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Max allowed output power for 0.7GHz

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vozel

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Hi

I would like to know what is the max alowed output power for the frequency of 0.7GHz( band 12) . I was looking for that information but have been unable to find it.

For exemple,
I found the max alowed output power for the ISM band on this website:
https://www.rcgroups.com/forums/sho...transmit-power-limits-on-915MHz-5-8GHz-2-4GHz

I am looking for the limit and similar rules like (1,2,3 from the website) but for the frequency of 0.7GHz (band 12). Where could I find it ?

Thank you!
 

Re: max alowed output power for 0.7GHz

There's no ISM band at 0.7 GHz. The frequency is assigned to a number of public and private radio services.

What application do you intend?
 

Re: max alowed output power for 0.7GHz

I already know that 0.7GHz is not ISM band. Is there a limit in that case? I will need to find the max for my cellphone project.
 

Re: max alowed output power for 0.7GHz

As for the FCC region, 700 - 800 MHz doesn't provide frequencies for cell phone operation. Refer to the frequency plan in 47 CFR Ch. 2 and the respective detail regulations listed therein, particularly Ch. 22
 

Re: max alowed output power for 0.7GHz

I already know that 0.7GHz is not ISM band. Is there a limit in that case? I will need to find the max for my cellphone project.

Depends on the country which you're living in..Some countries allow to transmit upto 100-200mW Output Power at that frequency.
But most of them have reserved 700MHz for TV Broadcasting and LTE.
 

Re: max alowed output power for 0.7GHz

Depends on the country which you're living in..Some countries allow to transmit upto 100-200mW Output Power at that frequency.
But most of them have reserved 700MHz for TV Broadcasting and LTE.

What is the maximum in USA, reserved for LTE ? and where can we find that information?
 

Re: max allowed output power for 0.7GHz

FCC part 15 tells you the allowed power level output at 700 MHz. It is pretty low.

You would have to operate with this in mind:
"If a Part 15 transmitter does cause interference to authorized radio communications,
even if the transmitter complies with all of the technical standards and equipment
authorization requirements in the FCC rules, then its operator will be required to cease
operation, at least until the interference problem is corrected
"


FCC limits.JPG

there is other fine print to read.

https://transition.fcc.gov/bureaus/oet/info/documents/bulletins/oet63/oet63rev.pdf

of course, this ONLY applies in the USA.
 

Re: max allowed output power for 0.7GHz

According to FCC frequency plan, GSM-710 band (LTE 12) is not available in the US. Respectively there's no admitted power level for intentional radiation.
 

Re: max allowed output power for 0.7GHz

FCC part 15 tells you the allowed power level output at 700 MHz. It is pretty low.

You would have to operate with this in mind:
"If a Part 15 transmitter does cause interference to authorized radio communications,
even if the transmitter complies with all of the technical standards and equipment
authorization requirements in the FCC rules, then its operator will be required to cease
operation, at least until the interference problem is corrected
"


View attachment 143024

there is other fine print to read.

https://transition.fcc.gov/bureaus/oet/info/documents/bulletins/oet63/oet63rev.pdf

of course, this ONLY applies in the USA.

How do we convert those values in dBm ? I am asking because I need the value right at the output of the antenna and not 3m away.
Like in this website for the ism band
https://www.rcgroups.com/forums/sho...transmit-power-limits-on-915MHz-5-8GHz-2-4GHz
they give the value in dBm for right after the antenna. how do we make the conversion for that ?
 
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Re: max allowed output power for 0.7GHz

5 mV/m @ 3m translates to 5 µW with dipole gain (2.1 dBi).

Either refer to your RF text book or use a tool like R&S Field Strength and Power Estimator.
 

Re: max allowed output power for 0.7GHz

5 mV/m @ 3m translates to 5 µW with dipole gain (2.1 dBi).

Either refer to your RF text book or use a tool like R&S Field Strength and Power Estimator.


Could you tell me how did you get those values of 5 µW with dipole gain (2.1 dBi) for 5 mV/m @ 3m?
Is it possible to use this website to get those values instead of the Field Strength and Power Estimator since I don't have acces to it.
https://www.giangrandi.ch/electronics/anttool/tx-field.shtml

but the problem is that when I enter the value of 5 mV/m, I don't get the 5 µW like you . How did you associate that value with 2.1 dBi. I can't find that in my rf text book . Do you know where I could? Also, it's still not the power value in dBm which I was looking for exactly .

Thank you
 


but the problem is that when I enter the value of 5 mV/m, I don't get the 5 µW like you . How did you associate that value with 2.1 dBi. I can't find that in my rf text book . Do you know where I could?

Dipole gain (2.1 dBi) is a standard assumption because it fits best the antenna situation of most field strength calculation setups. B.t.w. I get the same 5 µW result using the linked tool

Fieldstrength.png

Also, it's still not the power value in dBm which I was looking for exactly.
I assumed yo far that you're aware of the relation between dBm and µW, very elementary RF knowledge. Consider that 1 mW equals 0 dBm. https://en.wikipedia.org/wiki/DBm

Regarding ETSI TS136101, my understanding is that the said 700 MHz band is available in Europe but not in the US. I didn't check latest FCC documents for possible updates.
 

Re: max allowed output power for 0.7GHz

According to FCC frequency plan, GSM-710 band (LTE 12) is not available in the US. Respectively there's no admitted power level for intentional radiation.

there maybe be specific keep-out frequencies in addition to that table i posted. The OP should check further!!!!

but if there are no specific discrete frequencies prohibited, that table DOES allow transmit if the power level is low enough.
 
Last edited:

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