Hi Albert,
You might take this consideration between the differences of the FET and BJT.
Field Effect Transistor Bipolar Junction Transistor
(FET) (BJT)
Low voltage gain High voltage gain
High current gain Low current gain
Very input impedance Low input impedance
High output impedance Low output impedance
Low noise generation Medium noise generation
Fast switching time Medium switching time
Easily damaged by static Robust
Voltage controlled device Current controlled device
More expensive than bipolar Cheap
Difficult to bias Easy to bias
Exhibits the properties of a Resistor
Hope it helps - http://goo.gl/CytPEB
You might take this consideration between the differences of the FET and BJT.
Field Effect Transistor Bipolar Junction Transistor
(FET) (BJT)
Low voltage gain High voltage gain
High current gain Low current gain
Very input impedance Low input impedance
High output impedance Low output impedance
Low noise generation Medium noise generation
Fast switching time Medium switching time
Easily damaged by static Robust
Voltage controlled device Current controlled device
More expensive than bipolar Cheap
Difficult to bias Easy to bias
Exhibits the properties of a Resistor
Hope it helps - http://goo.gl/CytPEB
