RF power amplifier

[ahmaaa]

can any one tell me a suitable power amplifier class &it's schematic that can be used for RF power amplifier that give 100mw output?

 

[Chippie]

Usually class C.....

What frequency?

Google is your friend...

 

[ahmaaa]

frequency is 1MEGAHZ
i was not able to find it on google

 

[Chippie]

try some different search parameters....

what is it for, what are you intending to do with it?

 

[ahmaaa]

for an AM transmitter

 

[ahmaaa]

also i need it to be linear power amplifier

 

[Chippie]

I found this without too much trouble....

AM Transmitter

Before you ask any more questions, I suggest you read the text that accompanies the circuit.....

 

[Papabravo]

100 mW is hardly what I would call a linear power amplifier. A kilowatt is more like it. A 100 mW signal on 1 MHz is smack in the middle of the AM broadcast band and would be of questionable legality.

 

[Chippie]

A 100 mW signal on 1 MHz is smack in the middle of the AM broadcast band and would be of questionable legality.

Yay....was gonna post that too, but we dont know where the op is from...may not be illegal...

 

[crutschow]

100 mW is hardly what I would call a linear power amplifier. A kilowatt is more like it. A 100 mW signal on 1 MHz is smack in the middle of the AM broadcast band and would be of questionable legality.

The classification as a linear amp has nothing to do with its power. It's the configuration of the amplifier generating the RF that determines whether it's linear or not. Class A and class B push-pull amps are linear, Class C is nonlinear.

 

[Papabravo]

Still I've never heard anybody refer to a 100 mW RF output as a power amplifier weather linear or not.

I would also argue that Class A is really the only linear type since Class B may have both crossover distortion and in some cases a deadband chracteristic. I might also point out that in class C the output is actually a reproduced copy of the input since only a portion of the input is used to kick a resonant circuit. Those all fit my description of non-linear, but that's really semantic hair splitting, and the OP obviously has some purpose in mind which he has not communicated to the forum.

100 mW can generally be produced by modest circuits at that frequency without any undue difficulty. For example an oscillator with 10 mA of output current and a 13.8V supply will have 138 mW of ouput power. A Colpitts or a Heartly with a 2N3904 should do the trick.

 

[stevez]

I was looking thru my 2009 ARRL Handbook and noticed one project - an SSB transmitter with a power amplifier. The output of the "power amplifier" was 100 mw. I had never seen that before ( a 100 mw amplifier referred to as if it was a linear amplifier). Author explains that with the 100 mw one should then be able to construct or purchase an amplifier for higher power levels.

 

[millwood]

do a google search on Harry's Homebrew Homepage and you will come up with tons of such circuits.