| 摘要 |
<p>PURPOSE:To enhance jamming-resistant capacity by transmitting a transmitting radio wave while taking the synchronism of operation timing and further together using the changing-over of three kinds of mode patterns for changing a scanning direction and further periodically changing over transmission frequency at every scanning. CONSTITUTION:As a transmission antenna, a phase array antenna 1a is used and, as a receiving antenna, a digital beam forming antenna 7 is used. The antenna 7 consists of antenna elements 1b, 3, a receiver 4 equipped with a filter bag discriminating receiving frequency provided at every antenna element, an A/D converter 5 and an operation means 6 discriminating transmitting radio waves from different directions at every directions. A timing controller 15 together uses three mode patterns, that is, a mode controlling the operations of a beam scanning controller 2a, a frequency synthesizer 2b and the converter 5 to take the synchronism thereof and periodically changing over transmission frequency at every scanning, a mode changing over transmission frequency periodically at every transmitting direction and a mode changing over transmission frequency in each transmitting direction at random at every scanning to perform change-over control.</p> |
