What is the name of a circuit that generates a signal at a specific frequency?

An oscillator is a circuit designed specifically to generate a continuous oscillating signal, typically at a specific frequency. Oscillators can produce various types of waveforms, such as sine, square, or triangle waves, depending on their design and application. They are fundamental components in many electronic systems, including clocks, radios, and signal generators.

The operation of an oscillator relies on the principles of feedback and resonance. By using reactive components like capacitors and inductors, it can establish a resonant frequency that determines the output signal's frequency. This makes oscillators essential for applications requiring stable frequency generation, such as in modulation, frequency synthesis, and timing applications.

Other choices may involve components that influence signals in different ways but do not primarily focus on generating a frequency. For instance, a low-pass filter primarily attenuates high-frequency signals while allowing low-frequency ones to pass, and both reactance and phase modulators relate to altering signals rather than producing a frequency independently.