Cost Effective, Field Intensity Meter for 5G Network

Does anyone have a cost-effective solution for an EM field intensity meter that will extend into the 5G spectrum.

Something with microwatt sensitivity that could be hung off a DMM and cover the 5GHz and 50GHz range?

The application is general sniffing, with a relative or non-calibrated readout.

Robert Martin

Reply to
Robert Martin
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Get a 5G cell phone, and a mesh bag that blocks ~x % of the signal. (x near 20-30% is ideal) Turn on phone, record signal. Put phone in bag, record signal. Put phone/ bag into another bag, record signal. Repeat till signal goes away, plot data.

Do the same thing at the next location.

George H.

Reply to
George Herold

Whats wrong with a half-turn coil(thick wire,silver coated ) , a fast Schottky diode and a small cap, wired to a cheap multymeter?

Reply to
Sjouke Burry

Where do you get a 50GHz Schottky? Or a loop of wire small enough?

Reply to
Clifford Heath

Why dont you try it and see what happens? That half the fun of electronics.

Reply to
Sjouke Burry

Which 5G spectrum and in what country? I would guess that you're in the UK. Hmmm... looks like no UK frequencies are listed. Sigh.

"5G Frequencies in the UK" Not very useful since is probably 2 years old.

Looks like 3.4GHz will be used.

2.3GHz will also be used, but is for 4G, not 5G. Terrible article but this is becoming rather boring. So could you kindly do some homework and determine what frequencies will be in use in your (UK?) area? Meanwhile, I'll work with 3.4GHz.

Cover as in tunable or 5-50GHz in one gulp? A 3.5 octave bandwidth meter is useless. Without an indication of what frequencies the meter is measuring, you could easily be measuring a nearby microwave point to point link, instead of a 5G base station. You're going to need some tuning. If so, how do you want the tuning to work.

There are cheap and portable spectrum analyzers that cover the 3.4GHz spectrum. Currently, they're made for the Wi-Fi 2.4 and 5GHz band, but could be adjusted or modified to receive 3.4GHz. At least you'll be able to see what you're measuring. Something like this:

In the bad old days before SDR, I would simply connect a dish antenna, cavity band pass filter(BPF), RF amplifier, diode detector, and DC amplifier in series. I would then swing the dish around looking for the source of the signals. Crude, amazingly accurate once calibrated, and useless in an RF polluted environment. When I needed to see what I was doing, but my spectrum analyzer maxed out at 1.2GHz, I would add a mixer and some signal source as a local oscillator, to downconvert the signal into the range of the spectrum analyzer. Today, I would probably use an SDR instead of the spectrum analyzer. Incidentally, I still have and use some HP Nixie tube counters that use various plugins to downconvert frequencies so that they fit in the 1-50MHz counter bandwidth.

Anyway, I don't have enough info to recommend anything in the way of a working instrument. You haven't described accurately what you expect to view, what you have to work with, what output you expect, how you expect to operate it, what manner of accuracy you need, what RF environment would you expect it to work, etc. Take a few steps backwards, generate some preliminary numbers, and try again.

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
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Reply to
Jeff Liebermann

That only measures intensity of the narrow band of frequencies used by that phone.

I am interested in a wider slice of the 5G spectrum (5GHz to 50GHz) as emitted by all devices within a particular radius.

There is soon going to be a demand for such an instrument that does not cost a fortune. Maybe one of the electronics magazines could commission its design as a DIY project. A front end for a DMM.

Robert Martin

Reply to
Robert Martin

What are you trying to measure ? The total biological doze to humans or the suitability of certain locations for cellular reception ?

My guess for the millimeter bands is that the cellular phone will have to use some MIMO style dynamic beam forming to create beams towards the best reflection. A single dipole will have a very small capture area in the mm-band. Using multiple dipoles will increase the capture area, but creates directivity. The beam must then be dynamically steered.

A single omnidirectional antenna element does not tell much about suitability for cellular reception.

Reply to
upsidedown

A satellite finder behind a suitable LNB/converter. Of course coverage of 50GHz is out of reach for the moment.

Reply to
bilou

Yes, but I would need one for each band. Never seen a multi-band unit. Has anyone?

Robert Martin

Reply to
Robert Martin

Good point. But there is going to be a lot of splatter. Will probably outlaw metal belt buckles.

Not looking to identify single sources. Just net ambient background interference, and non-calibrated. A sniffer.

Robert Martin

Reply to
Robert Martin

Enhance/modify this?

No mention of its frequency range tho & judging by the simplicity probably fairly limited...

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Cheers, 

Chris.
Reply to
Chris

Interesting kit and construction style. But strange no specs are given.

Robert Martin

Reply to
Robert Martin

Not going to work terribly well, because a cell phone will do an arbitrary number of bursts in the test interval. Might be OK if you do peak-capture, but the statistical meaning of a peak is ... open to interpretation. Real-time averaging might take a LONG time before giving a meaningful indication.

Reply to
whit3rd

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