DIRECTION FINDER

PURPOSE:To obtain high-accuracy direction finding data even in the main beam direction of element antennas by forming the element antennas of monopulse type antennas in an amplitude comparison type direction finder. CONSTITUTION:The amplitude comparison type direction finder has the element antennas formed of monopulse type antennas 14-17. When an electromagnetic wave arrives from an azimuth A, the arrival wave is caught by the antennas 14 and 15 to output a SIGMA signal and a DELTA signal. The SIGMA signals are outputted from switches 18 and 19 and amplified and detected by receivers 5 and 6 and then a level comparing circuit 9 finds the arrival azimuth of the electromagnetic wave the input level difference between the SIGMA signals. When the electromagnetic wave arrives from an azimuth B, the switch 19 outputs the DELTA signal of the antenna 14. The circuit 9 finds the arrival azimuth of the electromagnetic wave from the level difference between the SIGMA signal 22a of the antenna and DELTA signal 22b. Consequently, the high-accuracy direction finding data is obtained.