Calculate the max. range of an GHZ Signal? + Directional GHZ Antenna? - Page 1
Forum section: electronics / rf-microwave

author: Lord of nothing
author_rank: Super Contributor
timestamp: May 02, 2025, 11:10:45 pm
content: Hia) Is there some Calculator where I can put in an Frequency and the calculate the best, longest possible range of an Signal?Like calculate when there is fog in the Air and use the best Antenna for that Frequency.b) For an Signal in the "lower" GHZ Range let say 1Ghz - 3Ghz what kind of Antenna give the best reception result?Can a Uda Yagi Atenna at that Freq even work? I see a lot of Dish Antenna Types in use also Flat Pannel Antenna.Thanks!

author: geggi1
author_rank: Frequent Contributor
timestamp: May 03, 2025, 07:25:54 am
content: radiomobile

author: tggzzz
author_rank: Super Contributor
timestamp: May 03, 2025, 09:06:59 am
content: You can find free space path loss calculators online, but the answer to your question requires more than that.For a start you would need to specify the signal bandwidth and modulation type, and acceptable error rate.Then you would have to take into account the actual path in terms of Fresnel and multipath reflections. Either you would have to make measurements, or the result would be statistical.

author: Lord of nothing
author_rank: Super Contributor
timestamp: May 03, 2025, 11:18:29 am
content: Can someone recommend one?The point is I have an crazy idea and would like try some calculator if it is even possible to get a signal or not before I buy equitment.

author: tggzzz
author_rank: Super Contributor
timestamp: May 03, 2025, 11:57:18 am
content: Quote from: Lord of nothing on May 03, 2025, 11:18:29 amSure; there's a selectionhere.

author: joeqsmith
author_rank: Super Contributor
timestamp: May 03, 2025, 02:51:06 pm
content: I take it that you are wanting to do something where there isn't a commercial solution available. I have a friend who lives out where there is no internet service. They pay the nearest home that has service to allow them to run a relay. From there, they run a small wireless network to the neighbors. The neighbors pay a small fee that paid for the equipment plus the first home's service. I am not sure what that distance is but everything is commercial equipment.https://www.mathworks.com/help/radar/ug/modeling-the-propagation-of-rf-signals.html

author: radiolistener
author_rank: Super Contributor
timestamp: May 04, 2025, 10:22:23 pm
content: Quote from: Lord of nothing on May 02, 2025, 11:10:45 pmhttps://www.pasternack.com/t-calculator-fspl.aspxthe missing part in your question is envrionment noise floor at selected frequency and bandwidth, receiver sensitvity and transmitter power.

author: alex843
author_rank: Contributor
timestamp: May 05, 2025, 08:11:21 am
content: Quote from: Lord of nothing on May 02, 2025, 11:10:45 pmIt is a little bit difficult to give an answer when we don't know the application or the type of application.- will the antenna be pointed into space, or will it be mounted on a tower on a high hill top?- are tropical storms going to be an issue, or are you going to have to deal with ice on the antenna?- how reliable does it need to be, is 99% availability enough, or do you need some sort of carrier grade 'five nines' availability.Long ago I was working with 1.5Ghz (L-band) rural radio systems and we mostly used Yagi antennas and sometimes a corner reflector design. The advantage of the Yagi was that you had decent gain, a reasonably low wind loading, and you could get them with a shroud to help stop the ice from forming on the antenna elements in the colder parts of the country.Parabolic dish antennas are great, but you might need to spend a lot of money on a strong tower and the antenna mounting system, to keep them from flying away in high winds, or damaging the tower they are mounted on. Of course in the lower GHz bands you don't need a solid dish, some sort of grid or mesh design can work and that reduces the wind loading.I'm assuming one antenna at each end of the path. Depending on the application and budget, you might be able to use some sort ofSpace diversityorMIMOsystem.But if you want to keep it simple, I'd probably try and see if I could make the numbers work with Yagi antennas at each end of the path.For a satellite system where you can probably mount the antenna on a study base located close to ground level, a parabolic dish might be worth considering.

author: timeandfrequency
author_rank: Frequent Contributor
timestamp: May 05, 2025, 10:18:01 am
content: Hello Lord of nothing,There's no easy answer to that question.A basic free (far) field attenuation in vacuum approximation formula is :Atten (dB) = 22 + 20 log(d/l)d = distance in metersl = wavelenght in metersSeems odd but give a good ballpark.As other members underscored, to calculate the effective range, many other parameters like TR power, TR antenna gain, RC sensitivity and noise figure, RC antenna gain, type of modulation, effective bandwidth, performance of the error correction algorythms (in case of digital data stream) have strong influence and must be considered.Rain/fog affects the free field attenuation and also lowersantenna performance[select the english translation on the right, if required].This additional attenuation depends onlink frequency, wave polarization, ...Up to15 dB additional attenuation @ 12.5 GHzfor a geostationary satellite.

author: alex843
author_rank: Contributor
timestamp: May 05, 2025, 10:39:26 am
content: Quote from: Lord of nothing on May 02, 2025, 11:10:45 pmForgot to answer this part, don't worry about rain fade or fog fade, or even tropical downpour if you are limiting yourself to 1Ghz - 3Ghz.This is going to be almost zero.Full paper here:Rain Effects on 5G millimeter Wave ad-hoc Mesh Networks Investigated with Different Rain ModelsMarch 2016 : Periodica Polytechnica Electrical Engineering and Computer ScienceÁkos Faragó1, Péter Kántor1, János Z. Bitó1https://www.researchgate.net/publication/301555825_Rain_Effects_on_5G_millimeter_Wave_ad-hoc_Mesh_Networks_Investigated_with_Different_Rain_Models

author: A.Z.
author_rank: Super Contributor
timestamp: May 05, 2025, 11:26:32 am
content: not just weather but height, distance, obstacles and btwat BOTH ends, not just at one

author: tggzzz
author_rank: Super Contributor
timestamp: May 05, 2025, 09:05:11 pm
content: Quote from: Lord of nothing on May 05, 2025, 12:06:05 pmWhat is it you want us to see in that video?Be aware that if you have a maximum legal power ISM band transmitter and you put an XdB directional antenna on it, then to remain legal you mustreducethe transmit power by XdB.No such restriction applies at the receiver.

author: rf-fil
author_rank: Regular Contributor
timestamp: May 07, 2025, 02:23:50 am
content: Radio Mobileis the actual answer. You need to have a call sign. Once in there, you will need to input all your system parameters and it'll give you a coverage map. If you don't know your system parameters (e.g. the required signal strength in uV), you can't calculate the coverage map.Btw, "range" = distance in one specific direction in the coverage map.In the real world, the terrain matters a lot. The free range formulas etc that other supplied don't work unless at least one of the radios is in the air or in space.Finally, if you are asking this type of question, the best choice is to pick one of the many existing systems. Don't try to design your own one, unless it's for self-education.