| 摘要 |
The directional/omnidirectional antenna, for satellites, has a rod radiator coaxial with a half-cylinder reflector which rotates against the satellites spin to give the antenna its directional properties. If this reflector fails to rotate it can be jettisoned by a pyrotechnic device triggered by a signal from earth, thereafter the antenna operates in its omnidirectional mode. The triggering can be by D.C. The current supply to the pyrotechnic device occurs over a switch arm and contact ring opposite the reflectors holder. The switch arm moves over the contact ring to operate the pyrotechnic device on receipt of a command signal. The arms motion is controlled either by an electromagnet or by a spring. |
