值来调整二阶通带中心频率的位置,从而实现二阶杂波抑制和改善滤波器上边阻带衰减特性的原理。最后设计了一个中心频率为3.65 GHz,分数带宽约为3.5%的微带多耦合SIR带通滤波器,仿真表明其频率响应在1阶杂波频点处有-10 dB左右的衰减,使得滤波器在上边阻带的衰减更陡峭,通带更对称。制作的电路在中心频率处的插入损耗测试结果为-3.2 dB,带宽大约为120 MHz,和仿真结果比较一致。
A compact multi-coupling microstrip bandpass filter based on microstrip stepped impedance resonator (SIR) characteristics was presented. The principle of second harmonic suppression with a proper impedance ratio was introduced, which improved the rejection at the stopband of the bandpass filter. A mierostrip multi-coupling SIR bandpass filter with 3. 65 GHz center frequency and 3. 5% fractional bandwidth was designed and fabricated. The result of simulating the filter showed -10 dB attenuation at the first harmonic center frequency, making the upper skirt deeper and the bandpass response more symmetric than filters without microstrip SIR. The experimental filter was measured and had -3.2 dB insert loss at the central frequency and a bandwidth of approximately 120 MHz. The measured result was consistent with the simulated one.
出处
《重庆大学学报(自然科学版)》
EI
CAS
CSCD
北大核心
2008年第10期1194-1197,共4页
Journal of Chongqing University
基金
重庆市自然科学基金资助项目(项目编号:2006BB3162)
关键词
阶梯阻抗谐振器
微带线
带通滤波器
stepped impedance resonator
microstrip line
bandpass filter