PNA-X N5242A接收器执行源功率校准失败

Hii ..我正在使用PNA-X N5242A进行测量。
我正在使用Trace S21进行测量和测量。
PNA-X的接收器B用于在DUT上执行测试之前以脉冲模式执行源功率校准。
DUT的输入功率* 0dBm * DUT的输出功率* 53 dBm *我在DUT的输出端使用50 dB衰减器来降低功率和功耗。
我的电缆损耗约为5 dB。
所以我在PNA的端口2处获得的功率小于0dBm。
我在过去1个月的源功率校准后进行了测试。
我每次都得到了理想的结果。
*问题：*突然有一天，当我执行源功率校准时，* PNA显示源功率校准失败*。
*所以我检查生成的Power @ R1（接收器），它显示-25dBm，尽管我从Port1产生0dBm电源。* *然后我连接端口1＆amp;
端口2通过电缆＆amp;
检查功率电平@接收器B，它还显示-25dBm。* *但是当我通过PPM *检查时，PNA正在生成精确的0dBm @端口1。
然后我打电话给安静的人检查PNA接收器，检查PNA后他告诉接收器A＆amp;
B变坏了，因为你输了大功率然后马克斯。
允许的功率水平。
*我无法理解它是如何发生的，因为我在DUT的输出端使用50 dB衰减器。
或者如果它发生，那么只有接收器B应该变坏，因为我正在使用S21跟踪。* *接收器A＆amp;有没有任何其他原因。
B可能会变坏吗？*我需要帮助来诊断原因。



     以下为原文

  Hii.. I am using PNA-X N5242A for my measurement. I am using Trace S21 for my measurement & Receiver B of PNA-X for performing source power calibration in Pulse mode before performing the test on DUT.

Input Power of DUT  *0dBm*

Output Power of DUT *53 dBm*

I am using 50 dB attenuators at the output of DUT to reduce the power & my cable loss is around 5 dB. So I am getting less than 0dBm power at port 2 of PNA.

I was performing test after source power calibration from last 1 month & I was getting desired results everytime.  

*Problem:*

suddenly on one day, When I performed source power calibration, *PNA shows source pow calibration failed*. *So I check generated Power @ R1 (receiver), it shows -25dBm eventhough I was generating 0dBm power from Port1.*
  
*Then I connect Port 1 & Port 2 through a cable & check the Power level @ receiver B, it also shows -25dBm.*

*but PNA was generating exact 0dBm @ port 1 when I check through PPM*.  

then I call agilent person to check the PNA reciever, after checking the PNA he told that receiver A & B has gone bad because you fed high power then Max. permissible power level.  

*I am not able to understand how it can happen, because I am using 50 dB pad at the output of DUT. or if it happen then only receiver B should go bad, because I am using S21 trace.*

*Is there any other reason by which receiver A & B can go bad?*

I need help to diagnose the reason.