A frequency synthesizer is an electronic device that generates a range of frequencies from a single reference frequency. It is commonly used in communication systems, such as radios and televisions, to produce the specific frequencies needed for transmitting and receiving signals. By using various techniques, frequency synthesizers can create stable and precise frequencies that are essential for clear communication. These devices often employ methods like phase-locked loops (PLLs) and direct digital synthesis (DDS) to achieve their output. Frequency synthesizers are crucial in modern technology, enabling applications in wireless communication, signal processing, and test equipment for accurate frequency generation.