Among the standard BJT configurations (common-emitter, common-collector, common-base), which type of gain is generally highest for the common-emitter (C-E) amplifier when considered as an overall amplifier stage?

Introduction / Context:
The three basic BJT amplifier configurations emphasize different strengths: common-emitter (C-E), common-collector (C-C/emitter follower), and common-base (C-B). Knowing which gain metric is characteristically strongest helps with topology selection for preamps, drivers, and buffers.

Given Data / Assumptions:

• Standard small-signal operating conditions.
• Proper biasing within the active region.
• Typical resistive loads and coupling networks.

Concept / Approach:
The C-E stage provides substantial voltage gain (often tens to hundreds) and non-unity current gain (β-like from base to collector path), so its overall power gain—the product of voltage and current gain—is typically the highest among the three. The C-C stage has high current gain but near-unity voltage gain (excellent buffer). The C-B stage offers voltage gain but current gain ≈ 1 (useful at high frequency).

Step-by-Step Reasoning:
1) C-E: significant Av and appreciable Ai → large Ap (power gain).2) C-C: Av ≈ 1 but Ai large → moderate Ap.3) C-B: Av can be high but Ai ≈ 1 → moderate Ap.4) Therefore, C-E typically exhibits the greatest power gain.

Verification / Alternative check:
Small-signal hybrid-π analysis shows Av ≈ −gm * RC (potentially large), while input resistance is modest, yielding notable current gain from base input to collector output. Their product produces high stage power gain relative to C-C and C-B.

Why Other Options Are Wrong:
Voltage or current alone: Each can be high in certain topologies, but the question asks for which gain is highest overall for C-E. Power gain best captures C-E superiority.

Resistance/bandwidth: Not “gains” in the same sense; bandwidth of C-E may be lower than C-B at RF.

Common Pitfalls:
Confusing buffer (C-C) behavior—excellent current gain but unity voltage—with high power amplification. C-E remains the workhorse for power gain.

Final Answer:
power