This behavior allows the transistor to perform two primary roles: It acts as an Amplifier .
| Topology (BJT/FET) | Voltage Gain | Input Impedance | Output Impedance | Phase Shift | |-------------------|--------------|----------------|------------------|--------------| | Common Emitter/Source | High (≥ -50) | Moderate | High | 180° | | Common Collector/Drain (Emitter Follower) | ≈ 1 | High | Very low | 0° | | Common Base/Gate | High (≈ RC/re) | Very low | High | 0° | This behavior allows the transistor to perform two
This is the workhorse of small-signal amplification. It provides voltage gain, current gain, and signal inversion. and signal inversion.
Ensuring signals flow efficiently between stages without loss. This behavior allows the transistor to perform two
Modern digital design uses MOSFETs, not BJTs.
Using a transistor to combine the incoming signal with a local oscillator to create an Intermediate Frequency (IF).