Effect of BJT common emitter amplifier resistor(Rc,Re) ratios? How to select it?
As you reduce Re, you reduce the voltage across it. Now you want to fix Vb at Vbe + V(Re) by selecting R1,R2. 

So far, so good ... but remember that Vbe is not precisely 0.6 or 0.7V, but a function of Ib (as is the voltage across a forward biassed diode) and of temperature : it decreases by 2mV/K. So over a 50K temperature range, Vbe can vary by 0.1V. Because you fixed Vb, this causes variations in V(Re), hence Ie, hence Ic, hence V(Rc).

So V(Re) should be large compared with these variations, and usually > Vbe unless you're seriously pressed for headroom (e.g. 3V supply). Here, I ask, how important is that last 10% (1dB) of voltage swing? I would suggest Rc/Re &lt; 10 as a good rule, and I'd look for 2*Vbe across Re if possible.