| 摘要 |
PURPOSE:To eliminate the need for the adjustment of amplitude and phase, feeding lines and to improve the broad band characteristic, by using a reflection type phased antenna. CONSTITUTION:A subarray antenna 12a has the characteristics which passes through electromagnetic waves of a frequency band and reflects the most parts of the waves, the antenna is inserted to a notch provided in a part of a mirror surface to be almost the same plane as the mirror surface, and a phase shifter 12b, an attenuator 12c, and a short-circuit plane 12d are fitted on the antenna 12a at the rear side of the reflecting mirror as layers. Electromagnetic waves incident to the antenna 12a are reflected other than the waves of one frequency band to be transmitted for the formation of a main beam. The transmitted waves of the frequency band pass through the phase shifter 12a and the attenuator 12c and are reflected on the short-circuit plane 12d, and pass through the attenuator and phase shifter again and are reflected to the outside through the antenna 12a. Further, the phase shifter and the attenuator are controlled to provide the required phase shift and attenuation for the electromagnetic waves, allowing to obtain a desired directivity. |
