Questions about class c amplifiers

[sina]

class c

hi I want to design class s amplifier.I want to know does it has any special point must be check.and I have another question I dont know why we use class c amplifiers and how we correct its distortion .

 

[CTT]

Re: class c

Hi,

Class S is usually used for pulse width techniques associated with
a switched-mode output stage (usually class-D like power stages).
You may want to llok carefully to the control signal generation
(non-overlapping, ...) which can be difficult depending on the
operating frequency.

In Class-C operation you do not have any DC current -> higher
efficiency but linearity and gain are lower than in class AB,A,B operating
modes. It is a very attractive mode for output powers around 0-5 dBm.

Is it an integrated design ?

CTT

 

[atmaca]

Re: class c

CTT
Can you suggest any material introducing operation modes of power amplifiers ??

 

[vfone]

Re: class c

**broken link removed**
http://www.highfrequencyelectronics.com/Archives/Jul03/HFE0703_RaabPart2.pdf
**broken link removed**

regards

 

[sina]

class c

thank you its good pdf I found that transistor conduct a percent of cycle and voltage will recover by tunk circuit .Is it right?

 

[CTT]

Re: class c

Yes, that is right, the current waveform is
not a sinewave component but if the Q of the
tank is high enough the voltage will be quite
sinusoidal.

Be careful that those reduced conduction angle technique
will introduce distorsion. If your modulation scheme has
a constant envelop then you will have no problem. If
not, then a C-class amplifier may not be suitable.


CTT

 

[flatulent]

Re: class c

On the selection of a transistor, you should make sure that it is designed for class C. The input power is higher in this class than A or B and the base or gate must be able to handle the drive power.