Iphone Antenna Design

Thread Starter

Bookishhh

Joined May 26, 2022
5
Greetings.

Is anyone here a mobile phone antenna aficionado by chance?

I have a problem I'm hoping you can help me solve. I want to buy the iphone that would give me the best chance to be able to send sms and make calls in my house.

I've just moved to a remote town New Zealand, where the cell reception is patchy enough to make a single sms send 20+ times (spammed into the receivers inbox). This is not the best way to communicate with potential employers.

I could look at modifying the perpetrating phone, but it's time for me to upgrade it. This time around I'd like to go with an iPhone.

4G LTE Band 28 (700mhz) is the strongest signal present here.

Could anyone tell me which 'newish' iphone has the best antenna for such a situation? I've been trying to educate myself on the subject, to make an informed choice myself, but antennas, this is a complex subject, and quite the rabbit hole.

I don't need 5g capability, not worried about speed. Just keen on getting a stable connection and to be able to make calls and send messages in every part of the room, and not just in the corner if I hold a metal chopstick in one hand, and hold the other 'just so'.

Regards and thanks.
Bookishhh
 

bassbindevil

Joined Jan 23, 2014
463
There are cellphone boosters where you mount a fixed antenna on the roof and it retransmits to your phone. Search for "cell phone signal booster". Or, what I did when I lived in a valley with poor coverage was to keep my phone in a spot that got a reliable signal, and use a Bluetooth-to-landline adapter so I could receive mobile phone calls on a landline cordless phone.
 

Thread Starter

Bookishhh

Joined May 26, 2022
5
There are cellphone boosters where you mount a fixed antenna on the roof and it retransmits to your phone. Search for "cell phone signal booster". Or, what I did when I lived in a valley with poor coverage was to keep my phone in a spot that got a reliable signal, and use a Bluetooth-to-landline adapter so I could receive mobile phone calls on a landline cordless phone.
Thanks for your response. I'm trying to 'sort it out' without resorting to such things, by simply buying a better antenna phone. The signal is here, it's just borderline.

If I can't do this, ill try this design first I think. The Rf repeaters cost almost 2k here.

https://www.instructables.com/DIY-2G3G4G-Wireless-Cell-Phone-Signal-Booster/?amp_page=true
 

Thread Starter

Bookishhh

Joined May 26, 2022
5
And I was thinking I could maybe even place the outside part of this antenna into the center of the satellite dish on the roof...
 

Ya’akov

Joined Jan 27, 2019
6,046
Welcome to AAC.

That method is known as a passive repeater and it would be much more effective using a direction antenna outside. There are antennas designed to cover the mobile bands, from 700MHz to 2.7GHz. They are not terrible expensive and will do much better than anything you will be able to build. Unless you have a network analyzer to determine that your antenna is resonant, you are unlikely to make it so, and that is critical

This is an example of such an antenna. I include it only as an example, you can find it, or something else, that is available locally.

1653646289661.png 1653646555136.png
On the other end you will want an omnidirectional antenna, like this one. Again an example only. You should use the largest diameter, shortest coaxial cable oyu can mange to connect them. If the cable is more than a few meters, and not very low loss, almost all the power will be lost heating it up.
 

Thread Starter

Bookishhh

Joined May 26, 2022
5
Welcome to AAC.

That method is known as a passive repeater and it would be much more effective using a direction antenna outside. There are antennas designed to cover the mobile bands, from 700MHz to 2.7GHz. They are not terrible expensive and will do much better than anything you will be able to build. Unless you have a network analyzer to determine that your antenna is resonant, you are unlikely to make it so, and that is critical

This is an example of such an antenna. I include it only as an example, you can find it, or something else, that is available locally.

On the other end you will want an omnidirectional antenna, like this one. Again an example only. You should use the largest diameter, shortest coaxial cable oyu can mange to connect them. If the cable is more than a few meters, and not very low loss, almost all the power will be lost heating it up.
Good info! Thank you very much. (and thanks for the warm welcome :) )

P.S. Still keen to hear from any mobile phone antenna (internal) nerds if there are any out here :))) Just sayin... ;)
 

Ya’akov

Joined Jan 27, 2019
6,046
Good info! Thank you very much. (and thanks for the warm welcome :) )

P.S. Still keen to hear from any mobile phone antenna (internal) nerds if there are any out here :))) Just sayin... ;)
I use an iPhone 12 Pro Max and anecdotally the radio performance is very good. It is better than my previous iPhone which was a 10. I have used iPhones since the first one and in the beginning they used a plastic radome on one e nd of the phone. Whne they changed to using the frame as the antenna there was initially some trouble but they’ve pretty much perfected it at this point. I don’t think differences among the current models would be enough to go from marginal to reliable. I do know going from 10 —> 12 was a big improvement.
 

Thread Starter

Bookishhh

Joined May 26, 2022
5
I use an iPhone 12 Pro Max and anecdotally the radio performance is very good. It is better than my previous iPhone which was a 10. I have used iPhones since the first one and in the beginning they used a plastic radome on one e nd of the phone. Whne they changed to using the frame as the antenna there was initially some trouble but they’ve pretty much perfected it at this point. I don’t think differences among the current models would be enough to go from marginal to reliable. I do know going from 10 —> 12 was a big improvement.
Thanks for that. I've done quite a lot of travelling in remote areas in my country over the last year or so and have found my old iPhone 7 much more reliable than my Android (LG V30) which seems anecdotally much better for folks in low reception areas in the States.
 
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