| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem that a conventional direction finder detects the radio wave direction from the phase of an amplitude modulated signal obtained by switching four cardioid antennas, where the number of samples for estimation is small, and the amplitude modulation is smooth, so the error of detection phase tends to occur, and the precision of the estimated direction of the radio waves is bad. SOLUTION: The radio wave direction finder comprises two cardioid antennas with perpendicular null directions and an omnidirectional antenna; a subtraction means for calculating the difference from a direction of a reception signal of either cardioid antenna rotated by the antenna pattern rotational means and the reception signal of the omnidirectional antenna; an evaluation function calculation means for calculating the output of the subtraction means and the reception signal of the other cardioid antenna for each rotation rotated by antenna pattern rotation means; and a direction detection means for obtaining an incident direction of the radio wave from the results of the above calculation means. COPYRIGHT: (C)2005,JPO&NCIPI
|
