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问：如何将ADS仿真得到的S参数保存成SNP文件供其他场合使用？
答：使用write_snp()函数。
write_snp()函数的帮助信息：
使用格式：
y = write_snp(FileName, S, Comment, FreqUnit, DataFormat, Zref, Znorm, ZorY, Precision, Delimiter)
参数定义：
FileName:保存的snp文件名S:S参数仿真结果的对象，默认就是SComment：备注信息，默认是空字符串" "FreqUnit：频率单位，默认是"GHz"，其他可选单位是"Hz"、"kHz"、"MHz"、"THz"DataFormat：数据格式，默认是"MA"，代表线性幅度+角度；其他可选格式是"DB"代表对数幅度+角度、"RI"代表实部+虚部Zref：参考阻抗，默认是50ΩZnorm：归一化阻抗，默认是50ΩZorY：0-选择使用Z矩阵完成S参数归一化变换，1-选择使用Y矩阵完成S参数归一化变换，默认是1Precision：数据精度，导出的S参数默认保留6位小数Delimiter：数据分隔符，snp文件默认使用空格作为分隔符注意：该函数仅支持一维扫描的S参数（即频率扫描），支持的端口数量为1~99。
假如你设计了一个功分器：
S参数仿真结果如下：
通过write_snp()函数将数据另存为snp文件，文件名"data.s3p"，频率单位"GHz"，数据格式为对数幅度+角度，参考阻抗50Ω：
上面是通过原理图添加公式（MeasEqn）来实现的，执行一次仿真后在当前工程(xxx_wrk)的data文件夹下就自动生成了一个对应的data.s3p文件：
xxx_wrk/data/data.s3p文件内容如下：
! freq dB(S11) phase(S11) dB(S12) phase(S12) dB(S13) phase(S13) ! dB(S21) phase(S21) dB(S22) phase(S22) dB(S23) phase(S23) ! dB(S31) phase(S31) dB(S32) phase(S32) dB(S33) phase(S33) !S-parm simulation data# GHz S dB R 501.000000 -10.352854 162.889736 -3.579042 -16.980123 -3.579042 -16.980123 -3.579042 -16.980123 -13.389864 121.062569 -5.930942 -33.054647 -3.579042 -16.980123 -5.930942 -33.054647 -13.389864 121.062569
1.100000 -10.444901 161.170943 -3.571395 -18.690122 -3.571395 -18.690122 -3.571395 -18.690122 -13.889192 116.343911 -6.256185 -35.319486 -3.571395 -18.690122 -6.256185 -35.319486 -13.889192 116.343911
1.200000 -10.546152 159.448840 -3.563002 -20.403757 -3.563002 -20.403757 -3.563002 -20.403757 -14.407162 111.818552 -6.586260 -37.422027 -3.563002 -20.403757 -6.586260 -37.422027 -14.407162 111.818552
1.300000 -10.656904 157.723034 -3.553898 -22.121338 -3.553898 -22.121338 -3.553898 -22.121338 -14.941509 107.470061 -6.919256 -39.378793 -3.553898 -22.121338 -6.919256 -39.378793 -14.941509 107.470061
1.400000 -10.777487 155.993148 -3.544122 -23.843155 -3.544122 -23.843155 -3.544122 -23.843155 -15.490592 103.281748 -7.253863 -41.206049 -3.544122 -23.843155 -7.253863 -41.206049 -15.490592 103.281748
1.500000 -10.908267 154.258818 -3.533717 -25.569488 -3.533717 -25.569488 -3.533717 -25.569488 -16.053303 99.237173 -7.589278 -42.919289 -3.533717 -25.569488 -7.589278 -42.919289 -16.053303 99.237173
1.600000 -11.049652 152.519693 -3.522725 -27.300597 -3.522725 -27.300597 -3.522725 -27.300597 -16.628990 95.320452 -7.925121 -44.532921 -3.522725 -27.300597 -7.925121 -44.532921 -16.628990 95.320452
1.700000 -11.202092 150.775436 -3.511193 -29.036729 -3.511193 -29.036729 -3.511193 -29.036729 -17.217388 91.516425 -8.261358 -46.060104 -3.511193 -29.036729 -8.261358 -46.060104 -17.217388 91.516425
1.800000 -11.366086 149.025723 -3.499169 -30.778109 -3.499169 -30.778109 -3.499169 -30.778109 -17.818553 87.810699 -8.598238 -47.512681 -3.499169 -30.778109 -8.598238 -47.512681 -17.818553 87.810699
1.900000 -11.542187 147.270239 -3.486703 -32.524948 -3.486703 -32.524948 -3.486703 -32.524948 -18.432818 84.189631 -8.936238 -48.901179 -3.486703 -32.524948 -8.936238 -48.901179 -18.432818 84.189631
2.000000 -11.731011 145.508682 -3.473846 -34.277435 -3.473846 -34.277435 -3.473846 -34.277435 -19.060752 80.640245 -9.276026 -50.234866 -3.473846 -34.277435 -9.276026 -50.234866 -19.060752 80.640245
2.100000 -11.933239 143.740756 -3.460654 -36.035739 -3.460654 -36.035739 -3.460654 -36.035739 -19.703124 77.150111 -9.618423 -51.521811 -3.460654 -36.035739 -9.618423 -51.521811 -19.703124 77.150111
2.200000 -12.149633 141.966174 -3.447181 -37.800008 -3.447181 -37.800008 -3.447181 -37.800008 -20.360882 73.707201 -9.964387 -52.768979 -3.447181 -37.800008 -9.964387 -52.768979 -20.360882 73.707201
2.300000 -12.381041 140.184655 -3.433485 -39.570369 -3.433485 -39.570369 -3.433485 -39.570369 -21.035134 70.299708 -10.314994 -53.982312 -3.433485 -39.570369 -10.314994 -53.982312 -21.035134 70.299708
2.400000 -12.628412 138.395917 -3.419624 -41.346924 -3.419624 -41.346924 -3.419624 -41.346924 -21.727132 66.915850 -10.671429 -55.166814 -3.419624 -41.346924 -10.671429 -55.166814 -21.727132 66.915850
2.500000 -12.892815 136.599677 -3.405658 -43.129753 -3.405658 -43.129753 -3.405658 -43.129753 -22.438258 63.543642 -11.034985 -56.326628 -3.405658 -43.129753 -11.034985 -56.326628 -22.438258 63.543642
2.600000 -13.175451 134.795646 -3.391647 -44.918912 -3.391647 -44.918912 -3.391647 -44.918912 -23.170015 60.170630 -11.407068 -57.465103 -3.391647 -44.918912 -11.407068 -57.465103 -23.170015 60.170630
2.700000 -13.477683 132.983518 -3.377653 -46.714431 -3.377653 -46.714431 -3.377653 -46.714431 -23.924011 56.783594 -11.789203 -58.584849 -3.377653 -46.714431 -11.789203 -58.584849 -23.924011 56.783594
2.800000 -13.801063 131.162965 -3.363737 -48.516314 -3.363737 -48.516314 -3.363737 -48.516314 -24.701942 53.368190 -12.183050 -59.687778 -3.363737 -48.516314 -12.183050 -59.687778 -24.701942 53.368190
2.900000 -14.147364 129.333623 -3.349963 -50.324540 -3.349963 -50.324540 -3.349963 -50.324540 -25.505567 49.908530 -12.590425 -60.775130 -3.349963 -50.324540 -12.590425 -60.775130 -25.505567 49.908530
3.000000 -14.518630 127.495076 -3.336391 -52.139059 -3.336391 -52.139059 -3.336391 -52.139059 -26.336666 46.386686 -13.013332 -61.847476 -3.336391 -52.139059 -13.013332 -61.847476 -26.336666 46.386686
3.100000 -14.917232 125.646834 -3.323084 -53.959799 -3.323084 -53.959799 -3.323084 -53.959799 -27.196980 42.782093 -13.453993 -62.904712 -3.323084 -53.959799 -13.453993 -62.904712 -27.196980 42.782093
3.200000 -15.345941 123.788305 -3.310103 -55.786655 -3.310103 -55.786655 -3.310103 -55.786655 -28.088113 39.070862 -13.914902 -63.946009 -3.310103 -55.786655 -13.914902 -63.946009 -28.088113 39.070862
3.300000 -15.808024 121.918753 -3.297509 -57.619500 -3.297509 -57.619500 -3.297509 -57.619500 -29.011386 35.224986 -14.398888 -64.969745 -3.297509 -57.619500 -14.398888 -64.969745 -29.011386 35.224986
3.400000 -16.307373 120.037240 -3.285361 -59.458177 -3.285361 -59.458177 -3.285361 -59.458177 -29.967613 31.211498 -14.909190 -65.973376 -3.285361 -59.458177 -14.909190 -65.973376 -29.967613 31.211498
3.500000 -16.848677 118.142546 -3.273717 -61.302503 -3.273717 -61.302503 -3.273717 -61.302503 -30.956767 26.991670 -15.449569 -66.953261 -3.273717 -61.302503 -15.449569 -66.953261 -30.956767 26.991670
3.600000 -17.437651 116.233049 -3.262634 -63.152269 -3.262634 -63.152269 -3.262634 -63.152269 -31.977486 22.520501 -16.024447 -67.904378 -3.262634 -63.152269 -16.024447 -67.904378 -31.977486 22.520501
3.700000 -18.081374 114.306548 -3.252166 -65.007241 -3.252166 -65.007241 -3.252166 -65.007241 -33.026375 17.746946 -16.639096 -68.819913 -3.252166 -65.007241 -16.639096 -68.819913 -33.026375 17.746946
3.800000 -18.788751 112.359984 -3.242365 -66.867159 -3.242365 -66.867159 -3.242365 -66.867159 -34.097046 12.615736 -17.299900 -69.690642 -3.242365 -66.867159 -17.299900 -69.690642 -34.097046 12.615736
3.900000 -19.571215 110.389005 -3.233281 -68.731738 -3.233281 -68.731738 -3.233281 -68.731738 -35.178911 7.072181 -18.014720 -70.503976 -3.233281 -68.731738 -18.014720 -70.503976 -35.178911 7.072181
4.000000 -20.443782 108.387234 -3.224961 -70.600674 -3.224961 -70.600674 -3.224961 -70.600674 -36.255852 1.071921 -18.793414 -71.242464 -3.224961 -70.600674 -18.793414 -71.242464 -36.255852 1.071921
由于数据太多，以下省略4.1GHz~9.0GHz的数据每次重新仿真就会自动将最新的结果写入到data.s3p文件中，如果将原理图中的公式禁用（Deactivate）则不再执行该函数。
预览data.s3p文件中的数据：
同样也可以在数据结果窗口中使用公式来执行该函数：
但是注意，这种方式输出的snp文件保存在当前工程目录(xxx_wrk)下，而不在下一层data目录
xxx_wrk/data.s3p历史文章
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