Chebysheve 滤波器计算结果

CST 的输入图形
计算结果
解算器类型： 模式分析 网格数： 237300
HFSS8.0仿真模型（包含初始网格设置）
HFSS9.0仿真模型（由8.0导入）
计算结果
8.0模型（Pass=18）
9.0模型（Pass=18）
已定参数
• Cavity dimensions 280 x 30 x 120 mm • Resonator diameter 10 mm • Buckets’ inner diameter 12 mm • Buckets’ outer diameter 16 mm • Buckets’ height 15 mm • Antennas’ diameter 26 mm • Antennas’ thickness 4 mm
仿真结果
优化以后
• Resonant frequency of the outermost resonators fR1= 400.058 MHz • Resonant frequency of the inner resonators fR2=399.926 MHz • Loaded Q QL=30.368 • Coupling coefficients K12=0.02825 , K23=0.02173 , K34=0.02068 • Length of the two outermost resonators = 113.44 mm • Length of the five inner resonators = 114.684 mm • Antenna distance = 1.928 mm • Distances between resonators are 25.286 mm , 28.3 mm , 28.78 mm
Chebysheve 滤波器计算结果
2005年10月
滤波器设计指标
• • • • Center Frequency：400MHz Ripple Bandwidth：15MHz Ripple：0.1dB Out-of band Rejection: 24dB at 390MHz and at 410MHz
24dbat390mhzandat410mhz已定参数?cavitydimensions280x30x120mm?resonatordiameter10mm?bucketsinnerdiameter12mm?bucketsouterdiameter16mm?bucketsheight15mm?antennasdiameter26mm?antennasthickness4mm待定参数?thelengthofthefirstandlastresonatingcylinderbothhaveequallength?thelengthofthefiveinteriorcylindersallfivehaveequallength?thedistancebetweenanantennaanditsnearestcylinder?threedistancesbetweenneighboringcylindersrememberthefilterissymmetric确定中间谐振柱长度l腔体之间耦合的计算方法ef对称面mf对称面放置理想电导体?pec?时腔体的谐振频率对称面放置理想磁导体?pem?时腔体的谐振频率hsinchinchangandkawthara
Initial Filter Design in HFSS
g1=g7=1.1812 H g3=g5=2.0967 H Kij = g2=g6=1.4228 F g4=1.5734 F.
bw gi⋅gj
Q =
g1 bw
Resonant frequency of the outermost resonators：fR1= 400 MHz Resonant frequency of the inner resonators ：fR2=400 MHz Loaded Q ：QL=31.498 Coupling coefficients： K12=0.02893 , K23=0.02171 , K34=0.02065 Length of the two outermost resonators = 113.399 mm Length of the five inner resonators = 114.69 mm Antenna distance = 1.879 mm Distances between resonators are 25.513 mm , 28.291 mm , 28.767 mm
确定中间谐振柱长度L
腔体之间耦合的计算方法
对称面放置理想 电导体（ 电导体（PEC） ） 时腔体的谐振频 率 对称面放置理想 磁导体（ 磁导体（PEM） ） 时腔体的谐振频 率
fe
fm
对称面
Hsin-Chin Chang and Kawthar A. Zaki, Fellow, IEEE，Evanescent-Mode Coupl ing of Dual-Mode Rectangular Waveguide Filters，IEEE TRANSACTIONS ON ， MICROWAVE THEORY AND TECHNIQUES, VOL. 39, NO. 8, AUGUST 1991
待定参数
• The length of the first and last resonating cylindelength of the five interior cylinders (all five have equal length) • The distance between an antenna and its nearest cylinder • Three distances between neighboring cylinders (remember the filter is symmetric)
单腔计算耦合
• PEC
f e = 0.4024; f m = 0.3924;
2 f e2 − f m = 0.0252 > 0 k= 2 2 fe + f m
电耦合
• PEM
双腔计算耦合
• 用参数扫描直接输出K值
计算结果
• S是柱表面之间的距离
计算QL的模型
• PML
计算的QL值
计算的K01值