某U低天线曲线，红色为测量曲线，蓝色为接入电缆曲线
A low U antenna for measuring curve curve, red, blue for access to cablecurve
6，阻抗测量
Impedance measurements
需要使用驻波电桥进行阻抗测量，测量时候，在电桥DUT端串入一个50欧姆的电阻。
Need to use the bridge to measure the impedance, measurement time,resistance in the bridge end DUT string into a 50 ohm.
6.1 SWR校准（如果已经校准该步省略）
SWR calibration (if you have omitted the step calibration)
进行SWR校准，详见12节SWR校准，如果不校准，测出来的阻抗不准确。
The SWR calibration, see section 12 SWR calibration, if not calibrated,impedance measurement is not accurate.
6.2 选择阻抗测量
Selection of impedance measurement
校准完毕后，选择阻抗测量模式
After calibration, select the impedance measurement model
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选择阻抗测量模式
Selection of impedance measurement model
选择完毕后会出现提示，不用理会。
After selection will be prompted, ignore.
6.2进行测量，从图上直接读出阻抗数值
Measurement, read directly from the chart impedance values
测量时候，需要在电桥DUT端串一个50欧电阻。
Measurement of time series, a 50 ohm resistor in bridge DUT need.
测量65欧电阻曲线
Measurement of 65 European resistance curve
7，测量器件连接方法
Measuring device connection method
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7.1，滤波器测方法1
Filter test method 1
如下图，适合滤波器输入输出阻抗均为50欧的情况，如果滤波器阻抗不匹配，用该法测量容易造成带宽错误，通带内波动大等测量不准确的情况。
The following diagram, suitable for the filter input and output impedance is 50 euro, if the filter impedance mismatch, the measurements are prone to errorin passband bandwidth, the big fluctuation of inaccurate measurement
of.
方法1，适合滤波输入输出阻抗为50欧的情况
Methods 1, suitable for filtering the input and outputimpedance of 50
ohm situation
7.2，滤波器测方法2
Filter test method 2
如果滤波器阻抗不对，需要进行阻抗匹配。可用变压器进行匹配。匹配后，滤波器的曲线测量才准确。
还可以用电阻进行匹配，该匹配方式插损非常大。
If the filter does not need the impedance, impedance matching. To match the available transformer. After matching, curve measurement filter was accurate.
Can also use the resistance matching, the matching method of insertion lossis very large.
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进行阻抗匹配的方法，该方法可测量插损
Method of impedance matching, this method can measure the insertion loss
7.3，中周测量方法1
Rf transformer measurement method 1
中周测量方法1
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Rf transformer measurement method 1
7.4，中周测量方法2
Rf transformer measurement method 2
中周测量方法2
Rf transformer measurement method 2
7.5，天线测量方法
Antenna measurement method
NWT系列扫频仪如果需要测量天线，需要在外附加一电桥，该电桥参考电路如下： NWT series frequency sweep meter if you need additional measuring antenna, a bridge on the bridge, a reference circuit are as follows:
驻波电桥原理图
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