stewa203
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Posts: 2
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I got this equation out of a book by Schubert and Kim.
Q = [(mdc/mac)*Vcc+C]/[1+mdc/mac]
mdc = slope of DC load line mac = slope of AC load line C = saturation voltage of the transistor
mdc = 1/[Rc +Re(beta+1)/beta] mac = 1/Rc
Q then will give the 'best' Vce for low frequency approximations
If you don't want to do the math, a good rule of thumb says you should drop about a third in voltage between Re, Vce, and Rc each.
A couple of pointers on this application. You will probably need a high DC current in the transistor. This will help with linearity at higher powers (800mW = 29 dBm) which is a lot of power. I personally have not designed any power amps, which is what you are trying to do. Also, this amplifier configuration has a high output impedance compared to your low antenna impedance. You will need some sort of tuning network to match the amplifier to the antenna, otherwise you will have a horrible VSWR problem.
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