Thread: Class-D RF PA
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Old October 3rd 04, 06:56 PM
Tim Wescott
 
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Philip de Cadenet wrote:

Hello Tim,

Look for class E. Class D describes an amplifier that switches faster
than the signal and has the output filtered to pass DC. Class E
describes an amplifier that switches _at_ the signal rate and has a
filter that has finite impedance at the fundamental and infinite
impedance at all the odd harmonics. The result is that the output
transistor drives a square-wave voltage and sees a sinusoidal current,
so all the power goes to the output with none wasted.

There have been articles in QEX and even QST -- they even explain what
I just said in sufficient detail to understand it.


Thanks for the information and article links.

I have some articles fromm Sokal and Raab on E. Also familiar with Steve
Coultier's class-E web site.

I have a QEX/QST compilation CD somewhere.

Do you have any month/year references to hand?

Tnx

No, but I've only been reading them for 15 years -- that should narrow
things down a bit.

Sorry (for the lack of info, if not the smartass answer).

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com