E4407B的参考电平怎么设置

Sgpars，在测量谐波时，有许多因素会影响测量。
具体而言，发生器的输出信号电平与输入混频器电平有关。
在较低的频率（-50 dBc，然后您将使用较窄的跨度技术来减少B / W滤波器，从而降低噪声基底的性能。



以下为原文

Sgpars,

When measuring harmonics there are many factors that can affect measurement. Specifically the output signal level of the generator in relationship to the input mixer level. On lower frequencies( -50 dBc, then you would use your technique of narrower spans to reduce the B/W filter, in which reduces your noise floor performance.

Dave

嗨 - 即使您将分析仪范围设置为仅查看1 GHz的基本信号，分析仪RF输入端的所有信号都将进入第一个混频器。
当您查看三次谐波功率电平时，您对输入衰减器的说法发生了变化，这让我想到了安捷伦科技应用笔记150中概述的输入衰减器测试，其中指出我们可以使用简单的测试来确定显示的失真分量是真输入信号还是内部
生成的信号。
更改输入衰减器。
如果失真分量的显示值保持不变，则分量是输入信号的一部分。
如果显示的值发生变化，则失真分量在内部生成，或者是外部和内部生成信号的总和。
我们继续更换衰减器，直到显示的失真没有改变，然后完成测量。
此外，值得注意的是参考电平和输入衰减之间的自动耦合。
当您更改其中一个参数时，请观察其他参数的耦合。
输入衰减器控制将在第一混频器处出现的功率量。
问候 -



以下为原文

Hi -

Even though you have the analyzer span set to only view the fundamental signal at 1 GHz, all signals present at the analyzer’s RF input are going to the first mixer. Your statement about the input attenuator changes when viewing the 3rd harmonic power level made me think of the input attenuator test outlined in Agilent Technologies application note 150 where it states we can use a simple test to determine whether displayed distortion components are true input signals or internally generated signals. Change the input attenuator. If the displayed value of the distortion components remains the same, the components are part of the input signal. If the displayed value changes, the distortion components are generated internally or are the sum of external and internally generated signals. We continue changing the attenuator until the displayed distortion does not change and then complete the measurement. Also, worth noting is the auto coupling between the reference level and the input attenuation. As you change one of the parameters watch the coupling of the other parameter. The input attenuator is controlling the amount of power that is going to be present at the first mixer.

Regards -