High Frequency, High Power Amplification

Status
Not open for further replies.

minini

Newbie
Joined
Nov 12, 2016
Messages
1
Location
hongkong
I was wondering if anyone could give me a little information on amplifiers.

What would be the best way to amplifying a small, 1v @ 1mA, very high frequency signal (3-5MHz) to a high power signal? The output signal would also need to be around 3-5MHz and something like 12v @ 1A.

My question is, what amplifier system would preform this task well, or the best? One option is using a class E amplifier with a square wave signal, or just purchasing a direct high power, high frequency OP AMP.

Unfortunately I don't think any of these "OP AMPS" exist, so I'm looking to build my own circuit. Preferably something simple, but anything that works will do.

Has anyone got any suggestions of which amplification system would work the best in this situation?

And after some advice from my friend, it looks as if the OPA564 chip(http://www.kynix.com/uploadfiles/pdf8798/OPA564AIDWP.pdf) would be the best fit for this task. What other components are necessary to operate the chip? Or can I just operate it straight out of the box? Basically I'd like some advice on how I can successfully operate the chip.
 

ka3jjz

Wiki Admin Emeritus
Joined
Jul 22, 2002
Messages
22,051
Location
Bowie, Md.
Well firstly, 3-5 Mhz is not considered 'very high frequency'. That's a designation that is usually reserved for frequencies above 30 Mhz. Or is that 3-5 Mhz wide? It's a little vague here...

If you mean 3.5 Mhz, you are on the very bottom of the 80 meter ham band. Is this an amateur radio application, in which case we would refer to this as QRP. Or is this something else? What is the application? What modulation schema are you working with here (AM, Sideband, digital, etc.)? There are a few designs from a company in Japan that works with QRP transceivers such as the Yaesu FT-817.

More information is needed - then this thread will be moved accordingly...Mike
 
Last edited:

RFBOSS

Member
Joined
Jul 31, 2016
Messages
86
My guess based on what little information that you have supplied is that the IC that you have asked about will not be a good fit for your application.

From the data sheet...

Full power bandwidth with a 10 volt peak to peak output (that is 2 volts short of your requirement) is only 1.3 MHz.

From what you posted...an output of 12 volts at 1 amp would be a power level of 12 watts and it would mean that you amplifier is driving a load impedance of 12 Ohms.

Is this correct?

Looking at the output verses frequency graph it looks like the output voltage would be down to about 5 volts by the time the frequency reaches 3 MHz and that would be only about 6 watts (based on a 12 Ohm impedance as indicated by your example) and even lower as the frequency goes higher. At 5 MHz the output voltage would be down to about 2.5 volts with a concurrent reduction in output power.

Understand that this is based on the limited information supplied.

More accurate information is needed regarding the application and implementation of your required amplifier.

Depending on the actual implementation my post may or may not be accurate.

Again more definite, specific information is needed in regard to the application and use.

And no that IC will not operate straight out of the box. Read or have your friend read the data sheet that you linked to and look at the applications schematics.

Again, what are you trying to do?
 

wyShack

Member
Joined
Nov 18, 2008
Messages
430
Location
Campbell County, Wyoming
There are a variety of ways to boost a low level signal to almost any power level. I have to agree, the real question is what you are trying to do. If your goal is to 'transmit' a signal 'over the air' a lot depends on the signal (BTW RF and square waves don't mix very well). What is the 'signal' (audio, telemetry, video or what). Most amplifiers are built for a purpose and the requirements vary (linear or not bandwidth of signal ect). Not trying to 'scare' you but quite a bit more information is needed to determine the requirements of a circuit.

Add some details and suggestions will likely follow
 
Status
Not open for further replies.
Top