NCJ Number
15606
Date Published
Unknown
Length
71 pages
Annotation
THE DEVELOPMENT OF A NEW BODY-MOUNTED ANTENNA FOR A POLICE OFFICER'S SINGLE-FREQUENCY, SINGLE-CHANNEL, PERSONAL RADIO SET IS DESCRIBED.
Abstract
THE MULTITURN LOOP ANTENNA IS SMALL AND COMPACT, RUGGED, LOW PROFILE, LIGHTWEIGHT, AND MEASURES 2.9 IN. X 2.9 IN. X 0.9 IN. HIGH. VSWR (VOLTAGE STANDING-WAVE RATIO) AND RADIATION PATTERNS ARE PRESENTED FOR THE ANTENNA MOUNTED ON A MAN'S SHOULDER AND FOR THE BODY IN A STANDING, STOOPING, AND PRONE POSITION, WITH VARIOUS HEAD AND ARM MOVEMENTS, AND WITH LIGHT AND HEAVY CLOTHING, RADIATION PATTERNS ARE ALSO PRESENTED TO SHOW THE BODY ABSORPTION LOSS CAUSED BY THE ANTENNA BEING MOUNTED AT WAIST LEVEL AS COMPARED WITH MOUNTING AT SHOULDER LEVEL. THE RADIATION PATTERNS ARE REFERENCED TO A 6.6-IN. HELICAL WHIP THAT IS COMMONLY USED BY POLICE OFFICERS. THE INSTANTANEOUS BANDWIDTH IS 1.4 MHZ (MEGAHERTZ) FOR A VSWR LESS THAN OR EQUAL TO 3:1. A DUAL-FREQUENCY MODEL FOR USE IN A TWO-FREQUENCY SIMPLEX PUSH-TO-TALK MODE IS ALSO SHOWN TO BE PRACTICAL. (AUTHOR ABSTRACT)