The ROF -DML -XX series of analog broadband direct-tuning transmitters use a highly linear microwave direct- coupled DFB laser (DML), a fully transparent operating mode without RF drive amplifiers and integrated automatic power control (APC) and automatic temperature control (ATC) circuit to ensures that the laser can transmit up to 18 GHz of microwave RF signals with long distances, high bandwidth and flat response, providing excellent linear optical fiber communication for a variety of analog broadband microwave applications. Due to the avoidance of expensive coaxial cable or waveguide, the transmission distance limit is canceled, which greatly improves the signal quality and reliability of microwave communication, being widely used in remote wireless, timing and reference signal distribution, telemetry and delay lines and other communication field.