完善资料让更多小伙伴认识你,还能领取20积分哦, 立即完善>
我很想知道VNA的噪声系数。
我们以E5071B为例。 据我所知,前端由输入端口和定向耦合器组成,然后是接收器。 我认为接收器的第一级是宽带混频器。 我不知道定向耦合器的耦合系数是多少,但我认为它是一种较低的损耗类型,如10 dB或更小,以获得最佳的方向性。 因此,我估计噪声系数是10 dB加上接收机噪声系数的总和,比如说,另外10 dB,总共20 dB。 捏造一些额外的损失,可能是25分贝。 有没有人有更好的主意? 罗恩 以上来自于谷歌翻译 以下为原文 I'm interested in knowing the noise figure of a VNA. Let's use the the E5071B as an example. I understand that the front end consists of the input port followed by a directional coupler and then to a receiver. I presume the receiver first stage is a broadband mixer. I don't know what the coupling coefficient of the directional coupler is, but I presume it is a lower loss type, like 10 dB or less, for best directivity. So, I would estimate the noise figure to be the sum of 10 dB plus the receiver noise figure of, let's say, another 10 dB for a total of 20 dB. Fudge in some additional losses and it might be 25 dB. Does anyone out there have a better idea? Ron |
|
相关推荐
6个回答
|
|
我不知道你的VNA,但看一下这个帖子:非主题,但是这里有一个很好的论坛来测量噪声系数问题吗?
Dr_joel告诉我如何计算8720D的NF。 *至于8720:易于计算NF:* *动态范围在10 Hz IF BW中约为100 dB或在1 Hz当量中为110。 kTB = 174,因此174-110 =噪声系数= 64 dB *。 令人惊讶的是,在8720D的情况下,NF有多高,但毫无疑问,你有一个非常不同的VNA,事情可能会有很大不同。 很明显,一些VNA能够进行噪声系数测量,如果VNA的噪声系数高于器件的增益,这是不可能的。 我会对一些安捷伦员工的反应感兴趣,因为我对这个主题感兴趣。 戴夫 编辑:drkirkby于2012年10月6日下午6:07 以上来自于谷歌翻译 以下为原文 I don't know your VNA, but take a look at this thread: Off-topic, but is there a good forum here for noise figure meter questions? where Dr_joel told me how to calculate the NF of my 8720D. *As to 8720: easy to compute NF:* *Dynamic range is about 100 dB in 10 Hz IF BW or 110 in 1Hz equiv. kTB=174, so 174-110=noise figure=64 dB*. I was amazed how high the NF was in the case of the 8720D, but no doubt you have a very different VNA, and things might be quite different. It's clear some VNAs are capable of noise figure measurements, which would not be possible if the noise figure of the VNA was higher than the gain of the device. I'll be interested in what response you get from some of the Agilent staff, as I have some interest in this topic. Dave Edited by: drkirkby on Oct 6, 2012 6:07 PM |
|
|
|
> {quote:title = Dr_joel写道:} {quote}>对噪声系数的两个主要影响是:接收器类型和耦合因子。
>>有三种或四种常见接收器类型,最差到最佳:> 1)基于采样器:非常高的噪声系数 - 8753和8720使用采样器工作在VCO的200至300次谐波> 2)高次谐波混频器(或 低谐波采样器) - 许多毫米波系统使用它; 谐波操作高达10或12或更多> 3)低谐波混频器 - PNA在26.5GHz以上的分析仪中使用三次谐波混频,PNA-L在13 GHz以上使用它,我认为。 > 4)基本混合 - 噪声系数最低。 >>耦合因子范围从50 dB(在微波耦合器的低端,接近10 MHz)到12 dB(在高端)> 8753使用16 dB,ENA类似但具有更接近的高功率版本 到20 dB。 >>将耦合系数添加到分析仪的噪声系数中,您就得到了整体噪声系数。 Fieldfox N9923A使用什么样的接收器? 由于电池耗尽和尺寸,我预计会有相当多的妥协。 以上来自于谷歌翻译 以下为原文 > {quote:title=Dr_joel wrote:}{quote} > Two principal impacts on noise figure are: receiver type and coupling factor. > > There are three or four common receiver types, for worst to best: > > 1) Sampler based: very high noise figure - 8753 and 8720 use samplers operating on 200th to 300th harmonic of the VCO > 2) High harmonic mixer (or low harmonic samplers) - many mm-wave systems use this; operation on harmonics up to 10 or 12 or more > 3) Low harmonic mixer - PNA uses third harmonic mixing in analyzers above 26.5GHz, PNA-L uses it above 13 GHz, I think. > 4) Fundamental mixing - Lowest noise figure. > > The coupling factor ranges from 50 dB (at the low end of the microwave couplers, near 10 MHz) to 12 dB (at the high end) > 8753 uses 16 dB, ENA is similar but has a high power version that is closer to 20 dB. > > Add the coupling factor to the noise figure of the analyzer and you have the overall noise figure. What sort of receiver does the Fieldfox N9923A use? I expect there has to be quite a few compromises on that due to battery drain and size. |
|
|
|
60user7 发表于 2019-3-25 08:21 从根本上说是混合的。 以上来自于谷歌翻译 以下为原文 Fundamentally mixed. |
|
|
|
E5071B使用什么接收器类型?
这种类型的噪声系数大致是什么? 以上来自于谷歌翻译 以下为原文 What receiver type is used in the E5071B? What would the noise figure of this type be, roughly? |
|
|
|
我相信它是基于混音器的。 我猜它在40 dB范围内,包括耦合器效应。 以上来自于谷歌翻译 以下为原文 I believe it is mixer based. I would guess it is in the 40 dB range including coupler effects. |
|
|
|
对不起,我的帖子在这里。 这是在另一个VNA论坛(关于编程)的意思。 我不知道怎么回复它导致这个消息出现在这个线程下DaveEdited:drkirkby于2012年10月11日下午2:14 以上来自于谷歌翻译 以下为原文 Sorry for the post of mine here. It was mean to be in another VNA forum (about programming). I've no idea how replying to it there caused the messsage to appear under this thread Dave Edited by: drkirkby on Oct 11, 2012 2:14 PM |
|
|
|
只有小组成员才能发言,加入小组>>
1285 浏览 0 评论
2373 浏览 1 评论
2192 浏览 1 评论
2064 浏览 5 评论
2948 浏览 3 评论
1108浏览 1评论
关于Keysight x1149 Boundary Scan Analyzer
752浏览 0评论
N5230C用“CALC:MARK:BWID?”获取Bwid,Cent,Q,Loss失败,请问大佬们怎么解决呀
924浏览 0评论
1287浏览 0评论
小黑屋| 手机版| Archiver| 电子发烧友 ( 湘ICP备2023018690号 )
GMT+8, 2024-12-23 12:49 , Processed in 1.398269 second(s), Total 55, Slave 49 queries .
Powered by 电子发烧友网
© 2015 bbs.elecfans.com
关注我们的微信
下载发烧友APP
电子发烧友观察
版权所有 © 湖南华秋数字科技有限公司
电子发烧友 (电路图) 湘公网安备 43011202000918 号 电信与信息服务业务经营许可证:合字B2-20210191 工商网监 湘ICP备2023018690号