hello, looking for info advice on 2.4ghz to 4.0ghz rf amplifier

[xopenex]

Hi

First off, what an awesome website. I have already realized that i am going to happily burn hours a day on here! lol

I only saw one other post, and it was similar but not quite what i am interested in. So i apologize in advance if i have re-questioned something that has already been asked!

I dont have much knowledge on the subject i am interested in, but those of you who do probably already know what i am trying to do based on the frequency ranges in the title. So my explanation, which will be lacking, is probably going to be good enough for the experienced here!

I am wanting to build a signal amplifier that can amplify laptop wifi 2.4ghz frequency, and also the frequency ranges for cell phone gsm 3g frequency ranges.

I have found what i am looking for, but they are priced from $130.00 and up! It would be nice to have, but at that price not completely necessary. So i started thinking about making my own, and got interested in the project as well!

i have found some websites that have parts, but i dont know enough about the subject to see if they would work for the project?

here is a link to the website with what i am trying to build...

www.analog.com/en/rfif-components/rfif-amplifiers/adl5321/products/product.html


here is one specific for the amplification of wifi 2.4ghz (I am just going straight to wifi card, so dont need to have funcitoning usb data)

www.radiolabs.com/products/wireless/wave-magnum.php

i have found a website with some parts, maybe they would work for the 2.4ghz range...?

www.nghobbies.com/cart/index.php?main_page=index&cPath=1_10_82_131_28


I think i would be happy just making one for the 2.4ghz at this point and then with what i learn from that, i should be able to figure out what to do for the other frequencies!


thanks in advance, im looking forward to learning about all this and building my own! cheers!

 

[RadioRon]

In order to amplify WiFi 2.4Ghz signals, you must first decide if you will amplify your transmissions, or the signal you are receiving, or both. WiFi uses time domain duplexing to allow signals in two directions to occupy the one RF channel. This means that any amplifier that you put inline between your wifi card and its antenna must be capable of amplifying in one of two directions depending on whether your wifi card is sending or receiving at that moment. For this reason, it is usual for an add-on amplifier for WiFi to be a complete "bidirectional" amplifier, which means that inside this unit, there are two amplifiers, one for receiving and one for transmitting. There is also two RF switches that change the signal path to select one or the other amplifier. The RF switches are controlled by a transmit power sensor that senses when your wifi card is transmitting. So, it is a bit more complex than just adding one RF amplifier as you suggest.

Further, I would add that in order to also be able to amplify 3G mobile phone signals, an amplifier would have to operate below 2.4 GHz, not above, to include the band 1.7 to 2.1 GHz and perhaps also 880 to 960MHz as well depending on the system.

I would further like to suggest that it is always much more productive to improve the antenna used by your wifi card rather than adding amplifiers, if your intention is to get better range.

Further, and finally, construction of a 2.4 GHz bi-directional amplifier from scratch is not a suitable project for a novice who is without experience at these frequencies. If you are set on this path, find a kit that has an already-designed printed circuit board that you can use, or better still use a ready built module.

 

[Nigel Goodwin]

$130 sounds a bargain - it's a FAR, FAR more difficult (and expensive) job then you would think.