power amplifier 40W output at 200Mhz.

[vodanhtieutot]

I have the problem when design RF 50W & 200Mhz power amplifier, because i knew some opamp can work at high frequency so i wonder i can use opamp (now i use AD8024) for power amplifier or using transistors (an9024), could anyone help me solve that problem?

 

[goldsmith]

Dear vodanhtieutot
Hi
Would you like that i introduce you , some better ways ?
Best Wishes
Goldsmith

 

[davenn]

I have the problem when design RF 50W & 200Mhz power amplifier, because i knew some opamp can work at high frequency so i wonder i can use opamp (now i use AD8024) for power amplifier or using transistors (an9024), could anyone help me solve that problem?

did you read the datasheet for the op-amp ? If so you would see that its not going to give 40-50W output. Its a very low level output.
for the power level that you require you are probably best to use at least a 2 or 3 stage amplifier so that the gain is evenly spread across all the devices and thereby retaining stability.
Have a look at some of the Mitsubishi power block modules, the RAxxxxxx series. They have a wide range of modules covering different frequencies and power levels.
Most will operate to full power out with ~ 100mW input.

Dave

 

[tony_lth]

You can use banlanced configuration to get better width and VSWR.

 

[vodanhtieutot]

You can use banlanced configuration to get better width and VSWR.

Would you please explain or tech me some circuit either get better width, VSWR or high power (40W) for frequency at 200Mhz.

---------- Post added at 19:11 ---------- Previous post was at 19:08 ----------

did you read the datasheet for the op-amp ? If so you would see that its not going to give 40-50W output. Its a very low level output.
for the power level that you require you are probably best to use at least a 2 or 3 stage amplifier so that the gain is evenly spread across all the devices and thereby retaining stability.
Have a look at some of the Mitsubishi power block modules, the RAxxxxxx series. They have a wide range of modules covering different frequencies and power levels.
Most will operate to full power out with ~ 100mW input.

Dave

I think you right but my design is using opamp compine with Wikison hybrid circuit to get high power but i worry Wikison hybrid have large attenuation.

 

[tony_lth]

I think you right but my design is using opamp compine with Wikison hybrid circuit to get high power but i worry Wikison hybrid have large attenuation.

I think That's impossible to use OpAmp to get 40W. If you can, could you give the part number of the OpAmp?

 

[davenn]

I think That's impossible to use OpAmp to get 40W. If you can, could you give the part number of the OpAmp?

exactly!! thats what I tried to tell the OP in an earlier post. The Op-amp he mentioned isnt going to do it. There are no Op-Amps that I'm aware of to produce hi power at any freq let alone 200MHz
I gave him an excellent suggestion but it seems to have been ignored

Dave

 

[goldsmith]

"think That's impossible to use OpAmp to get 40W"
Hi Dear All
for op amp , there are many selections e.g AD9631 or .... etc . but as the other said it is impossible to get this power from an op amp at this frequency .
I have a better suggestion .
Why op amp ? you can use Gali amp series . e.g gali-5 . see below , please :
https://www.minicircuits.com/pdfs/GALI-5+.pdf
It is a wide band amp that has 4 pins , and will send your amplified signal on supply . and you can lockout it with an RFC simply . and then you can use a class C or E or F as power amplifier after gali-5 . and with this simple way you can achieve your desired power .
Best Wishes
Goldsmith

---------- Post added at 11:05 ---------- Previous post was at 11:03 ----------

BTW : i forgot to say , that if your input signal is weak , you can use chain amplifiers that consist some gali-5 or some op amps . but some gali-5 will be better ( but if your signal is very weak , you'd better to use some op amps and then gali-5 and power amp .

 

[davenn]

Yup there are a number of MMIC's like the GALI-5 that will produce enough power to drive various MItsubishi power block modules

Dave