可以用N9020A频谱分析仪测量100GHz信号吗

嗨，不幸的是，N9020A分析仪没有外部混音选项。
N9030A和带选件532或544的N9010A均支持外部混音和EXM选项，但N9020A不支持外部混音。
您可以选择在N9020A上购买带有选件532或544和EXM的N9010A，或者用于带有选件EXM的N9030A。
这会改变您的分析仪的性能，但您将获得一些N9020A交易的信用。
然后，您可以购买外部混音器，以测量高达100 GHz的频率。
另一种选择不需要您购买新的分析仪，但需要外部混频器和信号源来产生LO。
主要限制是信号的带宽。
例如，让我建议将11970W作为外部混音器（http://www.home.agilent.com/en/pd-1000001194%3Aepsg%3Apro-pn-11970W/waveguide-harmonic-mixer-75-to-110
？-ghz CC = US＆安培; LC = ENG）。
以下是该用户手册的链接，该手册具有第21页的11970W规格：http：//cp.literature.agilent.com/litweb/pdf/11970-90040.pdf用户手册的第15页，
混频器的IF输出的dB带宽报告为DC至1.3 GHz。
只要您的信号在此1.3 GHz带宽内，您就不应该使用此外部混音器和N9020A进行分析。
因此IF的中心为650 MHz。
现在让我们再看一下第21页。
用于此混频器的LO谐波数为18.对于100 GHz的输入RF信号和650 MHz的IF，您需要一个LO（100 GHz - 650 MHz）/ 18 = ~5.519 GHz。
该手册还指出，输入LO功率为14.5至16.0 dBm时，将获得最佳精度。
因此，您需要一个信号源，可以产生5.52 GHz的CW音调和14.5到16.0的功率电平。
此设置的连接如下 - 您的100 GHz信号将进入混频器的RF输入（WR-10波导法兰）。
您的5.52 GHz源音将进入LO输入（SMA连接器）。
IF输出将以650 MHz为中心，从混频器（SMA连接器）到N9020A信号分析仪的RF输入。
然后，您可以使用分析仪进行基于频谱和信号的测量。
使用此配置可​​以进行所有扫描测量（如上所述，高达1.3 GHz带宽）。
根据所需的测量结果，您可能会受到N9020A中分析带宽的限制。
如果您需要I / Q数据或希望解调信号，您需要确保N9020A中的分析带宽足够宽，以满足信号带宽。
目前，N9020A可以提供高达160 MHz的分析带宽。
如果您需要在N9020A中升级带宽，以下是在线带宽升级工具的有用链接：http：//www.agilent.com/find/BW-selector此配置不需要您的分析仪的其他选项
。
请注意，您需要注意混合器和信号分析仪的测量精度。
如果您对此有任何其他疑问，请与我们联系。
最诚挚的问候，斯科特



     以下为原文

  Hi,

Unfortunately, the N9020A analyzer does not have an external mixing option. Both the N9030A and the N9010A with option 532 or 544 support external mixing with option EXM, but the N9020A does not support external mixing.

One option for you is to trade in your N9020A for an N9010A with option 532 or 544 and EXM, or for an N9030A with option EXM. This would change the performance of your analyzer, but you would receive some credit for trading in your N9020A. You could then purchase an external mixer in order to measure up to 100 GHz.

Another option would not require you to buy a new analyzer, but it would require an external mixer and a signal source to generate the LO. The main limitation is bandwidth of the signal. For example, let me suggest the 11970W as the external mixer (http://www.home.agilent.com/en/pd-1000001194%3Aepsg%3Apro-pn-11970W/waveguide-harmonic-mixer-75-to-110-ghz?cc=US&lc=eng). Here is a link to the user manual, which has specifications for the 11970W on page 21: http://cp.literature.agilent.com/litweb/pdf/11970-90040.pdf

On page 15 of the user manual, the 3 dB bandwidth of the IF output from the mixer is reported as DC to 1.3 GHz. As long as your signal is within this 1.3 GHz bandwidth, you should not have any problems analyzing it with this external mixer and your N9020A. The center of the IF is therefore at 650 MHz.

Now let's look at page 21 again. The LO harmonic number used for this mixer is 18. For an input RF signal at 100 GHz and an IF of 650 MHz, you would need an LO at (100 GHz - 650 MHz) / 18 = ~5.519 GHz. The manual also states that the best accuracy will occur for an input LO power of 14.5 to 16.0 dBm. Therefore, you would need a signal source that can produce a CW tone at 5.52 GHz and power level of 14.5 to 16.0. 

The connections for this setup would be as follows- your 100 GHz signal would go into the RF input of the mixer (a WR-10 waveguide flange). Your 5.52 GHz source tone would go into the LO input (SMA connector). The IF output would be centered at 650 MHz and would go from the mixer (SMA connector) to the RF input of your N9020A signal analyzer. You would then be able to make spectrum- and signal-based measurements with your analyzer. All swept measurements would be possible with this configuration (up to 1.3 GHz bandwidth as I mentioned).

Depending upon the measurements required, you may be limited by the analysis bandwidth in your N9020A. If you need I/Q data or wish to demodulate your signal, you will need to ensure that the analysis bandwidth in your N9020A is wide enough for the bandwidth of your signal. Currently, you can have up to 160 MHz of analysis bandwidth in the N9020A. If you need to upgrade your bandwidth in the N9020A, here is a useful link to the online bandwidth upgrade tool: http://www.agilent.com/find/BW-selector

No other options for your analyzer would be required with this configuration. Note that you will need to pay attention to the measurement accuracy of both the mixer and the signal analyzer for this measurement.

Please let me know if you have any additional questions about any of this.

Best Regards,
Scott

嗨再次，关于我上面提出的外部混音配置还有一个评论。
请注意，11970W的转换损耗约为40 dB。
这可能会显着限制测量的动态范围。
因此，在信号到达N9020A之前（在混频器的IF输出和信号分析仪的RF输入之间的路径中），您可能需要一个外部放大器来提高信噪比。
最诚挚的问候，斯科特



     以下为原文

  Hi again,

One more comment to make about the external mixing configuration that I proposed above.

Note that the conversion loss of the 11970W is around 40 dB. This could limit the dynamic range of your measurement significantly. You may therefore need an external amplifier to improve your signal-to-noise ratio before the signal reaches the N9020A (in the path between the IF output of the mixer and the RF input of the signal analyzer).

Best Regards,
Scott

嗨斯科特，非常感谢你的回复。
如果我有任何其他问题，我会通过手册并告诉您。



     以下为原文

  Hi Scott,

Thank you very much for the reply. I will go through the manual and will let you know if I have any other questions.