| 摘要 |
A personal communication device with an extendable helical antenna made of an elastic conductive spring is configured to change its height along the antenna axis over a ground plane, having a low profile stowed position pressed down between the ground plane and a rigide cover, and an operational position where the rigid cover is removed and the antenna is extended by its own spring force A second planar antenna may be placed over the same ground plane, not exceeding the footprint of the helical antenna, thus utilizing a small volume, yet achieving considerable electromagnetic decoupling between the antennas due to their different radiation patterns In one embodiment, these antennas are installed in a Personal Locator Beacon (PLB) for Search and Rescue (SAR), where the planar antenna is coupled to a Global Navigation Satellite System (GNSS) receiver, and the helical antenna is coupled to a VHF/UHF radio |
