Multi-Band Antenna System for AGILE

• NCJ Number: 196504
• Date Published: January 2002
• Length: 10 pages
• Grant Number(s): 2000-RB-CX-K002
• Agencies: NIJ-Sponsored
• Publication Type: Report (Technical Assistance)

Annotation

This document presents an overview of the Spoiler Antenna System Phase II design.

Abstract

Mission Research Corporation (MRC) is developing work for the “Multi-band Antenna System for AGILE” project. MRC has performed work in other areas of antenna design and development, including VHF antenna matching network redesign, first article spoiler antenna system gain and pattern, and post design development of field-testing recommendations. The spoiler antenna system consists of three antennas covering the public safety frequency bands of 150 MHz, 400 MHz, and 800 MHz inserted inside a trunk-mounted spoiler housing. Each antenna element is constructed from 5/16-inch diameter brass thread rod drilled and tapped to accommodate 6-32 brass machine screws at one end for 800 MHz or both ends for the other two bands. The 400 MHz and 800 MHz antennas are attached directly to the radio equipment through 17 feet of RG-58A/U coax cable terminate in the appropriate coax connector. These antennas are directly fed at the base with no impedance matching network necessary. The MRC spoiler antenna system is compatible with a single port SDR, if all three antennas are combined into one port with a device such as a Tri-Plexer. This antenna is compatible with existing and legacy radio equipment in its current configuration. When used with a SDR during the VHF frequency-changing mode, either more antenna bandwidth or re-tuning of the matching network is required. This can be resolved by using an automatic antenna tuner or similar technology to maintain the antenna at minimum VSWR. Only minor differences exist between aftermarket air spoilers currently in use by law enforcement agencies and the MRC spoiler antenna system. The spoiler antenna system weighs approximately 5 pounds more than RRP’s stock aftermarket spoilers, due to the inclusion of the brass antenna elements and the associated mounting hardware. When compared to a spoiler manufactured from metal, the spoiler is of similar or less weight. 14 Figures, 2 references