Question 6A362

A Class B linear RF amplifier in saturation means its output current has reached its maximum possible value, unable to increase further regardless of the input signal. When modulated: * Positive excursions of the modulating signal would normally cause the RF output amplitude to increase. However, since the amplifier is already saturated, it cannot produce a higher output current. These positive peaks will be clipped or limited. * Negative excursions of the modulating signal can still cause the RF output amplitude to decrease. The resulting waveform is asymmetrical: the positive peaks are limited, while the negative peaks are allowed. This asymmetry causes the average power of the modulated carrier to be *less* than the unmodulated carrier power. This reduction in average carrier power due to limiting on positive modulation peaks is defined as **negative carrier shift**. * **A) Incorrect:** Saturation means current cannot increase, preventing positive shift and further amplification on positive peaks. * **B) Incorrect:** Class B amplifiers operate near cut-off but modulate and amplify signals *above* cut-off. This statement misrepresents Class B operation. * **D) Incorrect:** As A and B are incorrect.