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R1 (K¦¸) 
R2 (K¦¸)
RC (Collector resistor)¼¯µç¼«µç×è (K¦¸) 
RE (Emitter resistor)·¢É伫µç×è (K¦¸) 
VP (Supply Voltage)µçÔ´µçѹ (V)
Beta (DC Current Gain)Ö±Á÷µçÁ÷ÔöÒæ
VBE (Base to emitter drop)»ù¼«-·¢É伫ѹ½µ (V)
Rs (Source Resistance): µçÔ´ÄÚ×è (¦¸)
RL (Load resistor)¸ºÔصç×è (¦¸) 
fT (Current Gain BW Product):µçÁ÷ÔöÒæ´ø¿í (MHz)
CCB (Cu Collector-Base Cap.): ¼¯µç¼«Óë»ù¼«¼äµçÈÝ (pF)
CBE (C¦Ð, Base-Emitter Cap.):»ù¼«ºÍ·¢É伫֮¼äµÄµçÈÝ(¿ÉÑ¡)  (pF)

VC (Collector Voltage)¼¯µç¼«µçѹ (V) 
VE (Emitter Voltage)·¢É伫µçѹ (V) 
VB (Base Voltage)»ù¼«µçѹ (V) 
IE (Emitter Voltage)·¢É伫µçѹ (mA) 
IC (Collector Voltage)¼¯µç¼«µçѹ (mA) 
IB (Base Voltage)»ù¼«µçѹ (mA) 
gm (Transconductance)¿çµ¼
r¦Ð (Input Resistance of BJT at low freq)¾§Ìå¹ÜÊäÈë×迹,µÍƵÂ浀 (¦¸)
re  (¦¸)
RIN (Input Resistance of Amp)·Å´óÆ÷ÊäÈë×迹 (K¦¸)

¡¡

A (Amplifier Voltage Gain)·Å´óÆ÷µÄµçѹÔöÒæ
fP1 (MHz)
fP2 (MHz)

Equations

VB=  VP*R2/(R1+R2)

VE= VB-VBE

IE=VE/RE

Alpha= Beta/(Beta+1);

IC= Alpha*IE

VC= VP -  IC*RC/2

IB=IC/Beta

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gm = Ic/25mA

re= Alpha/gm

r¦Ð= Beta/gm

A=Alpha* r¦Ð*RC/(Rs+2*r¦Ð)/re

fP1=1/(2*¦Ð*(Rs||2*r¦Ð)*(CBE/2+CBC))

fP2=1/(2*¦Ð*RC*CBC)

¡¡

fT= gm/(2¦Ð*(CBE+CBC))

The lower pole is dominate: 

¡¡

.