Antenna for Unattended Ground Sensor

摘要

An unattended ground sensor unit (30) is disclosed comprising an antenna (2) which is accommodated mainly in a head portion (5) of the unit. The antenna (2) comprises a base conductor (100) and a top conductor (102), both of which are circular plates arranged in a horizontal plane. An antenna rod (204) is electrically connected to the top conductor (102). A hole is provided in the base conductor (100) and the antenna rod (204) extends through the hole to be connected to antenna control circuitry on a printed circuit board (104) on the reverse side of the base conductor (100). An insulating ring (106) is provided around the antenna rod (204) where it extends through the base conductor (100) so that the antenna (rod 204) is electrically insulated from the base conductor (100). Two shorting pins (205) are provided between the top conductor (102) and the base conductor (100). The shorting pins (20) are provided on diametrically opposite sides of the antenna rod (204). A dielectric spacer (202) is provided having a keying cut-out (112) that can be engaged to resist its rotation.

主权项

1. The antenna of claim 18 further comprising one or more shorting pins connected to the first conductor and extending between the first and second conductors, wherein the one of more shorting pins are electrically connected to both the first and second conductors.