Abstract: Low impedance loop antennas utilize a loop separated into a plurality of radiating segments fed in parallel. A four point feed loop antenna, including radiating segments 12, 13, 14, 15 had a measured input impedance varying from 1.8 to 5.8 Ohms over a range of 5 to 15 MHz, without excessive radiation Q degradation. An incorporated feed network includes transmission line segments, with conductors on opposite surfaces of a thin substrate, connecting the radiating segments to a centrally mounted coaxial connector for parallel excitation. Operating bandwidth of the loop antenna is determined by the characteristic impedance of the transmission line feed segments. Low impedance loop antennas which are small relative to operating wavelength can be fabricated on a thin flexible substrate for field transport and use. Incorporation of the antenna into a jacket or other clothing enables field use while minimizing restriction of activity of the user.
Type:
Grant
Filed:
January 28, 1999
Date of Patent:
December 12, 2000
Assignees:
BAE SYSTEMS Aerospace Inc., Advanced Systems