RF circuits, or radio frequency circuits, are electronic circuits designed to operate at radio frequencies, typically ranging from 3 kHz to 300 GHz. These circuits are essential for transmitting and receiving signals in various applications, including telecommunications, broadcasting, and wireless communication. They often include components like antennas, amplifiers, and oscillators to manage the signals effectively. The design of RF circuits requires careful consideration of factors such as impedance matching, signal integrity, and noise reduction. Engineers use specialized tools and techniques to ensure that these circuits function efficiently and reliably. Common applications of RF circuits include cell phones, radios, and satellite communications.