Which type of amplifier is associated with common mode rejection?

The differential amplifier is specifically designed to amplify the difference between two input signals while simultaneously rejecting any signals that are common to both inputs, which is known as common mode signals. This characteristic is crucial in many applications, especially in environments with high levels of electrical noise, where unwanted signals can interfere with the desired measurement. By focusing on the difference between the two inputs, differential amplifiers provide greater accuracy and stability in signal processing.

In contrast, the other types of amplifiers mentioned do not primarily focus on differentiating between two signals in the same way. A half cycle amplifier typically allows only one polarity of input signal to be amplified, lacking the capability to handle both positive and negative signals in a balanced manner. Bipolar amplifiers can refer more generally to amplifiers that operate with bipolar junction transistors (BJTs) and may not emphasize common mode rejection. Referential amplifiers, which may not even be a standard classification, do not inherently imply common mode rejection. Thus, the differential amplifier's design and function make it the appropriate answer for common mode rejection.