RF test equipment generates test signals or analyzes transmitted signals from RF components or RF equipment. Typically, RF testing equipment is used in conjunction with RF transmitters, electronic devices that create continuously varying electric current, encode sine waves, and broadcast radio waves. Modulation techniques are used to encode the sign wives for subsequent broadcast as radio signals. There are several basic modulation methods. Examples include amplitude modulation (AM), frequency modulation (FM), and on-off key (OOK). To verify the success of a modulation technique, RF test equipment is used to analyze the quality of the transmitted radio signal.