| 摘要: |
| 为抑制平面带通滤波器的二次谐波，实现高选择性和低插入损耗，提出了一种新型
Koch岛分形结构，并将其应用到平面耦合微带线带通滤波器的设计中。仿真及测试结果表明
：所设计的新型Koch岛分形耦合微带线带通滤波器的中心频率为3 GHz，3 dB通带
宽度为10%；与传统的耦合微带线带通滤波器相比，该新型滤波器的二次谐波降低了1
1.5 dB，选择特性提高了5 dB/GHz，通带内最大回波损耗降低了4.7 dB，尺寸缩
小了近5%。该新型滤波器具有尺寸小、重量轻、成本低且性能好等优点。 |
| 关键词: 微波电路 耦合微带线 带通滤波器 Koch岛 分形结构 谐波
抑制 |
| DOI： |
|
| 基金项目:国家自然科学基金资助项目(60971118) |
|
| A Novel Microstrip Coupled-Line Bandpass Filter Based on Koch Island |
| LI Tian-peng,WANG Guang-ming,LIANG Jian-gang |
| (The Missile Institute, Air Force Engineering University, Sanyuan 713800, China) |
| Abstract: |
| To suppress the second harmonic and realize high selectivity and low insertion l
oss,a novel microstrip coupled-line bandpass filter(BPF) operating at 3 GHz
is p
resented by introducing Koch-island-fractal-shaped structure. Simulation and
mea
surement results indicate that the proposed filter is with significant superiori
ty in terms of 11.5 dB of deeper suppression of second harmonic, steeper sel
ectiv
ity of 5 dB/GHz, better insertion loss of 4.7 dB as well as 5% of size r
eduction w
ith respect to its conventional counterpart. The 3 dB bandwidth(insertion lo
ss) i
s up to 10%. What′s more, the designed filter has such advantages as small siz
e, light weight, low cost, and good capability. |
| Key words: microwave circuit microstrip coupled-line bandpass filter(BPF) Koch island f
ractal-shaped structure harmonic suppression |
