The design of the present radio direction finder is based on amplitude comparison to find the angle of arrival (AOA) of the received signal by eight antennas circularly distributed. The characteristics of the signal are specified to provide the identification of the source in addition to the direction. The equation of (AOA) was derived by taking the ratio of signal amplitudes between each two adjacent antennas due to their associated AOA over (360) direction .The database for source identification is included also. A simple design by using detectors to detect the pulse and digital signals was used. A personal computer is used to satisfy the principle of operation. This facility make the system operate on a wide band of frequency about (2-18) GHz. This system is suitable for detection of radar signals and digital transmitter signals such as base stations and mobile stations.