Variable capacitance diodes, commonly known as Varicaps or Varactors, are semiconductor devices designed to change their capacitance with applied voltage. These diodes find extensive use in electronic circuits where frequency modulation and tuning are critical, such as in voltage-controlled oscillators (VCOs) and radio frequency (RF) tuning circuits. Varicaps provide a dynamic capacitance that can be controlled by adjusting the applied voltage, enabling precise tuning of resonant circuits. This feature is particularly valuable in communication systems, radar applications, and other wireless technologies where maintaining accurate frequency control is essential for optimal performance.