What type of coupling uses two resistors and a capacitor connected together?

The type of coupling that uses two resistors and a capacitor connected together is known as resistive-capacitive coupling. This method involves connecting components in such a way that the resistors help to set the gain and stabilize the circuit, while the capacitor serves to block any DC component of the signal while allowing AC signals to pass through. This coupling technique is common in various audio and signal processing applications, where you want to maintain signal integrity while decoupling different stages of a circuit.

Resistive-capacitive coupling effectively allows for a smooth transition of alternating current signals between different parts of a circuit without letting direct current interfere, which is crucial for amplifying AC signals in an efficient manner. This coupling method is particularly beneficial in applications where the coupling capacitor also contributes to filtering, as it can help eliminate unwanted low-frequency noise.

Other coupling methods, such as impedance coupling, transformer coupling, and direct coupling, each have distinct characteristics and applications that do not specifically involve the combination of two resistors and a capacitor in the same manner as resistive-capacitive coupling.