Q值对滤波特性的影响1.pptx

1、Q值对滤波器滤波特性的影响,中心频率：10.575GHz 带宽：200MHz 滤波器级数：7阶,滤波器拓扑结构如下,滤波器拓扑结构如下 300 300 300 300 300 300 300 m66 = 13.0113e-03 m55 = 41.3935e-03 m44 = 33.298e-03 m33 = 11.018e-03 m22 = 3.962e-03 m67 = 1.03104 m56 = 717.907e-03 m45 = 687.459e-03 m34 = 694.708e-03 m23 = 744.405e-03 m12 = 1.11719 m01 = 1.20288 m11=

2、m77=0,Q=300,滤波器拓扑结构如下 8000 300 300 300 300 300 8000 m66 = 4.36562e-03 m55 = 19.7918e-03 m44 = 61.7533e-03 m33 = 61.0965e-03 m22 = 24.0029e-03 m67 = 915.486e-03 m56 = 735.233e-03 m45 = 705.558e-03 m34 = 679.579e-03 m23 = 713.891e-03 m12 = 1.06347 m01 = 1.09722 m11=m77=0,Q1=Q7=8000,滤波器拓扑结构如下 300 8000

3、300 300 300 8000 300 m66 = 5.96075e-03 m55 = -35.4089e-03 m44 = -16.6564e-03 m33 = -2.71184e-03 m22 = 3.79651e-03 m67 = 1.0832 m56 = 665.73e-03 m45 = 637.292e-03 m34 = 657.118e-03 m23 = 750.055e-03 m12 = 1.01495 m01 = 1.20737 m11=m77=0,Q2=Q6=8000,滤波器拓扑结构如下 300 300 8000 300 8000 300 300 m66 = 32.2336

4、e-03 m55 = 22.2837e-03 m44 = 4.53024e-03 m33 = -3.30043e-03 m22 = 6.89597e-03 m67 = 1.13412 m56 = 709.815e-03 m45 = 560.394e-03 m34 = 661.87e-03 m23 = 666.089e-03 m12 = 1.26387 m01 = 1.48972 m11=m77=0,Q3=Q5=8000,结果对比,上图中四条曲线是高Q值在不同位置时的S21曲线， 红色曲线是Q值都取300 1曲线是Q1=Q7=8000 2曲线是Q2=Q6=8000 3曲线是Q3=Q4=8000

5、红色曲线与1、2、3曲线比较可知，Q值增大可以减小插入损耗，同时会改善低Q值“塌肩”现象；1、2、3曲线比较，高Q值的谐振器在中间比高Q 值谐振器在两边的。,滤波器拓扑结构如下,滤波器拓扑结构如下 300 300 300 300 300 300 300 m66 = 508.3e-03 m55 = 63.6097e-03 m44 = -296.514e-03 m33 = -99.3516e-03 m22 = -384.596e-03 m67 = 961.21e-03 m56 = 973.661e-03 m45 = 1.72371 m34 = 1.66825 m23 = 970.85e-03 m4

6、6 = 693.201e-03 m24 = 670.203e-03 m12 = 963.622e-03 m01 = 1.03383 m11=m77= -0.0015810654,Q值全取300,滤波器拓扑结构如下 8000 8000 300 300 8000 300 300 m66 = -5.90452e-03 m55 = -590.604e-03 m44 = 48.3419e-03 m33 = 640.685e-03 m22 = 35.7356e-03 m67 = 1.55819 m56 = 819.464e-03 m45 = 617.332e-03 m34 = 612.555e-03 m2

7、3 = 686.829e-03 m46 = 413.329e-03 m24 = 348.88e-03 m12 = 1.41481 m01 = 1.5067 m11=m77= -0.0015810654,第3、4、5个Q值取8000,滤波器拓扑结构如下 8000 300 300 8000 8000 300 300 m66 = 53.2567e-03 m55 = -594.816e-03 m44 = 24.0248e-03 m33 = 565.362e-03 m22 = 28.6704e-03 m67 = 1.54088 m56 = 744.7e-03 m45 = 631.933e-03 m34

8、= 578.251e-03 m23 = 650.877e-03 m46 = 394.953e-03 m24 = 324.016e-03 m12 = 1.32003 m01 = 1.60597 m11=m77= -0.0015810654,2、3、4,滤波器拓扑结构如下 300 8000 300 300 8000 8000 300 m66 = -12.599e-03 m55 = -597.442e-03 m44 = -63.2141e-03 m33 = 555.25e-03 m22 = -8.58713e-03 m67 = 1.44457 m56 = 641.638e-03 m45 = 587.

9、957e-03 m34 = 564.679e-03 m23 = 821.656e-03 m46 = 302.664e-03 m24 = 358.783e-03 m12 = 1.65426 m01 = 1.5706 m11=m77= -0.0015810654,4、5、6,上图中两条曲线都是由3个Q值为8000仿真得出。 红色曲线Q3=Q4=Q5=8000 蓝色曲线Q4=Q5=Q6=8000 第3条Q2=Q3=Q4=8000 比较两图可知三个高Q都在中间时曲线两边陡峭性都很好;高Q在中间偏左时，左边陡峭性好，而右边差；高Q偏右时，右边陡峭性好，左边差。,在交叉耦合结构中，中间三个谐振器Q值对滤波特性影响较大，很大程度上改善矩形系数以及插入损耗。,二、 并联结构滤波器,滤波器拓扑结构如下,Q=300,Q1=Q5=8000,Q2=Q4=8000,Q=300；Q6=Q7=8000,Q=300;Q1=Q5=8000,Q=300;Q2=Q4=8000（红）,由以上几幅图可以看出，当滤波器结构排成两排，一排五个谐振器，一排两个，此时第2排两个谐振器Q值以及第1排中间三个会影响滤波特性，改善矩形系数，插损，第二排两个谐振器Q值