Cascade Wideband Amplifier Design
I am seeking help for designing the above topic. I have a few IC that can work from 10MHz to 50GHz and I would like to design an amplifier with 30dBm power.
However, I have no experience on how to start and work around on the DC block, interstate cap and matching circuit.
Would appreciate if someone can advise me what is the best approach to design this amp and especailly the gain faltness portion. Thanks.
This is quite wideband and cascade connections may not give this bandwidth and power level. Instead of that, "distributed amplifier configuration" should be used. For this kind of amplifiers, there are lots of document and paper. But it's quite difficult to implement.
You are trying to do a very difficult job.
Have you serched if the present technology permit a BW*Power= 50 [GHz*W] ?
In any case, you'are right! One of the problem is the BW of the Blocking capacitor.
Generally you may use a "koala" configuration, 2 ore more // capacitor with different value (i.e. .1pF//1pF//10pF) to lower the parasitic inductance of the capacitors.
DLI produce some special single layer cap to be mounted directly on ustrip witout any (inductive) bondwire.
look for CapGap on http://www.dilabs.com/Products/Single_Layer.htm
Good luck !
What I can think of:
1.Forget about matching. The BW is way to big to even consider it. The only thing you could consider is interstage mismatch for a flat gain.
2.As mentioned, travelling wave amplifier is appropriate. But you will need very fast technology
3.You could try to use feedback, but I have no idea if you will succeed such a bandwidth
4.I fear you will have to live with some gain variation over the frequency band.
I keep on wondering: why would somebody need something like that? Perhaps it's a possiblity to switch amplifiers depending on the input frequency?
hi camel_RF
you have not specified the exact band width required for your application; the only thing you have specified is tht you have ICs working form 10 MHz to 50 GHz ; moreover getting 30 dBm out of the amplifier over such a wide band is next to impossible; if you could be more specific about your aplication then maybe you can be helped out