Seeking Someone to Do a Ferrites Project

i have being using ferrite bead in my protoyping board sort of trial and error or best practice way and never attempted to understand its essential. definitely looking forward to an essentials article from E14. Having said that, the design kit contains various types of high current and high frequency EMI suppressing ferrite beads. Although i not sure how to deal and test with EMI, if i were to play with the ferrite beads, it would be in power supply related circuit. I would like to measure, visualize and hopefully understand the impedance change over frequency as per its theoritical charateristic. While i don't have a $30k impedance analyzer to play with, there exist low cost AD5933 based impedance analyzer module with controller board on site such as Taobao (https://www.taobao.com/list/item/673727667622.htm?spm=a21wu.10013406.taglist-content.4.38d420ae87uow2) . we can use a microcontroller / pc based I2C control to command the module to perform impedance analysis over a dc to dc converter. we can get various cheap dc-dc up converter (which has high frequency) from taobao, such as ADP5070 based module https://item.taobao.com/item.htm?spm=a230r.1.14.71.5e787b9094h5mC&id=587411536412&ns=1&abbucket=7#detail , and replace the ferrite beads on the board (they are SMD) and perform the impedance sweep over frequency. While this experiment is not geared towards circuit design, it seems highly doable on a tight budget of less than $100 and 3 weeks work

Hi Weiwei,

Nice find. I think that would work very well. The frequency range is limited, but in that range I think it would be awesome. I've wanted to build one using the AD chip for ages, but other things get in the way. Something ready-made like that sounds really neat.

I'd love for a Tiny SA ultra to find its way into my Christmas stocking LOL

https://tinysa.org/wiki/pmwiki.php?n=TinySA4.Specification 

I'd love for a Tiny SA ultra to find its way into my Christmas stocking LOL

https://tinysa.org/wiki/pmwiki.php?n=TinySA4.Specification 

Amazing what a low price that is, for that performance : ) 

I have an ancient HP8558B (cost about £500 (830 CAD) from Ebay about 8 years ago, which I really need to throw away it's not very usable. (It has sat in the shed for years as a result - and no point re-selling it, it's not a very nice thing to do to anyone!). It's performance is awful compared to that TinySA ultra, but there was not much of an option at that time.

This one's an interesting device! There are spectrum analyser PCBs versions (without display) available on banggood and maybe on AliExpress too! I guess they will be a cheaper alternative to the integrated display ones. 

That board is not the same league as the Tiny SA Ultra however. The screenshots below are from watching a few minutes of this video review. I may have got it wrong.

From those screenshots I think the resolution bandwidth cannot be directly set, and so I believe it will have no granularity either. That makes it more a "RF meter with spectrum view" at best, since there is no actual ability to analyze the spectrum to any useful level. Maybe I'm wrong though since as mentioned, I didn't watch the entire video. I think it would be better to just get the TinySA Ultra. (But I have not used that either! so this is all just speculation from me).

Low-cost SA - a great find.

I know! They are currently sold out :( Speaking of low cost instruments, here's what my nano VNA had to say.

I have some Wurth Elektronik WE-CBF SMT ferrite beads kicking around, specifically the 742792118 ( 1206 case, 70 mOhm DCR, Zmax 600 Ohms). So, lets take a peak at it with my nano VNA. I soldered the DUT to an SMA jack:

I connected the DUT to port 1 of my VNA for an S11 impedance measurement

From the datasheet we expect the quality factor to be unity at approximately 20 MHz and reach a peak impedance of 600 Ohms at 80 MHz

My nano VNA recorded a peak impedance of 560 ohms at approximately 70 MHz, close enough!

The intersection of resistance and reactance occurred at 21 MHz, close enough!

The bead is exceptionally lossy or dissipative for frequencies above 20 MHz

Great ferrite bead and not too shabby of a result for a $60 VNA lol

Cool. A Nano is also on my wish list ....