I need some help putting together a wideband, radio frequency amplifier and a UWB antenna.

Thread Starter

genekuli

Joined Oct 21, 2018
103
Hello,
I would really appreciate it if there was somebody who could just help me by telling me how to make this. It needs to be only the very bare bone components without any filters.
I just need to be told what I need to buy and how to put it together. Ultra wideband, frequency range: ~1-10GHz, 50-100W amplifier.
Thank you,
Gene
 
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Papabravo

Joined Feb 24, 2006
15,525
Hello,
I would really appreciate it if there was somebody who could just help me by telling me how to make this. It needs to be only the very bare bone components without any filters.
I just need to be told what I need to buy and how to put it together. Ultra wideband, frequency range: ~1-10GHz, 50-100W amplifier.
Thank you,
Gene
Yeah. that's a pretty tall order. Were you planning to buy the parts on eBay and cobble together a breadboard? How big is your wallet for the materials and test equipment for this project?
To buy one you have to call for a quote. that is purely to avoid the sticker shock.
 
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Thread Starter

genekuli

Joined Oct 21, 2018
103
Yeah. that's a pretty tall order. Were you planning to buy the parts on eBay and cobble together a breadboard? How big is your wallet for the materials and test equipment for this project?
To buy one you have to call for a quote. that is purely to avoid the sticker shock.
I am thinking of using these components:
Broadband RF Low Noise Amplifier
Antenna UWB-1 3.1GHz-9GHz Ultra Wide Band Omnidirectional
but i need more power, so can i wire the amp in series up to 50W of power?
 

Thread Starter

genekuli

Joined Oct 21, 2018
103
the antenna will be inside a metal enclosure so there will be zero transmissions out of the box. Like a microwave oven but UWB.
the amp. needs to be UWB, it is only preferable for it to be in the high MHz because the antenna can be smaller.
but it occurred to me, i used to have a ham radio that was a good one and had a very broad range of bands, so there in that 100W ham radio must have been exactly what i need right? that is a UWB 100W RF transmitter amp. so surely i can buy one of those amps separately or take it out of another ham radio, right?
In case you are wondering what i am doing with this, it is for an experiment and the antenna will be inside a metal enclosure so there will be zero transmissions out of the box. Like a microwave oven but UWB.
 

Papabravo

Joined Feb 24, 2006
15,525
I am thinking of using these components:
Broadband RF Low Noise Amplifier
Antenna UWB-1 3.1GHz-9GHz Ultra Wide Band Omnidirectional
but i need more power, so can i wire the amp in series up to 50W of power?
I see what you are up to. I thought you wanted to design and build one from scratch. You cannot put power amplifiers in series to get more power. It doesn't work that way unless the amplifiers have separate and larger power supplies. Where do you think the power comes from? If you want a 100 Watt amplifier, that is what you start with. BTW you're not going to be able to do this on the cheap. How much is your budget?
 
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Yaakov

Joined Jan 27, 2019
2,492
To emphasize @Papabravo's point about cost, this module (https://ophirrf.com/wp-content/uploads/2015/10/5803031.pdf) as an example, which doesn't even have your stated bandwidth, is so expensive it requires quoting from any source that sells it. This is a special-purpose, custom part. You can find them for sale used, but you will have to get a quote from the dealer. I would not be surprised by thousands of dollars.
 

Papabravo

Joined Feb 24, 2006
15,525
Then there is the test equipment you will require to verify proper operation. That could amount to some serious pocket change. Like hundreds of Kilobucks
 

Alec_t

Joined Sep 17, 2013
11,984
The spec of the amp in your link doesn't mention power output capability, but from the pic I'd be surprised if it were anywhere near 5W, yet alone 50-100W.
 

bertus

Joined Apr 5, 2008
21,258
Hello,
The spec of the amp in your link doesn't mention power output capability, but from the pic I'd be surprised if it were anywhere near 5W, yet alone 50-100W.
Looking at the page, I would think there is a MMIC inside.
The maximum output power will be around 13 dBm, wich is about 20 mW.
Have a look at the mmics table attached.

Bertus
 

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Thread Starter

genekuli

Joined Oct 21, 2018
103
I see what you are up to. I thought you wanted to desing and build one from scratch. You cannot put power amplifiers in series to get more power. It doesn't work that way unless the amplifiers have separate and larger power supplies. Where do you think the power comes from? If you want a 100 Watt amplifier, that is what you start with. BTW you're not going to be able to do this on the cheap. How much is your budget?
Your answers are so helpful, so to begin with the antenna first.
so i have been searching around for the last few days looking for suitable items, since I don't know anything. Could you please tell me if this antenna is good for TX 100W UWB? At least I can then try to find the suitable UWB power amp within that frequency range.
just to make sure I understand, does a clipped signal from an overdriven amp extend out of the designed frequency range of the amp? That is, say I overdrive an amp that is designed for 140-150MHz, will it produce outside this frequency range when it is clipped due to being overdriven due to the harmonics produced? I need it to be as wide a signal as possible due to clipping.
thank you,
Gene
 

Papabravo

Joined Feb 24, 2006
15,525
First things first. You can't tell jack about an antenna by looking at a picture of it. Especially a picture with no dimensional information on it. The only way to tell anything about is to put it on a Vector Network Analyzer and sweep it over the frequency range of interest to tell if will match with a given transmitter. I'm going to go out on a limb here and guess that you do not have a Vector Network analyzer that goes out to 10 GHz. Do you? Before you ask, I'm retired and I don't have access to one of those puppies either. They are just a wee bit out of my price range for hobby work. I don't even know anyone who has one.

I wouldn't worry about over driving an amplifier at the moment, but it is a bad bad thing and causes all sorts of spurious radiation. Probably enough to trigger a visit from the FCC. They take a dim view of guys with transmitters who are just messing about on random frequency bands. You actually might need a good lawyer to keep you out of jail if you go out of your way to annoy them.
 
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dendad

Joined Feb 20, 2016
3,795
In case you are wondering what i am doing with this, and the antenna will be inside a metal enclosure so there will be zero transmissions out of the box.
It would be interesting to have you explain what you are actually trying to do.
But, from your questions, I can only assume you do not have the expertise to be playing around with this sort of thing.
This can be VERY dangerous. Not only to you but to others near by.
And, I would think, unless you can construct things correctly, potentially quite illegal.
What are you actually thinking of doing? "it is for an experiment " does not cut it!
 
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