5G Frequency Range Extender for Electromagnetic Field Meters

Thread Starter

Sir Kit

Joined Feb 29, 2012
21
As the 5G cell phone network moves higher up the frequency spectrum, a lot of previously useful EMF meters are being rendered obsolete. Dedicated 5G meters, say up to 25GHz, are as yet few in number and relatively expensive.

Is there any way to extend the frequency range of a 3GHz meter to read over 10GHz. For example, by fitting a module inline between the meter and a suitable antenna? Even if this affects accuracy and calibration, it would still be of some use to those of us waiting for an affordable 5G meter.

If there is no off-the-shelf solution, what would be the design approach of building such an extender?
 

Papabravo

Joined Feb 24, 2006
12,559
As the frequency range goes up the expense of design, fabrication, and testing go up as well. There is very little hope for you to do anything on the cheap. Best idea is to save up fro what you need.
 

shortbus

Joined Sep 30, 2009
7,091
So, my question is, once you can measure the EMF what will you do about it? To my limited knowledge other than living in a Faraday cage designed for that particular frequency there is no way to avoid EMF.
 

Janis59

Joined Aug 21, 2017
819
I had a client who want me to design such apparatus. My idea was to use two identical 1/100C 18 bit digital thermometry IC to ARM, where one measures ampule with polar solvent and another measures identical weight ampule with non-polar solvent. But the price even I draw a very low, was hitting him off, so the project is still opened. But I wonder if any is already fabricated readymade now. By the way, this principle allows to catch another ghost-field - the airport radars, having a terawatts and petawatts, but for so short as below the femtoseconds and once a many seconds interval until next such peak. Therefore "normal" field measurers never see it.
 

nsaspook

Joined Aug 27, 2009
6,506
As the 5G cell phone network moves higher up the frequency spectrum, a lot of previously useful EMF meters are being rendered obsolete. Dedicated 5G meters, say up to 25GHz, are as yet few in number and relatively expensive.

Is there any way to extend the frequency range of a 3GHz meter to read over 10GHz. For example, by fitting a module inline between the meter and a suitable antenna? Even if this affects accuracy and calibration, it would still be of some use to those of us waiting for an affordable 5G meter.

If there is no off-the-shelf solution, what would be the design approach of building such an extender?
You could use a few Mini-Circuits modules to make a down-converter if you don't want to build.
https://www.minicircuits.com/WebStore/Mixers.html
https://www.minicircuits.com/app/AN00-010.pdf
 

Papabravo

Joined Feb 24, 2006
12,559
The TS said that the ones he is interested in are relatively expensive. There is a reason for that, as most of us know. If there is a cheap way to do then monkeys will...oh never mind. Rock on Wayne. Rock on Garth.
 
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Thread Starter

Sir Kit

Joined Feb 29, 2012
21
The TS said that the ones he is interested in are relatively expensive. There is a reason for that, as most of us know. If there is a cheap way to do then monkeys will...oh never mind. Rock on Wayne. Rock on Garth.
So then, maybe we have to wait for someone to design and market a 5G meter for "non-professional" use. I suppose it will happen. There are currently dozens of such affordable products that work up to 3 or 6GHz. Basically just sensors with some type of quantitative display.

Any additional ideas for the interim for reading EMF's between 8 and 25 GHz would be very much appreciated.
 

Papabravo

Joined Feb 24, 2006
12,559
I understand your frustration, but you might be waiting a very long time before such a device can be cost reduced to the point you will find it affordable. To get some idea of the magnitude of the problem look at prices for a spectrum analyzer. Compare one with a max frequency of 1 GHz, 3 GHz., 10 GHz, 25 GHz. and notice the highly non-linear increases in price. admittedly you are not looking for a spectrum analyzer, but it is the RF front end that contains the cost, not the display and and the case. There just is no comparison in complexity between the 3 GHz. unit and the 25 GHz. unit. Just for fun jot down the wavelength of a 3 GHz. signal and a 25 GHz. signal.
λ@3GHz = 0.1 M or about 3.937 inches
λ@25GHz = 0.12 M or about 0.472 inches.
So what does that mean? It means that any trace longer than a quarter of an inch is an antenna that will radiate RF energy like a fire hose moves water and further is susceptible to all manner of incoming RF. So designing a PC board that actually works is no small task. Most of us probably lack the CAD resources to simulate and model such a circuit, let alone construct it, test it, and manufacture it. There are hams out there who thrive on this stuff (not me however), who might be able to help if you can make a connection.
 

Thread Starter

Sir Kit

Joined Feb 29, 2012
21
I understand your frustration, but you might be waiting a very long time before such a device can be cost reduced to the point you will find it affordable.
The first intrepid soul to produce an affordable 5G meter is obviously going to make a bucket of money. Any takers? There are radar receivers that operate in the same band.

BTW how about twisted PCB tracks? We need those too ;-)
 

shortbus

Joined Sep 30, 2009
7,091
The first intrepid soul to produce an affordable 5G meter is obviously going to make a bucket of money. Any takers? There are radar receivers that operate in the same band.

BTW how about twisted PCB tracks? We need those too ;-)
Again I ask, what use is the detection? What will you or anyone do with the information it detects? You're never going to get them to stop using 5G, they are probably at work right now on 6G.
 

Thread Starter

Sir Kit

Joined Feb 29, 2012
21
I never said anything about stopping 5G. However, if someone wanted to limit their exposure as a precaution , than a detector would certainly be of some use.
 

shortbus

Joined Sep 30, 2009
7,091
I never said anything about stopping 5G. However, if someone wanted to limit their exposure as a precaution , than a detector would certainly be of some use.
Again how? Your exposure or anyone's exposure is only limited by the use of the 5G. How does knowing the amount of 5G in the area, which is everywhere that there is cell phone service help the person with the detector? It would be like keeping a Geiger counter on you when in reality there is radiation every where on Earth, knowing the strength doesn't make it go away.

I guess my point is where there is 5G you will be exposed to 5G, no way of "limiting" the exposure, other than going where it isn't available. If you are talking about near exposure from your own phone that is on you, nothing in this world makes you have a 5G phone.
 
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