| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain a radar antenna which is used also as a transmitting-receiving antenna and which is miniaturized by a method wherein a plane antenna is installed with reference to a square patch in such a way that the polarization direction of transmitted radio waves is at right angles to the polarization direction of received radio waves, a polarization rotating plate is provided and a polarization selection plate is provided. SOLUTION: When an electric signal for transmission is applied from a feeder 5, radio waves are radiated from a square patch 4, and the direction of the radiated radio waves is downward. When the radio waves are incident on a polarization rotating plate 2, the rotation of a polarization of 45 deg. is given, and the radio waves are polarized at 45 deg. after their passage. The polarization passage direction of a polarization selection plate 3 is set so as to agree with that of the polarization rotating plate 2, and the radio waves which are passed through the rotating plate 2 are passed through the selection plate 3 without any loss. The polarization direction in the reception of reflected radio waves is a direction identical to that in their transmitting operation in the polarization selection plate 3. When the radio waves in the polarization direction are incident on the polarization rotating plate 2, they are changed into radio waves which are turned at 45 deg. to a direction identical to the polarization rotating direction in the transmitting operation. When the radio waves are incident on the square patch 4, a received output is obtained from a feeder 6.</p> |
