Compact Chamber for Impedance and Power Testing of VHF Whip Antennas

摘要

The report summarizes the accomplishments on a program to develop a compact test chamber suitable for production testing of VHF vehicular antennas. A compact test chamber consisting of a 12 foot long aluminum cylinder, 1 foot in diameter and lined with Eccosorb NZ-1 ferrite material was developed. This chamber was calibrated with respect to open-field antenna characteristics. Results from an extensive evaluation are presented which attest to the usefulness of the chamber in meeting production and/or field test and alignment requirements. Investigations of the reflectivity characteristics of a number of absorbing materials, the effects of absorbing materials in the near-field of antennas, and the effects of ground plane size on antenna characteristics are described and results from these programs are presented. (Author)