# GHz signal of 1 Amp

Discussion in 'Electronic Design' started by Efthimios, Oct 17, 2007.

1. ### EfthimiosGuest

Hallow people!!

I am physics student and I need to create a GHz signal with an
amplitude close to 1 Amp for an experiment.

Does any of you know if this is possible????

And if yes how??

2. ### John DevereuxGuest

Microwave oven and a metal ring?

3. ### EfthimiosGuest

Good idea but I do not think I can get 1 Amp.

5. ### EfthimiosGuest

Thanks a lot. Yes i think that will help.

6. ### EfthimiosGuest

Do you know how much an Amplifier like this will cost??

7. ### Phil HobbsGuest

Depends on the impedance level. Most microwaves produce 800W or more of
2.4 GHz--with a 50-ohm impedance, you only need 6% coupling efficiency
to get 1A rms. Figuring out how much you actually got will be the
interesting part...you could probably just run a bit of heavy coax to a
properly designed probe, e.g. strip the braid off the last 3 cm of the
coax to make a 1/4-wave probe, and be very careful about RF burns due to
not grounding the coax shield or doing anything else idiotic. RF burns
are much nastier than ordinary burns, because they're caused by RF arcs.
They're typically third degree, with the smell of charred flesh--and
because they're often very deep, they can be very slow to heal. (On the
other hand, if you got hit by the same arc at DC or 60 Hz, you'd
probably be dead). If you don't have anyone there who understands high
power RF, buy something from AR instead, and forget everything I said
above.

Cheers,

Phil Hobbs

9. ### Tom BruhnsGuest

As others have asked, 1 amp through what impedance? 1 amp (rms) at 50
ohms is only 50 watts. If you think you can't get 1 amp induced in a
metal ring in a microwave oven, you've probably never tried it (and
then tried to remove the ring with your bare fingers).

A magnetron is a good way to generate a lot of microwave power
cheaply, but it's possible you have other needs, too, that you haven't
told us about. Does the frequency matter? How about frequency
stability? How accurately do you want to control the 1 amp? Does the
load change over time (e.g. as it heats up)? What, exactly, is the
load? (I can fairly easily get you one amp out of my signal generator
that can output only +20dBm, if it's through a load of my choosing.
Using a quarter wave long transmission line resonant at the frequency
of interest, made from copper pipe, I can transform the 50 ohm output
to a very low impedance. 1 amp at 0.1 ohms is only 0.1 watts, or
+20dBm.)

Cheers,
Tom

10. ### Tim WescottGuest

At zero volts? Sure! You just need a resonant circuit and a way to
excite it.

So what _power_ level do you need?

--
Tim Wescott
Control systems and communications consulting
http://www.wescottdesign.com

Need to learn how to apply control theory in your embedded system?
"Applied Control Theory for Embedded Systems" by Tim Wescott
Elsevier/Newnes, http://www.wescottdesign.com/actfes/actfes.html

11. ### Jan PanteltjeGuest

One amp, and no other thing mentioned, could just be the collector current
in a transistor.
Could be a simple circuit.

12. ### colinGuest

you can use something like a large PHEMT or MESFET

Colin =^.^=

13. ### JosephKKGuest

Efthimios posted to sci.electronics.design:
First you have to be able to talk coherently about the task.

14. ### JosephKKGuest

Efthimios posted to sci.electronics.design:
How about you do some calculations instead of guessing and dismissing
and disrespecting?

15. ### JosephKKGuest

Efthimios posted to sci.electronics.design:
Twit, your schoolwork assignment is to design and cost estimate it by
volume.

16. ### LVMarcGuest

yeah it is more than possible .. can source an amplifier circa 75 watts
output.. has extra head room so that you may take this output and apply
it to NON 50 ohm physics test cells you are likely to have. Have
significant exwepricne in this power level and physics est cells!

best regards,

marc